Control device, control system, control method and program

Abstract

To make both safety and operation efficiency of a robot compatible.SOLUTION: A control part controls operation of a robot on the basis of operation trajectory information. A sensing part senses a position of the robot and a position of a person. A determining part determines whether or not a first distance between the position of the robot and the position of the person is shorter than a first predetermined distance. A predicting part predicts a future position of the robot on the basis of the position of the robot and also predicts a future position of the person on the basis of the position of the person. A changing part, when a second distance between the future position of the robot and the future position of the person is shorter than a second predetermined distance, changes the operation trajectory information so that the second distance becomes longer than the second predetermined distance. The control part, when the first distance is shorter than the first predetermined distance, stops or decelerates operation of the robot, no matter whether the operation trajectory information is changed or not. The control part, when the first distance is above the first predetermined distance and when the operation trajectory information is changed, controls the operation of the robot on the basis of the changed operation trajectory information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control system, a control device, a control method, and a program. [Background technology]

[0002] When humans coexist and cooperate with robots such as industrial robots and collaborative robots, there are cases where a safety distance between the robot and humans is ensured using safety sensors, etc., and cases where a speed limit for the robot is ensured. In either case, in order to meet the requirements for safety certification, the operation of the robot is restricted when a human approaches the vicinity of the robot, which reduces the system's uptime and productivity. Patent Document 1 discloses that the operation of the robot is stopped when it is determined that the position of a human is within a predetermined radius. Patent Document 2 discloses that the robot determines whether there is a possibility of contact with a human in the future, and changes the robot's trajectory if there is a possibility of contact. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-8562 A [Patent Document 2] JP 2020-46779 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, the robot stops its operation when the human and robot are close to each other, but frequent stops of the robot's operation may reduce the robot's operation efficiency. Conventionally, the robot's trajectory is changed when there is a possibility that the robot may come into contact with a human in the future, but in this case, safety is not ensured after the robot's trajectory is changed. In addition, it is difficult to meet safety standards when using only machine learning-based control.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a technique that can achieve both safety and the operational efficiency of a robot. [Means for solving the problem]

[0006] A control device according to one aspect of the present invention includes a control unit that controls the movement of the robot based on movement trajectory information indicating a movement trajectory of the robot; a determination unit that determines whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a prediction unit that predicts a future position of the robot based on the position of the robot and predicts the future position of the person based on the position of the person; and a modification unit that determines whether a second distance between the future position of the robot and the future position of the person is shorter than a second predetermined distance and, if the second distance is shorter than the second predetermined distance, modifies the movement trajectory information so that the second distance is equal to or greater than the second predetermined distance. If the first distance is shorter than the first predetermined distance, the control unit stops or decelerates the movement of the robot regardless of whether the movement trajectory information has been changed, or, if the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, controls the movement of the robot based on the changed movement trajectory information.

[0007] When the first distance is shorter than the first predetermined distance, the control unit stops or decelerates the robot's motion regardless of whether the motion trajectory information has been changed. In this manner, the control unit prioritizes stopping or decelerating the robot's motion over controlling the robot's motion based on the changed motion trajectory information. When the first distance is shorter than the first predetermined distance, the robot stops or slows down its motion, thereby avoiding collision or contact between the robot and a person. When the first distance is equal to or greater than the first predetermined distance and the motion trajectory information has been changed, the control unit controls the robot's motion based on the changed motion trajectory information. By controlling the robot's motion based on the changed motion trajectory information, future collisions or contact between the robot and a person can be avoided, and future stopping or deceleration of the robot's motion can be suppressed. According to the control device, the robot's motion is stopped or decelerated based on the positional relationship between the robot's position and the person's position, and the robot's motion is controlled based on the changed motion trajectory information, thereby improving the robot's motion efficiency while ensuring safety. Therefore, both safety and robot motion efficiency can be achieved.

[0008] In the control device according to the above aspect, the detection unit detects the position of the robot and the position of the person at regular or irregular intervals, the determination unit determines whether the first distance is shorter than the first predetermined distance each time the position of the robot and the position of the person are detected, and the prediction unit predicts the future position of the robot and the future position of the person each time the position of the robot and the position of the person are detected. By the detection unit detecting the position of the robot and the position of the person at regular or irregular intervals, the determination unit can determine whether the first distance is shorter than the first predetermined distance over time, and the prediction unit can predict the future position of the robot and the future position of the person over time. Therefore, it is possible to avoid collision or contact between the robot and the person according to changes in the position of the robot over time and changes in the position of the person over time, and it is possible to avoid collision or contact between the robot and the person in the future.

[0009] In the control device according to the above aspect, when the first distance is equal to or greater than the first predetermined distance, the determination unit transmits a first signal to the control unit, and when the control unit receives the first signal after stopping the robot's motion and the motion trajectory information is changed after receiving the first signal, the control unit resumes the robot's motion and controls the robot's motion based on the motion trajectory information changed after receiving the first signal, or when the control unit receives the first signal after decelerating the robot's motion and the motion trajectory information is changed after receiving the first signal, the control unit returns the motion speed of the robot to the speed before decelerating and controls the robot's motion based on the motion trajectory information changed after receiving the first signal. After stopping or decelerating the robot's motion and before receiving the first signal, the control unit does not control the robot's motion based on the changed motion trajectory information even if the motion trajectory information is changed. With this control, the stop or deceleration of the robot's motion is prioritized over the robot's motion based on the changed motion trajectory information, thereby improving safety.

[0010] In the control device according to the above aspect, the determination unit transmits a second signal to the change unit when the first distance is shorter than the first predetermined distance, and determines whether a third distance between the position of the robot and the position of the person detected after transmitting the second signal to the change unit is shorter than the first predetermined distance, and transmits a third signal to the change unit when the third distance is equal to or greater than the first predetermined distance. The change unit does not change the motion trajectory information from after receiving the second signal until receiving the third signal. The change unit does not change the motion trajectory information from after receiving the second signal until receiving the third signal. Therefore, even if the shortest distance between the future position of the robot and the future position of the person becomes shorter than the second predetermined distance during the period from after receiving the second signal until receiving the third signal, the change unit does not change the motion trajectory information. With such control, the stop or deceleration of the robot's motion is prioritized over the motion of the robot based on the changed motion trajectory information, thereby improving safety.

[0011] In the control device according to the one aspect described above, when the first distance is equal to or greater than the first predetermined distance, the determination unit transmits a fourth signal to the control unit, and the control unit determines whether the robot is moving If the fourth signal is received after stopping the robot and the motion trajectory information has not changed, the robot resumes motion and controls the robot motion based on the motion trajectory information, or if the fourth signal is received after slowing down the robot's motion speed and the motion trajectory information has not changed, the robot's motion speed is restored and the robot motion is controlled based on the motion trajectory information. If stopping or slowing down the robot motion can avoid a collision or contact between the robot and a person, the robot's motion can be resumed, thereby improving the robot's motion efficiency while ensuring the safety of the control device.

[0012] In the control device according to the above aspect, the prediction unit predicts a future position of the robot based on a plurality of positions of the robot. In the control device according to the above aspect, the prediction unit predicts a future position of the robot based on a position of the robot and the motion trajectory information. In the control device according to the above aspect, the prediction unit predicts a future position of the robot based on a plurality of positions of the robot and the motion trajectory information. This improves the prediction accuracy of the future position of the robot. In the control device according to the above aspect, the prediction unit predicts a future position of the person based on a plurality of positions of the person. This improves the prediction accuracy of the future position of the person. The prediction unit predicts the future position of the robot and the future position of the person by machine learning. This improves the prediction accuracy of the future position of the robot and the future position of the person.

[0013] The present invention can also be understood as a control system that performs at least a part of the above-mentioned processing, a control method that includes at least a part of the above-mentioned processing, or a program for implementing such a method or a recording medium on which such a program is non-temporarily recorded. Note that the above-mentioned means and processing can be combined with each other as much as possible to constitute the present invention. Effect of the Invention

[0014] According to the present invention, it is possible to provide a technique that can achieve both safety and robot operation efficiency. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic configuration diagram of a control system according to this embodiment. [Diagram 2] FIG. 2 is a block diagram of the control device according to the present embodiment. [Diagram 3] FIG. 3 is a flowchart illustrating the process flow of the control system according to this embodiment. [Figure 4] FIG. 4 is a block diagram of the control device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <Application Examples> FIG. 1 is a schematic diagram of a control system according to this embodiment. In the control system of FIG. 1, in an environment where a robot 1 and a person (worker) 10 coexist, for example, in a production site such as a factory, the movement of the person 10 is grasped and the robot 1 is controlled. The robot 1 of FIG. 1 is a vertical articulated robot, and has a base 11 and an arm 12 connected to the base 11. The robot 1 is not limited to a vertical articulated robot, and may be a robot employing another system such as a horizontal articulated robot. An end effector (hand) for grasping an object is attached to the tip of the arm 12. Furthermore, the robot 1 has a servo motor for operating the arm 12.

[0017] The control system includes a robot 1, a robot controller 2, a control device 3 that transmits motion instruction signals and motion trajectory information to the robot controller 2, and a sensor 4 as a detection unit that detects the position of the robot 1 and the position of a person 10 at regular or irregular intervals. The robot controller 2 controls the movement of the robot 1 based on the movement trajectory information. The robot controller 2 is an example of a control unit. The movement trajectory information is information indicating the movement trajectory of the robot 1, and includes, for example, information on the start point, end point, path from the start point to the end point, and intermediate points between the start point and the end point of the movement of the arm 12 of the robot 1. The robot controller 2 also controls the start, stop, deceleration, and acceleration of the movement of the robot 1 according to a movement instruction signal from the control device 3. The movement instruction signal includes signals such as instructions to start and stop the movement of the robot 1, and instructions to decrease and increase the movement speed of the robot 1.

[0018] The sensor 4 detects the position of the robot 1 and the position of the person 10, and sends the detection result to the control device 3. The sensor 4 is a distance measurement sensor that measures the distance to an object. The sensor 4 may be a RADAR (Radio Detection and Ranging), a LiDAR (light detection and ranging), or a three-dimensional camera. The sensor 4 may also be a sensor system that combines at least two of the RADAR, the LiDAR, and the three-dimensional camera. The position of the robot 1 may be a relative position within the detection range of the sensor 4. The position of the robot 1 may be a position of each part of the robot 1. For example, the position of the robot 1 may be a position of the tip of the arm 12, a position of an end effector attached to the tip of the arm 12, or a position of the base 11. The position of the person 10 may be a relative position within the detection range of the sensor 4. The position of the person 10 may be a position of each part of the person 10. For example, the position of the person 10 may be a position of the hand, the foot, or the head of the person 10.

[0019] The control device 3 has a safety determination unit 31, a prediction processing unit 32, and a trajectory planning unit 33. The safety determination unit 31 determines whether or not the distance (first distance) between the position of the robot 1 and the position of the person 10 is shorter than a first predetermined distance. When the distance between the position of the robot 1 and the position of the person 10 is equal to or greater than the first predetermined distance, the safety determination unit 31 transmits an instruction signal to the robot controller 2 to start the operation of the robot 1. When the robot controller 2 receives the instruction signal to start the operation of the robot 1 before the start of the operation of the robot 1, such as immediately after the power is turned on to the robot 1, the robot controller 2 controls the operation of the robot 1 based on the operation trajectory information. The safety determination unit 31 or the trajectory planning unit 33 transmits the operation trajectory information to the robot controller 2, and the robot controller 2 may store the received operation trajectory information in the storage unit of the robot controller 2. The operation trajectory information may be stored in advance in the storage unit of the robot controller 2. The first predetermined distance is a distance that can be set arbitrarily, and may be the maximum distance from the center position of the robot 1 in the movable area of ​​the robot 1, or may be the maximum distance from the center position of the robot 1 in an area larger than the movable area of ​​the robot 1.

[0020] When the distance between the position of the robot 1 and the position of the person 10 is shorter than a first predetermined distance, the safety judgment unit 31 transmits to the robot controller 2 an instruction signal to stop the movement of the robot 1 (hereinafter referred to as a stop signal) or an instruction signal to decelerate the movement of the robot 1 (hereinafter referred to as a deceleration signal). When the robot controller 2 receives a stop signal after starting to control the movement of the robot 1 based on the movement trajectory information, it stops the movement of the robot 1. When the robot controller 2 receives a deceleration signal after starting to control the movement of the robot 1 based on the movement trajectory information, it decelerates the movement of the robot 1. The stop signal and the deceleration signal are examples of a first signal.

[0021] The prediction processing unit 32 predicts the future position of the robot 1 based on the position of the robot 1 detected by the sensor 4. The future position of the robot 1 is the position of the robot 1 a predetermined time after the current time. The prediction processing unit 32 predicts the future position of the person 10 based on the position of the person 10 detected by the sensor 4. The future position of the person 10 is the position of the person 10 a predetermined time after the current time.

[0022] The trajectory planning unit 33 calculates a trajectory for the future based on the future position of the robot 1 and the future position of the person 10. The trajectory planning unit 33 determines the positional relationship between the robot 1 and the person 10 in the future, and determines whether or not to change the movement trajectory information based on the determination result. The trajectory planning unit 33 determines whether or not the distance (second distance) between the future position of the robot 1 and the future position of the person 10 is shorter than the second predetermined distance. When the distance between the future position of the robot 1 and the future position of the person 10 is shorter than the second predetermined distance, the trajectory planning unit 33 changes the movement trajectory information so that the distance between the future position of the robot 1 and the future position of the person 10 is equal to or greater than the second predetermined distance. The trajectory planning unit 33 is an example of a change unit. The second predetermined distance is a distance that can be arbitrarily set, and may be the maximum distance from the center position of the robot 1 in the movable area of ​​the robot 1, or may be the maximum distance from the center position of the robot 1 in an area larger than the movable area of ​​the robot 1. The first predetermined distance and the second predetermined distance may be the same distance, or the first predetermined distance and the second predetermined distance may be different distances. When the distance between the future position of the robot 1 and the future position of the person 10 is equal to or greater than the second predetermined distance, the trajectory planning unit 33 does not change the movement trajectory information.

[0023] When the robot controller 2 receives a stop signal from the safety determination unit 31, the robot controller 2 stops the motion of the robot 1 regardless of whether the motion trajectory information has been changed. When the robot controller 2 receives a deceleration signal from the safety determination unit 31, the robot controller 2 decelerates the robot 1 regardless of whether the motion trajectory information has been changed. Even if the motion trajectory information has been changed, the robot controller 2 stops or decelerates the motion of the robot 1 in response to the stop signal or deceleration signal. In this way, the robot controller 2 prioritizes stopping or decelerating the motion of the robot 1 over controlling the motion of the robot 1 based on the changed motion trajectory information. The robot controller 2 stops or decelerates the motion of the robot 1 in response to the stop signal or deceleration signal, thereby making it possible to avoid collision or contact between the robot 1 and the person 10. Furthermore, the sensor 4 detects the positions of the robot 1 and the person 10 at regular or irregular intervals, making it possible to avoid collision or contact between the robot 1 and the person 10 in response to changes over time in the positions of the robot 1 and the person 10.

[0024] When the robot controller 2 does not receive a stop signal or a deceleration signal from the safety determination unit 31 and the motion trajectory information has been changed, the robot controller 2 controls the motion of the robot 1 based on the changed motion trajectory information. That is, when the distance between the position of the robot 1 and the position of the person 10 is equal to or greater than the first predetermined distance and the motion trajectory information has been changed, the robot controller 2 controls the motion of the robot 1 based on the changed motion trajectory information. By the robot controller 2 controlling the motion of the robot 1 based on the changed motion trajectory information, it is possible to avoid future collisions and contacts between the robot 1 and the person 10. In addition, by the sensor 4 detecting the positions of the robot 1 and the person 10 at regular or irregular intervals, it is possible to avoid future collisions and contacts between the robot 1 and the person 10 according to the changes over time in the positions of the robot 1 and the person 10.

[0025] According to the control system including the control device 3, the operation efficiency of the robot 1 can be improved while ensuring safety by simultaneously stopping or decelerating the operation of the robot 1 based on the positional relationship between the position of the robot 1 and the position of the person 10 and controlling the operation of the robot 1 based on the changed operation trajectory information. Therefore, it is possible to achieve both safety and the operation efficiency of the robot 1. In addition, it is easier to satisfy safety standards compared to the case of only machine learning-based control. Therefore, safety certification of the control device 3 and the control system becomes easier, and advanced control technology can be applied to situations where the robot 1 and the person 10 coexist and cooperate with each other.

[0026] 1, the robot controller 2 and the control device 3 are separate entities, but the robot controller 2 and the control device 3 may be integrated. The functions of the control device 3 may be incorporated into the robot controller 2, or the functions of the robot controller 2 may be incorporated into the control device 3.

[0027] <System configuration> The control system will be described with reference to Figures 1 and 2. The parts of the entire control system related to the safety system are called safety-related parts, and the parts other than the safety system are called non-safety-related parts. In this embodiment, the safety judgment unit 31 mainly functions as the safety-related unit 5, and the prediction processing unit 32 and the trajectory planning unit 33 mainly function as the non-safety-related units 6.

[0028] The safety determination unit 31 has a processing unit 311, a memory 312, and an output unit 313. The processing unit 311 reads out a program stored in the memory 312 and performs control of each unit of the safety determination unit 31, signal processing, arithmetic processing, etc. The processing unit 311 also processes the detection result received from the sensor 4 and stores it in the memory 312. The processing unit 311 may be configured by a computer having, for example, a processor such as a CPU, a RAM, a non-volatile storage device (for example, a ROM, a flash memory, etc.). The form of the computer does not matter. All or part of the functions provided by the processing unit 311 may be configured by a circuit such as an ASIC or an FPGA. The memory 312 stores data necessary for the processing unit 311 to perform processing. The memory 312 may be a RAM, a non-volatile storage device, etc. The output unit 313 outputs a signal generated by the processing unit 311 to the robot controller 2.

[0029] The safety determination unit 31 determines the positional relationship between the robot 1 and the person 10 based on the position of the robot 1 and the position of the person 10. The safety determination unit 31 determines the positional relationship between the robot 1 and the person 10 every time it receives a detection result from the sensor 4. That is, the safety determination unit 31 determines whether the distance between the position of the robot 1 and the position of the person 10 is shorter than a first predetermined distance every time the positions of the robot 1 and the person 10 are detected. Therefore, the safety determination unit 31 determines whether the distance between the position of the robot 1 and the position of the person 10 is shorter than the first predetermined distance over time. The safety determination unit 31 generates a stop signal or a deceleration signal based on the determination result, and transmits the stop signal or the deceleration signal to the robot controller 2.

[0030] The prediction processing unit 32 includes a processing unit 321, a memory 322, and an output unit 323. The processing unit 321 reads out a program stored in the memory 322 and performs control of each unit of the prediction processing unit 32, signal processing, arithmetic processing, and the like. The processing unit 321 also processes the detection result received from the sensor 4 and stores it in the memory 322. The processing unit 321 may be configured by a computer having, for example, a processor such as a CPU, a RAM, a non-volatile storage device, and the like. The form of the computer does not matter. All or part of the functions provided by the processing unit 321 may be configured by a circuit such as an ASIC or FPGA. The memory 322 stores data necessary for the processing unit 321 to perform processing. The memory 322 may be a RAM, a non-volatile storage device, and the like. The output unit 323 outputs a signal generated by the processing unit 321 to the trajectory planning unit 33.

[0031] The prediction processing unit 32 predicts the future position of the robot 1 based on the position of the robot 1, and predicts the future position of the person 10 based on the position of the person 10. The prediction processing unit 32 predicts the future position of the robot 1 and the future position of the person 10 every time the positions of the robot 1 and the person 10 are detected. Therefore, the prediction processing unit 32 predicts the future position of the robot 1 and the future position of the person 10 over time. The prediction processing unit 32 may predict the future position of the robot 1 and the future position of the person 10 by machine learning using AI (artificial intelligence). The prediction processing unit 32 may accumulate the position of the robot 1 in the memory 322 or another storage device every time the position of the robot 1 is detected, and predict the future position of the robot 1 based on multiple positions of the robot 1. The prediction processing unit 32 may predict the future position of the robot 1 based on the position and movement trajectory information of the robot 1. The prediction processing unit 32 may predict the future position of the robot 1 based on multiple positions and movement trajectory information of the robot 1. As a result, the prediction accuracy of the future position of the robot 1 is improved. The prediction processing unit 32 accumulates the position of the person 10 in the memory 322 or other storage device every time the position of the person 10 is detected, and calculates the position based on the multiple positions of the person 10. The prediction processing unit 32 may predict the future position of the person 10. This improves the prediction accuracy of the future position of the person 10. The prediction processing unit 32 generates a signal including the future position of the robot 1 and the future position of the person 10 for the trajectory planning unit 33, and transmits the signal to the trajectory planning unit 33.

[0032] The trajectory planning unit 33 has a processing unit 331, a memory 332, and an output unit 333. The processing unit 331 reads out a program stored in the memory 332 and performs control of each unit of the trajectory planning unit 33, signal processing, arithmetic processing, etc. The processing unit 331 also processes a signal received from the prediction processing unit 32 and stores it in the memory 332. The processing unit 331 may be configured by a computer having, for example, a processor such as a CPU, a RAM, a non-volatile storage device, etc. The form of the computer does not matter. All or part of the functions provided by the processing unit 331 may be configured by a circuit such as an ASIC or FPGA. The memory 332 stores data necessary for the processing unit 331 to perform processing. The memory 332 may be a RAM, a non-volatile storage device, etc. The output unit 333 outputs a signal generated by the processing unit 331 and predetermined information to the robot controller 2.

[0033] The trajectory planning unit 33 judges the future positional relationship between the robot 1 and the person 10 based on the future position of the robot 1 and the future position of the person 10, and decides whether to change the movement trajectory information based on the judgment result. When the movement trajectory information is changed, the trajectory planning unit 33 transmits the changed movement trajectory information to the robot controller 2. The robot controller 2 receives the changed movement trajectory information and stores the changed movement trajectory information in the memory unit of the robot controller 2.

[0034] In the above, an example is shown in which the motion trajectory information and the changed motion trajectory information are stored in the storage unit of the robot controller 2, but the present invention is not limited to this example. The motion trajectory information and the changed motion trajectory information may be stored in an external storage device connected to the robot controller 2. The robot controller 2 may acquire the motion trajectory information from the external storage device. When the motion trajectory information is changed, the trajectory planning unit 33 may store the changed motion trajectory information in the external storage device and transmit a signal indicating that the motion trajectory information has been changed to the robot controller 2. When the robot controller 2 receives a signal indicating that the motion trajectory information has been changed, it may acquire the changed motion trajectory information from the external storage device.

[0035] The flow of processing in the control system will be described with reference to the flowchart in Fig. 3. In the flowchart in Fig. 3, the safety-related unit 5 (safety judgment unit 31) performs the processing of steps S102 to S104, and the non-safety-related unit 6 (prediction processing unit 32, trajectory planning unit 33) performs the processing of steps S105 to S109.

[0036] The sensor 4 detects the position of the robot 1 and the position of the person 10, and transmits the detection result to the safety judgment unit 31 and the prediction processing unit 32 (step S101). When the safety judgment unit 31 receives the detection result from the sensor 4, it calculates the shortest distance between the position of the robot 1 and the position of the person 10 (step S102). The safety judgment unit 31 calculates the distance between the position of each part of the robot 1 and the position of each part of the person 10, and determines the shortest distance among the multiple calculated distances as the shortest distance between the position of the robot 1 and the position of the person 10. The safety-related unit 5 (safety judgment unit 31) determines whether the shortest distance between the position of the robot 1 and the position of the person 10 is shorter than a first predetermined distance (step S103).

[0037] If the shortest distance between the position of the robot 1 and the position of the person 10 is shorter than the first predetermined distance (step S103: YES), the safety determination unit 31 transmits a stop signal or a deceleration signal to the robot controller 2 (step S104). If the robot controller 2 receives a stop signal, it stops the movement of the robot 1, and if it receives a deceleration signal, it decelerates the movement of the robot 1. The safety determination unit 31 determines that the shortest distance between the position of the robot 1 and the position of the person 10 is shorter than the first predetermined distance (step S103: YES). If the distance is equal to or greater than the first predetermined distance (step S103: NO), no stop signal or deceleration signal is transmitted to the robot controller 2. Every time the safety determination unit 31 receives a detection result from the sensor 4, the processes of steps S102 to S104 are executed.

[0038] When the prediction processing unit 32 receives the detection result from the sensor 4, it predicts the future position of the robot 1 and the future position of the person 10 (step S105). The prediction processing unit 32 calculates the shortest distance between the future position of the robot 1 and the future position of the person 10 (step S106). In other words, the prediction processing unit 32 calculates the shortest distance between the future position of the robot 1 and the position of the person 10. The prediction processing unit 32 calculates the distance between the future position of each part of the robot 1 and the future position of each part of the person 10, and determines the shortest distance among the calculated distances as the shortest distance between the future position of the robot 1 and the future position of the person 10. The trajectory planning unit 33 determines whether the shortest distance between the future position of the robot 1 and the future position of the person 10 is shorter than a second predetermined distance (step S107).

[0039] When the shortest distance between the future position of the robot 1 and the future position of the person 10 is shorter than the second predetermined distance (step S107: YES), the trajectory planning unit 33 changes the movement trajectory information so that the distance between the future position of the robot 1 and the future position of the person 10 is equal to or greater than the second predetermined distance (step S108). The trajectory planning unit 33 transmits the changed movement trajectory information to the robot controller 2 (step S109). When the robot controller 2 has not received a stop signal or a deceleration signal and the movement trajectory information has been changed, the robot controller 2 controls the movement of the robot 1 based on the changed movement trajectory information. When the shortest distance between the future position of the robot 1 and the future position of the person 10 is equal to or greater than the second predetermined distance (step S107: NO), the trajectory planning unit 33 does not change the movement trajectory information. Each time the prediction processing unit 32 receives a detection result from the sensor 4, the processing of steps S105 to S109 is executed.

[0040] When the robot controller 2 receives a stop signal, it stops the motion of the robot 1 regardless of whether the motion trajectory information has been changed, and when the robot controller 2 receives a deceleration signal, it decelerates the motion of the robot 1 regardless of whether the motion trajectory information has been changed. In this way, the robot controller 2 prioritizes stopping or decelerating the motion of the robot 1 over controlling the motion of the robot 1 based on the changed motion trajectory information. That is, in the control system, the priority of the safety-related part 5 is set higher than the priority of the non-safety-related part 6, and processing by the high-priority safety-related part 5 and processing by the non-safety-related part 6 are performed in parallel. A first method and a second method for setting the priority of the safety-related part 5 higher than the priority of the non-safety-related part 6 will be described.

[0041] (First Method) The first method is a process in which, when the motion of the robot 1 is stopped or decelerated, the robot controller 2 ignores the change in the motion trajectory information by the trajectory planning unit 33 until the shortest distance between the position of the robot 1 and the position of the person 10 becomes equal to or greater than the first predetermined distance. When the shortest distance between the position of the robot 1 and the position of the person 10 is equal to or greater than the first predetermined distance (step S103: NO), the safety determination unit 31 transmits a first safety signal to the robot controller 2. The first safety signal is an example of the first signal. When the robot controller 2 receives the first safety signal after stopping the motion of the robot 1 by receiving a stop signal, and the motion trajectory information is changed after receiving the first safety signal, the robot controller 2 resumes the motion of the robot 1. Then, the robot controller 2 controls the motion of the robot 1 based on the motion trajectory information changed after receiving the first safety signal. When the robot controller 2 receives the first safety signal after decelerating the motion of the robot 1 by receiving a deceleration signal, and the motion trajectory information is changed after receiving the first safety signal, the robot controller 2 returns the motion speed of the robot 1 to the speed before deceleration. Then, the robot controller 2 controls the movement of the robot 1 based on the movement trajectory information changed after receiving the first safety signal.

[0042] After stopping the operation of the robot 1 and before receiving the first safety signal, even if the operation trajectory information is changed, the robot controller 2 does not control the operation of the robot 1 based on the changed operation trajectory information. After decelerating the operation of the robot 1 and before receiving the first safety signal, even if the operation trajectory information is changed, the robot controller 2 does not control the operation of the robot 1 based on the changed operation trajectory information. In this way, by setting the priority of the safety-related part 5 higher than the priority of the non-safety-related part 6, the safety of the control system can be improved.

[0043] (Second Method) The second method is a process in which, when the motion of the robot 1 is stopped or decelerated, the trajectory planning unit 33 suspends the change of the motion trajectory information until the shortest distance between the position of the robot 1 and the position of the person 10 becomes equal to or greater than the first predetermined distance. When the shortest distance (first distance) between the position of the robot 1 and the position of the person 10 is shorter than the first predetermined distance (step S103: YES), the safety determination unit 31 transmits a danger signal to the trajectory planning unit 33. The danger signal is an example of a second signal. The safety determination unit 31 determines whether or not the distance (third distance) between the position of the robot 1 and the position of the person 10 detected by the sensor 4 after transmitting the danger signal to the trajectory planning unit 33 is shorter than the first predetermined distance (step S103). When the distance (third distance) between the position of the robot 1 and the position of the person 10 is equal to or greater than the first predetermined distance, the safety determination unit 31 transmits a change signal to the trajectory planning unit 33. The change signal is an example of a third signal. The trajectory planning unit 33 does not change the motion trajectory information after receiving the danger signal until receiving the change signal. Therefore, even if the shortest distance between the future position of the robot 1 and the future position of the person 10 becomes shorter than the second predetermined distance after the trajectory planning unit 33 receives a danger signal and before receiving a change signal, the trajectory planning unit 33 does not change the motion trajectory information. In this way, by setting the priority of the safety-related unit 5 higher than the priority of the non-safety-related unit 6, the safety of the control system can be improved.

[0044] The sensor 4 detects the position of the robot 1 and the position of the person 10 at regular or irregular intervals. A case will be described where the safety determination unit 31 receives a detection result from the sensor 4 after transmitting a stop signal or a deceleration signal to the robot controller 2. When the safety determination unit 31 receives a detection result from the sensor 4 after transmitting a stop signal or a deceleration signal to the robot controller 2, it calculates the shortest distance between the position of the robot 1 and the position of the person 10 (step S102). The safety determination unit 31 determines whether the shortest distance between the position of the robot 1 and the position of the person 10 detected by the sensor 4 after transmitting a stop signal or a deceleration signal to the robot controller 2 is shorter than a first predetermined distance (step S103).

[0045] The safety determination unit 31 transmits a second safety signal to the robot controller 2 when the shortest distance between the position of the robot 1 detected by the sensor 4 and the position of the person 10 after transmitting a stop signal or a deceleration signal to the robot controller 2 is equal to or greater than a first predetermined distance. The second safety signal is an example of a fourth signal. When the robot controller 2 receives the second safety signal after stopping the operation of the robot 1 due to receiving a stop signal and the operation trajectory information has not been changed, the robot controller 2 resumes the operation of the robot 1 and controls the robot 1 based on the operation trajectory information. When the collision or contact between the robot 1 and the person 10 can be avoided by stopping the operation of the robot 1, the operation of the robot 1 is resumed, thereby improving the operation efficiency of the robot 1 while ensuring the safety of the control system.

[0046] When the robot controller 2 receives a second safety signal after decelerating the motion of the robot 1 in response to the deceleration signal and the motion trajectory information has not been changed, the robot controller 2 returns the motion speed of the robot 1 to the speed before deceleration and controls the robot 1 based on the motion trajectory information. When a collision or contact between the robot 1 and the person 10 can be avoided by decelerating the motion of the robot 1, the motion speed of the robot 1 is returned to the speed before deceleration to ensure the safety of the control system. This makes it possible to improve the operation efficiency of the robot 1 while ensuring the required stability.

[0047] The flowchart in FIG. 3 shows an example in which the safety-related unit 5 makes a judgment using the shortest distance between the position of the robot 1 and the position of the person 10, but is not limited to this example. For example, the safety-related unit 5 may make a judgment using the longest distance between the position of the robot 1 and the position of the person 10. Furthermore, the flowchart in FIG. 3 shows an example in which the non-safety-related unit 6 makes a judgment using the shortest distance between the future position of the robot 1 and the future position of the person 10, but is not limited to this example. For example, the non-safety-related unit 6 may make a judgment using the longest distance between the future position of the robot 1 and the future position of the person 10.

[0048] In the above, the prediction processing unit 32 predicts the future position of the robot 1 and the future position of the person 10, but is not limited to this configuration. As shown in FIG. 4, the first prediction processing unit 32A may predict the future position of the robot 1, and the second prediction processing unit 32B may predict the future position of the person 10. The prediction processing unit 32A has a processing unit 321A, a memory 322A, and an output unit 323A. The configurations of the processing unit 321A, the memory 322A, and the output unit 323A are the same as those of the processing unit 321, the memory 322, and the output unit 323. The prediction processing unit 32B has a processing unit 321B, a memory 322B, and an output unit 323B. The configurations of the processing unit 321B, the memory 322B, and the output unit 323B are the same as those of the processing unit 321, the memory 322, and the output unit 323.

[0049] The sensor 4 detects the position of the robot 1 and the position of the person 10, and transmits the detection results to the safety determination unit 31, the first prediction processing unit 32A, and the second prediction processing unit 32B. Upon receiving the detection result from the sensor 4, the first prediction processing unit 32A predicts the future position of the robot 1. Upon receiving the detection result from the sensor 4, the second prediction processing unit 32B predicts the future position of the person 10. Other points are similar to the prediction processing unit 32.

[0050] Each process described above may be regarded as a method executed by a computer. Also, a program for causing a computer to execute each process described above may be provided to the computer via a network or from a computer-readable recording medium that non-temporarily holds data. The computer can function as the robot controller 2 or the control device 3 by loading and executing the above program. The computer can function as the robot controller 2 and the control device 3 by loading and executing the above program.

[0051] <Additional Notes> A control unit (2) that controls the movement of the robot (1) based on movement trajectory information indicating the movement trajectory of the robot (1); a determination unit (31) that determines whether a first distance between a position of the robot detected by a detection unit (4) and a position of a person is shorter than a first predetermined distance; a prediction unit (32) that predicts a future position of the robot (1) based on a position of the robot (1) and predicts a future position of the person based on a position of the person; a change unit (33) that determines whether a second distance between a future position of the robot (1) and a future position of the person is shorter than a second predetermined distance, and, if the second distance is shorter than the second predetermined distance, changes the motion trajectory information so that the second distance is equal to or greater than the second predetermined distance; Equipped with The control unit (2) If the first distance is shorter than the first predetermined distance, the motion of the robot (1) is stopped or decelerated regardless of whether the motion trajectory information is changed or not, or The first distance is equal to or greater than the first predetermined distance, and the motion trajectory information has been changed. In this case, the movement of the robot (1) is controlled based on the changed movement trajectory information. Control device (3). [Explanation of symbols]

[0052] 1: Robot 2: Robot controller 3: Control device 4: Sensor 5: Safety-related department 6: Non-safety related parts 10:People 31: Safety judgment section 32: Prediction processing unit 32A: First prediction processing unit 32B: Second prediction processing unit 33: Orbit Planning Department

Claims

1. A control unit that controls a motion of the robot based on motion trajectory information indicating a motion trajectory of the robot; a determination unit that determines whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a prediction unit that predicts a future position of the robot based on a position of the robot and predicts a future position of the person based on a position of the person; a change unit that determines whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and changes the movement trajectory information if the second distance is shorter than the second predetermined distance so that the second distance is equal to or greater than the second predetermined distance; Equipped with The control unit is If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, the determination unit determines whether the first distance is shorter than the first predetermined distance each time a position of the robot and a position of the person are detected; the prediction unit predicts a future position of the robot and a future position of the person every time a position of the robot and a position of the person are detected; The determination unit transmits a first signal to the control unit when the first distance is equal to or greater than the first predetermined distance; The control unit is When the first signal is received after the robot operation is stopped and the motion trajectory information is changed after the first signal is received, the robot operation is resumed and the motion of the robot is controlled based on the motion trajectory information changed after the first signal is received; or When the first signal is received after the motion of the robot is decelerated and the motion trajectory information is changed after the first signal is received, the motion speed of the robot is reduced to the speed before the deceleration. and controls the motion of the robot based on the motion trajectory information changed after receiving the first signal. Control device.

2. A control unit that controls a movement of the robot based on movement trajectory information indicating a movement trajectory of the robot; a determination unit that determines whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a prediction unit that predicts a future position of the robot based on a position of the robot and predicts a future position of the person based on a position of the person; a change unit that determines whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and changes the movement trajectory information if the second distance is shorter than the second predetermined distance so that the second distance is equal to or greater than the second predetermined distance; Equipped with The control unit is If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, the determination unit determines whether the first distance is shorter than the first predetermined distance each time a position of the robot and a position of the person are detected; the prediction unit predicts a future position of the robot and a future position of the person every time a position of the robot and a position of the person are detected; The determination unit is if the first distance is less than the first predetermined distance, sending a second signal to the change unit; and determining whether a third distance between the position of the robot and the position of the person detected after transmitting the second signal to the change unit is shorter than the first predetermined distance, and transmitting a third signal to the change unit if the third distance is equal to or greater than the first predetermined distance; The change unit does not change the motion trajectory information after receiving the second signal until receiving the third signal. Control device.

3. A control unit that controls a movement of the robot based on movement trajectory information indicating a movement trajectory of the robot; a determination unit that determines whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a prediction unit that predicts a future position of the robot based on a position of the robot and predicts a future position of the person based on a position of the person; a change unit that determines whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and changes the movement trajectory information if the second distance is shorter than the second predetermined distance so that the second distance is equal to or greater than the second predetermined distance; Equipped with The control unit is If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, the determination unit determines whether the first distance is shorter than the first predetermined distance each time a position of the robot and a position of the person are detected; the prediction unit predicts a future position of the robot and a future position of the person every time a position of the robot and a position of the person are detected; The determination unit transmits a fourth signal to the control unit when the first distance is equal to or greater than the first predetermined distance; The control unit is When the fourth signal is received after the motion of the robot is stopped and the motion trajectory information has not been changed, the motion of the robot is resumed and the motion of the robot is controlled based on the motion trajectory information; or When the fourth signal is received after the motion speed of the robot is reduced and the motion trajectory information has not been changed, the motion speed of the robot is restored and the motion of the robot is controlled based on the motion trajectory information. Control device.

4. The control device according to claim 1 , wherein the prediction unit predicts a future position of the robot based on a plurality of positions of the robot.

5. The control device according to claim 1 , wherein the prediction unit predicts a future position of the robot based on a position of the robot and the motion trajectory information.

6. The control device according to claim 1 , wherein the prediction unit predicts a future position of the robot based on a plurality of positions of the robot and the motion trajectory information.

7. The control device according to claim 1 , wherein the prediction unit predicts a future position of the person based on a plurality of positions of the person.

8. The control device according to claim 1 , wherein the prediction unit predicts a future position of the robot and a future position of the person by machine learning.

9. A control unit that controls a motion of the robot based on motion trajectory information indicating a motion trajectory of the robot; a determination unit that determines whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a first prediction unit that predicts a future position of the robot based on a position of the robot; A second prediction unit that predicts a future location of the person based on the location of the person; a change unit that determines whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and changes the movement trajectory information if the second distance is shorter than the second predetermined distance so that the second distance is equal to or greater than the second predetermined distance; Equipped with The control unit is If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, The determination unit determines the first distance each time the position of the robot and the position of the person are detected. determining whether the distance is less than the first predetermined distance; The first prediction unit predicts a future position of the robot each time the position of the robot is detected, The second prediction unit predicts a future position of the person each time the position of the person is detected, The determination unit transmits a first signal to the control unit when the first distance is equal to or greater than the first predetermined distance; The control unit is When the first signal is received after the robot operation is stopped and the motion trajectory information is changed after the first signal is received, the robot operation is resumed and the motion of the robot is controlled based on the motion trajectory information changed after the first signal is received; or When the first signal is received after the motion of the robot is decelerated and the motion trajectory information is changed after the first signal is received, the motion speed of the robot is returned to a speed before the deceleration, and the motion of the robot is controlled based on the motion trajectory information changed after the first signal is received. Control device.

10. A control unit that controls a movement of the robot based on movement trajectory information indicating a movement trajectory of the robot; a determination unit that determines whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a first prediction unit that predicts a future position of the robot based on a position of the robot; A second prediction unit that predicts a future location of the person based on the location of the person; a change unit that determines whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and changes the movement trajectory information if the second distance is shorter than the second predetermined distance so that the second distance is equal to or greater than the second predetermined distance; Equipped with The control unit is If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, the determination unit determines whether the first distance is shorter than the first predetermined distance each time a position of the robot and a position of the person are detected; The first prediction unit predicts a future position of the robot each time the position of the robot is detected, The second prediction unit predicts a future position of the person each time the position of the person is detected, The determination unit is if the first distance is less than the first predetermined distance, sending a second signal to the change unit; and determining whether a third distance between the position of the robot and the position of the person detected after transmitting the second signal to the change unit is shorter than the first predetermined distance, and transmitting a third signal to the change unit if the third distance is equal to or greater than the first predetermined distance; The change unit does not change the motion trajectory information after receiving the second signal until receiving the third signal. Control device.

11. A control device according to any one of claims 1 to 10; The robot; The detection unit, A control system comprising:

12. The computer a control step of controlling a motion of the robot by a control unit based on motion trajectory information indicating a motion trajectory of the robot; a determining step of determining whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a prediction step of predicting a future position of the robot based on a position of the robot and predicting a future position of the person based on a position of the person; a modification step of determining whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and, if the second distance is shorter than the second predetermined distance, modifying the movement trajectory information so that the second distance is equal to or greater than the second predetermined distance; Run In the control step, If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, In the determining step, each time a position of the robot and a position of the person are detected, it is determined whether or not the first distance is shorter than the first predetermined distance; In the prediction step, a future position of the robot and a future position of the person are predicted each time a position of the robot and a position of the person are detected; If the first distance is equal to or greater than the first predetermined distance in the determining step, a first signal is transmitted to the control unit; In the control step, When the control unit receives the first signal after stopping the operation of the robot and the motion trajectory information is changed after the control unit receives the first signal, the operation of the robot is resumed, and the motion of the robot is controlled based on the motion trajectory information changed after the control unit receives the first signal; or When the control unit receives the first signal after decelerating the motion of the robot and the motion trajectory information is changed after the control unit receives the first signal, the motion speed of the robot is returned to the speed before deceleration, and the motion of the robot is controlled based on the motion trajectory information changed after the control unit receives the first signal. Control methods.

13. A computer comprising: a control step of controlling a motion of the robot based on motion trajectory information indicating a motion trajectory of the robot; a determining step of determining whether a first distance between a position of the robot and a position of a person detected by a detection unit is shorter than a first predetermined distance; a prediction step of predicting a future position of the robot based on a position of the robot and predicting a future position of the person based on a position of the person; a modifying step of determining whether a second distance between a future position of the robot and a future position of the person is shorter than a second predetermined distance, and, if the second distance is shorter than the second predetermined distance, modifying the movement trajectory information by a modifying unit so that the second distance is equal to or greater than the second predetermined distance; Run In the control step, If the first distance is shorter than the first predetermined distance, stopping or slowing down the motion of the robot regardless of whether the motion trajectory information has changed, or When the first distance is equal to or greater than the first predetermined distance and the movement trajectory information has been changed, the movement of the robot is controlled based on the changed movement trajectory information; The detection unit detects a position of the robot and a position of the person at regular or irregular intervals, In the determining step, each time a position of the robot and a position of the person are detected, it is determined whether or not the first distance is shorter than the first predetermined distance; In the prediction step, a future position of the robot and a future position of the person are predicted each time a position of the robot and a position of the person are detected; In the determining step, if the first distance is less than the first predetermined distance, sending a second signal to the change unit; and determining whether a third distance between the position of the robot and the position of the person detected after transmitting the second signal to the change unit is shorter than the first predetermined distance, and transmitting a third signal to the change unit if the third distance is equal to or greater than the first predetermined distance; In the changing step, the change unit does not change the motion trajectory information from after receiving the second signal until receiving the third signal. Control methods.

14. A program for causing a computer to execute the steps according to claim 12 or 13.

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