JP6904104B2 - Picking system - Google Patents

Description

The present invention relates to a picking system for picking a target article from a group of articles randomly arranged in a predetermined area.

There is a picking system that picks articles one by one from the top by a picking robot for a group of articles composed of a plurality of stacked articles (for example, Patent Document 1).

This picking system is a system that detects the misalignment of an article and corrects the position where the picking robot holds the article based on the misalignment. As a result, it is possible to reduce pick-up mistakes of articles.

Japanese Unexamined Patent Publication No. 07-277512

However, when trying to hold the target article to be picked from a group of articles randomly arranged in a predetermined area, it is provided at the tip of the picking robot with other articles arranged in the vicinity of the target article. In some cases, the target article cannot be held due to interference with the holding member.

The present invention has been made in view of the above problems, and picking is performed by changing the mutual positional relationship of suction nozzles according to the size of the suction surface of the target article and determining interference with other articles in the changed state. Regarding the system.

In order to achieve the above object, the picking system, which is one of the present inventions, is a picking system for picking a target article from a group of articles which are a plurality of articles arranged in a predetermined area, and images the group of articles. A camera that outputs image information, a control device connected to the camera, and a picking robot whose picking operation is controlled by the control device are provided, and the picking robot sucks a predetermined suction surface of a target article. The control is provided with a plurality of nozzles to be held and a scaling mechanism for scaling a virtual region, which is the smallest region including all the plurality of nozzles on a surface parallel to the suction surface, by changing the positional relationship of the nozzles. The device is determined as a feature amount acquisition unit that acquires the feature amount of the suction surface of the target article from the image information acquired from the camera, and a nozzle position determination unit that determines the nozzle position from the determined size of the suction surface. It is characterized by having an interference presence / absence determining unit that determines whether or not the nozzle interferes with other articles other than the target article when sucking and holding the target article based on the nozzle position and the image information.

According to this, by determining whether or not the target article can be picked by taking into account the nozzle position on the nozzle base, as compared with picking only an article that does not interfere with other articles without taking into account the nozzle position. The number of suction surfaces of the target article that can be suction-held can be increased, and the choice of flow lines when the nozzle approaches the target article can be increased. This makes it possible to improve the picking efficiency.

Further, the control device may include a suction selection unit that independently controls whether or not the plurality of nozzles suck the target article.

According to this, when approaching the target article, the target article can be sucked and held only by the selected nozzle without moving until all the nozzles are located on the suction surface. Further, even in a situation where other articles are adsorbed at the same time when the target article is adsorbed, only the target article can be adsorbed and held without adsorbing the other articles.

Further, when the nozzle position determining unit determines that the nozzle interferes with another article, the nozzle position determining unit redetermines the nozzle position, which is a virtual area narrower than the virtual area at the previously determined nozzle position. The interference presence / absence determination unit may determine whether or not the nozzle interferes with another article other than the target article based on the redetermined nozzle position and image information.

According to this, the suction surface of the target article that can be sucked and held can be further increased, and the picking efficiency can be improved.

It should be noted that the implementation of the present invention also corresponds to the implementation of a program for causing a computer to execute each process included in the picking system. Of course, implementing a recording medium on which the program is recorded also corresponds to the implementation of the present invention.

According to the picking system of the present invention, the picking efficiency can be improved by changing the nozzle position with respect to the nozzle base.

FIG. 1 is a perspective view showing a picking system. FIG. 2 is a perspective view showing the vicinity of the nozzle. FIG. 3 is a block diagram showing each processing unit of the control device together with the mechanism unit. FIG. 4 is a flowchart showing the operation flow of the picking system. FIG. 5 is a perspective view showing another example 1 of the scaling mechanism. FIG. 6 is a plan view showing another example 2 of the scaling mechanism.

Next, an embodiment of the picking system according to the present invention will be described with reference to the drawings. The following embodiments are merely examples of the picking system according to the present invention. Therefore, the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept of the present invention are not necessarily necessary for achieving the object of the present invention, but more. Described as constituting a preferred form.

In addition, the drawings are schematic views in which emphasis, omission, and ratio are adjusted as appropriate to show the invention of the present application, and may differ from the actual shape, positional relationship, and ratio.

FIG. 1 is a perspective view showing a picking system.

As shown in the figure, the picking system 100 automatically picks one target article 201 from an article group 200 composed of a plurality of articles randomly arranged in a predetermined area and moves it to another place. The system is provided with a control device 101, a camera 102, and a picking robot 104.

The article to be picked by the picking system 100 is not particularly limited, and examples thereof include pharmaceuticals, daily necessities, and foods contained in a package. The appearance shape of the article is not particularly limited, but a rectangular parallelepiped including a cube can be exemplified. Further, the article is housed in a case forming a predetermined area, but the case is not shown.

The camera 102 is a device that captures an image of the upper surface portion of the article group 200 in which articles are randomly arranged from above the article group 200. The type of the camera 102 is not particularly limited, and for example, a digital camera capable of acquiring an image in the visible light region as an image signal can be shown.

The camera 102 may be one capable of acquiring an image in an infrared region, a camera 102 capable of acquiring an image in an ultraviolet region, or the like. Further, the camera 102 is attached to a picking robot 104, a dedicated drive mechanism, or the like, images the article group 200 from a plurality of viewpoints, and acquires three-dimensional information about the article group 200 based on the captured images. However, the article group 200 may be provided with a plurality of optical systems and an image pickup element, and may be capable of three-dimensionally imaging the article group 200. The camera 102 also includes a three-dimensional sensor such as a TOF (Time of Flight) camera and an LRF (Laser Range Finder).

The picking robot 104 is a robot capable of picking the target article 201 from the article group 200, and has a plurality of nozzles 141 capable of sucking and holding one plane of the target article 201 and a plurality of nozzles 141. It is provided with an expansion / contraction mechanism 143 that can change the nozzle position, which is a positional relationship.

In the case of the present embodiment, the articulated robot is exemplified as the picking robot 104, but the picking robot 104 is not limited to this, and is configured by combining a parallel link robot and a plurality of linear motion mechanisms. It may be a robot or the like that does not have a joint. Further, in the picking robot 104, the picking operation including the change of the position of the nozzle 141 is controlled by the control device 101.

FIG. 2 is a perspective view showing the vicinity of the nozzle.

The nozzle 141 is a tubular member having a flexible annular flexible member 144 at its tip, and the opposite side of the flexible member 144 is connected to a vacuum pump via a flexible tube (not shown). ing. The number of nozzles 141 included in the picking robot 104 is not limited as long as it has a plurality of nozzles 141, but in the case of the present embodiment, the picking robot 104 includes five nozzles 141. The positional relationship of the nozzles 141 is such that one nozzle 141 is arranged at the center and the other four nozzles 141 are evenly arranged on the circumference centered on the central nozzle 141. The nozzle 141 arranged at the center is fixed to the picking robot 104. In the other nozzle 141, the nozzle position can be changed by the expansion / contraction mechanism 143.

Further, in the case of the present embodiment, each nozzle 141 is connected to one vacuum pump via a solenoid valve 142 (see FIG. 3), and the inside of the nozzle 141 is evacuated by opening and closing the solenoid valve 142. You can choose whether or not to do it.

The scaling mechanism 143 changes the positional relationship of the plurality of nozzles 141 in the virtual region 140, which is the smallest region including all the plurality of nozzles 141 on the plane parallel to the suction surface of the target article 201 (XY plane in the drawing). It is a mechanism that expands and contracts.

The expansion / contraction mechanism 143 is not particularly limited, but in the case of the present embodiment, the expansion / contraction mechanism 143 is a telescopic mechanism, the base end portion is fixed to the main body of the picking robot 104, and one nozzle is provided at the tip end portion. 141 is fixed. Further, the expansion / contraction mechanism 143 is provided with four telescopic mechanisms radially and evenly centered on the fixed nozzle 141, and the control device 101 controls the expansion and contraction of the telescopic mechanism to control the expansion and contraction of the telescopic mechanism, whereby the picking robot 104 main body of the nozzle 141 is provided. The virtual area 140 can be expanded or contracted by changing the position with respect to. Further, the scaling mechanism 143 is arranged in the virtual area 140 and does not protrude outward from the nozzle 141 arranged on the outermost circumference of the virtual area 140. As a result, it is possible to avoid interference between the scaling mechanism 143 and other articles.

Further, in the case of the present embodiment, the scaling mechanism 143 can change not only the size of the virtual area 140 but also the shape of the virtual area 140 by expanding and contracting the telescopic mechanism independently. There is.

FIG. 3 is a block diagram showing each processing unit of the control device together with the mechanism unit.

As shown in the figure, the control device 101 is a device that is connected to the camera 102 and controls the picking robot 104 based on the image information output from the camera 102, and is a feature amount acquisition unit 121 and a nozzle position determination unit. It includes 111 and an interference presence / absence determination unit 112. In the case of the present embodiment, the control device 101 further includes a flow line determination unit 113 and a suction selection unit 131.

Specifically, for example, the control device 101 is a device that executes each process by operating the processor according to an instruction included in a computer program stored in the storage device, and a hardware circuit that executes each process. It is a device equipped with at least one. Further, the hardware circuit is a circuit including at least one of a digital circuit and an analog circuit.

The feature amount acquisition unit 121 is a processing unit that acquires image information in which the entire upper surface of the article group 200 imaged by the camera 102 is captured, and acquires the feature amount of the suction surface of the target article 201 based on the acquired image information. .. Specifically, the feature amount acquisition unit 121 processes the image information which is a digital signal to obtain the feature amount such as the shape, area, center of gravity, and position of each surface of not only the target article 201 but also other articles. Calculate and output. In addition, the feature amount acquisition unit 121 calculates the feature amount for the imaged article, and also calculates the positional relationship between the articles and the overlapping state.

The nozzle position determination unit 111 is a processing unit that determines the nozzle position from the size of the suction surface of the target article 201 acquired by the feature amount acquisition unit 121. In the case of the present embodiment, a plurality of suction surfaces of the target article 201 are imaged by the camera 102, and the nozzle position determination unit 111 determines a plurality of nozzle positions corresponding to each suction surface.

Specifically, for example, when the nozzle position determination unit 111 arranges the nozzles 141 along the normal direction of the suction surface of the determined target article 201, all the nozzles 141 can suck the suction surface and are virtual. The nozzle position is determined so that the region 140 is maximized.

Based on the nozzle position determined by the nozzle position determining unit 111 and the image information obtained from the camera 102, the interference presence / absence determining unit 112 attracts and holds the target article 201 with other articles other than the target article and the nozzle 141. This is a processing unit that determines whether or not there is interference.

Specifically, for example, the interference presence / absence determination unit 112 assumes a state in which the nozzle 141 is fixed at the nozzle position determined by the nozzle position determination unit 111, and is straight along the normal direction of the suction surface of the target article 201. When the nozzle 141 is brought close to the suction surface, it is determined whether or not other articles interfere with each other depending on whether or not they are on the flow line of the nozzle 141. Further, when there are a plurality of adsorption surfaces that may be adsorbed on the target article 201, the presence or absence of interference with all the adsorption surfaces is determined.

The interference presence / absence determination unit 112 may further determine whether or not the suction surface of the target article 201 can be held without interfering with the current nozzle position by using some of the plurality of nozzles 141. That is, at the current nozzle position, it may be determined whether or not the target article 201 can be sucked and held without interference by removing at least one nozzle 141 from the suction surface.

The suction selection unit 131 is a processing unit that independently controls whether or not a plurality of nozzles suck the target article 201. In the case of the present embodiment, the suction selection unit 131 determines that the suction surface of the target article 201 can be held by the interference presence / absence determination unit 112 by using some of the plurality of nozzles 141, and the nozzle 141 When it is determined that the picking robot 104 does not move the nozzle 141 extra by the combination, the solenoid valve 142 is controlled so that only the corresponding nozzle 141 can be vacuum-sucked.

The flow line determining unit 113 is a processing unit that derives and determines a flow line that moves until the nozzle 141 comes into contact with the suction surface and sucks and holds the target article 201. Further, when the target article 201 is adsorbed and held by the nozzle 141, the flow line determining unit 113 may have a plurality of adsorption surfaces on which the nozzle 141 can be adsorbed without interfering with other articles, or with respect to one adsorption surface. If at least one of the cases where the target article 201 can be sucked and held by different numbers of nozzles 141 exists, the movement line on which the nozzles 141 move is determined for each suction surface and when the target article 201 is sucked by different numbers of nozzles 141. Derivation is performed to determine a flow line capable of adsorbing and holding the target article 201 most efficiently. In the case of the present embodiment, the flow line determining unit 113 determines the flow line that minimizes the moving distance of the nozzle 141 as the flow line that can attract and hold the target article 201 most efficiently.

Next, the operation of the picking system 100 will be described.

FIG. 4 is a flowchart showing the operation flow of the picking system.

First, the article group 200 is carried into the picking position (S101). The carry-in method is not particularly limited, but for example, the article group 200 is carried to the picking position by being carried by a conveyor or the like.

With the article group 200 arranged at the picking position, the camera 102 takes an image of the entire article group 200 from above (S102).

Next, the feature amount acquisition unit 121 acquires the feature amounts of all the suction surfaces of the target article 201 from the obtained image information, and further exists in the feature amounts of other articles and the target article 201 and its vicinity. The overlapping state with other articles is also acquired (S103).

In the case of the present embodiment, the interference presence / absence determination unit 112 here does not change the nozzle position, but reduces the number of nozzles 141 that contribute to suction holding to reduce the virtual suction surface, thereby making the dried article or other article. It is determined whether or not the target article 201 can be adsorbed and held without interfering with (S104).

When it is determined that the target article 201 can be held even if the number of nozzles 141 that contribute to suction holding is reduced (S104: Yes), the process shifts to the process of determining the flow line of the nozzle 141. When it is determined that the target article 201 cannot be held even if the number of nozzles 141 is reduced (S104: No), the process proceeds to the next step.

In the nozzle position determining unit 111, all the nozzles 141 can suck the suction surfaces of the target article 201 for all the suction surfaces of the target article 201 acquired by the feature amount acquisition unit 121, and the virtual area 140 becomes the maximum. The nozzle position is determined so as to (S105). As a result, the size (area) and shape of the virtual area 140 are determined.

The interference presence / absence determination unit 112 determines whether or not there is another article on the flow line toward the suction surface of the nozzle 141 based on the nozzle position determined by the nozzle position determination unit 111 with respect to all the suction surfaces of the target article 201. Is determined and the presence or absence of interference is determined (S106). In the case of the present embodiment, when it is determined that at least one of all the suction surfaces has interference (S106: Yes), the nozzle position determining unit 111 first determines the suction surface determined to have interference. The next nozzle position that becomes the virtual area 140 narrower than the virtual area 140 at the nozzle position is redetermined (S105).

Next, the interference presence / absence determination unit 112 determines whether or not the nozzle 141 interferes with another article based on the next redetermined nozzle position and image information (S106).

The above repetition is repeated when the nozzle 141 does not interfere with other articles on all the suction surfaces, or when the virtual area 140 cannot be reduced due to the structural limit of the expansion / contraction mechanism 143 although it interferes. (S106: No).

Next, the flow line determination unit 113 derives the flow line of the nozzle 141 until the target article 201 is attracted and held. When there are a plurality of suction surfaces, the flow lines of the nozzle 141 to the plurality of suction surfaces are derived, and the shortest flow line is determined from these. Further, the flow line determining unit 113 derives the flow line of the nozzle 141 when the target article 201 is sucked and held by reducing the number of nozzles 141 that contribute to suction holding (S107).

Based on the flow line determined as described above, the picking robot 104 operates to pick the target article 201 (S108). When the nozzle 141 that attracts and holds the target article 201 is selected in the picking operation, the suction selection unit 131 controls the solenoid valve 142 to select the nozzle 141 that contributes to the suction and holding.

As described above, a series of operations for picking the first target article 201 after the article group 200 is brought into the picking position is completed.

By this operation, the virtual area which is the arrangement area of the nozzle 141 is made variable, so that the target article 201 can be sucked and held without the nozzle 141 and other articles interfering with each other. Further, it may be possible to increase the number of suction surfaces that can hold suction, and in this case, it is possible to increase the choice of flow lines for bringing the nozzle 141 closer to the target article 201, and select the most efficient flow line. It becomes possible to do. As a result, the picking efficiency can be improved.

For the target article 201 having a large suction surface, the target article 201 can be stably sucked and held by expanding the virtual area 140. It is possible to flexibly deal with the target article 201 having a small suction surface.

Further, for the target article 201 in the form of a soft sheet such as vinyl or paper, the target article 201 may be deformed by the vacuum pressure by expanding the virtual area 140 and widening the interval between the nozzles 141 to disperse the suction points. It is possible to suppress the phenomenon of wrinkling.

The invention of the present application is not limited to the above-described embodiment. For example, another embodiment realized by arbitrarily combining the components described in the present specification and excluding some of the components may be the embodiment of the present invention. In addition, the present invention also includes modifications obtained by making various modifications that can be conceived by those skilled in the art within the scope of the gist of the present invention, that is, the meaning indicated by the wording described in the claims, with respect to the above-described embodiment. Is done.

For example, in the above embodiment, the expansion / contraction mechanism 143 includes a plurality of telescopic mechanisms, and the virtual area 140 of the nozzle 141 is expanded / contracted by the expansion / contraction of the telescopic mechanism. However, the expansion / contraction mechanism 143 has a link mechanism as shown in FIG. The virtual area 140 may be expanded or contracted by rotating the nozzle 141 while maintaining the parallel state of the nozzle 141.

Further, as shown in FIG. 6, the expansion / contraction mechanism 143 may be one in which a plurality of partial internal gears 146, which are a part of the internal gears, are engaged with one external gear 145. According to the expansion / contraction mechanism 143, by rotating the external gear 145 fixedly attached to the picking robot 104, each partial internal gear 146 is rotated and attached to the tip of the partial internal gear 146. The position of the nozzle 141 can be changed to expand or contract the virtual area 140.

Further, the step of reducing the number of nozzles 141 that contribute to the suction holding of the target article 201 and determining whether or not the suction holding is possible is not an essential step and may be omitted.

Further, in the above embodiment, the case where the interference presence / absence determination unit 112 determines the presence / absence of interference with all the adsorption surfaces having the possibility of holding the adsorption has been described, but the flow lines are in ascending order and the adsorption area is large. The presence or absence of interference may be determined in a predetermined order such as the order, and the process may be terminated when a suction surface without interference is found.

100 Picking system 101 Control device 102 Camera 104 Picking robot 111 Nozzle position determination unit 112 Interference presence / absence determination unit 113 Flow line determination unit 121 Feature amount acquisition unit 131 Suction selection unit 140 Virtual area 141 Nozzle 142 Solenoid valve 143 Expansion / contraction mechanism 144 Flexible member 145 External gear 146 Partial internal gear 200 Article group 201 Target article

Claims (2)

A picking system that picks a target article from a group of articles that are a plurality of articles arranged in a predetermined area.
A camera that captures a group of articles and outputs image information,
The control device connected to the camera and
A picking robot whose picking operation is controlled by the control device is provided.
The picking robot
A plurality of nozzles that suck and hold a predetermined suction surface of the target article,
It is provided with a scaling mechanism for scaling a virtual region, which is the smallest region including all of the plurality of nozzles on a plane parallel to the suction surface, by changing the positional relationship of the nozzles.
The control device is
A feature amount acquisition unit that acquires a feature amount of the suction surface of the target article from the image information acquired from the camera, and a feature amount acquisition unit.
A nozzle position determining unit that determines the nozzle position from the determined suction surface size,
Based on the determined nozzle position and the image information, it possesses and determining interference presence determining unit whether said other article other than the target article nozzle interfering the target object when holding suction,
The nozzle position determining unit
When the interference presence / absence determination unit determines that the nozzle interferes with another article, the nozzle position that becomes a virtual area narrower than the virtual area at the previously determined nozzle position is redetermined.
The interference presence / absence determination unit is
A picking system that determines whether or not the nozzle interferes with an article other than the target article based on the redetermined nozzle position and image information. The control device is
The picking system according to claim 1, further comprising a suction selection unit that independently controls whether or not the plurality of nozzles suck the target article.

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