CN112644984B

CN112644984B - Control method, control system, conveying device and component mounting system

Info

Publication number: CN112644984B
Application number: CN202011074087.9A
Authority: CN
Inventors: 佐藤宽之
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2019-10-10
Filing date: 2020-10-09
Publication date: 2024-09-24
Anticipated expiration: 2040-10-09
Also published as: CN112644984A

Abstract

Provided are a control method, a control system, a conveying device and a component mounting system, which can restrain the deviation of the conveying device from a reference posture and can easily make the conveying device follow a track. The control method includes at least one of a first steering angle control process and a second steering angle control process. The first steering angle control process is a process of controlling the steering angle (θ) of the conveying device (1) in a state in which the plurality of steering wheels (2) of the conveying device (1) that conveys the conveyed object are arranged in the front-rear direction and the plurality of steering wheels (2) are provided. The second steering angle control process is a process of controlling the steering angle (θ) of the conveyor (1) in a state where the plurality of steered wheels (2) of the conveyor (1) are aligned in a direction intersecting the front-rear direction.

Description

Control method, control system, conveying device and component mounting system

Technical Field

The present disclosure relates generally to control methods, control systems, conveying devices, and component mounting systems. More specifically, the present disclosure relates to a control method and a control system for controlling a conveying apparatus, a conveying apparatus having the control system mounted thereon, and a component mounting system using the conveying apparatus.

Background

In document 1 (JP 2012-53838A), an apparatus for transporting materials, products, and the like by driving a plurality of unmanned transport vehicles (transport devices) along a travel path such as a track laid in a factory or the like is disclosed.

Disclosure of Invention

Problems to be solved by the invention

The present disclosure aims to provide a control method, a control system, a conveying device and a component mounting system, which can inhibit deviation of the conveying device from a reference posture and can easily enable the conveying device to follow a track.

Means for solving the problems

The control method of an aspect of the present disclosure has at least one of a first steering angle control process and a second steering angle control process. The first steering angle control process is a process of controlling a steering angle of a conveying apparatus that conveys a conveyed object in a state where the plurality of steered wheels are arranged in a front-rear direction. The second steering angle control process is a process of controlling the steering angle of the conveying apparatus in a state where the plurality of steered wheels of the conveying apparatus are aligned in a direction intersecting the front-rear direction.

The control system according to an aspect of the present disclosure includes at least one of a first steering angle control processing unit and a second steering angle control processing unit. The first steering angle control processing unit controls the steering angle of a conveyor device that conveys a conveyed object, in a state in which the plurality of steering wheels are arranged in the front-rear direction, and the conveyor device has a plurality of steering wheels. The second steering angle control processing unit controls the steering angle of the conveyor device in a state where the plurality of steered wheels of the conveyor device are aligned in a direction intersecting the front-rear direction.

A conveying device according to an aspect of the present disclosure includes the control system and the main body. The main body part is provided with the control system and conveys the conveyed objects.

A component mounting system of an aspect of the present disclosure is a system including at least one component mounter that mounts components onto a substrate. The component mounter includes a component supply device that supplies the component, and a mounting body including a mounting head that mounts the component on the substrate. The component supply device is transported to the mounting body by the transport device controlled by the control system described above.

Effects of the invention

The present disclosure has the following advantages: the deviation of the conveying device from the reference posture is suppressed, and the conveying device is easy to follow the track.

Drawings

Fig. 1 is a schematic plan view showing an example of a conveying apparatus to which the control system of embodiment 1 is directed.

Fig. 2 is a block diagram showing an outline of the control system.

Fig. 3 is an explanatory diagram showing an example of speed control during operation of the control system.

Fig. 4 is an explanatory diagram of an outline of a component mounting system constructed by using the control system.

Fig. 5 is a flowchart showing an example of the operation of the control system.

Fig. 6 is an explanatory diagram showing an example of control of the conveying device by the control system of the comparative example.

Fig. 7 is an explanatory diagram showing another example of the operation of the control system according to embodiment 1.

Fig. 8 is an explanatory diagram showing an example of still another operation of the control system.

Fig. 9 is a schematic plan view showing an example of the arrangement of the sensor in the conveying apparatus.

Fig. 10 is a schematic plan view showing an example of a conveying device to which the control system according to embodiment 2 is directed.

Fig. 11 is an explanatory view of a first steering angle in the operation of the control system.

Fig. 12 is an explanatory diagram of the second steering angle in the operation of the control system.

Fig. 13 is an explanatory diagram of the resultant steering angle in the operation of the control system.

Fig. 14 is an explanatory diagram of the inverted phase control in the operation of the control system.

Fig. 15 is an explanatory diagram of the inverted phase control in the operation of the control system.

Fig. 16 is an explanatory diagram of the inverted phase control in the operation of the control system.

Fig. 17 is a flowchart showing an example of the operation of the control system.

Fig. 18 is a schematic plan view showing an example of a conveying device to which the control system of embodiment 3 is directed.

Fig. 19 is an explanatory diagram of the positional shift amount and the rotational shift amount during the operation of the control system.

Fig. 20 is an explanatory diagram of the reference steering angle in the operation of the control system.

Fig. 21 is an explanatory view of a first steering angle in the operation of the control system.

Fig. 22 is an explanatory diagram of the second steering angle and the resultant steering angle in the operation of the control system.

Fig. 23 is an explanatory diagram of the inverted phase control in the operation of the control system.

Fig. 24 is an explanatory diagram of the inverted phase control in the operation of the control system.

Fig. 25 is an explanatory diagram of the inverted phase control in the operation of the control system.

Fig. 26 is an explanatory diagram showing an example of speed control during operation of the control system.

Fig. 27 is an explanatory view of an outline of a component mounting system constructed by using the control system.

Fig. 28 is a flowchart showing an example of the operation of the control system.

Fig. 29 is an explanatory diagram showing an example of control of the conveying device by the control system of the comparative example.

Fig. 30 is an explanatory diagram showing an example of control of the conveying device by the control system of embodiment 3.

Fig. 31 is an explanatory diagram showing another example of the operation of the control system.

Reference numerals illustrate:

100. A control system;

200. A component mounting system;

11. An acquisition unit;

12. A correction unit;

1. a conveying device;

10. a main body portion;

2. a steering wheel;

21. a front wheel;

22. a rear wheel;

5. A connecting part;

8. A component supply device;

9. A component mounting machine;

90. A mounting main body;

A1 Conveying objects;

B1 A moving surface;

an L1 track;

ST1 acquisition;

ST2 correction step;

ST3, a speed correction step;

θ steering angle;

θ1 first steering angle;

θ2 second steering angle;

θ3 synthesizes the steering angle.

Detailed Description

(Embodiment 1)

(1) Summary of the inventionsummary

As shown in fig. 1, the control method of the present embodiment is a method for controlling the conveyor 1 such that the conveyor 1 that conveys the conveyed object A1 (see fig. 4) follows the track L1. The control method is implemented by the control system 100 (refer to fig. 2). In the present embodiment, the transport object A1 has wheels a11 and is configured to be movable together with the transport device 1.

In the present embodiment, the conveyor 1 has a plurality of diverting wheels 2 aligned in the front-rear direction of the conveyor 1, and moves on the moving surface B1 to convey the conveyed article A1. The term "front-rear direction" as used in the present disclosure refers to the longitudinal direction of the conveyor 1, and refers to the direction in which the conveyor 1 travels as "front" and the direction opposite thereto as "rear". The conveying device 1 may be configured to perform in the width direction orthogonal to the longitudinal direction. The front-rear direction in this case is the width direction.

The blank arrow in fig. 1 indicates the traveling direction of the conveying device 1. In fig. 1, the double-headed arrows indicate the "front" and "rear" of the conveying device 1. These arrows in fig. 1 are merely designated for illustration and are not accompanied by entities. In fig. 1, the wheels such as the plurality of steered wheels 2 of the conveyor 1 are drawn in solid lines, but in reality, these wheels are hidden in the main body 10 of the conveyor 1 (described later). In fig. 1, the track L1 is drawn as a solid line, but in reality, a portion of the track L1 overlapping the conveyor 1 is hidden in the main body 10 of the conveyor 1. The same applies to the drawings other than fig. 1.

The transport device 1 is introduced into facilities such as a distribution center (including a distribution center), a factory, an office, a store, a school, and a hospital. The moving surface B1 is a surface on which the conveyor 1 moves, and when the conveyor 1 moves in a facility, the floor or the like of the facility becomes the moving surface B1, and when the conveyor 1 moves outdoors, the floor or the like becomes the moving surface B1. The following description will be given of a case where the conveying device 1 is introduced into a factory. In the drawings other than fig. 1, the moving surface B1 is not illustrated.

In the present embodiment, the plurality of steering wheels 2 includes a front wheel 21 located in front of the conveyor 1 and a rear wheel 22 located in rear of the conveyor 1. That is, the conveyor 1 is configured to move on the moving surface B1 by the two steered wheels 2. In the present embodiment, the conveyor device 1 has two auxiliary wheels 3 in addition to the two steered wheels 2, but these auxiliary wheels 3 are not included in the steered wheels 2 whose steering angle θ can be changed by the control system 100. Each auxiliary wheel 3 is a driven wheel. The term "steering angle" as used in the present disclosure refers to an angle formed between the front-rear direction of the conveyor device 1 and the wheel surface (in other words, the turning direction of the wheels) of the wheels (steering wheel 2) in a plan view of the conveyor device 1 from above. The "wheel surface" as referred to in the present disclosure refers to a surface of the wheel (steering wheel 2) that is in contact with the moving surface B1.

The "track" referred to in the present disclosure defines a movement path of the conveying device 1 when the conveying device 1 conveys the conveyed object A1 to the destination. In the present embodiment, the rail L1 is provided on the moving surface B1 on which the conveyor 1 moves. Specifically, the track L1 is a linear object such as a magnetic tape or a magnetic mark provided on the moving surface B1. The control system 100 controls the conveyor 1 so that the conveyor 1 follows the track L1 based on detection of the track L1 by a sensor 4 (described later) mounted on the conveyor 1. Thereby, the conveying device 1 can follow the track L1 and convey the conveyed object A1 to the destination. The term "follow the track" may include movement of the conveyor 1 along the track L1 without overlapping the track L1, in addition to movement of the conveyor 1 along the track L1.

The control method of the conveying apparatus 1 according to the present embodiment includes an acquisition step ST1 and a correction step ST2 (see fig. 5).

The acquisition step ST1 is a step of acquiring offset information. The offset information is information related to the offset of the conveying device 1 with respect to the track L1 on which the conveying device 1 travels. In the present embodiment, information on the offset of the sensor 4 with respect to the track L1 is acquired as offset information.

The correction step ST2 is a step of correcting the steering angle θ for each of the plurality of steered wheels 2 based on the offset information acquired in the acquisition step ST 1. That is, in the present embodiment, the correction is not performed based on the offset information so that the plurality of steered wheels 2 are unified into the same steering angle θ, but the steering angles θ of the plurality of steered wheels 2 are corrected individually. Of course, as a result of the correction step ST2, there may be a case where the steering angles θ of the respective plurality of steered wheels 2 are the same.

Therefore, the present embodiment has an advantage that the deviation of the conveyor 1 from the reference posture is suppressed and the conveyor 1 is easily caused to follow the track L1. The "reference posture" as referred to in the present disclosure refers to a posture of the conveyor 1 such that the front-rear direction of the conveyor 1 is parallel to the track L1. It should be noted that "parallel" includes not only complete parallelism but also a concept of substantially parallelism.

(2) Detailed description

(2.1) Integral Structure

The control system 100 according to the present embodiment will be described below with reference to fig. 1 and 2. In the present embodiment, the control system 100 is built in a main body 10 (described later) of the conveying apparatus 1, and is configured to be capable of communicating with the host system 6. That is, the conveying apparatus 1 includes a control system 100 and a main body 10 on which the control system 100 is mounted and which conveys the conveyed article A1. The term "communicable" in the present disclosure means that information can be exchanged directly or indirectly via the network NT1, the repeater 7, or the like by an appropriate communication scheme of wired communication or wireless communication. In the present embodiment, the host system 6 and the plurality of conveyor apparatuses 1 can communicate with each other in both directions, and both of transmitting information from the host system 6 to the conveyor apparatuses 1 and transmitting information from the conveyor apparatuses 1 to the host system 6 can be realized.

The upper system 6 is a system for uniformly controlling the plurality of conveying apparatuses 1, and is realized by a server apparatus, for example. The host system 6 indirectly controls the plurality of conveying apparatuses 1 by giving instructions to the plurality of conveying apparatuses 1, respectively.

In the present embodiment, the host system 6 has a computer system having one or more processors and memories as a main configuration. Therefore, the functions of the host system 6 are realized by executing the programs recorded in the memory by one or more processors. The program may be recorded in advance in a memory, may be provided via an electric communication line such as the internet, or may be provided by recording on a non-transitory recording medium such as a memory card.

(2.2) Conveying appliance

Next, the structure of the conveying device 1 according to the present embodiment will be described in more detail. As shown in fig. 1, the conveyor 1 is an unmanned conveyor for conveying a conveyed article A1, and autonomously travels to a destination by connecting the conveyed article A1. In the present embodiment, the upper system 6 communicates with the conveyor 1 via the network NT1 and the relay 7, and indirectly controls the movement of the conveyor 1.

The conveyor 1 runs autonomously on a flat moving surface B1, which is constituted by, for example, the ground or the like. Here, the conveyor 1 includes a battery, and operates using electric energy stored in the battery, for example. In the present embodiment, the conveying device 1 travels on the moving surface B1 in a state where the conveyed object A1 is connected. Thus, the conveyor 1 can convey the conveyed article A1 to another place by, for example, pulling or pushing the conveyed article A1 placed at the place by the conveyor 1.

The conveying device 1 includes a main body 10. The body 10 is formed in a rectangular parallelepiped shape. In the present embodiment, a coupling portion 5, such as a hook, capable of hooking a part of the conveyed article A1 is provided on a side surface of the main body 10. The "side surface of the main body" referred to herein means a surface along the track L1 when the conveying device 1 assumes the reference posture. Therefore, in the present embodiment, by hooking a part of the conveyed article A1 to the coupling portion 5, the conveyed article A1 can be coupled to the conveying apparatus 1. That is, the conveying device 1 includes a coupling portion 5 for coupling the conveyed article A1 to one surface (side surface) of the main body portion 10 of the conveying device 1 along the rail L1.

The conveyor 1 has a plurality of (here, four) wheels at the lower portion of the main body 10. The front wheel 21 located at the front of the main body 10 and the rear wheel 22 located at the rear of the main body 10 among the four wheels are both steered wheels 2. Further, two wheels among the 4 wheels, which are located at both ends in the width direction at the center portion of the main body portion 10, are auxiliary wheels 3 (driven wheels). In the present embodiment, both of the steering wheels 2 also serve as driving wheels, and by individually driving these driving wheels, the conveying device 1 can be moved in a desired direction on the moving surface B1. Further, each of the two steered wheels 2 is configured to be capable of changing the steering angle θ within a range sufficient to return to the path when the conveyor 1 is deviated from the path following the track L1.

(2.3) Control System

Next, the configuration of the control system 100 according to the present embodiment will be described in more detail. As shown in fig. 2, the control system 100 includes a detection unit 101, a control unit 102, a communication unit 103, a storage unit 104, and a traveling device 105. In the present embodiment, the detection unit 101, the control unit 102, the communication unit 103, the storage unit 104, and the traveling device 105 are included in the components of the control system 100, but only the control unit 102 may be included in the components of the control system 100.

The detection unit 101 detects the behavior of the main body 10, the peripheral condition of the main body 10, and the like. The term "behavior" as used in the present disclosure refers to actions, situations, and the like. That is, the behavior of the main body 10 includes an operation state of the main body 10 indicating whether the main body 10 is running or stopped, a speed (and a speed change) of the main body 10, an acceleration acting on the main body 10, a posture of the main body 10, and the like. Specifically, the detection unit 101 includes, for example, a speed sensor, an acceleration sensor, a gyro sensor, and the like, and detects the behavior of the main body 10 by these sensors. The Detection unit 101 includes, for example, an image sensor (camera), a sonar sensor, a radar, a Light Detection and ranging (Light Detection AND RANGING), and other sensors, and detects the peripheral condition of the main body 10 by these sensors.

The detection unit 101 further includes a position determination unit that determines the position of the main body 10, that is, the current position of the conveying device 1. As an example, the position determining unit includes a receiver that receives beacon signals transmitted by radio waves from a plurality of transmitters. The plurality of transmitters are disposed at a plurality of positions within the range in which the conveying device 1 moves. The position determining unit measures the position of the main body 10 based on the positions of the plurality of transmitters and the received radio wave intensities of the beacon signals in the receiver. The position determining unit may be realized by using a satellite positioning system such as GPS (Global Positioning System ).

Further, the detection section 101 includes a plurality of sensors 4. The plurality of sensors 4 are provided in the vicinity of the plurality of steered wheels 2, respectively. In the present embodiment, the plurality of steered wheels 2 are two of front wheels 21 and rear wheels 22. Therefore, the plurality of sensors 4 are a first sensor 41 provided in the vicinity of the front wheel 21 (here, the front end of the main body 10), and a second sensor 42 provided in the vicinity of the rear wheel 22 (here, the rear end of the main body 10).

The plurality of sensors 4 are bar-shaped magnetic sensors, and detect the relative positional relationship between the sensors 4 and the track L1, that is, the positional displacement of the sensors 4 with respect to the track L1 by detecting the magnetic flux generated by the track L1. In the present embodiment, the first sensor 41 detects the positional displacement of the front wheel 21 with respect to the rail L1 by detecting the positional displacement of the first sensor 41 with respect to the rail L1. In addition, the second sensor 42 detects the positional displacement of the rear wheel 22 with respect to the rail L1 by detecting the positional displacement of the second sensor 42 with respect to the rail L1. As an example, the "positional shift" is represented by the shortest distance between the center of the sensor 4 and the track L1.

The communication unit 103 is configured to be capable of communicating with the host system 6. In the present embodiment, the communication unit 103 communicates with any one of the plurality of relays 7 provided in the area where the conveying apparatus 1 is operated by wireless communication using radio waves as a medium. Therefore, the communication unit 103 and the upper system 6 communicate indirectly via at least the network NT1 and the repeater 7.

That is, each repeater 7 is a device (access point) that relays communication between the communication unit 103 and the higher-level system 6. The repeater 7 communicates with the higher-level system 6 via the network NT 1. In the present embodiment, as an example, wireless communication conforming to standards such as Wi-Fi (registered trademark), bluetooth (registered trademark), zigBee (registered trademark), and low-power wireless (specific low-power wireless) which does not require permission is adopted for communication between the repeater 7 and the communication unit 103. The network NT1 is not limited to the internet, and for example, a local communication network in an area where the transport apparatus 1 is operated or in an operation company in the area may be applied.

The storage unit 104 is implemented by a non-transitory recording medium such as a rewritable nonvolatile semiconductor memory. The storage unit 104 stores, for example, map information related to a map of an area in which the transport apparatus 1 is operated, instruction information provided from the host system 6, and the like.

The traveling device 105 receives a control command from the control unit 102, and individually drives a plurality of driving wheels (two steering wheels 2 in the present embodiment) provided in the main body 10, thereby traveling the conveying device 1 in a desired direction.

The control unit 102 has a computer system having one or more processors and memories as a main configuration. Therefore, the functions of the control unit 102 are realized by executing the programs recorded in the memory by one or more processors. The program may be recorded in advance in a memory, may be provided via an electric communication line such as the internet, or may be provided by recording on a non-transitory recording medium such as a memory card.

The control unit 102 controls the conveying apparatus 1 based on the detection result of the detection unit 101. In the present embodiment, the control unit 102 includes the acquisition unit 11 and the correction unit 12 for controlling the conveying apparatus 1. The acquisition unit 11 and the correction unit 12 are each realized as a function executed by the control unit 102.

The acquisition unit 11 communicates with the plurality of sensors 4 to acquire offset information related to the offset of the conveyor 1 with respect to the track L1. That is, the acquisition unit 11 is the subject of the execution of the acquisition step ST 1. The offset information may be information generated by the sensor 4 performing an appropriate process on the detection result, or may be information generated by the acquisition unit 11 that has received the detection result of the sensor 4 performing an appropriate process on the detection result of the sensor 4.

Here, the information acquired from the first sensor 41 among the plurality of sensors 4 corresponds to information related to the positional displacement of the front wheel 21 located in the vicinity of the first sensor 41 with respect to the track L1. The information acquired from the second sensor 42 among the plurality of sensors 4 corresponds to information on the positional displacement of the rear wheel 22 with respect to the track L1, which is located in the vicinity of the second sensor 42. That is, in the present embodiment, the offset information acquired by the acquisition unit 11 includes a plurality of pieces of "steered wheel offset information" related to the positional offset of each of the plurality of steered wheels 2 with respect to the track L1. In the present embodiment, the plurality of steered wheel offset information includes first offset information related to the positional offset of the front wheels 21 with respect to the track L1, and second offset information related to the positional offset of the rear wheels 22 with respect to the track L1.

The correction unit 12 corrects the steering angle θ for each of the plurality of steered wheels 2 based on the offset information acquired by the acquisition unit 11. That is, the correction unit 12 is the subject of the correction step ST 2. In the present embodiment, the correction unit 12 corrects the steering angle θ based on the corresponding one of the plurality of pieces of steered wheel offset information acquired by the acquisition unit 11 for each of the plurality of steered wheels 2. In other words, the correction step ST2 is a step of correcting the steering angle θ based on the corresponding steering wheel offset information for each of the plurality of steered wheels 2.

Specifically, the correction unit 12 corrects the steering angle θ of the front wheel 21 based on the first offset information acquired by the acquisition unit 11 so that the wheel surface of the front wheel 21 follows the track L1. The correction unit 12 corrects the steering angle θ of the rear wheel 22 so that the wheel surface of the rear wheel 22 follows the track L1, based on the second offset information acquired by the acquisition unit 11. In the present embodiment, the correction amount of the steering angle θ of each of the front wheels 21 and the rear wheels 22 is determined by PID (Proportional-Integral-Differential) control.

As an example, the steering angle θ of the front wheels 21 is "θf", the steering angle θ of the rear wheels 22 is "θb", and the steering angles θf and θb are represented by the following equations (1) and (2), respectively. In the formula (1), "Df" represents the amount of shift of the front wheel 21, and "Kf" represents the correction coefficient (proportionality coefficient) of the front wheel 21. In the expression (2), "Db" represents the offset amount of the rear wheel 22, and "Kb" represents the correction coefficient (scaling coefficient) of the rear wheel 22.

[ Number 1]

θf＝Kf·Df…(1)

θb＝Kb·Db…(2)

Here, each of the steering angles θf and θb represented by the equations (1) and (2) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the steering angles θf and θb are expressed by the following equations (3) and (4), respectively. In the expression (3), "Dfi" represents the shift integral amount of the front wheel 21, "Dfd" represents the shift differential amount of the front wheel 21, "Kfi" represents the correction coefficient (integral coefficient) of the front wheel 21, and "Kfd" represents the correction coefficient (differential coefficient) of the front wheel 21. In the expression (4), "Dbi" represents the offset integral amount of the rear wheel 22, "Dbd" represents the offset differential amount of the rear wheel 22, "Kbi" represents the correction coefficient (integral coefficient) of the rear wheel 22, and "Kbd" represents the correction coefficient (differential coefficient) of the rear wheel 22.

[ Number 2]

θf＝Kf·Df+Kfi·Dfi+Kfd·Dfd…(3)

θb＝Kb·Db+Kbi·Dbi+Kbd·Dbd…(4)

In the present embodiment, the correction unit 12 corrects the speeds of the plurality of steered wheels (drive wheels) 2 in addition to the steering angle θ for each of the plurality of steered wheels 2 as described above. Specifically, the correction unit 12 corrects the speed (peripheral speed) of each of the plurality of steered wheels 2 based on the steering angle θ corrected as described above for each of the steered wheels 2. In other words, the control method further has a speed correction step ST3 in which, for each of the plurality of steered wheels 2, the speed of the corresponding steered wheel 2 is corrected based on the steering angle θ corrected in the correction step ST2 in the speed correction step ST 3.

Hereinafter, a process of determining the speeds of the plurality of steered wheels 2 will be described with reference to fig. 3. In fig. 3, it is assumed that the conveyor 1 moves rightward. In fig. 3, "α" represents the steering angle θ of the front wheels 21, "β" represents the steering angle θ of the rear wheels 22, "V _α" represents the speed of the front wheels 21, "V _β" represents the speed of the rear wheels 22, and "W" represents the distance between the center of the front wheels 21 and the center of the rear wheels 22. In fig. 3, "r _α" is the turning radius of the front wheel 21 centered on the intersection point X1 of the straight line extending the axis of the front wheel 21 and the straight line extending the axis of the rear wheel 22, and "r _β" is the turning radius of the rear wheel 22 centered on the intersection point X1 of the straight line extending the axis of the front wheel 21 and the straight line extending the axis of the rear wheel 22.

Here, the turning radius of the front wheels 21 and the turning radius of the rear wheels 22 vary according to the steering angle θ of the front wheels 21 and the steering angle θ of the rear wheels 22. Therefore, the radius of gyration of the front wheel 21 and the radius of gyration of the rear wheel 22 are substantially different from each other. Therefore, there is the possibility that: if the speed of the front wheels 21 is the same as the speed of the rear wheels 22, the angular speed of the front wheels 21 does not match the angular speed of the rear wheels 22, and it is not possible to match the operation of the front wheels 21 with the operation of the rear wheels 22, and the steering wheel 2 of either one idles, so that it is difficult for the conveyor 1 to follow the track L1.

In contrast, in the present embodiment, the correction unit 12 corrects the speed for each of the plurality of steered wheels 2 based on the steering angle θ, thereby matching the angular speed of the front wheels 21 with the angular speed of the rear wheels 22, and obtaining a match between the operation of the front wheels 21 and the operation of the rear wheels 22. Here, the ratio of the speed of the front wheel 21 to the speed of the rear wheel 22 (hereinafter, simply referred to as "speed ratio") in the case where the angular speed of the front wheel 21 coincides with the angular speed of the rear wheel 22 is represented by the following formula (5).

[ Number 3]

That is, the speed ratio is not dependent on the size of the conveyor 1 (for example, the distance "W" between the center of the front wheel 21 and the center of the rear wheel 22, etc.), and can be determined based on the steering angle θ of the front wheel 21 and the steering angle θ of the rear wheel 22.

As described above, the correction unit 12 controls the conveyor 1 to follow the track L1 by correcting the steering angle θ for each of the front wheels 21 and the rear wheels 22 and correcting the speeds of the front wheels 21 and the rear wheels 22 based on the corrected steering angle θ.

(2.4) Component mounting System

As shown in fig. 4, in the present embodiment, the transport object A1 is a component supply device 8 having one or more feeders, as an example. The component supply device 8 supplies components to a mounting body 90 of a component mounter 9 provided in a factory. The "component mounter" here is, for example, a machine that mounts components onto an object such as a substrate. The mounting body 90 includes a mounting head that mounts the component to the substrate. That is, in the present embodiment, the transport device 1 is controlled by the control system 100 to transport the component supply device 8 as the transport object A1 to the installation place of the mounting body 90 of the component mounter 9. Thereby, the component mounting system 200 can be constructed. In other words, the component mounting system 200 is a system including at least one component mounter 9 that mounts components onto a substrate. The transport device 1 controlled by the control system 100 transports the component supply device 8 to the mounting body 90.

Here, the conveying device 1 is preferably connectable to a portion of the component supply device 8 located on the opposite side of the portion from which the component is discharged to the mounting body 90. In this case, when the component feeder 8 is transported to the installation site of the mounting body 90 of the component mounter 9, the part of the component feeder 8 from which the components are discharged is directed toward one of the mounting bodies 90. Therefore, when the component feeder 8 is transported to the installation site of the mounting body 90 of the component mounter 9, the above-described operation of changing the direction of the component feeder 8 so that the discharge portion is directed to the mounting body 90 is not performed.

(3) Action

An example of the operation of the control system 100 according to the present embodiment will be described below with reference to fig. 5. In the operation example shown in fig. 5, it is assumed that the conveyor 1 is moving to the destination while conveying the conveyed article A1 and following the track L1. During the movement of the conveyor 1, the acquisition unit 11 acquires the first offset information by periodically acquiring the detection result from the first sensor 41 (S1). Similarly, the acquisition unit 11 acquires the second offset information by periodically acquiring the detection result from the second sensor 42 (S2). The acquisition of the first offset information and the second offset information by the acquisition unit 11 is performed substantially simultaneously. Steps S1 and S2 correspond to the acquisition step ST1.

Next, the correction unit 12 corrects the steering angle θ of the front wheels 21 based on the first offset information acquired by the acquisition unit 11 (S3). Similarly, the correction unit 12 corrects the steering angle θ of the rear wheel 22 based on the second offset information acquired by the acquisition unit 11 (S4). The correction of the steering angle θ of the front wheels 21 and the correction of the steering angle θ of the rear wheels 22 by the correction portion 12 are performed almost simultaneously. Steps S3 and S4 correspond to the correction step ST2.

Then, the correction unit 12 corrects the speed ratio of the front wheels 21 to the rear wheels 22 based on the corrected steering angle θ of the front wheels 21 and the corrected steering angle θ of the rear wheels 22 (S5). That is, the correction portion 12 corrects the speed of the front wheel 21 and the speed of the rear wheel 22. Step S5 corresponds to the speed correction step ST3.

Then, the control unit 102 controls the front wheels 21 based on the steering angle θ of the front wheels 21 corrected by the correction unit 12 and the speed of the front wheels 21 (S6). Similarly, the control unit 102 controls the rear wheels 22 based on the steering angle θ of the rear wheels 22 corrected by the correction unit 12 and the speed of the rear wheels 22 (S7). The above-described processing is periodically repeated (for example, every several tens of milliseconds) until the conveying device 1 reaches the destination (S8: yes). Thereby, the conveyor 1 moves toward the destination following the track L1 while suppressing the deviation from the reference posture.

(4) Advantages are that

The advantages of the control system 100 according to the present embodiment will be described below in comparison with those of the control system of the comparative example. As shown in fig. 6, it is assumed that the control system of the comparative example controls the conveying apparatus 1 that conveys the conveyed article A1. The conveyor 1 has a sensor 40 at the front end of the conveyor 1 instead of two sensors 4. The control system of the comparative example controls the conveyor 1 based on the detection result of the sensor 40 so that the conveyor 1 follows the track L1.

In the control system of the comparative example, when the conveyor 1 is controlled so that the conveyor 1 follows the track L1, the positional displacement of the sensor 40 with respect to the track L1 can be corrected, but it is difficult to correct the displacement of the entire conveyor 1 with respect to the track L1.

Here, in the conveyor 1 shown in fig. 6, the steering wheel 2 is located at a position deviated from the center of gravity of the conveyed object A1, and therefore, the traveling resistance is biased, and thus, the advancing property of the conveyor 1 is easily lost. Therefore, when the conveyor 1 that conveys the conveyed article A1 is controlled by the control system of the comparative example, the conveyor 1 follows the track L1 in a state inclined from the reference posture because of the offset of the traveling resistances of the conveyed article A1 and the conveyor 1. Therefore, in the case where the conveying apparatus 1 is controlled by the control system of the comparative example, there is a problem as follows: the ratio of the conveyor 1 and the conveyed object A1 to the width of the passage tends to be large, and it is difficult to move the conveyor 1 on a narrow passage.

In contrast, in the present embodiment, the correction unit 12 corrects the steering angle θ based on the corresponding one of the plurality of pieces of steering wheel offset information acquired by the acquisition unit 11 for each of the plurality of steered wheels 2. That is, in the present embodiment, the positional displacement of the front wheel 21 with respect to the rail L1 is corrected so that the front wheel 21 follows the rail L1, and the positional displacement of the rear wheel 22 with respect to the rail L1 is corrected so that the rear wheel 22 follows the rail L1.

Therefore, in the present embodiment, since the conveyor 1 is controlled such that all of the steered wheels 2 (here, the front wheels 21 and the rear wheels 22) follow the track L1, even when the conveyed object A1 is conveyed and moving, correction is performed such that the posture of the conveyor 1 becomes the reference posture. Therefore, the present embodiment has an advantage that the deviation of the conveyor 1 from the reference posture is suppressed and the conveyor 1 is easily caused to follow the track L1.

(5) Modification examples

The above-described embodiment is merely one embodiment of various embodiments of the present disclosure. The above-described embodiments may be modified in various ways depending on the design and the like, as long as the objects of the present disclosure can be achieved. The same functions as those of the control method (control system 100) according to the above embodiment may be embodied by a computer program, a non-transitory recording medium storing the computer program, or the like. A program of an aspect of the present disclosure causes one or more processors to execute the control method described above.

The following describes modifications of the above embodiment. The modified examples described below can be appropriately combined and applied.

The control system 100 of the present disclosure includes a computer system in the control section 102 or the like, for example. The computer system has a processor and a memory as hardware as a main structure. The functions of the control system 100 as the present disclosure are realized by a processor executing a program recorded in a memory of a computer system. The program may be recorded in advance in a memory of the computer system, may be provided via an electric communication line, or may be provided on a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive readable by the computer system. The processor of a computer system is composed of one or more electronic circuits including a semiconductor Integrated Circuit (IC) or a large scale integrated circuit (LSI). The term "integrated circuit" as used herein, such as an IC or LSI, is defined as a different degree of Integration, and includes an integrated circuit called a system LSI, a VLSI (very large scale integrated circuit) or a ULSI (Ultra LARGE SCALE integrated circuit). Further, an FPGA (Field-Programmable gate array) programmed after the LSI is manufactured, or a logic device capable of reconstructing a bonding relationship inside the LSI or a circuit division inside the LSI can be used as a processor. The plurality of electronic circuits may be integrated into one chip or may be provided in a distributed manner on a plurality of chips. The plurality of chips may be integrated in one device or may be provided in a plurality of devices in a distributed manner. The computer system described herein includes a microcontroller having one or more processors and one or more memories. Thus, with respect to microcontrollers, it is also possible for one or more electronic circuits to be formed comprising semiconductor integrated circuits or large-scale integrated circuits.

In addition, it is not necessary that the plurality of functions in the control system 100 be integrated into one housing in the control system 100, and the constituent elements of the control system 100 may be provided in a plurality of housings in a distributed manner. Further, the functions of at least a part of the control system 100 may also be realized by a cloud (cloud computing) or the like.

In the above embodiment, for example, as shown in fig. 7, the control system 100 may cause the conveyor 1 to follow the track L1 by so-called differential control in which the steering angle θ of the plurality of steered wheels 2 is fixed and the conveyor 1 is moved by the speed difference between the plurality of steered wheels 2.

In the above embodiment, for example, as shown in fig. 8, the control system 100 may rotate the conveying device 1 as follows: the steering angle θ of the plurality of steered wheels 2 is fixed so that the plurality of steered wheels 2 follow a circumferential track centered on an intersection X1 at which straight lines extending the respective axes of the plurality of steered wheels 2 intersect.

In the above embodiment, for example, as shown in fig. 9, a plurality of sensors 4 may be disposed between a plurality of steered wheels 2. In fig. 9, the plurality of sensors 4 are depicted as solid lines, but in reality, the plurality of sensors 4 are hidden in the main body 10 of the conveying apparatus 1 (described later). The same applies to fig. 10 to 16.

In the above embodiment, the correction unit 12 may not perform the control of correcting the speeds of the plurality of steered wheels 2. In this case, as in the above embodiment, it is not necessary that all of the plurality of steered wheels 2 double as driving wheels, and at least one of the steered wheels 2 double as driving wheels.

In the above embodiment, instead of correcting the speeds of the plurality of steered wheels 2, the correction unit 12 may correct the torques applied to the shafts of the plurality of steered wheels 2.

In the above-described embodiment, the correction amount of the steering angle θ of each of the plurality of steered wheels 2 may be determined by P (Proportional) control or PI (Proportional-Integral) control, in addition to PID control.

In the above embodiment, the rail L1 may not be provided on the moving surface B1. That is, the track L1 may not have an entity. For example, the track L1 may be a virtual track in the map information given to the conveying device 1. In this case, the sensor 4 is not a magnetic sensor, and may be configured to detect a positional shift of the sensor 4 with respect to the virtual orbit by a combination of a satellite positioning system such as GPS and LiDAR.

In the above embodiment, the control system 100 is mounted on the conveying apparatus 1, but is not limited thereto. For example, the host system 6 may function as the control system 100. In this case, the upper system 6 executes the acquisition step ST1, and in this acquisition step ST1, the detection result of the sensor 4 is acquired from the conveying apparatus 1 by wireless communication, thereby acquiring the offset information. In this case, the host system 6 executes the correction step ST2 and the speed correction step ST3, and in the correction step ST2 and the speed correction step ST3, the steering angle θ and the speed are corrected for each of the plurality of steered wheels 2 based on the obtained offset information, and the command changed to the corrected steering angle θ and speed is transmitted to the conveying device 1 by wireless communication.

In the above embodiment, the connection portion 5 is not limited to the form of hooking a part of the transport object A1 such as a hook, and may be a form of attracting the transport object A1 by an electromagnet.

In the above embodiment, the conveying device 1 may not have the coupling portion 5. For example, the conveyor 1 may have a structure in which the conveyor 1 is loaded with the conveyed article A1. That is, the conveying device 1 may be capable of conveying the conveyed article A1.

(Embodiment 2)

(1) Detailed description

As shown in fig. 10, the conveyor 1 of the present embodiment is different from the conveyor 1 of the above-described embodiment 1 in that a plurality of sensors 4 (here, a first sensor 41 and a second sensor 42) are arranged between a plurality of steered wheels 2 (here, a front wheel 21 and a rear wheel 22).

In the control system 100 of the present embodiment, offset information acquired by the acquisition unit 11 is different from the control system 100 of embodiment 1 described above. Specifically, in the present embodiment, the offset information includes rotational offset information and positional offset information. The rotational displacement information is information related to the inclination displacement of the conveyor 1 from the reference posture of the conveyor 1 with respect to the track L1. The positional deviation information is information related to the positional deviation of the conveying device 1 from the reference posture.

In the present embodiment, the acquisition unit 11 acquires the rotational offset information and the positional offset information based on the detection results of the first sensor 41 and the second sensor 42. Specifically, the acquisition unit 11 acquires, as the positional displacement information, an intermediate value of the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1 (that is, the positional displacement amount D1 between the control point P1 of the main body 10 of the conveying device 1 and the track L1). The control point P1 is the center of the main body 10 of the conveying apparatus 1. In addition, the control point P1 is an intermediate point between the center of the first sensor 41 and the center of the second sensor 42. The acquisition unit 11 acquires, as rotation shift information, a rotation shift amount D2, the rotation shift amount D2 being an angle having a tangent (tangent) of a distance D11 and a difference D12 between the centers of the first sensor 41 and the second sensor 42. The difference D12 is a difference between the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1.

The correction of the steering angle θ of each of the plurality of steered wheels 2 by the correction unit 12 in the control system 100 of the present embodiment is different from the control system 100 of embodiment 1 described above. Specifically, in the present embodiment, the correction unit 12 corrects the steering angle θ for each of the plurality of steered wheels 2 based on the rotational offset information and the positional offset information acquired by the acquisition unit 11. In other words, the correction step ST2 is a step of correcting the steering angle θ based on the rotation shift information and the positional shift information for each of the steered wheels 2 of the plurality of steered wheels 2.

A process of correcting the steering angle θ of each of the plurality of steered wheels 2 by the correction unit 12 will be described below with reference to fig. 11 to 13. First, the correction unit 12 calculates a first steering angle θ1 for each of the steered wheels 2 of the plurality of steered wheels 2. The first steering angle θ1 is an angle obtained based on the positional deviation information. As shown in fig. 11, the first steering angle θ1 is an angle at which the conveyor 1 is moved in parallel without being rotated, and the positional deviation D1 (see fig. 10) is zero (that is, the control point P1 is placed on the track L1). Therefore, the first steering angle θ11 of the front wheel 21 and the first steering angle θ12 of the rear wheel 22 have the same value.

Next, the correction unit 12 calculates a second steering angle θ2 for each of the steered wheels 2 of the plurality of steered wheels 2. The second steering angle θ2 is an angle obtained based on the rotational offset information. As shown in fig. 12, the second steering angle θ2 is an angle at which the conveyor 1 is rotated so that the rotational offset D2 (see fig. 10) becomes zero (that is, the conveyor 1 becomes a reference posture). Here, the second steering angle θ21 of the front wheel 21 and the second steering angle θ22 of the rear wheel 22 are in reverse phase with each other as described later.

Then, the correction unit 12 corrects the steering angle θ based on the combined steering angle θ3 obtained by combining the calculated first steering angle θ1 and second steering angle θ2 for each of the plurality of steered wheels 2. In other words, the correction step ST2 is a step of correcting the steering angle θ based on the synthesized steering angle θ3 obtained by synthesizing the first steering angle θ1 and the second steering angle θ2 for each of the plurality of steered wheels 2. As shown in fig. 13, the resultant steering angle θ31 of the front wheels 21 is an angle obtained by adding the first steering angle θ11 of the front wheels 21 to the second steering angle θ21 of the front wheels 21. The resultant steering angle θ32 of the rear wheel 22 is an angle obtained by adding the first steering angle θ12 of the rear wheel 22 to the second steering angle θ22 of the rear wheel 22.

Here, when calculating the second steering angle θ2, the correction unit 12 executes reverse phase control for calculating the second steering angle θ2 of each of the plurality of steered wheels 2 so that the second steering angle θ21 of the front wheel 21 and the second steering angle θ22 of the rear wheel 22 are in reverse phases with each other. The term "reverse phase to each other" as used in the present disclosure refers to a relationship between the steering angle θ of the front wheel 21 when the front wheel 21 is rotated clockwise or counterclockwise and the steering angle θ of the rear wheel 22 when the rear wheel 22 is rotated in the opposite direction to the front wheel 21. For example, when the second steering angle θ21 of the front wheels 21 is assumed to be 30 degrees, the second steering angle θ22 of the rear wheels 22 becomes-30 degrees when the relationship of the reverse phases to each other is satisfied. In other words, the correction step ST2 has the steps of: when the steering angle θ is corrected based on the rotation shift information, the steering angle θ of the front wheel 21 located in front of the conveyor 1 among the plurality of steered wheels 2 and the steering angle θ of the rear wheel 22 located behind the conveyor 1 among the plurality of steered wheels 2 are set to be in inverse phase with each other.

The advantages of the above-described inverted phase control will be described below with reference to fig. 14 to 16. First, it is assumed that the conveying device 1 is controlled by correcting the steering angle θ of each of the front wheels 21 and the rear wheels 22 by the first steering angle θ1 calculated by the correction unit 12. In this case, as shown in fig. 14, inertia represented by an inertia vector V1 toward the first steering angle θ1 acts on the conveyor 1.

In this state, it is assumed that the conveying device 1 is controlled by correcting only the front wheels 21 with the steering angle θ110 obtained by further adding the second steering angle θ21. In this case, as shown in fig. 15, the yaw moment about the ground contact point between the rear wheel 22 and the moving surface B1 acts on the conveyor 1, so that the inertia vector V1 changes rapidly to the inertia vector V2. In this way, when the inertia acting on the conveyor 1 changes rapidly, there is a possibility that the balance between the conveyor 1 and the conveyed object A1 is easily broken or the loss of the propelling force of the conveyor 1 increases.

In contrast, in the present embodiment, the above-described problem is eliminated by performing the above-described inverted phase control. That is, when the correction unit 12 performs the reverse phase control in the state shown in fig. 14 of the conveyor 1, as shown in fig. 16, inertia indicated by an inertia vector V3 in the tangential direction of the revolving orbit of the conveyor 1 acts on the conveyor 1. Since the inertia vector V3 is in almost the same direction as the inertia vector V1 immediately before the reverse phase control is performed, the change in inertia acting on the conveyor 1 can be suppressed as much as possible. Therefore, the present embodiment has an advantage that the balance between the conveyor 1 and the conveyed object A1 is hardly broken and the loss of the propelling force of the conveyor 1 can be suppressed.

As an example, the resultant steering angle θ31 of the front wheels 21 and the resultant steering angle θ32 of the rear wheels 22 are represented by the following formulas (6) to (9), respectively. In the expression (8), "Dx" represents the positional deviation amount, and "Kx" represents the positional correction coefficient (scaling coefficient). In expression (9), "Dr" represents the rotation shift amount, and "Kr" represents the rotation correction coefficient (scaling coefficient).

[ Number 4]

θ31＝θ1+θ2…(6)

θ32＝θ1-θ2…(7)

θ1＝Kx·Dx…(8)

θ2＝Kr·Dr…(9)

Here, each of the steering angles θ1 and θ2 represented by the formulas (8) and (9) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the steering angles θ1 and θ2 are expressed by the following equations (10) and (11), respectively. In the expression (10), "Dxi" represents the integral amount of the positional deviation, "Dxd" represents the differential amount of the positional deviation, "Kxi" represents the positional correction coefficient (integral coefficient), and "Kxd" represents the positional correction coefficient (differential coefficient). In the expression (11), "Dri" represents the integral amount of the rotational offset, "Drd" represents the differential amount of the rotational offset, "Kri" represents the rotational correction coefficient (integral coefficient), and "Krd" represents the rotational correction coefficient (differential coefficient).

[ Number 5]

θ1＝Kx·Dx+Kxi·Dxi+Kxd·Dxd…(10)

θ2＝Kr·Dr+Kri·Dri+Krd·Drd…(11)

(2) Action

An example of the operation of the control system 100 according to the present embodiment will be described below with reference to fig. 17. In the operation example shown in fig. 17, it is assumed that the conveyor 1 is moving to the destination while conveying the conveyed article A1 and following the track L1. During the movement of the conveyor 1, the acquisition unit 11 acquires positional displacement information and rotational displacement information by periodically acquiring detection results from the first sensor 41 and the second sensor 42 (S9). Step S9 corresponds to the acquisition step ST1.

Next, the correction unit 12 calculates the first steering angle θ1 of each of the front wheels 21 and the rear wheels 22 based on the positional deviation information acquired by the acquisition unit 11 (S10). The correction unit 12 calculates the second steering angle θ2 of each of the front wheel 21 and the rear wheel 22 based on the rotational offset information acquired by the acquisition unit 11 (S11). Then, the correction unit 12 calculates a resultant steering angle θ3 of each of the front wheels 21 and the rear wheels 22 based on the calculated first steering angle θ1 and second steering angle θ2 (S12). Then, the correction unit 12 corrects the steering angle θ of each of the front wheels 21 and the rear wheels 22 based on the calculated resultant steering angle θ3 (S13). Steps S10 to S13 correspond to the correction step ST2.

Then, the correction unit 12 corrects the speed ratio of the front wheels 21 to the rear wheels 22 based on the corrected steering angle θ of the front wheels 21 and the corrected steering angle θ of the rear wheels 22 (S14). That is, the correction portion 12 corrects the speed of the front wheel 21 and the speed of the rear wheel 22. Step S14 corresponds to the speed correction step ST3.

Then, the control unit 102 controls the front wheels 21 based on the steering angle θ of the front wheels 21 corrected by the correction unit 12 and the speed of the front wheels 21 (S15). Similarly, the control unit 102 controls the rear wheels 22 based on the steering angle θ of the rear wheels 22 corrected by the correction unit 12 and the speed of the rear wheels 22 (S16). The above-described processing is periodically repeated (for example, every several tens of milliseconds) until the conveying device 1 reaches the destination (S17: yes). Thereby, the conveyor 1 moves toward the destination following the track L1 while suppressing the deviation from the reference posture.

(3) Advantages are that

As described above, in the present embodiment, all of the steering wheels 2 (here, the front wheels 21 and the rear wheels 22) of the conveyor 1 are controlled so that the inclination displacement of the conveyor 1 from the reference posture of the conveyor 1 with respect to the rail L1 and the position displacement of the conveyor 1 from the reference posture are corrected. Therefore, in the present embodiment, even when the conveyed object A1 is conveyed and moving, correction is performed so that the posture of the conveying device 1 becomes the reference posture. Therefore, in the present embodiment, similarly to embodiment 1, there is an advantage that the deviation of the conveyor 1 from the reference posture is suppressed and the conveyor 1 is easily caused to follow the track L1.

(4) Modification examples

The configuration described in embodiment 2 and the various configurations described in embodiment 1 (including modifications) can be appropriately combined and used.

In embodiment 2, the correction unit 12 corrects the steering angle θ based on the resultant steering angle θ3 for each of the plurality of steered wheels 2, but is not limited thereto. For example, the correction unit 12 may alternately perform the process of correcting the steering angle θ based on the first steering angle θ1 and the process of correcting the steering angle θ based on the second steering angle θ2. In other words, the correction step ST2 may alternately execute the first lower step and the second lower step for each of the plurality of steered wheels 2. The first lower step is a step of correcting the steering angle θ based on the rotation offset information, and corresponds to a step of correcting the steering angle θ based on the first steering angle θ1 calculated in step S10 of fig. 17. The second lower step is a step of correcting the steering angle θ based on the positional deviation information, and corresponds to a step of correcting the steering angle θ based on the second steering angle θ2 calculated in step S11 of fig. 17.

In embodiment 2 described above, the sensor 4 is configured to detect physical quantities that can generate positional displacement information and rotational displacement information. For example, the sensor 4 may be a plurality of rod-shaped magnetic sensors arranged in a ring shape, or may be one ring-shaped magnetic sensor. The sensor 4 may be an imaging device provided in either one of the conveyor devices 1 to capture the track L1. The sensor 4 may be an imaging device that images the conveyor 1 from the outside of the conveyor 1. The sensor 4 may be a GPS module or a geomagnetic sensor if accuracy of the positional offset information and the rotational offset information is not required.

In embodiment 2 described above, the correction unit 12 may not perform the reverse phase control when calculating the second steering angle θ2. That is, the correction unit 12 may bring the second steering angle θ21 of the front wheel 21 and the second steering angle θ22 of the rear wheel 22 into phase with each other.

Embodiment 3

Hereinafter, a control method according to embodiment 3 will be described with reference to fig. 18. In the present embodiment, a method of controlling the conveyor device 1 when the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) are arranged in a direction intersecting the front-rear direction will be described.

Here, when a plurality of steered wheels 2 are arranged in the front-rear direction as in embodiments 1 and 2 and are arranged in the direction intersecting the front-rear direction as in embodiment 3, the control method may be different from each other, or a common control method may be used. When the control methods are different, the control method may be switched according to the directions of the plurality of steered wheels 2.

That is, the control system of the present embodiment includes at least one of the first steering angle control processing unit and the second steering angle control processing unit. The first steering angle control processing unit controls the steering angle θ of the conveyor 1 in a state where the plurality of steered wheels 2 of the conveyor 1 that conveys the conveyed object A1 are arranged in the front-rear direction and the plurality of steered wheels 2 are provided. The second steering angle control processing unit controls the steering angle θ of the conveyor 1 in a state where the plurality of steered wheels 2 of the conveyor 1 are aligned in a direction intersecting the front-rear direction. In the present embodiment, the control unit 102 has a function as a first steering angle control processing unit and a function as a second steering angle control processing unit.

The control method of the present embodiment includes at least one of a first steering angle control process and a second steering angle control process. The first steering angle control process is a process of controlling the steering angle θ of the conveying apparatus 1 in a state where the plurality of steered wheels 2 of the conveying apparatus 1 that conveys the conveyed object A1 are arranged in the front-rear direction and have the plurality of steered wheels 2. The second steering angle control process is a process of controlling the steering angle θ of the conveyor 1 in a state where the plurality of steered wheels 2 of the conveyor 1 are aligned in a direction intersecting the front-rear direction.

As an example of the control method of the steering angle θ in the first steering angle control process and the second steering angle control process, there is a first control method in which the steering angle θ is corrected for each of the plurality of steered wheels 2 based on the corresponding steered wheel offset information (see embodiment 1). As another example of the control method, there is a second control method in which the steering angle θ is corrected based on the rotation shift information and the positional shift information (see embodiment 2).

In the case where the plurality of steered wheels 2 are aligned in a direction intersecting the front-rear direction, the second control method is preferably employed, but the first control method can also be employed. In the case of adopting the first control method, for example, the sensors 4 are arranged on the left and right sides in fig. 18, and the first sensor 41 on the left detects the positional displacement of the first sensor 41 with respect to the rail L1, whereby the positional displacement of the first wheel 21 with respect to the rail L1 can be detected. In addition, the second sensor 42 on the right detects the positional displacement of the second sensor 42 with respect to the rail L1, and thereby the positional displacement of the second wheel 22 with respect to the rail L1 can be detected. The conveyor 1 may be controlled so that the positional offsets of the first wheel 21 and the second wheel 22 are equal to each other.

The following will be described: in the case where the plurality of steered wheels 2 are aligned in a direction intersecting the front-rear direction, a second control method is adopted as the control method of the conveying apparatus 1.

(1) Summary of the inventionsummary

In the present embodiment, the conveyor 1 has a plurality of diverting wheels 2 arranged in a direction intersecting the front-rear direction of the conveyor 1, and is a device that moves on a moving surface B1 to convey a conveyed article A1. The term "front-rear direction" as used in the present disclosure refers to the width direction of the conveyor 1, and refers to the direction in which the conveyor 1 travels as the "front" and the opposite direction as the "rear". In the present embodiment, the "direction intersecting the front-rear direction" is the longitudinal direction of the conveying device 1, and is the left-right direction in fig. 18. As in embodiment 1, the conveying device 1 may be configured to travel in the longitudinal direction. The front-rear direction in this case is the longitudinal direction.

The blank arrow in fig. 18 indicates the traveling direction of the conveying device 1. In fig. 18, the cross arrows indicate "front", "rear", "left" and "right" of the conveying device 1. These arrows in fig. 18 are merely indicated for illustration, and are not accompanied by an entity. In fig. 18, the wheels such as the plurality of steered wheels 2 of the conveyor 1 are drawn in solid lines, but in reality, these wheels are hidden in the main body 10 of the conveyor 1 (described later). In fig. 18, the track L1 is drawn as a solid line, but in reality, a portion of the track L1 overlapping the conveyor 1 is hidden in the body portion 10 of the conveyor 1. The same applies to the drawings other than fig. 18.

In the present embodiment, the plurality of steering wheels 2 includes a first wheel 21 located at a first end in the longitudinal direction of the conveyor 1 and a second wheel 22 located at a second end in the longitudinal direction of the conveyor 1. That is, the conveyor 1 is configured to move on the moving surface B1 by the two steered wheels 2. In the present embodiment, the conveying device 1 includes four auxiliary wheels 3 in addition to two steered wheels 2, but these auxiliary wheels 3 are not included in the steered wheels 2 whose steering angle θ (see fig. 20) can be changed by the control system 100.

The control method of the conveying apparatus 1 according to the present embodiment includes an acquisition step ST1 and a correction step ST2 (see fig. 28).

The acquisition step ST1 is a step of acquiring rotational offset information and positional offset information. The rotational displacement information is information related to the inclination displacement of the conveyor 1 from the reference posture of the conveyor 1 with respect to the track L1. The positional deviation information is information related to the positional deviation of the conveying device 1 from the reference posture. The "reference posture" as referred to in the present disclosure refers to a posture of the conveying device 1 in which the front-rear direction of the conveying device 1 is parallel to the track L1. It should be noted that "parallel" includes not only complete parallelism but also a concept of substantially parallelism. In the present embodiment, the acquisition unit 11 acquires rotation shift information and positional shift information based on detection results of each of the first sensor 41 and the second sensor 42 described later.

The correction step ST2 is a step of correcting the steering angle θ for each of the plurality of steered wheels 2 based on the rotational offset information and the positional offset information acquired in the acquisition step ST 1. That is, in the present embodiment, the steering angle θ of each of the plurality of steered wheels 2 is corrected individually, instead of correcting the plurality of steered wheels 2 to be the same steering angle θ based on the rotation offset information and the positional offset information. Of course, as a result of the correction step ST2, there may be a case where the steering angles θ of the respective plurality of steered wheels 2 are the same.

Therefore, the present embodiment has an advantage that the deviation of the conveyor 1 from the reference posture is suppressed and the conveyor 1 is easily caused to follow the track L1.

(2) Detailed description

(2.1) Integral Structure

As in embodiment 1, the host system 6 shown in fig. 2 communicates with the conveyor 1 via the network NT1 and the relay 7, and indirectly controls the movement of the conveyor 1. The relationship between the conveyor 1 and the host system 6, the network NT1, and the repeater 7 is the same as that of embodiment 1, and therefore, the description thereof is omitted.

(2.2) Conveying appliance

As shown in fig. 18, the conveying device 1 includes a main body 10. The body 10 is formed in a rectangular parallelepiped shape. In the present embodiment, a coupling portion 5, such as a hook, capable of hooking a part of the conveyed article A1 is provided on a side surface of the main body 10. The "side surface of the main body" referred to herein is a surface intersecting the rail L1 when the conveyor 1 assumes the reference posture. Therefore, in the present embodiment, by hooking a part of the conveyed article A1 to the coupling portion 5, the conveyed article A1 can be coupled to the conveying apparatus 1. That is, the conveying apparatus 1 includes a coupling portion 5 for coupling the conveyed article A1 to one surface (back surface) of the main body portion 10 of the conveying apparatus 1 intersecting the rail L1.

The conveyor 1 has a plurality of (here, six) wheels at the lower portion of the main body 10. The first wheel 21 located at a first end (left end) in the longitudinal direction (left-right direction) of the main body 10 and the second wheel 22 located at a second end (right end) in the longitudinal direction of the main body 10 among the six wheels are both steered wheels 2. Further, two of the six wheels located on both sides of the main body 10 with the first sensor 41 interposed therebetween and two of the six wheels located on both sides of the main body 10 with the second sensor 42 interposed therebetween are auxiliary wheels 3 (driven wheels). In the present embodiment, both of the steering wheels 2 also serve as driving wheels, and by individually driving these driving wheels, the conveying device 1 can move in a desired direction on the moving surface B1. Further, each of the two steered wheels 2 is configured to be capable of changing the steering angle θ within a range sufficient to return to the path when the conveyor 1 is deviated from the path following the track L1.

(2.3) Control System

Next, the configuration of the control system 100 according to the present embodiment will be described in more detail. As shown in fig. 2, the control system 100 includes a detection unit 101, a control unit 102, a communication unit 103, a storage unit 104, and a traveling device 105. The detection unit 101, the control unit 102, the communication unit 103, the storage unit 104, and the traveling device 105 are not described in the same manner as in embodiment 1.

The detection unit 101 includes a plurality of sensors 4. The plurality of sensors 4 (here, the first sensor 41 and the second sensor 42) are provided between the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22), respectively. The first sensor 41 is provided between the two auxiliary wheels 3 at the front end of the main body 10. The second sensor 42 is provided between the two auxiliary wheels 3 at the rear end of the main body 10.

The plurality of sensors 4 are bar-shaped magnetic sensors, and detect the relative positional relationship between the sensors 4 and the track L1, that is, the positional displacement of the sensors 4 with respect to the track L1 by detecting the magnetic flux generated by the track L1. As an example, the "positional shift" is represented by the shortest distance between the center of the sensor 4 and the track L1.

The acquisition unit 11 acquires rotational offset information and positional offset information by communicating with the plurality of sensors 4. That is, the acquisition unit 11 is a main body for acquiring step ST1 (see fig. 28). In the present embodiment, the acquisition unit 11 acquires the rotational offset information and the positional offset information based on the detection results of the first sensor 41 and the second sensor 42. Specifically, as shown in fig. 19, the acquisition unit 11 acquires, as the positional displacement information, an intermediate value of the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1 (that is, the positional displacement amount D1 between the control point P1 of the main body 10 of the conveying device 1 and the track L1). The control point P1 is the center of the main body 10 of the conveying apparatus 1. In addition, the control point P1 is an intermediate point between the center of the first sensor 41 and the center of the second sensor 42. The acquisition unit 11 acquires, as rotation shift information, a rotation shift amount D2, the rotation shift amount D2 being an angle having a tangent (tangent) of a distance D11 and a difference D12 between the centers of the first sensor 41 and the second sensor 42. The difference D12 is a difference between the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1.

The correction unit 12 corrects the steering angle θ for each of the plurality of steered wheels 2 based on the rotational offset information and the positional offset information acquired by the acquisition unit 11. That is, the correction unit 12 is the subject of the correction step ST2 (see fig. 28). In the present embodiment, the correction unit 12 individually corrects the steering angle θ of the first wheel 21 and the steering angle θ of the second wheel 22 based on the rotational offset information and the positional offset information acquired by the acquisition unit 11. In the present embodiment, the correction amount of the steering angle θ of each of the first wheel 21 and the second wheel 22 is determined by PID (Proportional-Integral-Differential) control.

The following describes a procedure for correcting the steering angle θ of each of the plurality of steered wheels 2 by the correction unit 12, with reference to fig. 20 to 22. First, the correction unit 12 calculates a reference steering angle θ0 for each of the steered wheels 2 of the plurality of steered wheels 2. The reference steering angle θ0 is an angle in which the steered wheel 2 advances along the track L1, and is an angle obtained based on the rotational offset information. In other words, the correction step ST2 includes a step of correcting the respective steered wheels 2 of the plurality of steered wheels 2 so that the steering angle θ coincides with the reference steering angle θ0.

Fig. 20 shows the conveying device 1 when the steering angle θ of each of the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) is set to the reference steering angle θ0. As shown in fig. 20, the reference steering angle θ0 of each of the plurality of steered wheels 2 coincides with the rotational offset amount D2. That is, the reference steering angle θ0 is calculated by obtaining the rotation offset D2. In fig. 20, the steering angle θ (reference steering angle θ0) of the first wheel 21 and the steering angle θ (reference steering angle θ0) of the second wheel 22 have the same value.

Next, the correction unit 12 calculates a first steering angle θ1 for each of the steered wheels 2 of the plurality of steered wheels 2. The first steering angle θ1 is an angle obtained based on the positional deviation information. The first steering angle θ1 is an angle at which the conveyor 1 is moved in parallel without being rotated, and the positional deviation D1 is zero (that is, the control point P1 is placed on the track L1). Fig. 21 shows the conveyor 1 when the steering angle θ of each of the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) is an angle obtained by adding the reference steering angle θ0 and the first steering angle θ1. Here, the first steering angle θ1 of the first wheel 21 and the first steering angle θ1 of the second wheel 22 have the same value. Therefore, in fig. 21, the steering angle θ of the first wheel 21 and the steering angle θ of the second wheel 22 have the same value. In the present embodiment, the first steering angle θ1 is represented by the following expression (12). In the expression (12), "K1" represents a correction coefficient for the positional deviation amount D1.

[ Number 6]

θ1＝K1·D1…(12)

Here, the first steering angle θ1 represented by the expression (12) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the first steering angle θ1 is represented by the following equation (13). In the expression (13), "Dli" represents the integral amount of the positional deviation, "D1D" represents the differential amount of the positional deviation, "K1i" represents the positional correction coefficient (integral coefficient), and "K1D" represents the positional correction coefficient (differential coefficient).

[ Number 7]

θ1＝K1.D1+K1i.D1i+K1d.D1d…(13)

Next, the correction unit 12 calculates a second steering angle θ2 for each of the steered wheels 2 of the plurality of steered wheels 2. The second steering angle θ2 is an angle obtained based on the rotational offset information. The second steering angle θ2 is an angle at which the conveyor 1 is rotationally moved so that the rotational offset D2 becomes zero (that is, the conveyor 1 becomes the reference posture). Fig. 22 shows the conveying device 1 in the case where the steering angle θ of each of the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) is an angle obtained by adding the reference steering angle θ0 to the first steering angle θ1 and the second steering angle θ2. Here, the second steering angle θ21 of the first wheel 21 and the second steering angle θ22 of the second wheel 22 are in inverse phase with each other as will be described later. Therefore, in fig. 22, the steering angle θ of the first wheel 21 and the steering angle θ of the second wheel 22 are different from each other.

In the present embodiment, the second steering angle θ2 (the second steering angle θ21 of the first wheel 21 and the second steering angle θ22 of the second wheel 22) is represented by the following formulas (14) to (18). In the equations (14) and (15), R0 represents a radius of gyration centered on the point X0 of the corrected control point P1. The point X0 represents the intersection point of the straight line extending the axis of the first wheel 21 and the straight line extending the axis of the second wheel 22. In the expression (16), "K2" represents a correction coefficient for the rotational offset amount D2. In the formulas (17), (18), "T0" represents the distance between the center of the first wheel 21 and the center of the second wheel 22.

[ Number 8]

T＝T0cos(θ0+θ1)…(17)

W0＝T0sin(θ0+θ1)…(18)

Here, the radius gyration R0 represented by the formula (16) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the radius of gyration R0 is represented by the following formula (19). In the expression (19), "D2i" represents the integral amount of the rotational offset, "D2D" represents the differential amount of the rotational offset, "K2i" represents the rotational correction coefficient (integral coefficient), and "K2D" represents the rotational correction coefficient (differential coefficient).

[ Number 9]

Then, the correction unit 12 corrects the steering angle θ based on the combined steering angle θ3 (see fig. 22) obtained by combining the calculated reference steering angle θ0, the first steering angle θ1, and the second steering angle θ2 for each of the plurality of steered wheels 2. In other words, the correction step ST2 is a step of correcting the steering angle θ based on the synthesized steering angle θ3 obtained by synthesizing the first steering angle θ1 and the second steering angle θ2 for each of the plurality of steered wheels 2. As shown in fig. 22, the resultant steering angle θ3 of the first wheel 21 is an angle obtained by adding the reference steering angle θ0 of the first wheel 21, the first steering angle θ1 of the first wheel 21, and the second steering angle θ21 of the first wheel 21. The resultant steering angle θ3 of the second wheel 22 is an angle obtained by adding the reference steering angle θ0 of the second wheel 22, the first steering angle θ1 of the second wheel 22, and the second steering angle θ22 of the second wheel 22.

Here, when calculating the second steering angle θ2, the correction unit 12 performs inverse phase control for calculating the second steering angle θ2 of each of the plurality of steered wheels 2 so that the second steering angle θ21 of the first wheel 21 and the second steering angle θ22 of the second wheel 22 are in inverse phase with each other. The term "reverse phase to each other" as used in the present disclosure refers to a relationship between the steering angle θ of the first wheel 21 when the first wheel 21 is rotated clockwise or counterclockwise and the steering angle θ of the second wheel 22 when the second wheel 22 is rotated in the opposite direction to the first wheel 21. For example, when the second steering angle θ21 of the first wheel 21 is assumed to be 30 degrees, the second steering angle θ22 of the second wheel 22 becomes-30 degrees when the relationship of the reverse phases to each other is satisfied. In other words, the correction step ST2 has the steps of: when the steering angle θ is corrected based on the rotation shift information, the steering angle θ of the first wheel 21 located at the first end (left end) in the longitudinal direction of the conveyor 1 among the plurality of steered wheels 2 and the steering angle θ of the second wheel 22 located at the second end (right end) in the longitudinal direction of the conveyor 1 among the plurality of steered wheels 2 become opposite phases to each other.

The advantage of the above-described inverted phase control will be described below with reference to fig. 23 to 25 by taking the conveying apparatus 1A as an example. The following description of the advantages of the reverse phase control is also true in the conveying apparatus 1 shown in fig. 18. The conveyor 1A differs from the conveyor 1 shown in fig. 18 in that the longitudinal direction of the conveyor 1 is taken as the traveling direction. That is, in the conveyor 1A, the longitudinal direction of the conveyor 1A is the front-rear direction, the first wheel 21 is the front wheel 21A, and the second wheel 22 is the rear wheel 22A. The conveyor 1A is different from the conveyor 1 shown in fig. 18 in that it includes two auxiliary wheels. In fig. 23 to 25, the plurality of sensors 4, the connecting portion 5, and the conveyed article A1 are not shown.

First, it is assumed that the conveyor 1A is controlled by correcting the steering angle θ of each of the front wheels 21A and the rear wheels 22A with the first steering angle θ1 calculated by the correction unit 12. In this case, as shown in fig. 23, inertia represented by an inertia vector V1 toward the first steering angle θ1 acts on the conveyor 1A.

In this state, it is assumed that the conveying device 1A is controlled by correcting only the front wheels 21A with the steering angle θ110 obtained by further adding the second steering angle θ21. In this case, as shown in fig. 24, the yaw moment about the ground contact point between the rear wheel 22A and the moving surface B1 acts on the conveyor 1A, so that the inertia vector V1 changes rapidly to the inertia vector V2. In this way, when the inertia acting on the conveyor 1A changes rapidly, there is a possibility that the balance between the conveyor 1A and the conveyed object A1 is easily broken or the loss of the propelling force of the conveyor 1A increases.

In this regard, the above-described problem can be eliminated by performing the above-described inverted phase control. That is, when the correction unit 12 performs the reverse phase control in the state shown in fig. 23 in the conveyor 1A, as shown in fig. 25, the inertia indicated by the inertia vector V3 in the tangential direction of the revolving orbit of the conveyor 1A acts on the conveyor 1A. Since the inertia vector V3 is in almost the same direction as the inertia vector V1 immediately before the reverse phase control is performed, the change in inertia acting on the conveyor 1A can be suppressed as much as possible. Therefore, there is an advantage that the balance between the conveyor 1A (conveyor 1) and the conveyed object A1 is hardly broken, and the loss of the propulsive force of the conveyor 1A (conveyor 1) can be suppressed.

In the present embodiment, the correction unit 12 corrects the steering angle θ for each of the plurality of steered wheels 2 as described above, and also corrects the speeds of the plurality of steered wheels (drive wheels) 2. Specifically, the correction unit 12 corrects the speed (peripheral speed) of each of the plurality of steered wheels 2 based on the steering angle θ corrected as described above for each of the steered wheels 2. In other words, the control method further has a speed correction step ST3 in which, for each of the plurality of steered wheels 2, the speed of the corresponding steered wheel 2 is corrected based on the steering angle θ corrected in the correction step ST2 in the speed correction step ST 3.

Hereinafter, a process of determining the speeds of the plurality of steered wheels 2 will be described with reference to fig. 26 by taking the conveyor 1A as an example. The conveyor 1A shown in fig. 26 is the same as the conveyor 1A shown in fig. 23 to 25. In fig. 26, it is assumed that the conveyor 1A moves rightward. In fig. 26, "α" represents the steering angle θ of the front wheel 21A, "β" represents the steering angle θ of the rear wheel 22A, "V _α" represents the speed of the front wheel 21A, "V _R" represents the speed of the rear wheel 22A, and "W" represents the distance between the center of the front wheel 21A and the center of the rear wheel 22A. In fig. 26, "r _α" represents the turning radius of the front wheel 21A centered on the intersection point X1 of the straight line extending the axis of the front wheel 21A and the straight line extending the axis of the rear wheel 22A, and "r _β" represents the turning radius of the rear wheel 22A centered on the intersection point X1 of the axial direction of the front wheel 21A and the axial direction of the rear wheel 22A.

Here, the turning radius of the front wheels 21A and the turning radius of the rear wheels 22A vary according to the steering angle θ of the front wheels 21A and the steering angle θ of the rear wheels 22A. Therefore, the radius of gyration of the front wheel 21A and the radius of gyration of the rear wheel 22A are substantially different from each other. Therefore, there is the possibility that: if the speed of the front wheels 21A is the same as the speed of the rear wheels 22A, the angular speed of the front wheels 21A does not match the angular speed of the rear wheels 22A, and it is not possible to match the operation of the front wheels 21A with the operation of the rear wheels 22A, and the steering wheel 2 of either one idles, so that it is difficult for the conveyor 1A to follow the track L1.

In contrast, the correction unit 12 corrects the speed of each of the plurality of steered wheels 2 based on the steering angle θ, thereby matching the angular speed of the front wheel 21A with the angular speed of the rear wheel 22A, and obtaining a match between the operation of the front wheel 21A and the operation of the rear wheel 22A. Here, the ratio of the speed of the front wheel 21A to the speed of the rear wheel 22A (hereinafter, simply referred to as "speed ratio") when the angular speed of the front wheel 21A coincides with the angular speed of the rear wheel 22A is represented by the following formula (20).

[ Number 10]

That is, the speed ratio is not dependent on the size of the conveyor 1A (for example, the distance "W" between the center of the front wheel 21A and the center of the rear wheel 22A, etc.), and can be determined based on the steering angle θ of the front wheel 21A and the steering angle θ of the rear wheel 22A.

As described above, the correction unit 12 controls the conveyor 1A (conveyor 1) to follow the track L1 by correcting the steering angle θ for each of the front wheels 21A (first wheels 21) and the rear wheels 22A (second wheels 22) and correcting the speeds of each of the front wheels 21A (first wheels 21) and the rear wheels 22A (second wheels 22) based on the corrected steering angle θ.

(2.4) Component mounting System

Fig. 27 is a diagram showing a case where the transport device 1 according to the present embodiment is used to transport the transport object A1 to the component mounter 9. The transport object A1 and the component mounter 9 have the same configuration as in embodiment 1, and therefore, description thereof is omitted.

(3) Action

An example of the operation of the control system 100 according to the present embodiment will be described below with reference to fig. 28. In the operation example shown in fig. 28, it is assumed that the conveyor 1 is moving to the destination while conveying the conveyed article A1 and following the track L1. During the movement of the conveyor 1, the acquisition unit 11 acquires positional displacement information and rotational displacement information by periodically acquiring detection results from the first sensor 41 and the second sensor 42 (S1). Step S1 corresponds to the acquisition step ST1.

Next, the correction unit 12 calculates the reference steering angle θ0 of each of the first wheel 21 and the second wheel 22 based on the positional deviation information acquired by the acquisition unit 11 (S2), and calculates the first steering angle θ1 of each of the first wheel 21 and the second wheel 22 (S3). The correction unit 12 calculates the second steering angle θ2 of each of the first wheel 21 and the second wheel 22 based on the rotational offset information acquired by the acquisition unit 11 (S4). Then, the correction unit 12 calculates a resultant steering angle θ3 of each of the first and second wheels 21 and 22 based on the calculated reference steering angle θ0, the first steering angle θ1, and the second steering angle θ2 (S5). Then, the correction unit 12 corrects the steering angle θ of each of the first wheel 21 and the second wheel 22 based on the calculated resultant steering angle θ3 (S6). Steps S2 to S6 correspond to the correction step ST2.

Then, the correction unit 12 corrects the speed ratio of the first wheel 21 to the second wheel 22 based on the corrected steering angle θ of the first wheel 21 and the corrected steering angle θ of the second wheel 22 (S7). That is, the correction unit 12 corrects the speed of the first wheel 21 and the speed of the second wheel 22. Step S7 corresponds to the speed correction step ST3.

Then, the control unit 102 controls the first wheel 21 based on the steering angle θ of the first wheel 21 corrected by the correction unit 12 and the speed of the first wheel 21 (S8). Similarly, the control unit 102 controls the second wheel 22 based on the steering angle θ of the second wheel 22 corrected by the correction unit 12 and the speed of the second wheel 22 (S9). The above-described processing is periodically repeated (for example, every several tens of milliseconds) until the conveying device 1 reaches the destination (S10: yes). Thereby, the conveyor 1 moves toward the destination following the track L1 while suppressing the deviation from the reference posture.

(4) Advantages are that

The advantages of the control system 100 according to the present embodiment will be described below in comparison with those of the control system of the comparative example. As shown in fig. 29, it is assumed that the control system of the comparative example controls the conveying device 300 that conveys the conveyed article A1. The conveyor 300 differs from the conveyor 1 in that the conveyor 300 has a sensor 40 located in the center of the conveyor 300 instead of two sensors 4. The conveyor 300 is different from the conveyor 1 in that it has two driving wheels 210, 220, instead of the first wheel 21 and the second wheel 22, which cannot change the steering angle θ. That is, the conveying apparatus 300 is a so-called differential type conveying apparatus that moves by utilizing the speed difference between the two driving wheels 210 and 220. As shown in fig. 29, it is assumed that the center of the conveyor 300 is located at a position offset from the track L1.

The control system of the comparative example controls the respective speeds of the two driving wheels 210, 220 based on the detection result of the sensor 40 such that the center of the sensor 40 (i.e., the center of the conveying device 300) rides on the track L1. In the example shown in fig. 29, the control system of the comparative example controls the driving wheels 210, 220 such that the speed of the other driving wheel 220 is greater than the speed of the one driving wheel 210. As a result, the conveyor 300 rotates counterclockwise, and therefore, as shown in fig. 30, the conveyor 300 is controlled such that the center of the sensor 40 rides on the rail L1.

However, in the example shown in fig. 30, the center of the sensor 40 is placed on the rail L1, but the conveyor 300 is inclined with respect to the reference posture. In the control system of the comparative example, the center of the sensor 40 is placed on the track L1, and therefore, the speeds of the driving wheels 210 and 220 are controlled so that the speeds of the driving wheels 210 and 220 are the same. Accordingly, the conveyor 300 maintains a state of being inclined with respect to the reference posture and advances, and thus, the center of the conveyor 300 is offset again with respect to the rail L1.

In this way, in the control system of the comparative example, the process of controlling the respective driving wheels 210, 220 to be placed on the rail L1 with the center of the sensor 40 is repeated until the conveying device 300 becomes the reference posture. Therefore, in the control system of the comparative example, there is a problem in that the time required for the conveyor 300 to maintain the reference posture and follow the track L1 is easily increased.

In the control system of the comparative example, although the positional displacement of the sensor 40 with respect to the rail L1 can be corrected, it is difficult to correct the displacement of the entire conveying apparatus 300 with respect to the rail L1. Therefore, when the conveyor 300 that conveys the conveyed article A1 is controlled by the control system of the comparative example, the conveyor 300 follows the track L1 in a state inclined from the reference posture due to the bias of the running resistances of the conveyed article A1 and the conveyor 300. Therefore, in the case where the conveying apparatus 300 is controlled by the control system of the comparative example, there is also the following problem: the ratio of the width of the conveyor 300 and the conveyed object A1 to the passage tends to be large, and it is difficult to move the conveyor 300 on a narrow passage.

In contrast, in the present embodiment, all of the steering wheels 2 (here, the first wheel 21 and the second wheel 22) of the conveyor 1 are controlled to correct the inclination displacement of the conveyor 1 from the reference posture of the conveyor 1 with respect to the rail L1 and the positional displacement of the conveyor 1 from the reference posture. Here, in the present embodiment, even when the conveyed object A1 is conveyed and moving, correction is performed so that the posture of the conveying device 1 becomes the reference posture. Therefore, the present embodiment has an advantage that the deviation of the conveyor 1 from the reference posture is suppressed and the conveyor 1 is easily caused to follow the track L1. In addition, the present embodiment has an advantage that the time required for the conveyor 1 to maintain the reference posture and follow the track L1 can be easily shortened as compared with the control system of the comparative example.

(5) Modification examples

The configuration described in embodiment 3 can be appropriately combined with the various configurations described in embodiments 1 and 2 (including modifications).

In embodiment 3 described above, for example, as shown in fig. 31, the control system 100 may cause the conveying device 1 to swing as follows: the steering angle θ of the plurality of steered wheels 2 is fixed so that the plurality of steered wheels 2 follow a circumferential track centered on an intersection point X1 at which the axial directions of the plurality of steered wheels 2 intersect.

In embodiment 3 described above, the correction unit 12 corrects the steering angle θ based on the resultant steering angle θ3 for each of the plurality of steered wheels 2, but is not limited thereto. For example, the correction unit 12 may alternately perform a process of correcting the steering angle θ based on the reference steering angle θ0, a process of correcting the steering angle θ based on the first steering angle θ1, and a process of correcting the steering angle θ based on the second steering angle θ2. In other words, the correction step ST2 may alternately execute the first low-level step and the second low-level step for each of the plurality of steered wheels 2. The first low-order step is a step of correcting the steering angle θ based on the rotation offset information, and corresponds to a step of correcting the steering angle θ based on the first steering angle θ1 calculated in step S3 of fig. 28. The second low-order step is a step of correcting the steering angle θ based on the positional deviation information, and corresponds to a step of correcting the steering angle θ based on the second steering angle θ2 calculated in step S4 of fig. 28.

In embodiment 3 described above, the correction unit 12 may not perform the reverse phase control when calculating the second steering angle θ2. That is, the correction unit 12 may bring the second steering angle θ21 of the first wheel 21 and the second steering angle θ22 of the second wheel 22 into phase with each other.

The control method of the conveyor 1 may include only one of a first steering angle control process in which the steering angle θ of the conveyor 1 is controlled in a state where the plurality of steered wheels 2 are aligned in the front-rear direction, and a second steering angle control process in which the steering angle θ of the conveyor 1 is controlled in a state where the plurality of steered wheels 2 are aligned in a direction intersecting the front-rear direction. The control method of the conveyor 1 may include both the first steering angle control process and the second steering angle control process.

(Summary)

As described above, the control method of the first aspect has at least one of the first steering angle control process and the second steering angle control process. The first steering angle control process is a process of controlling the steering angle (θ) of the conveying device (1) in a state in which the plurality of steering wheels (2) of the conveying device (1) that conveys the conveyed object (A1) are arranged in the front-rear direction and the plurality of steering wheels (2) are provided. The second steering angle control process is a process of controlling the steering angle (θ) of the conveyor (1) in a state where the plurality of steered wheels (2) of the conveyor (1) are aligned in a direction intersecting the front-rear direction.

According to this aspect, there is an advantage that the deviation of the conveying device (1) from the reference posture is suppressed and the conveying device (1) is easily caused to follow the track (L1).

In the control method of the second aspect, the first steering angle control process has an acquisition step (ST 1) and a correction step (ST 2) on the basis of the first aspect. The acquisition step (ST 1) is a step of acquiring offset information related to the offset of the conveyor (1) relative to the track (L1) on which the conveyor (1) is traveling. The conveying device (1) has a plurality of steering wheels (2) arranged along the front-rear direction and conveys the conveyed object (A1). The correction step (ST 2) is a step of correcting the steering angle (theta) for each of the plurality of steered wheels (2) based on the offset information acquired in the acquisition step (ST 1).

In the control method of the third aspect, on the basis of the second aspect, the offset information includes a plurality of steered wheel offset information related to positional offsets of the plurality of steered wheels (2) with respect to the track (L1), respectively. The correction step (ST 2) corrects the steering angle (theta) for each of the plurality of steered wheels (2) based on the corresponding steered wheel offset information.

In the control method of the fourth aspect, in addition to the second aspect, the offset information includes rotational offset information related to an inclination offset of the conveying device (1) from the reference posture of the conveying device (1) with respect to the rail (L1), and positional offset information related to a positional offset of the conveying device (1) from the reference posture. The correction step (ST 2) corrects the steering angle (theta) based on the rotation offset information and the position offset information on the basis of each steering wheel (2) of the plurality of steering wheels (2).

In the control method of the fifth aspect, on the basis of the fourth aspect, the correction step (ST 2) alternately executes the first lower step and the second lower step for each of the plurality of steered wheels (2). The first lower step corrects the steering angle (θ) based on the positional offset information. The second lower step corrects the steering angle (θ) based on the rotational offset information.

In the control method of the sixth aspect, the correction step (ST 2) corrects the steering angle (θ) based on the synthesized steering angle (θ3) for each of the plurality of steered wheels (2) on the basis of the fourth aspect. The synthetic steering angle (θ3) is an angle obtained by synthesizing a first steering angle (θ1) obtained based on the positional deviation information and a second steering angle (θ2) obtained based on the rotational deviation information.

In the control method according to a seventh aspect, in the fourth to sixth aspects, the correction step (ST 2) causes the steering angle (θ) of the front wheels (21) and the steering angle (θ) of the rear wheels (22) to be in anti-phase with each other when the steering angle (θ) is corrected based on the rotational offset information. The front wheel (21) is located in front of the conveying device (1) among the plurality of steering wheels (2). The rear wheel (22) is located behind the conveyor (1) among the plurality of steered wheels (2).

According to this aspect, there is an advantage that the balance between the conveyor (19) and the conveyed object (A1) is hardly broken, and the loss of the propulsive force of the conveyor (1) can be suppressed.

The control method according to the eighth aspect is the control method according to any one of the second to seventh aspects, further comprising a speed correction step (ST 3). The speed correction step (ST 3) is a step of correcting the speed of the corresponding steered wheel (2) based on the steering angle (θ) corrected in the correction step (ST 2) for each of the plurality of steered wheels (2).

According to this aspect, the matching of the respective operations of the plurality of steering wheels (2) is easy to achieve, and therefore, there is an advantage that the conveying device (1) can be easily made to follow the track (L1).

In the control method according to a ninth aspect, the plurality of steered wheels (2) includes a front wheel (21) located in front of the conveying device (1) and a rear wheel (22) located behind the conveying device (1) on the basis of any one of the second to eighth aspects.

According to this aspect, there is an advantage that the two-wheeled conveyor (1) is prevented from deviating from the reference posture and the conveyor (1) is easily caused to follow the track (L1).

In the tenth aspect of the control method, in the second to ninth aspects, the rail (L1) is provided on a moving surface (B1) on which the conveying device (1) moves.

According to this aspect, there is an advantage that it is easy to detect the offset of the conveying device (1) with respect to the track (L1) compared with the case where the track (L1) is a virtual track on the electronic map.

In the control method according to an eleventh aspect, in the second to tenth aspects, the conveying device (1) includes a coupling portion (5), and the coupling portion (5) couples the conveyed object (A1) to one surface of the main body portion (10) of the conveying device (1) along the track (L1).

According to this aspect, there is an advantage that even the conveyed article (A1) which is difficult to be loaded on the conveying device (1) is easy to convey.

In the control method according to a twelfth aspect, the second steering angle control process includes an acquisition step (ST 1) and a correction step (ST 2) on the basis of any one of the first to eleventh aspects. The acquisition step (ST 1) is a step of acquiring rotational offset information and positional offset information. The rotational displacement information is information related to the inclination displacement of the conveyor (1) from the reference posture of the conveyor (1) relative to the track (L1). The positional deviation information is information related to the positional deviation of the conveying device (1) from the reference posture. The conveying device (1) has a plurality of steering wheels (2) arranged in a direction intersecting the front-rear direction and conveys the conveyed object (A1). The correction step (ST 2) is a step of correcting the steering angle (theta) for each of the plurality of steered wheels (2) based on the rotational offset information and the positional offset information acquired in the acquisition step (ST 1).

In the control method of the thirteenth aspect, the correction step (ST 2) includes a step of correcting the steering angle (θ) to be a reference steering angle (θ0) in a direction of proceeding along the track (L1) for each of the plurality of steered wheels (2) on the basis of the twelfth aspect.

In the control method of the fourteenth aspect, the correction step (ST 2) alternately executes the first low-level step and the second low-level step for each of the plurality of steered wheels (2) on the basis of the thirteenth aspect. The first low-order step corrects the steering angle (θ) based on the positional deviation information. The second lower step corrects the steering angle (θ) based on the rotational offset information.

In the control method of the fifteenth aspect, on the basis of the thirteenth aspect, the correction step (ST 2) corrects the steering angle (θ) based on the synthesized steering angle (θ3) for each of the plurality of steered wheels (2). The synthetic steering angle (θ3) is an angle obtained by synthesizing a first steering angle (θ1) obtained based on the positional deviation information and a second steering angle (θ2) obtained based on the rotational deviation information.

In the control method according to a sixteenth aspect, in the twelfth to fifteenth aspects, the correction step (ST 2) causes the steering angle (θ) of the first wheel (21) and the steering angle (θ) of the second wheel (22) to be in anti-phase with each other when the steering angle (θ) is corrected based on the rotation offset information. The first wheel (21) is located at a first end in the longitudinal direction of the conveying device (1) among the plurality of steering wheels (2). The second wheel (22) is located at a second end in the longitudinal direction of the conveying device (1) among the plurality of steering wheels (2).

According to this aspect, there is an advantage that the balance between the conveyor (1) and the conveyed object (A1) is hardly broken, and the loss of the propulsive force of the conveyor (1) can be suppressed.

The control method according to the seventeenth aspect is the control method according to any one of the twelfth to sixteenth aspects, further comprising a speed correction step (ST 3). The speed correction step (ST 3) is a step of correcting the speed of the corresponding steered wheel (2) based on the steering angle (θ) corrected in the correction step (ST 2) for each of the plurality of steered wheels (2).

In the eighteenth aspect of the control method, in the twelfth to seventeenth aspects, the plurality of steering wheels (2) includes a first wheel (21) located at a first end in the longitudinal direction of the conveying device (1), and a second wheel (22) located at a second end in the longitudinal direction of the conveying device (1).

In the control method according to a nineteenth aspect, in the twelfth to eighteenth aspects, the rail (L1) is provided on a moving surface (B1) on which the conveying device (1) moves.

In the control method according to a twentieth aspect, in the twelfth to nineteenth aspects, the conveying device (1) includes a connecting portion (5), and the connecting portion (5) connects the conveyed object (A1) to a surface of the main body portion (10) of the conveying device (1) intersecting the rail (L1).

In the control method according to a twenty-first aspect, the first steering angle control process includes a first acquisition step (ST 1: see fig. 5 and 17) and a first correction step (ST 2: see fig. 5 and 17) in addition to any one of the first to twentieth aspects. The first acquisition step (ST 1) is a step of acquiring offset information related to offset of a track (L1) on which the conveying device (1) travels, the track having a plurality of steering wheels (2) arranged in the front-rear direction and conveying the conveyed object (A1) and the conveying device (1). The first correction step (ST 2) is a step of correcting the steering angle (θ) for each of the plurality of steered wheels (2) based on the offset information acquired in the first acquisition step (ST 1). The second steering angle control process includes a second acquisition step (ST 1: see FIG. 28) and a second correction step (ST 2: see FIG. 28). The second acquisition step (ST 1) is a step of acquiring rotational offset information and positional offset information. The rotational displacement information is information related to the inclination displacement of the conveying device (1) from the reference posture of the conveying device (1) relative to the rail (L1), and the conveying device (1) is provided with a plurality of steering wheels (2) arranged in a direction crossing the front-rear direction and conveys the conveying object (A1). The positional deviation information is information related to the positional deviation of the conveying device (1) from the reference posture. The second correction step (ST 2) corrects the steering angle (theta) for each of the plurality of steered wheels (2) based on the rotational offset information and the positional offset information acquired in the second acquisition step (ST 1).

The program of the twenty-second aspect causes one or more processors to execute the control method of any one of the first to twenty-first aspects.

The control system (100) of the twenty-third aspect is provided with at least one of a first steering angle control processing unit and a second steering angle control processing unit. The first steering angle control processing unit controls the steering angle (theta) of the conveying device (1) in a state in which the plurality of steering wheels (2) of the conveying device (1) that conveys the conveyed object (A1) are arranged in the front-rear direction and the plurality of steering wheels (2) are provided. The second steering angle control processing unit controls the steering angle (theta) of the conveying device (1) in a state in which the plurality of steering wheels (2) of the conveying device (1) are aligned in a direction intersecting the front-rear direction

The control system (100) according to a twenty-fourth aspect is the control system according to the twenty-third aspect, wherein the first steering angle control processing unit includes an acquisition unit (11) and a correction unit (12). The acquisition unit (11) acquires offset information relating to the offset of the conveyor (1) relative to the track (L1) on which the conveyor (1) is traveling. The conveying device (1) has a plurality of steering wheels (2) arranged along the front-rear direction and conveys the conveyed object (A1). A correction unit (12) corrects the steering angle (theta) for each of the plurality of steered wheels (2) based on the offset information acquired by the acquisition unit (11).

The control system (100) according to a twenty-fifth aspect is the control system according to the twenty-third or twenty-fourth aspect, wherein the second steering angle control processing unit includes an acquisition unit (11) and a correction unit (12). An acquisition unit (11) acquires rotational offset information and positional offset information. The rotational displacement information is information related to the inclination displacement of the conveyor (1) from the reference posture of the conveyor (1) relative to the track (L1). The positional deviation information is information related to the positional deviation of the conveying device (1) from the reference posture. The conveying device (1) has a plurality of steering wheels (2) arranged in a direction intersecting the front-rear direction and conveys the conveyed object (A1). A correction unit (12) corrects the steering angle (theta) for each of the plurality of steered wheels (2) based on the rotational offset information and the positional offset information acquired by the acquisition unit (11).

The conveying device (1) according to a twenty-sixth aspect is provided with the control system (100) according to any one of the twenty-third to twenty-fifth aspects and the main body (10). The main body (10) is equipped with a control system (100) for conveying the conveyed article (A1).

The component mounting system (200) of the twenty-seventh aspect is a system including at least one component mounter (9) that mounts components onto a substrate. The component mounting machine (9) has a component supply device (8) for supplying components, and a mounting body (90) including a mounting head for mounting components on a substrate. The component supply device (8) is conveyed to the mounting body (90) by the conveying device (1) controlled by the control system (100) according to any one of the twenty-third to twenty-fifth aspects.

According to this aspect, the component supply device (8) can be stably transported to the installation site of the mounting body (90) of the component mounting machine (9) by the transport device (1), and therefore, there is an advantage that the stabilization of the component supply with respect to the mounting body (90) is easily achieved.

In the component mounting system (200) according to the twenty-eighth aspect, in the twenty-seventh aspect, the conveying device (1) can be connected to a portion of the component supply device (8) located on a side opposite to a portion where the component is discharged to the mounting body (90).

According to this aspect, there are the following advantages: when the component supply device (8) is transported to the installation place of the installation body (90) of the component installation machine (9), the operation of changing the direction of the component supply device (8) to enable the above-mentioned discharging position to face the installation body (90) is not needed.

The method according to the second to twenty-first aspects is not essential for the control method, and can be omitted appropriately.

However, the control method of the eighth aspect may be executed regardless of whether there is control to correct so that the conveying device 1 follows the track L1. That is, the control method of the twenty-ninth aspect has a speed control step of the conveying device (1). The conveying device (1) has a plurality of steering wheels (2) arranged along the front-rear direction and conveys the conveyed object (A1). The speed control step is a step of correcting the speed of the corresponding steered wheel (2) based on the steering angle (θ) for each of the plurality of steered wheels (2).

Claims

1. A control method, comprising:

An acquisition step of acquiring rotation offset information of a conveying device having a plurality of steering wheels arranged in a direction intersecting a front-rear direction and conveying a conveyed object, the rotation offset information being related to an inclination offset of the conveying device from a reference posture with respect to a rail, and the positional offset information being related to a positional offset of the conveying device from the reference posture; and

A correction step of correcting a steering angle for each of the plurality of steered wheels based on the rotational offset information and the positional offset information acquired in the acquisition step,

The correction step performs PID control on the radius of gyration R0 of the conveyor device based on a rotational offset amount D2, which is the offset of the inclination of the conveyor device from the reference posture, and a correction coefficient K2 for the rotational offset amount D2, and the proportional term of the PID control is the following formula K2/D2.

2. The control method according to claim 1, wherein,

The correction step alternately performs, for each of the plurality of steered wheels, a first lower step of correcting the steering angle based on the positional deviation information and a second lower step of correcting the steering angle based on the rotational deviation information.

3. The control method according to claim 1, wherein,

The correction step corrects the steering angle based on a synthesized steering angle, which is an angle obtained by synthesizing a first steering angle obtained based on the positional deviation information and a second steering angle obtained based on the rotational deviation information, for each of the plurality of steered wheels.

4. The control method according to any one of claims 1 to 3, wherein,

The correction step causes the steering angle of a front wheel located in front of the conveying device and the steering angle of a rear wheel located behind the conveying device of the plurality of steered wheels to be in reverse phase with each other when the steering angle is corrected based on the rotational offset information.

5. The control method according to any one of claims 1 to 3, wherein,

The control method further has a speed correction step of correcting, for each of the plurality of steered wheels, a speed of the corresponding steered wheel based on the steering angle corrected in the correction step.

6. The control method according to claim 1, wherein,

The correction step includes the steps of: the steering angle is corrected to be a reference steering angle in a direction along the track for each of the plurality of steered wheels.

7. The control method according to claim 6, wherein,

The correction step alternately performs, for each of the plurality of steered wheels, a first low-level step of correcting the steering angle based on the positional deviation information and a second low-level step of correcting the steering angle based on the rotational deviation information.

8. The control method according to claim 6, wherein,

9. The control method according to any one of claims 6 to 8, wherein,

The correction step makes the steering angle of a first wheel located at a first end in a longitudinal direction of the conveying device and the steering angle of a second wheel located at a second end in the longitudinal direction of the conveying device out of the plurality of steered wheels be in inverse phase with each other when the steering angle is corrected based on the rotational offset information.

10. The control method according to any one of claims 6 to 8, wherein,

The control method corrects, for each of the plurality of steered wheels, the speed of the corresponding steered wheel based on the steered angle corrected in the correction step.

11. A control method, comprising:

An acquisition step of acquiring offset information on an offset of a conveying device that conveys a conveyed object, the offset information being related to an offset of a track on which the conveying device travels, the conveying device having a plurality of steering wheels arranged in a front-rear direction; and

A correction step of correcting a steering angle for each of the plurality of steered wheels based on the offset information acquired in the acquisition step,

The offset information includes a plurality of steered wheel offset information related to positional offsets of the plurality of steered wheels with respect to the track respectively,

The correction step corrects the steering angle based on corresponding steering wheel offset information for each of the plurality of steering wheels,

The offset information includes rotational offset information related to an inclination offset Dr of the conveying device from a reference posture of the conveying device with respect to the rail and positional offset information related to a positional offset Dx of the conveying device from the reference posture,

The correction step performs PID control on a steering angle [ theta ] 31 of a front wheel located in front of the conveying device among the plurality of steering wheels and a steering angle [ theta ] 32 of a rear wheel located behind the conveying device among the plurality of steering wheels, and when proportional terms of the PID control are set to [ theta ] 1, [ theta ] 2, the following holds,

θ31＝θ1+θ2

θ32＝θ1-θ2

θ1＝Kx·Dx

θ2＝Kr·Dr

Where Kx is a first scaling factor and Kr is a second scaling factor.

12. The control method according to claim 11, wherein,

13. The control method according to claim 11 or 12, wherein,

14. A control system is provided with:

An acquisition unit that acquires rotational displacement information of a conveying device that has a plurality of steering wheels arranged in a direction intersecting the front-rear direction and conveys a conveyed object, the rotational displacement information being related to a displacement of the conveying device from a reference posture relative to a rail, and the positional displacement information being related to a displacement of the conveying device from the reference posture; and

A correction unit that corrects a steering angle for each of the plurality of steered wheels based on the rotational offset information and the positional offset information acquired by the acquisition unit,

The correction unit performs PID control on the radius of gyration R0 of the conveying apparatus based on a rotational offset amount D2, which is the offset of the inclination of the conveying apparatus from the reference posture, and a correction coefficient K2 for the rotational offset amount D2, and the proportional term of the PID control is the following expression K2/D2.

15. A control system is provided with:

an acquisition unit that acquires offset information on an offset of a conveyor device that conveys a conveyed object, the offset information being related to an offset of a track on which the conveyor device travels, the conveyor device having a plurality of steered wheels arranged in a front-rear direction; and

A correction unit that corrects a steering angle for each of the plurality of steered wheels based on the offset information acquired by the acquisition unit,

The correction section corrects the steering angle for each of the plurality of steered wheels based on corresponding steered wheel offset information,

The correction unit performs PID control on a steering angle [ theta ] 31 of a front wheel located in front of the conveying device among the plurality of steering wheels and a steering angle [ theta ] 32 of a rear wheel located behind the conveying device among the plurality of steering wheels, and when proportional terms of the PID control are represented by [ theta ] 1 and [ theta ] 2, the following holds,

θ31＝θ1+θ2

θ32＝θ1-θ2

θ1＝Kx·Dx

θ2＝Kr·Dr

Where Kx is a first scaling factor and Kr is a second scaling factor.

16. A conveying device is provided with:

The control system of claim 14 or 15; and

And a main body part for carrying the control system and conveying the conveyed objects.

17. A component mounting system includes at least one component mounter that mounts components onto a substrate,

The component mounting machine includes:

a component supply device that supplies the component; and

A mounting body including a mounting head for mounting the component to the substrate,

The component supply device is transported to the mounting body by the transport device controlled by the control system according to claim 14 or 15.

18. The component mounting system of claim 17 wherein,

The conveying device may be connected to a portion of the component supply device located on a side opposite to a portion where the component is discharged to the mounting body.