Robot system simulation device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2022-11-29
- Publication Date
- 2026-05-01
AI Technical Summary
Existing robot systems experience increased cycle times due to the presence of unexpected moving objects within their operating range, which can lead to unnecessary deceleration or stopping, disrupting the efficiency of the robot's operations.
A simulation device that includes sensors to detect moving objects, a control device to manage the robot's operations, and a processor to calculate and simulate the impact of these objects on the robot's cycle time, allowing for the prediction and optimization of delays by analyzing layout and movement information.
Enables the prediction and minimization of cycle time delays by determining the overlap between moving objects' paths and the robot's detection areas, allowing for layout adjustments to maintain desired operational efficiency.
Abstract
Description
Robot system simulation device
[0001] The present disclosure relates to a simulation device for a robot system.
[0002] There is a robot system that controls the robot to slow down or stop its movement when a cooperating worker approaches the robot within a predetermined distance while it is working. There is also a simulation device that simulates the movement of the robot and the cooperating worker in order to reduce the time it takes for the robot to slow down or stop for such a robot system (see, for example, Patent Document 1).
[0003] JP 2017-24113 A
[0004] However, generally, a moving object, such as an automated guided vehicle, performing a task separate from the robot system may enter or remain within the operating range of a robot. In this case, the sensor detects the moving object, causing the robot to slow down or stop, increasing the cycle time of the robot system. Therefore, it is desirable to keep the cycle time of the robot system within a desired time, even when a moving object other than the originally intended moving object, such as a collaborating worker, is present within the operating range of the robot.
[0005] One aspect of the present disclosure is a simulation device for a robot system comprising at least one robot, at least one sensor that detects a moving object within a detection area around the robot, and at least one control device that controls the robot, wherein when the sensor detects the moving object, the control device corresponding to the sensor slows down or stops the operation of the robot, the simulation device for a robot system comprising 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 accepts input of movement information of the moving object, the processor executes a simulation of the operation of the robot system based on the layout information and the movement information, and calculates a delay time for the operation when the moving object is not detected within the detection area.
[0006] 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; FIG. 2 is a block diagram showing a simulation device according to an embodiment of the present disclosure; FIG. 3 is a flowchart illustrating a simulation method using the simulation device of FIG. 2; FIG. 4 is a time chart showing the operation of a robot in the robot system of FIG. 1 when no moving object is present in the imaging range; FIG. 5 is a time chart showing movement information input to the simulation device of FIG. 2; FIG. 6 is a time chart showing the operation of a robot in the robot system of FIG. 1, taking into account the entry of a moving object into the imaging range; FIG. 7 is a plan view showing a modified example of the layout of the robot system of FIG. 1;
[0007] A simulation device 1 for a robot system 10 according to an embodiment of the present disclosure will be described below with reference to the drawings. First, the robot system 10 to which the simulation device 1 according to the present embodiment is applied will be described.
[0008] 1, the robot system 10 includes at least one robot 20, at least one camera (sensor) 31, 32 that captures images of the surroundings of the robot 20, and at least one control device 40. For ease of explanation, FIG. 1 shows only a portion of the robot system 10, and illustrates the one robot 20, two cameras 31, 32, and one control device 40 provided in the robot system 10.
[0009] The robot 20 is, for example, a six-axis articulated robot. The robot 20 is installed between two work tables WT1 and WT2 that are arranged at a horizontal distance from each other. The robot 20 performs the task of picking up a plurality of work pieces W that are randomly piled up on the work table WT1 one by one and moving them to the work table WT2.
[0010] The cameras 31 and 32 are, for example, two-dimensional cameras that capture two-dimensional images. The cameras 31 and 32 are installed above the workbenches WT1 and WT2 facing downward, and are provided with conical imaging ranges (detection areas) s1 and s2 at positions that include the workbenches WT1 and WT2, respectively. This allows the cameras 31 and 32 to capture two-dimensional images of the imaging ranges s1 and s2 at a predetermined frame rate.
[0011] The control device 40 includes at least one processor (not shown) and memories such as RAM and ROM (not shown), and is connected to the robot 20 and the cameras 31 and 32. The memory of the control device 40 stores an operation program for operating the robot 20. The processor of the control device 40 executes the operation program stored in the memory to operate each axis of the robot 20 and cause the robot 20 to perform a desired task.
[0012] The control device 40 also transmits an image capturing command to one of the cameras 31, 32 corresponding to the posture of the robot 20 to capture images at a predetermined frame rate. That is, the control device 40 causes the camera 31, 32 on the side toward which the wrist of the robot 20 is facing to capture a two-dimensional image, and receives the two-dimensional image.
[0013] The control device 40 also processes the received two-dimensional image to extract all moving objects included in the two-dimensional image. The control device 40 then excludes the robot 20 (including tools attached to the robot 20) from the extracted moving objects and determines whether any moving objects A other than the robot 20 are included. If all of the extracted moving objects include a moving object A other than the robot 20, the control device 40 slows down or stops the movement of each axis of the robot 20. In other words, the cycle time of the robot system 10 is delayed by the time the movement of the robot 20 is slowed down or stopped.
[0014] Next, a simulation device 1 according to an embodiment of the present disclosure will be described with reference to the drawings. The simulation device 1 according to the present embodiment is realized by a computer such as a personal computer.
[0015] The simulation device 1 includes, for example, an input device 2, a memory 3 such as a ROM and a RAM, at least one processor 4 such as a CPU, and a display device 5, as shown in FIG.
[0016] The input device 2 is configured by, for example, a keyboard, a touch panel, an operation panel, a serial interface such as USB, etc. The input device 2 also receives movement information of at least one moving object A input by an operator operating the simulation apparatus 1. The movement information is, for example, information such as the movement path of the moving object A and the time at each position on the movement path relative to the start time of the operation program of the robot system 10.
[0017] Layout information of the robot system 10 in the factory is stored in the memory 3. The layout information includes, for example, information on the positions and sizes of the components of the robot system 10, the work tables WT1 and WT2, and the shooting ranges s1 and s2, as well as information on 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.
[0018] The memory 3 also stores a simulation program and an operation program for the robot system 10. The simulation program is executed by a processor 4 (described later), whereby the operation program for the robot system 10 is executed in a virtual space on the computer.
[0019] Furthermore, the memory 3 stores an ideal cycle time of the robot system 10, i.e., a cycle time when the moving object A does not enter the imaging ranges s1 and s2 and the operation of the robot 20 does not slow down or stop. The memory 3 also stores movement information of the moving object A input to the input device 2.
[0020] The processor 4 retrieves the movement information of the moving body A stored in the memory 3 and the layout information of the robot system 10, and determines, based on both pieces of information, whether the movement path of the moving body A overlaps with the shooting ranges s1 and s2.
[0021] Furthermore, the processor 4 executes the simulation program stored in the memory 3 to place, in a virtual space on the computer, the robot system 10, a passage P in its vicinity, and a mobile object A moving on the passage P. Then, using the movement information and layout information retrieved from the memory 3, the processor 4 executes a simulation of the operation program of the robot system 10 and the operation of the mobile object A placed in the virtual space.
[0022] Furthermore, the processor 4 calculates the cycle time of the operation program based on the results of the simulation, taking into account the operation delay of the robot 20 caused by the moving body A entering the shooting ranges s1 and s2.
[0023] The display device 5 is configured with a liquid crystal display or the like. The processor 4 causes the display device 5 to display the layout of the robot system 10 and its surroundings, and the shooting ranges s1 and s2, superimposed on each other, based on the layout information. The processor 4 also causes the display device 5 to display, together with the layout information, a delay time calculated by comparing the calculated cycle time of the operation program with the ideal cycle time stored in the memory 3.
[0024] The operation of the simulation device 1 according to this embodiment configured as described above will be described below with reference to the flowchart shown in FIG. 3, taking as an example a method for simulating the operation of the robot system 10 shown in FIG.
[0025] First, an operator operating the simulation device 1 inputs layout information of the robot system 10 into the input device 2 (step S1). As a result, a 3D model indicating the passage P near the robot 20 and the relative positional relationships of each component of the robot system 10 and the imaging ranges s1 and s2 with respect to the passage P is stored in the memory 3. The operator also inputs the operation program for the robot system 10 and a previously calculated ideal cycle time for the operation program into the input device 2 along with the layout information, and stores them in the memory 3.
[0026] The example shown in Figure 4 is an example of a time chart of an operation program input to the input device 2, in which the wrist tip of the robot 20 moves back and forth between the work tables WT1 and WT2 at intervals of n seconds, causing the robot 20 to perform the desired task.
[0027] Next, the operator inputs the movement path of each moving object A and the time at each position on the movement path into the input device 2 as movement information of all moving objects A moving along the passage P near the robot 20 (step S2). The input movement information is stored in the memory 3.
[0028] In this state, the processor 4 retrieves the layout information and movement information stored in the memory 3 and compares the two pieces of information. The processor 4 then determines whether the movement path of the moving object A included in the movement information overlaps with the shooting ranges s1 and s2 included in the layout information (step S3). If the processor 4 determines that the movement path and the shooting ranges s1 and s2 overlap, it extracts the overlapping time periods and stores them in the memory 3. That is, as shown in FIG. 5, the memory 3 stores the time periods during which the moving object A is present in each of the shooting ranges s1 and s2 relative to the elapsed time from the start time of the operation program of the robot system 10.
[0029] Thereafter, the processor 4 executes the simulation program stored in the memory 3 (step S4). When the simulation program is executed, the processor 4 sets the robot system 10, the passage P, and the moving body A in a virtual space on the computer based on the layout information read from the memory 3. Then, the processor 4 operates the robot system 10 in the virtual space according to the operation program, and operates the moving body A based on the movement information.
[0030] In this case, for example, when the robot 20 is working with its wrist tip facing the workbench WT1, if a moving object A enters the image capture range s1, the robot 20 will stop or decelerate. Therefore, as shown in Figures 4 to 6, the operation program will be delayed by the time the robot 20 stops or decelerates while working on the workbench WT1 side. Similarly, when the robot 20 is working with its wrist tip facing the workbench WT2, if a moving object A enters the image capture range s2, the robot 20 will stop or decelerate, and the operation program will be delayed by the time the robot 20 stops or decelerates.
[0031] The processor 4 calculates the cycle time of the operation program delayed due to the entry of the moving object A into the photographing ranges s1 and s2 (step S5). The processor 4 also calculates the delay time of the operation program by comparing the cycle time calculated from the simulation results with the ideal cycle time stored in the memory 3. This delay time is calculated separately into the delay time during work on the workbench WT1 side of the robot 20 and the delay time during work on the workbench WT2 side.
[0032] 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 times calculated by the processor 4 due to the moving object A entering the shooting ranges s1 and s2 in association with the shooting ranges s1 and s2 displayed based on the layout information.
[0033] On the other hand, if the processor 4 determines that the moving path of the moving object A does not overlap with the photographing ranges s1 and s2 (step S3), the execution of the simulation program described above is omitted. Then, the processor 4 causes the display device 5 to display a message indicating that the moving object A has not entered the photographing ranges s1 and s2 (step S6).
[0034] In this way, the operator can check whether there is a possibility of a delay in the cycle time of the robot system 10 by checking the display device 5. Furthermore, if there is a possibility of a delay in the cycle time, the operator can check the delay time of the operation program of the robot system 10 calculated from the simulation results, which is displayed on the display device 5.
[0035] Therefore, the operator can determine whether the cycle time exceeds the desired time based on the display on the display device 5. If the cycle time exceeds the desired time, the operator can change the layout of the robot system 10 so as to reduce the delay time of the operation program.
[0036] In this case, the operator can distinguish between the delay time caused by the moving object A entering the photographing range s1 and the delay time caused by the moving object A entering the photographing range s2, based on the display on the display device 5. Therefore, of the two delay times, the delay time that has the greater impact on the cycle time can be given priority for shortening, and the layout of the robot system 10 can be changed more efficiently.
[0037] For example, in the robot system 10 of FIG. 1, if the majority of the delay in the cycle time is due to the delay time on the side of the photographing range s1, the entire robot system 10 may be moved away from the aisle P adjacent to the workbench WT1.
[0038] In this embodiment, the movement information input to the input device 2 includes the movement route of the moving object A and the time at each position on the movement route, but the present invention is not limited to this.
[0039] For example, if the number of times that moving object A enters the image capture ranges s1 and s2 per unit time and the duration of stay per entry are known, this information may be input as movement information to the input device 2. In this case, the processor 4 multiplies the number of times that moving object A enters the image capture ranges s1 and s2 by the duration of stay per entry. As a result, the processor 4 calculates the cumulative duration of stay per unit time of moving object A in the image capture range s1 and the cumulative duration of stay per unit time of moving object A in the image capture range s2.
[0040] Since the longer the cumulative stay time, the longer the delay time that may be applied to the cycle time of the operation program may be, it can be estimated that a delay time proportional to the cumulative stay time occurs in each of the shooting ranges s1 and s2. Therefore, the processor 4 may execute a simulation of the operation program and calculate the cycle time taking into account a delay time proportional to the cumulative stay time of the moving object A in each of the shooting ranges s1 and s2.
[0041] In addition, if the frequency with which moving body A enters the shooting ranges s1 and s2 per unit time and the length of time it stays there per entry are known as levels divided into multiple stages, these levels may be used as movement information.
[0042] For example, if the frequency of entry of moving object A into the shooting ranges s1 and s2 and the duration of stay per entry are each classified into five levels, a score corresponding to the magnitude of the level is assigned to each level. The cumulative duration of stay of moving object A in each shooting range s1 and s2 can also be estimated by multiplying the score assigned to the level of entry frequency by the score assigned to the level of duration of stay and adding them up.
[0043] Furthermore, in this embodiment, if the cycle time of the robot system 10 exceeds a desired time, the delay time of the operation program is reduced by changing the layout of the robot system 10. Alternatively, the delay time may be reduced by changing the operation program of the robot system 10 without changing the layout of the robot system 10. Alternatively, the delay time may be reduced by changing the movement method of the mobile object A moving along the passage P, i.e., the movement path or movement speed of the mobile object A.
[0044] In this case, the display device 5 may display the time periods during which the operation of the robot 20 will be stopped in correspondence with the time of the operation program based on the simulation results, as shown in Fig. 6. This allows the operator to understand the timing of the operation program currently being executed at which the operation of the robot 20 will be stopped. Therefore, the operator may change the operation program of the robot system 10 or the movement method of the moving object A so that the moving object A enters the imaging ranges s1 and s2 to avoid that timing.
[0045] Furthermore, in this 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 may be one or three or more.
[0046] In this embodiment, the simulation device 1 is applied to the robot system 10 in which the cameras 31 and 32 are installed above the work tables WT1 and WT2, respectively. Alternatively, the simulation device 1 may be applied to the robot system 10 in which one camera (sensor) 33 is fixed to the wrist of the robot 20 and has an imaging range (detection area) s3 surrounding the tip of the wrist, as shown in FIG.
[0047] Furthermore, in this embodiment, the robot system 10 to which the simulation device 1 is applied has the cameras 31 and 32 disposed above the work tables WT1 and WT2, respectively. Therefore, the imaging ranges s1 and s2 expand in a conical shape from above to below the work tables WT1 and WT2, respectively. In other words, it is necessary to take into consideration that the imaging ranges s1 and s2 for detecting the moving object A change in the height direction. Alternatively, the cameras 31 and 32 of the robot system 10 to which the simulation device 1 is applied may each be configured by arranging a plurality of line sensors, such as area sensors, adjacent to each other.
[0048] In this case, the size of the shooting ranges s1 and s2 is constant in the height direction. Therefore, the simulation device 1 can two-dimensionally determine the overlap between the moving object A and the shooting ranges s1 and s2. Therefore, even if the layout information input to the input device 2 is a two-dimensional model, the accuracy of the simulation of the operation program does not decrease.
[0049] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the invention or the concept and spirit of the present invention derived from the content of the claims and their equivalents. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these.
[0050] The following supplementary notes are further disclosed regarding the above-described embodiment and modified examples. (Supplementary Note 1) A simulation device 1 for a robot system 10 includes at least one robot 20, at least one sensor 31, 32, 33 that detects moving objects within detection areas s1, s2, s3 around the robot 20, and at least one control device 40 that controls the robot 20, and when the sensors 31, 32, 33 detect the moving object A, the control device 40 corresponding to the sensor 31, 32, 33 slows down or stops the movement of the robot 20, the simulation device 1 for the robot system 10 includes at least one processor 4, at least one memory 3, and an input device 2, the memory 3 stores layout information of the robot system 10, the input device 2 accepts input of movement information of the moving object A, and the processor 4 executes a simulation of the movement of the robot system 10 based on the layout information and the movement information, and calculates a delay time for the movement when the moving object A is not detected within the detection areas s1, s2, s3. (Supplementary Note 2) The simulation device 1 for a robot system 10 according to Supplementary Note 1, wherein the processor 4 calculates a cycle time of the operation of the robot system 10. (Supplementary Note 3) The simulation device 1 for a robot system 10 according to Supplementary Note 1 or Supplementary Note 2, further comprising a display device 5 that displays the layout information, and wherein the processor 4 causes the display device to display areas s1, s2, s3 in which the moving object A is detected by the sensors 31, 32, 33, superimposed on the layout information based on the movement information and the layout information. (Supplementary Note 4) The simulation device 1 for a robot system 10 according to any one of Supplementary Notes 1 to 3, wherein the movement information includes a movement path of the moving object A and a time when the moving object A is present at each position on the movement path. (Supplementary Note 5) The simulation device 1 for a robot system 10 according to any one of Supplementary Notes 1 to 3, wherein the movement information includes the number of times the moving object A enters the detection areas s1, s2, s3 per unit time and a stay time per entry.(Supplementary Note 6) The simulation device 1 for a robot system 10 according to any one of Supplementary Notes 1 to 3, wherein the movement information includes levels that are divided into a plurality of stages for the number of times the moving object A enters the detection areas s1, s2, s3 and the duration of time spent per entry, and the processor 4 estimates the delay time based on a sum of values obtained by quantifying each of the levels. (Supplementary Note 7) The simulation device 1 for a robot system 10 according to any one of Supplementary Notes 1 to 6, wherein the processor 4 determines whether or not there is a possibility that the moving object A will enter the detection areas s1, s2, s3 based on the movement information input to the input device 2, and when it is determined that there is a possibility that the moving object A will enter the detection areas s1, s2, s3, the processor 4 executes the simulation.
[0051] REFERENCE SIGNS LIST 1 Simulation device 2 Input device 3 Memory 4 Processor 5 Display device 10 Robot system 20 Robot 31 Camera (sensor) 32 Camera (sensor) 33 Camera (sensor) 40 Control device A Moving object s1 Shooting range (detection area) s2 Shooting range (detection area) s3 Shooting range (detection area)
Claims
1. A simulation device for a robot system comprising at least one robot, at least one sensor for detecting moving objects within a detection area surrounding the robot, and at least one control device for controlling the robot, wherein when the sensor detects the moving object, the control device corresponding to the sensor slows down or stops the robot's movement, It comprises at least one processor, at least one memory, and an input device, The memory stores the layout information of the robot system, The input device receives input of movement information of the moving body, A robot system simulation device in which the processor performs a simulation of the operation of the robot system based on the layout information and the movement information, and calculates the delay time of the operation in the case when the moving body is not detected within the detection area.
2. The robot system simulation device according to claim 1, wherein the processor calculates the cycle time of the operation of the robot system.
3. The system includes a display device that displays the aforementioned layout information, The robot system simulation apparatus according to claim 1 or 2, wherein the processor causes the processor to display on the display device the region in which the moving body is detected by the sensor, superimposed on the layout information, based on the movement information and the layout information.
4. The simulation apparatus for a robot system according to claim 1 or 2, wherein the movement information includes the movement path of the moving body and the time at which the moving body is located at each position along the movement path.
5. The simulation apparatus for a robot system according to claim 1 or claim 2, wherein the movement information includes the number of times the moving body enters the detection area per unit time and the duration of stay per entry.
6. The movement information includes levels that categorize the number of times the moving object enters the detection area and the duration of each entry into multiple levels. The simulation apparatus for a robot system according to claim 1 or 2, wherein the processor estimates the delay time based on the sum of the numerical values obtained by quantifying each of the levels.
7. The processor determines, based on the movement information input to the input device, whether or not there is a possibility of the moving body entering the detection area. The simulation device for a robot system according to claim 1 or 2, wherein the processor executes the simulation when it is determined that the moving body may enter the detection area.