Simulation device for robot system

Abstract

The present invention provides a simulation device (1) of a robot system comprising at least one robot, at least one sensor for detecting a moving body within a detection area around the robot, and at least one control device for controlling the robot, the control device being configured to control the robot when the sensor detects the moving body. A control device corresponding to the sensor slows down or stops the action of the robot. A simulation device (1) of a robot system includes at least one processor (4) that simulates an operation of the robot system based on layout information and movement information, at least one memory (3) that stores layout information of the robot system, and an input device (2) that receives an input of movement information of a moving body. And calculates the delay time of the operation when the moving body is not detected in the detection area.

Description

Technical Field

[0001] The present disclosure relates to a simulation device for a robot system. Background Art

[0002] There is a description of a related art robot system. When the robot is working and a collaborative worker approaches within a predetermined distance of the robot, the robot is controlled to slow down or stop moving.

[0003] In addition, for such a robot system, in order to shorten the time for the robot to decelerate or stop, there is a simulation device for simulating the actions of the robot and the workers working with the robot (for example, see Patent Document 1).

[0004] [Prior Art Documents]

[0005] [Patent Documents]

[0006] [Patent Document 1] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-24113 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, in general, a moving body such as an automated guided vehicle (AGV) that performs a task different from the robot system may enter or stay within the operation range of the robot. In this case, when the sensor detects the moving body, the action of the robot will decelerate or stop, thereby increasing the cycle time of the robot system.

[0009] Therefore, even if there are other moving bodies (such as collaborative workers) other than the originally planned moving bodies within the operation range of the robot, it is desirable to control the cycle time of the robot system within the expected time range.

[0010] Means for Solving the Problems

[0011] One aspect of the present disclosure is a simulation device for a robot system, the robot system including at least one robot, at least one sensor, and at least one control device, wherein the sensor is used to detect moving bodies within a detection area around the robot, and the controller is used to control the robot. When the sensor detects a moving body, the control device corresponding to the sensor slows down or stops the action of the robot. The simulation device for the robot system includes at least one processor, at least one memory, and an input device, wherein the memory stores layout information of the robot system, the input device receives an input of moving information of the moving body, the processor simulates the operation of the robot system based on the layout information and the moving information, and calculates the delay time of the operation when no moving body is detected within the detection area. Brief Description of the Drawings

[0012] Figure 1 is a plan view showing the layout of a robot system to which a simulation device according to an embodiment of the present disclosure is applied.

[0013] Figure 2 is a block diagram showing a simulation device according to an embodiment of the present disclosure.

[0014] Figure 3 is a flowchart showing a simulation method of a simulation device using Figure 2 the.

[0015] Figure 4 is a timing chart showing the operation of a robot in a robot system when there is no moving body within the imaging range Figure 1 thereof.

[0016] Figure 5 is a timing chart showing the movement information input to Figure 2 the simulation device.

[0017] Figure 6 is a timing chart showing Figure 1 the action of a robot in the robot system thereof, taking into account the entry of a moving body into the imaging range.

[0018] Figure 7 is a timing chart showing Figure 6 a modified example of the layout of the robot system in. DETAILED DESCRIPTION

[0019] A simulation device 1 of a robot system 10 according to an embodiment of the present disclosure will be described below with reference to the drawings.

[0020] First, a robot system 10 to which the simulation device 1 according to the present embodiment is applied will be described.

[0021] As Figure 1 shown, the robot system 10 includes at least one robot 20, at least one camera (sensor) (31, 32) for photographing an image of the surrounding environment of the robot 20, and at least one control device 40. For ease of explanation, Figure 1 only a part of the robot system 10 is shown, and one robot 20, two cameras (31, 32), and one control device 40 provided in the robot system 10 are shown.

[0022] The robot 20 is, for example, a six-axis multi-joint robot. The robot 20 is installed between two worktables WT1 and WT2 arranged at intervals in the horizontal direction. In addition, the robot 20 also performs an operation of picking up a plurality of workpieces W randomly stacked on the worktable WT1 one by one and moving them to the worktable WT2.

[0023] The cameras 31 and 32 are, for example, two-dimensional cameras that capture two-dimensional images. The cameras 31 and 32 are mounted downward above the worktables WT1 and WT2, and have conical imaging ranges (detection areas) s1 and s2 at positions including the worktables WT1 and WT2, respectively. Thus, the cameras 31 and 32 can capture two-dimensional images of the imaging ranges s1 and s2 at a prescribed frame rate.

[0024] The control device 40 includes at least one processor (not shown) and memories (not shown) such as RAM and ROM, and is connected to the robot 20 and the cameras 31 and 32.

[0025] An operation program for operating the robot 20 is stored in the memory of the control device 40. Then, the processor of the control device 40 executes the operation program stored in the memory to operate the respective axes of the robot 20 and cause the robot 20 to perform a desired task.

[0026] In addition, the control device 40 sends an image capture command to one of the cameras 31 and 32 corresponding to the posture of the robot 20 to capture an image at a predetermined frame rate. That is, the control device 40 causes the cameras 31 and 32 on the wrist side of the robot 20 to capture two-dimensional images and receives the two-dimensional images.

[0027] Furthermore, the control device 40 performs image processing on the received two-dimensional image to extract all moving objects included in the two-dimensional image. Then, the control device 40 excludes the robot 20 (including tools etc. mounted on the robot 20) from the extracted moving bodies, and determines whether there is a moving body A other than the robot 20. If all of the extracted moving bodies include the moving body A other than the robot 20, the control device 40 slows down or stops the movement of the respective axes of the robot 20. In other words, the cycle time of the robot system 10 is delayed by the time for decelerating or stopping the operation of the robot 20.

[0028] Next, the simulation device 1 according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0029] The simulation device 1 of the present embodiment is implemented by a computer such as a personal computer.

[0030] As Figure 2 shown, the simulation device 1 includes, for example, an input device 2, memories 3 such as ROM and RAM, at least one processor 4 such as a CPU, and a display device 5.

[0031] The input device 2 is composed of, for example, a keyboard, a touch panel, an operation panel, and a serial interface such as USB. In addition, the input device 2 receives the movement information of at least one moving body A input by the operator of the operation simulation device 1. The movement information includes, for example, the movement path of the moving body A, and information such as the time at each position on the movement path calculated with reference to the start time of the action program of the robot system 10.

[0032] The memory 3 stores the layout information of the robot system 10 in the factory. The layout information is, for example, information about the positions and sizes of the respective components of the robot system 10, the workbenches WT1, WT2, and the imaging ranges s1, s2, and information about the position and shape of the passage P near the robot 20. All of this layout information is converted into a three-dimensional model and stored in the memory 3.

[0033] In addition, the memory 3 also stores the simulation program and the action program of the robot system 10. The simulation program is executed by the processor 4 described later, so that the action program of the robot system 10 is executed in the virtual space on the computer.

[0034] In addition, the memory 3 stores the ideal cycle time of the robot system 10, that is, the cycle time when the moving body A does not enter the imaging ranges s1, s2 and the actions of the robot 20 do not decelerate or stop. The memory 3 also stores the movement information of the moving body A input through the input device 2.

[0035] The processor 4 extracts the movement information of the moving body A and the layout information of the robot system 10 stored in the memory 3, and judges whether the movement path of the moving body A overlaps with the imaging ranges s1 and s2 based on these two pieces of information.

[0036] In addition, the processor 4 executes the simulation program stored in the memory 3 to configure the robot system 10, the passage P near it, and the moving body A moving on the passage P in the virtual space on the computer. Then, the processor 4 uses the motion information and layout information extracted from the memory 3 to simulate the action program of the robot system 10 and the movement of the moving body A configured in the virtual space.

[0037] In addition, the processor 4 calculates the cycle time of the action program according to the simulation result, taking into account the action delay of the robot 20 caused by the moving body A entering the imaging range (s1, s2).

[0038] The display device 5 is composed of a liquid crystal display or a similar device. Based on the layout information, the processor 4 causes the display device 5 to display the layout of the robot system 10 and its surroundings, and superimposes it on the imaging ranges s1 and s2. In addition, the processor 4 also displays, on the display device 5, the delay time calculated, for example, by comparing the calculated cycle time of the motion program with the ideal cycle time stored in the memory 3, together with the layout information.

[0039] The operation of the simulation device 1 of the present embodiment configured as described above will be described below.

[0040] Hereinafter, reference will be made to Figure 3 the flowchart shown to describe a method for simulating the operation of the robot system 10 shown. Figure 1

[0041] First, an operator operating the simulation device 1 inputs the layout information of the robot system 10 into the input device 2 (step S1). As a result, a three-dimensional model is stored in the memory 3, which shows the passage P near the robot 20, and the relative positional relationship of each component of the robot system 10 and the imaging ranges s1 and s2 with respect to the passage P. The operator also inputs the layout information, the motion program of the robot system 10, and the ideal cycle time of the pre-calculated motion program into the input device 2 together, and stores them in the memory 3.

[0042] Figure 4 The example shown is an example of the timing chart of the motion program input to the input device 2, in which the tip of the wrist of the robot 20 moves back and forth between the workbenches WT1 and WT2 at intervals of n seconds, so that the robot 20 performs the required tasks.

[0043] Next, the operator inputs, into the input device 2, the movement paths of the respective moving bodies A and the times at each position on the movement paths as the movement information of all the moving bodies A moving on the passage P near the robot 20 (step S2). The input motion information is stored in the memory 3.

[0044] In this state, the processor 4 acquires the layout information and the movement information stored in the memory 3, and compares the two pieces of information. Then, the processor 4 determines whether the movement paths of the moving bodies A included in the movement information overlap with the imaging ranges s1 and s2 included in the layout information (step S3). When the processor 4 determines that the movement path overlaps with the imaging ranges s1 and s2, the overlapping time period is extracted and stored in the memory 3. That is, as Figure 5 shown, the memory 3 stores the time periods during which the moving body A exists within each image imaging range s1 and s2, which are the times elapsed from the start time of the motion program of the robot system 10.

[0045] ​Subsequently, the processor 4 runs the simulation program stored in the memory 3 (step S4).

[0046] When running the simulation program, the processor 4 sets the robot system 10, the passage P, and the moving body A in the virtual space of the computer according to the layout information read from the memory 3. Then, the processor 4 operates the robot system 10 within the virtual space according to the action program and operates the moving body A based on the movement information.

[0047] At this time, for example, when the robot 20 is performing an operation with the wrist tip facing the workbench WT1, if the moving body A enters the imaging range s1, the robot 20 stops or decelerates. Therefore, as Figures 4 to 6 shown, when the robot 20 is performing an operation on the side of the workbench WT1, the action program delays the time for the robot 20 to stop or decelerate.

[0048] Similarly, when the robot 20 is performing an operation with the wrist tip facing the workbench WT2, when the moving body A enters the imaging range s2, the robot 20 stops or decelerates, and the action program delays the time for the robot 20 to stop or decelerate.

[0049] The processor 4 calculates the cycle time of the action program delayed due to the moving body A entering the imaging ranges s1 and s2 (step S5). In addition, the processor 4 compares the cycle time calculated according to the simulation result with the ideal cycle time stored in the memory 3 to calculate the delay time of the action program. This delay time is calculated separately for the delay time when the robot 20 is operating on the side of the workbench WT1 and the delay time when operating on the side of the workbench WT2.

[0050] Then, the processor 4 causes the display device 5 to display the calculated cycle time and delay time together with the layout information stored in the memory 3 (step S6). For example, the display device 5 displays the delay time caused by the moving body A entering the imaging ranges s1 and s2 calculated by the processor 4 corresponding to the imaging ranges s1 and s2 displayed based on the layout information.

[0051] On the other hand, if the processor 4 determines that the movement path of the moving body A does not overlap with the imaging ranges s1 and s2 (step S3), the execution of the above simulation program is omitted. Then, the processor 4 causes the display device 5 to display a message indicating that the moving body A has not entered the imaging ranges s1 and s2 (step S6).

[0052] In this way, the operator can confirm whether the cycle time of the robot system 10 is likely to be delayed by viewing the display device 5. In addition, if the cycle time is likely to be delayed, the operator can view the delay time of the action program of the robot system 10 calculated based on the simulation result displayed on the display device 5.

[0053] Therefore, the operator can determine whether the cycle time exceeds the expected time based on the display content of the display device 5. If the cycle time exceeds the expected time, the layout of the robot system 10 can be changed to shorten the delay time of the action program.

[0054] In this case, by observing the display of the display device 5, the operator can distinguish and understand the delay time caused by the moving body A entering the imaging range s1 and the delay time caused by the moving body A entering the imaging range s2. Therefore, it is possible to preferentially shorten the delay time that has a greater impact on the cycle time among the two delay times, and thus it is possible to change the layout of the robot system 10 more effectively.

[0055] For example, in Figure 1 In the robot system 10 shown, if most of the delay in the cycle time is caused by the delay time on the s1 side of the imaging range, the entire robot system 10 can be moved away from the passage P near the workbench WT1.

[0056] It should be noted that in this embodiment, the moving path of the moving body A and the time at each position on the moving path are input as moving information to the input device 2, but the present invention is not limited to this.

[0057] For example, if the number of times the moving body A enters the imaging ranges s1 and s2 per unit time and the staying time each time it enters are known, these information can be input as moving information to the input device 2.

[0058] At this time, the processor 4 multiplies the number of times the moving body A enters the imaging ranges s1 and s2 by the staying time each time it enters. Thus, the processor 4 calculates the cumulative staying time per unit time of the moving body A within the imaging range s1 and the cumulative staying time per unit time of the moving body A within the imaging range s2.

[0059] Since the longer the cumulative staying time, the longer the delay time caused to the cycle time of the action program, it can be presumed that within each imaging range s1, s2, there will be a delay time proportional to the cumulative staying time.

[0060] Therefore, the processor 4 can execute the simulation of the action program and calculate the cycle time considering the delay time proportional to the cumulative staying time of the moving body A within each imaging range s1 and s2.

[0061] In addition, if the frequency of the moving body A entering the imaging ranges s1, s2 per unit time and the staying time each time it enters are divided into multiple stages, these stages can be used as moving information.

[0062] For example, if the frequencies of the mobile body A entering the imaging ranges s1 and s2 and the residence time for each entry are each divided into five levels, a score is assigned to each level according to the magnitude of the level. It is also possible to estimate the cumulative residence time of the mobile body A in the respective imaging ranges s1 and s2 by multiplying the points assigned to the entry frequency level by the points assigned to the residence time level and then adding them up.

[0063] In addition, in the present embodiment, if the cycle time of the robot system 10 exceeds the expected time, the layout of the robot system 10 is changed to shorten the delay time of the action program. As an alternative, instead of changing the layout of the robot system 10, the delay time can be reduced by changing the action program of the robot system 10. Or, the delay time can be shortened by changing the moving mode of the mobile body A moving along the passage P, that is, the moving path or moving speed of the mobile body A, etc.

[0064] In this case, as Figure 6 shown, the display device 5 can also display the time period during which the robot 20 stops moving corresponding to the time of the action program according to the simulation result.

[0065] Thereby, the operator can grasp the timing at which the robot 20 stops moving in the action program being executed. Therefore, the operator can make the mobile body A enter the imaging ranges s1 and s2 at times that avoid these time points by adjusting the action program of the robot system 10 or modifying the moving path planning of the mobile body A.

[0066] In addition, in the present embodiment, the robot system 10 to which the simulation device 1 is applied has two imaging ranges s1 and s2, but the number of imaging ranges can be one or more than three.

[0067] In the present embodiment, the simulation device 1 is applied to the robot system 10 in which cameras 31 and 32 are respectively provided above the workbenches WT1 and WT2. As an alternative, the simulation device 1 can be applied to the robot system 10 equipped with a single camera (sensor) 33 that is fixed to the wrist of the robot 20 and has an imaging range (detection area) s3 around the tip of the wrist, as Figure 7 shown.

[0068] In the present embodiment, the robot system 10 to which the simulation device 1 is applied has cameras 31 and 32 respectively provided above the workbenches WT1 and WT2. Therefore, the imaging ranges s1 and s2 respectively expand conically downward from above the workbenches WT1 and WT2. That is, it is necessary to consider the change in the imaging ranges s1 and s2 for detecting the mobile body A in the height direction.

[0069] Alternatively, for each of the cameras 31 and 32 of the robot system 10 that applies the simulation device 1, a configuration can be adopted in which a plurality of line sensors (such as area sensors) are arranged adjacent to each other.

[0070] In this case, the sizes of the imaging ranges s1 and s2 are constant in the height direction. Therefore, the simulation device 1 can determine the overlap between the moving body A and the imaging ranges s1 and s2 in a two-dimensional plane. Therefore, even if the layout information input to the input device 2 is a two-dimensional model, the simulation accuracy of the action program will not be reduced.

[0071] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments. These embodiments can be subject to various additions, replacements, modifications, partial deletions, etc., as long as they do not depart from the gist of the present invention or the idea and spirit of the present invention derived from the content described in the claims and their equivalents. For example, in the above embodiments, the order of each operation and the order of each process are shown only as examples, but the present invention is not limited thereto.

[0072] The above embodiments and variations are further described in the following appendices.

[0073] (Appendix 1)

[0074] A simulation device 1 for a robot system 10, the robot system 10 including at least one robot 20, at least one sensor 31, 32, 33 for detecting a moving body within detection areas s1, s2, s3 around the robot 20, and at least one control device 40 for controlling the robot 20. When the sensors 31, 32, 33 detect the moving body A, the control device 40 corresponding to the sensors 31, 32, 33 causes the robot 20 to decelerate or stop. The simulation device 1 includes at least one processor 4, at least one memory 3, and an input device 2. The memory 3 stores the layout information of the robot system 10. The input device 2 receives the input of the movement information of the moving body A. The processor 4 calculates the layout information and the movement information based on the layout information and the movement information. The simulation device 1 of the robot system 10 simulates the action of the robot system 10 based on the above and calculates the action delay time when the moving body A is not detected within the detection areas s1, s2, s3.

[0075] (Appendix 2)

[0076] The simulation device 1 of the robot system 10 as described in Appendix 1, wherein the processor 4 calculates the cycle time of the operation of the robot system 10.

[0077] (Appendix 3)

[0078] The simulation device 1 of the robot system 10 as described in Supplementary Note 1 or Supplementary Note 2 includes a display device 5 that displays layout information. The processor 4 overlays and displays, on the display device, the areas s1, s2, and s3 where the moving body A is detected by the sensors 31, 32, and 33 based on the movement information and the layout information.

[0079] (Supplementary Note 4)

[0080] For the simulation device 1 of the robot system 10 as described in any one of Supplementary Notes 1 to 3, the movement information includes the movement path of the moving body A and the time at each position where the moving body A appears on the movement path.

[0081] (Supplementary Note 5)

[0082] For the simulation device 1 of the robot system 10 as described in any one of Supplementary Notes 1 to 3, the movement information includes the number of times the moving body A enters the detection areas s1, s2, and s3 per unit time and the residence time each time it enters.

[0083] (Supplementary Note 6)

[0084] For the simulation device 1 of the robot system 10 as described in any one of Supplementary Notes 1 to 3, the movement information includes grades that divide the number of times the moving body A enters the detection areas s1, s2, and s3 and the residence time each time it enters into multiple stages. The processor 4 estimates the delay time based on the sum of the values quantified for each grade.

[0085] (Supplementary Note 7)

[0086] For the simulation device 1 of the robot system 10 as described in any one of Supplementary Notes 1 to 6, the processor 4 determines whether the moving body A is likely to enter the detection areas s1, s2, and s3 based on the movement information input to the input device 2. If it is determined that the moving body A is likely to enter the detection areas s1, s2, and s3, the processor 4 performs the simulation.

[0087]

Symbol Explanation

[0088] 1 Simulation device

[0089] 2 Input device

[0090] 3 Memory

[0091] 4 Processor

[0092] 5 Display device

[0093] 10 Robot system

[0094] 20 Robot

[0095] 31 Camera (sensor)

[0096] 32 cameras (sensors)

[0097] 33 cameras (sensors)

[0098] 40 control device

[0099] A moving body

[0100] s1 imaging range (detection area)

[0101] s2 imaging range (detection area)

[0102] s3 imaging range (detection area).

Claims

1. A simulation device for a robot system, the robot system including at least one robot, at least one sensor, and at least one control device, wherein, The sensor is used to detect moving objects within a detection area around the robot. The control device is used to control the robot. When the sensor detects a moving object, the control device corresponding to the sensor causes the robot to decelerate or stop. The simulation device includes: at least one processor, at least one memory, and an input device; wherein the memory stores layout information of the robot system; the input device receives input of the movement information of the moving object; and the processor simulates the actions of the robot system based on the layout information and the movement information, and calculates the delay time of the actions when the moving object is not detected within the detection area.

2. The simulation device of the robot system according to claim 1, wherein, The processor calculates the cycle time of the operation of the robot system.

3. The simulation device of the robot system according to claim 1 or 2, wherein, It further includes a display device for displaying the layout information. The processor superimposes the area where the sensor detects the moving object on the layout information based on the movement information and the layout information and displays it on the display device.

4. The simulation device of the robot system according to any one of claims 1 to 3, wherein, The movement information includes the movement path of the moving object and the time when the moving object appears at each position on the movement path.

5. The simulation device of the robot system according to any one of claims 1 to 3, wherein, The movement information includes the number of times the moving object enters the detection area per unit time and the residence time for each entry.

6. The simulation device of the robot system according to any one of claims 1 to 3, wherein, The movement information includes a level obtained by multi-level partitioning of the number of times the moving object enters the detection area and the residence time for each entry. The processor estimates the delay time based on the sum of the values obtained by quantifying each level respectively.

7. The simulation device of the robot system according to any one of claims 1 to 6, wherein, The processor determines whether the moving object is likely to enter the detection area based on the movement information input to the input device. When it is determined that the moving object is likely to enter the detection area, the processor performs the simulation.

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