JP7760965B2 - Conveying System - Google Patents

Description

The present invention relates to a conveying system.

Patent Document 1 below discloses an automatic assembly device for automatically assembling vehicle parts. This automatic assembly device is configured to grasp, transport, and attach vehicle parts to the vehicle body using a gripping hand attached to a robot, and to fasten the vehicle parts to the vehicle body using a fastener tightening device attached to another robot. This automatic assembly device uses robots to automate the sophisticated assembly work of vehicle parts that was previously performed by workers.

Japanese Unexamined Patent Publication No. 59-53275

When using the above-mentioned automated assembly equipment, the robot must be made larger to accommodate heavy vehicle parts. Furthermore, if it is envisioned that vehicle parts will be assembled by robots from both sides of the vehicle body, multiple robots must be used. Therefore, in either case, the problem of high equipment costs can arise.

To address these issues, it is effective to use a robot known as a "collaborative robot" that can assist workers in their work. By working collaboratively with workers on tasks ranging from transporting items such as vehicle parts to assembling them, this collaborative robot can reduce the burden on the robot. This allows for the use of small robots to transport vehicle parts, keeping equipment costs low.

However, when using collaborative robots, the following problems can occur. If the robot arm transports vehicle parts at a slow speed, workers will have to move slowly or intermittently to match this transport speed, reducing work efficiency. However, if the robot arm transports vehicle parts at an excessively fast speed, it will become difficult for workers to keep up with the robot arm's movements. In this case, transport work cannot be carried out continuously, and work efficiency will decrease, just as when the transport speed is slow. This problem of reduced work efficiency can occur not only when transporting vehicle parts before they are assembled into the vehicle body, but also when simply transporting various transported items such as vehicle parts.

The present invention was made in consideration of these issues, and aims to provide effective technology for creating a low-cost, highly efficient transport system in which workers and collaborative robots work together to transport items.

One aspect of the present invention is
A transportation system that transports an object in collaboration between a worker and a collaborative robot,
a robot arm provided on the collaborative robot to hold the transported object in parallel with the worker holding the transported object;
a detection device for detecting external load information relating to an external load input to the robot arm;
a control device for controlling the collaborative robot;
an imaging device for imaging the worker;
Equipped with
the control device is configured to, when it is recognized that the worker is performing the action of carrying the transported object based on the image information acquired by the photographing device in a case where the external load information detected by the detection device exceeds a threshold, determine that the external load is input from the worker to the robot arm via the transported object, and perform worker tracking control to cause the movement of the robot arm to follow the action of carrying the transported object by the worker based on the external load information detected by the detection device ;
the control device is configured to perform an abnormality notification control of notifying a system abnormality without performing the worker following control when it is recognized that the worker is not performing a transport operation of the transported object based on image information from the photographing device in a case where the external load information detected by the detection device exceeds a threshold value;
is located.

In the transportation system described above, the robot arm of the collaborative robot is used to hold the transported object in parallel with the worker holding the transported object. That is, the worker and the collaborative robot collaborate so that they separately access the transported object and hold it. This allows the weight load of the transported object to be shared between the worker and the collaborative robot, and has the advantage of allowing the use of small, inexpensive robots without increasing the number of them, compared to a structure in which the object is transported by robots alone. However, because the operator and the robot arm can operate separately, there is a possibility that differences will arise between the movements of the operator and the robot arm. In this case, the worker will have to move in tandem with the movement of the robot arm, which could result in a decrease in work efficiency.

The transportation system of this embodiment is therefore configured to perform worker-following control, which causes the collaborative robot to follow the worker. This worker-following control is a control that, when an external load is input from the worker to the robot arm via the transported object, causes the movement of the robot arm to follow the worker's movement of transporting the object based on external load information detected by a detection device. With this worker-following control, by having the robot arm follow the worker's movement, transportation work that matches the worker's movement can be performed in collaboration with the collaborative robot, improving the work efficiency of transporting objects.

As described above, the above-mentioned aspects make it possible to provide an effective technology for creating a transportation system in which a worker and a collaborative robot work together to transport objects, at low cost and with excellent work efficiency.

1 is a perspective view showing the overall configuration of a transport system according to a first embodiment. FIG. 2 is a block diagram of a first arithmetic processing unit of the control device in FIG. 1 . FIG. 2 is a block diagram of a second arithmetic processing unit of the control device in FIG. 1 . 2 is a flowchart of a transport process control by the transport system of FIG. 1 . 5 is a flowchart of the worker following control in FIG. 4 . 5 is a flowchart of the abnormality notification control in FIG. 4 .

Preferred embodiments of the above aspects are described below.

In the transport system of the above aspect, the robot arm preferably has a shaft that constitutes an arm joint and a drive motor built into the shaft, and the detection device preferably has a current measurement unit that measures the motor current of the drive motor, and is configured to detect, as the external load information, the fluctuation value of the motor current measured by the current measurement unit when the external load is input.

With this transport system, external load information regarding the external load input to the robot arm can be detected as a fluctuation value of the motor current using the current measurement unit of the detection device. Therefore, the detection structure for external load information can be simplified by using the current measurement unit.

In the transportation system of the above aspect, the control device, in the worker tracking control, preferably derives the worker transport speed of the transported item by the worker from the fluctuation value of the motor current measured by the current measurement unit of the detection device, and feedback controls the drive motor of the robot arm so that the robot transport speed of the transported item by the collaborative robot approaches this worker transport speed.

This transportation system performs worker tracking control, which causes the movement of the robot arm to follow the worker's movement to transport the object, by feedback controlling the drive motor of the robot arm so that the speed at which the collaborative robot transports the object approaches the speed at which the worker transports the object.

The transportation system of the above aspect preferably includes a camera that captures an image of the worker, and when the control device recognizes that the worker is currently transporting the transported item based on image information acquired by the camera, it determines that the external load has been input to the robot arm from the worker via the transported item, and accurately performs the worker tracking control.

This transportation system uses a camera to capture an image of the worker to recognize whether the worker is currently transporting an object, and then determines based on the recognition results whether an external load has been input from the worker to the robot arm via the object. In this case, the accuracy of determining the cause of the external load input to the robot arm can be improved, preventing unnecessary execution of worker tracking control.

In the transportation system of the above aspect, when the control device recognizes, based on image information from the imaging device, that the worker is not currently transporting the object, it is preferable that the control device perform anomaly notification control to notify of a system abnormality without performing the worker tracking control.

With this transport system, if the cause of the external load input to the robot arm is not caused by the worker, the worker can be quickly notified by the abnormality notification control that the cause is a system abnormality.

In the transport system of the above aspect, the collaborative robot is preferably configured so that the weight capacity of the robot arm is less than the weight of the object being transported.

With this transport system, the collaborative robot itself can be made smaller by configuring it so that the weight capacity of the robot arm is less than the weight of the object being transported.

The specific structure of a transport system, which is one embodiment of the above-mentioned aspect, will be described below with reference to the drawings.

(Embodiment 1)
1, the transportation system 1 of the first embodiment is for transporting an object 10 in collaboration between a worker C and a collaborative robot 20. The transportation system 1 is mainly composed of the collaborative robot 20, a detection device 30, a control device 40, and an imaging device 70. Other elements may be added to these components as appropriate.

1. Configuration of Collaborative Robot 20 The collaborative robot (hereinafter also simply referred to as "robot") 20 is an articulated robot. The robot 20 has a robot arm 21. The robot arm 21 is provided on the robot 20 so as to hold the transported object 10 in parallel with the worker C who is holding the transported object 10. In other words, the robot arm 21 is configured to directly hold the transported object 10 with a holding portion 21a, which is the tip of the arm, and the holding portion 21a holds the transported object 10 at a location different from the location of the transported object 10 that the worker C directly holds by grasping it from both sides with his fingers Ca.

Therefore, "collaboration" in this embodiment refers to a situation in which worker C and robot arm 21 independently access and hold transported object 10 during transportation. In this case, worker C directly holds transported object 10, while robot arm 21 simultaneously directly holds transported object 10. In contrast, for example, a situation in which worker C grabs and holds robot arm 21 while it is holding transported object 10 is essentially different from "collaboration" as defined here, since while robot arm 21 directly holds transported object 10, worker C does not directly hold transported object 10.

The transported item 10 is transported, for example, from point A, designated by the symbol "10(A)," to point B, designated by the symbol "10(B)," through collaboration between worker C and robot 20. At this time, point B may simply be the destination to which the transported item 10 is transferred, or, if the transported item 10 is a vehicle part, it may be the destination to which this vehicle part is to be assembled into the vehicle body.

The robot 20 is preferably configured so that the weight capacity of its robot arm 21 is less than the weight of the transported object 10. In this case, the load of the weight of the transported object 10 is shared between the worker C and the robot 20. This has the advantage that the robot 20 itself can be made smaller than in a structure in which the weight capacity of the robot arm 21 exceeds the weight of the transported object 10.

The size and shape of the transported object 10 are not particularly limited, as long as it can be transported by worker C and robot 20 in a shared manner. Various items, including vehicle parts, can be used as the transported object 10. Worker C can grasp and hold the transported object 10, or support and hold the transported object 10 from below.

The robot arm 21 has multiple shafts 22 that form its arm joints, and a drive motor 23 built into each shaft 22. Each drive motor 23 functions to drive the robot arm 21 so as to control the position and orientation of the holding part 21a to the desired state.

The number of shafts 22 and drive motors 23 in the robot arm 21 is not particularly limited and can be changed as needed. Furthermore, the structure of the holding portion 21a of the robot arm 21 is not particularly limited. Possible structures for the holding portion 21a include, for example, a structure that grasps and holds the transported object 10, a structure that supports and holds the transported object 10 from below, and a structure that holds the transported object 10 by suction.

2. Configuration of the Detection Device 30 The detection device 30 functions to detect external load information IF relating to the external load F input from the holding unit 21 a to the robot arm 21. To achieve this function, the detection device 30 is electrically connected to the drive motor 23 and has a current measurement unit 31 as a current sensor that measures the motor current of the drive motor 23.

This detection device 30 can detect the fluctuation value of the motor current measured by the current measurement unit 31 when an external load F is input to the robot arm 21 as external load information IF. In other words, when an external load F is input to the robot arm 21, the motor current in the drive motor 23 increases to maintain the posture of the robot arm 21 against this external load F. Therefore, it can be determined that this increase in motor current is due to the external load F. Therefore, the fluctuation value of the motor current is considered to be external load information IF that indirectly indicates the external load F.

External load information IF detected by the detection device 30 is transmitted to the control device 40, which is electrically connected to the detection device 30. In this case, the external load F refers to the input load input by the worker C who is holding the transported object 10. Therefore, the load equivalent to the weight of the transported object 10 is excluded from the external load F.

The detection device 30 only needs to have at least the function of detecting external load information IF, and may include components such as a voltage sensor that detects fluctuations in the motor voltage of the drive motor 23, or a torque sensor (mechanical sensor) that detects fluctuations in the torque acting on the drive motor 23, instead of or in addition to the current measurement unit 31. The detection device 30 may also be built into the robot 20 or the control device 40, or may be configured as a device separate from the robot 20 or the control device 40.

3. Configuration of the control device 40 The control device 40 is a control panel having the function of controlling the robot 20. In particular, the control device 40 controls the movement of the robot arm 21 so that the transported object 10 is transported while being held by the holding portion 21a of the robot arm 21. The control device 40 is also provided with an alarm 41 for notifying of abnormalities in the robot 20.

4. Configuration of the Image Capturing Device 70 The image capturing device 70 is configured with a camera capable of capturing images of the worker C and the surrounding area. With this image capturing device 70, an image is captured by an image capturing element by receiving light reflected from the subject. A charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor is typically used as the image capturing element. With this image capturing device 70, it is possible to acquire image information IG, which is three-dimensional image data showing the state of the worker C and the surrounding area. The image information IG acquired by the image capturing device 70 is then transmitted to the control device 40, which is electrically connected to the image capturing device 70.

5. Structure of the arithmetic processing unit of the control device 40 The control device 40 has a first arithmetic processing unit 50 (see FIG. 2) and a second arithmetic processing unit 60 (see FIG. 3). The control device 40 is equipped with a known CPU (Central Processing Unit), ROM, RAM, an interface for inputting and outputting data to and from external devices, and the like, in order to execute arithmetic processing in each arithmetic processing unit.

As shown in FIG. 2, the first calculation processing unit 50 of the control device 40 includes external load information acquisition units 51 and 52, a data input unit 53, a robot transport speed acquisition unit 54, a data storage unit 55, a model generation unit 56, a model storage unit 57, a worker transport speed derivation unit 58, and a transport speed evaluation unit 59.

The external load information acquisition unit 51 acquires external load information IF from the detection device 30 and inputs this external load information IF to the data storage unit 55. In response to this, the external load information acquisition unit 52 acquires external load information IF from the detection device 30 and inputs this external load information IF to the worker transport speed derivation unit 58.

The data input unit 53 inputs various data required to generate the transport speed estimation model Ma into the data storage unit 55. The transport speed estimation model Ma is a model that defines the relationship between the external load information IF and the transport speed of the transported item 10 by the worker C (the "worker transport speed Va" described below). This transport speed estimation model Ma is a set model that includes set parameters (also referred to as a "trained model that includes trained parameters"). Therefore, the "various data" referred to here includes a work dataset, a work program (pre-work parameters), and the like that have been prepared in advance for machine learning (commonly referred to as "AI learning") of the transport speed of the transported item 10 by the worker C.

The robot transport speed acquisition unit 54 acquires the robot transport speed Vb from the robot 20. This robot transport speed Vb is the speed at which the robot 20 transports the transported object 10, and in this embodiment, corresponds to the movement speed of the holding portion 21a of the robot arm 21. For example, a detection means such as a rotary encoder (not shown) that is built into the drive motor 23 and is capable of detecting the amount of mechanical displacement of rotation can be used, and the robot transport speed Vb can be calculated based on the data detected by this detection means.

The model generation unit 56 generates a transport speed estimation model Ma through machine learning using the working data set read from the data storage unit 55. The model generation unit 56 then outputs the generated transport speed estimation model Ma to the model storage unit 57. Note that instead of generating the transport speed estimation model Ma through machine learning, the model generation unit 56 may generate the transport speed estimation model Ma according to a correlation model, regression model, mapping data, etc. that are pre-stored in the data storage unit 55.

The worker carrying speed derivation unit 58 inputs the external load information IF acquired by the external load information acquisition unit 52 into the carrying speed estimation model Ma read from the model storage unit 57. As a result, the worker carrying speed derivation unit 58 derives the worker carrying speed Va, which is the speed at which the transported object 10 is carried by the worker C. In this embodiment, this worker carrying speed Va corresponds to the movement speed of the fingers Ca of the worker C, which move substantially integrally with the transported object 10.

The transport speed evaluation unit 59 compares the worker transport speed Va derived by the worker transport speed derivation unit 58 with the robot transport speed Vb acquired by the robot transport speed acquisition unit 54, corrects the robot transport speed Vb as necessary, and outputs a control signal Sa to the robot 20 for controlling the drive motor 23 of the robot arm 21. Therefore, for a robot 20 controlled at the corrected robot transport speed Vb, the robot transport speed Vb is acquired again by the robot transport speed acquisition unit 54.

As shown in FIG. 3, the second calculation processing unit 60 of the control device 40 includes image information acquisition units 61 and 62, a data input unit 63, a data storage unit 64, a model generation unit 65, a model storage unit 66, and a worker condition evaluation unit 67.

The image information acquisition unit 61 acquires image information IG from the photographing device 70 and inputs this image information IG to the data storage unit 64. In response to this, the image information acquisition unit 62 acquires image information IG from the photographing device 70 and inputs this image information IG to the worker condition evaluation unit 67.

The data input unit 63 inputs various data required to generate the worker state estimation model Mb into the data storage unit 64. The worker state estimation model Mb is a model that defines the relationship between the image information IG and the state of the transport work of worker C. This worker state estimation model Mb is a set model that includes set parameters (also referred to as a "trained model that includes trained parameters"). Therefore, the "various data" referred to here includes a work dataset and a work program (pre-work parameters) that have been prepared in advance for machine learning of the state of the transport work of worker C.

The model generation unit 65 generates a worker state estimation model Mb through machine learning using the work data set read from the data storage unit 64. The model generation unit 65 then outputs the generated worker state estimation model Mb to the model storage unit 66. Note that instead of generating the worker state estimation model Mb through machine learning, the model generation unit 65 may generate the worker state estimation model Mb according to a correlation model, regression model, mapping data, etc. that are pre-stored in the data storage unit 64.

The worker state evaluation unit 67 inputs the image information IG acquired by the image information acquisition unit 62 into the worker state estimation model Mb read from the model storage unit 66. As a result, the worker state evaluation unit 67 derives the state of worker C's transportation work (information such as the presence or absence of worker C, the direction of worker C's movement, and the movement trajectory of worker C), and based on this, determines whether worker C is actually carrying the transported item 10.

6. Transport Process Control by Transport System 1 Next, transport process control by the transport system 1 configured as described above will be described with particular reference to FIGS.

The transport processing control according to the first embodiment is achieved by sequentially executing steps S101 to S108 in FIG. 4. If necessary, other steps may be added, any step may be divided into multiple steps or deleted, or the order of the steps may be changed.

In step S101, worker C activates the camera 70, thereby starting image capture by the camera 70. By constantly acquiring image information IG from the camera 70, step S101 makes it possible to constantly monitor the status of worker C's transport work.

Step S102 is a step in which worker C starts robot control by activating the robot 20. By this step S101, the robot 20 is ready to transport the transported item 10 in collaboration with worker C.

In step S103, the current measurement unit 31 of the detection device 30 measures the motor current of the drive motor 23 and determines whether the fluctuation value of the measured motor current exceeds a preset threshold. In step S103, the fluctuation value of the motor current actually measured in the drive motor 23 is evaluated. If it is determined in step S103 that the fluctuation value of the motor current exceeds the threshold, the process proceeds to step S104. This step S103 is executed, for example, by the first calculation processing unit 50 of the control device 40.

Step S104 is a step for determining whether worker C is currently performing transportation work. In this step S104, the determination result by the worker status evaluation unit 67 of the control device 40 (see Figure 3) is used. This step S104 makes it possible to identify whether worker C is actually performing transportation work for the transported item 10. If it is determined in step S104 that worker C is currently performing transportation work (in the case of "Yes" in Figure 4), the process proceeds to step S105; if not (in the case of "No" in Figure 4), the process proceeds to step S106.

In this embodiment, when it is recognized in step S104 based on image information IG from the imaging device 70 that worker C is performing a carrying operation, it is determined that an external load F (see Figure 1) has been input from worker C to the robot arm 21 via the transported object 10, and "worker tracking control" is executed in step S105. Worker tracking control is generally a control that causes the movement of the robot arm 21 to follow the movement of worker C to carry the transported object 10 based on external load information IF detected by the detection device 30.

In contrast, when it is recognized in step S104 based on the image information IG from the imaging device 70 that worker C is not currently performing transport work, it is determined that an abnormality has occurred in the transport system 1, and "abnormality notification control" is executed in step S106 without executing "worker tracking control" in step S105. Note that if the answer is "No" in step S104, step S106 may be skipped and the transport processing control may be terminated directly.

Step S107 is a step in which worker C stops the robot 20, thereby ending robot control. In addition, step S108 is a step in which worker C stops the imaging device 70, thereby ending imaging by this imaging device 70.

As shown in Figure 5, "operator tracking control," which corresponds to step S105 in Figure 4, includes steps S105a to S105e.

Step S105a is a step for deriving the worker transport speed Va. In this step S105a, the worker transport speed derivation unit 58 (see Figure 2) of the control device 40 is used. According to this step S105a, by inputting the external load information IF (in this embodiment, the fluctuation value of the motor current of the drive motor 23) into the transport speed estimation model Ma, it is possible to derive the worker transport speed Va, which corresponds to the movement speed of the fingers Ca of the worker C.

Step S105b is a step for acquiring the robot transport speed Vb. In this step S105b, the robot transport speed acquisition unit 54 (see Figure 2) of the control device 40 is used. In this step S105b, the robot transport speed Vb, which corresponds to the movement speed of the holding part 21a of the robot arm 21, can be derived by detecting the amount of mechanical displacement of the rotation of the drive motor 23 using a detection means such as a rotary encoder.

Step S105c is a step in which the worker transport speed Va derived in step S105a is compared with the robot transport speed Vb derived in step S105b. This step S105c uses the transport speed evaluation unit 59 (see Figure 2) of the control device 40. This step S105c calculates the speed difference between the worker transport speed Va and the robot transport speed Vb.

Step S105d is a step for determining whether or not correction of the robot transport speed Vb is necessary. In this step S105d, the transport speed evaluation unit 59 of the control device 40 is used, as in step S105c. According to step S105d, if the speed difference between the worker transport speed Va and the robot transport speed Vb is large enough to exceed the threshold, it is determined that correction of the robot transport speed Vb is necessary, and the process proceeds to step S105e. On the other hand, if the speed difference between the worker transport speed Va and the robot transport speed Vb is small enough to be below the threshold, it is determined that correction of the robot transport speed Vb is not necessary, and the process of step S105 is terminated.

Step S105e is a step for correcting the robot transport speed Vb. In this step S105e, the transport speed evaluation unit 59 of the control device 40 is used, as in steps S105c and S105d. In this step S105e, the robot transport speed Vb is corrected so that it approaches the worker transport speed Va. Then, a control signal Sa for achieving the corrected robot transport speed Vb is output to the robot 20, and the drive motor 23 of the robot arm 21 is controlled based on this control signal Sa.

After step S105e is executed, the process returns to step S105b, and the series of processes (feedback control) from step S105b to step S105e are executed sequentially. As a result, the drive motor 23 of the robot arm 21 is feedback-controlled so that the robot transport speed Vb approaches the worker transport speed Va.

This type of feedback control makes it possible to match the robot transport speed Vb with the worker transport speed Va, or to approximate the robot transport speed Vb to the worker transport speed Va. Therefore, the movement of the robot arm 21 can be made to follow the transporting movement of the transported object 10 by the worker C so that the transport speed Vb on the robot 20 side approaches the transport speed Va on the worker C side. As a result, the robot 20 can be made to perform collaborative work that matches the work pace of the worker C.

As shown in Figure 6, the "abnormality notification control" corresponding to step S106 in Figure 4 includes steps S106a and S106b.

Step S106a is a step in which robot control is forcibly terminated in accordance with the determination result of an abnormality occurring in the transport system 1. Furthermore, step S106b outputs a control signal to the alarm 41 to notify the abnormality in accordance with the determination result of an abnormality occurring in the transport system 1. As a result, the alarm 41 outputs an abnormality notification state to notify the occurrence of the abnormality using an output mode such as audio output, screen output, or print output.

The above-described first embodiment provides the following advantages:

In the transportation system 1 of embodiment 1, the robot arm 21 of the robot 20 is used to hold the transported object 10 in parallel with the worker C who is holding the transported object 10. That is, the worker C and the collaborative robot 20 cooperate so that the worker C and the robot arm 21 separately access and hold the transported object 10. This allows the weight load of the transported object 10 to be shared between the worker C and the robot 20, and has the advantage of allowing the use of small, inexpensive robots 20 without increasing the number, compared to a structure in which the object is transported by the robot 20 alone. On the other hand, because the operator C and the robot arm 21 can operate separately, it is conceivable that there may be a difference in the movement of the operator C and the movement of the robot arm 21. In this case, the worker C will have to move in accordance with the movement of the robot arm 21, which may result in a decrease in work efficiency.

The transportation system 1 of this embodiment is therefore configured to perform worker following control, which causes the robot 20 to follow the worker C. This worker following control is a control that causes the movement of the robot arm 21 to follow the movement of the transported object 10 by the worker C, based on external load information IF detected by the detection device 30, when an external load F is input from the worker C to the robot arm 21 via the transported object 10. With this worker following control, by having the robot arm 21 follow the movement of the worker C, transport work that matches the movement of the worker C can be performed in collaboration with the robot 20, thereby improving the work efficiency of the transport work of the transported object 10.

Therefore, according to embodiment 1, it is possible to create a transportation system 1 in which a worker C and a robot 20 work together to transport an object 10, which is inexpensive and has excellent work efficiency.

According to the transport system 1 of embodiment 1, external load information IF regarding the external load F input to the robot arm 21 can be detected as a fluctuation value of the motor current using the current measurement unit 31 of the detection device 30. Therefore, the detection structure for the external load information IF can be simplified by using the current measurement unit 31.

According to the transportation system 1 of embodiment 1, by feedback controlling the drive motor 23 of the robot arm 21 so that the robot transportation speed Vb of the robot 20 approaches the worker transportation speed Va of the worker C, it is possible to accurately perform worker tracking control, which causes the movement of the robot arm 21 to follow the transportation movement of the transported object 10 by the worker C.

The transportation system 1 of embodiment 1 uses a camera device 70 that captures an image of the worker C to recognize whether the worker C is currently transporting the transported object 10, and then determines based on the recognition result whether an external load F has been input from the worker C to the robot arm 21 via the transported object 10. In this case, the accuracy of determining the cause of the external load F input to the robot arm 21 can be improved, and unnecessary worker tracking control can be prevented from being executed.

According to the transport system 1 of embodiment 1, if the cause of the external load F input to the robot arm 21 is not caused by the worker C, the abnormality notification control can quickly notify the worker C that this cause is due to a system abnormality.

According to the transport system 1 of embodiment 1, the robot 20 is configured so that the weight capacity of the robot arm 21 is less than the weight of the transported object 10, thereby making it possible to reduce the size of the robot 20 itself.

While the present disclosure has been described with reference to the above-described embodiments, it is understood that the present disclosure is not limited to those embodiments or structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. In addition, various combinations and embodiments, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

In the above embodiment, an example was given of a case in which the transport speed Vb of the robot 20 is made to approach the transport speed Va of the worker C in the worker-following control. However, as long as the movement of the robot arm 21 can be made to follow the transporting action of the transported object 10 by the worker C, a transport parameter other than the transport speed of the robot 20 may be made to approach the transport parameter other than the transport speed of the worker C. Transport parameters other than the transport speed can include, for example, the transport trajectory and transport direction.

In the above embodiment, the external load information IF is the fluctuation value of the motor voltage of the drive motor 23, and the worker transport speed Va is derived from this fluctuation value of the motor voltage. However, instead of or in addition to this, the fluctuation value of the motor voltage of the drive motor 23 or the fluctuation value of the torque acting on the drive motor 23 may be used as the external load information IF, and the worker transport speed Va may be derived from this external load information IF.

In the above embodiment, an example was given of a case in which a camera device 70 that captures an image of worker C is used to determine whether worker C is currently transporting the transported item 10. However, the camera device 70 may be omitted, for example, if an alternative to the camera device 70 can be used, or if there is no need to determine whether worker C is currently transporting the transported item 10.

In the above embodiment, an example was given of a case where the weight capacity of the robot arm 21 of the robot 20 is less than the weight of the transported object 10, but if necessary, a structure may be adopted in which the weight capacity of the robot arm 21 is equal to or greater than the weight of the transported object 10.

1 Transport system 10 Transported object 20 Robot (collaborative robot)
22 Shaft 23 Drive motor 21 Robot arm 30 Detector 31 Current measuring unit 40 Control device 70 Imaging device C Worker F External load IF External load information IG Image information Va Worker transport speed Vb Robot transport speed

Claims (4)

A transportation system that transports an object in collaboration between a worker and a collaborative robot,
a robot arm provided on the collaborative robot to hold the transported object in parallel with the worker holding the transported object;
a detection device for detecting external load information relating to an external load input to the robot arm;
a control device for controlling the collaborative robot;
an imaging device for imaging the worker;
Equipped with
the control device is configured to, when it is recognized that the worker is performing the action of carrying the transported object based on the image information acquired by the photographing device in a case where the external load information detected by the detection device exceeds a threshold, determine that the external load is input from the worker to the robot arm via the transported object, and perform worker tracking control to cause the movement of the robot arm to follow the action of carrying the transported object by the worker based on the external load information detected by the detection device ;
The control device is configured to perform abnormality notification control to notify of a system abnormality without performing the worker tracking control when the external load information detected by the detection device exceeds a threshold value and it is recognized based on image information from the photographing device that the worker is not currently performing the transport operation of the transported item . the robot arm has a shaft portion that constitutes an arm joint and a drive motor built into the shaft portion,
2. The transport system according to claim 1, wherein the detection device has a current measurement unit that measures a motor current of the drive motor, and is configured to detect a fluctuation value of the motor current measured by the current measurement unit when the external load is input as the external load information. The transportation system of claim 2, wherein the control device, in the worker following control, derives the worker transport speed of the transported object by the worker from the fluctuation value of the motor current measured by the current measurement unit of the detection device, and feedback controls the drive motor of the robot arm so that the robot transport speed of the transported object by the collaborative robot approaches this worker transport speed. The transport system described in any one of claims 1 to 3, wherein the collaborative robot is configured so that the weight capacity of the robot arm is less than the weight of the object being transported.