JP7479205B2 - ROBOT SYSTEM, CONTROL DEVICE, AND CONTROL METHOD - Google Patents

Description

The present invention relates to a robot system, a control device, and a control method.

As a technique for correcting deviation of an actual trajectory from a planned trajectory by a robot system, for example, Patent Document 1 describes a manufacturing method for an article in which a first workpiece held by a gripper of a robot is assembled to a second workpiece arranged on a mounting surface, the manufacturing method comprising: a first step of measuring deviation of an actual trajectory from a target trajectory of the gripper; a second step of determining a position and orientation of the second workpiece relative to the robot based on the deviation measured in the first step and the shape of the second workpiece; and a third step of moving the second workpiece to the position and orientation determined in the second step and having the robot perform an assembly operation.

JP 2019-93504 A

According to the technology described in Patent Document 1, the deviation between the target hand trajectory and the actual hand trajectory is measured, the position and orientation of the second workpiece are determined based on the deviation of the hand and the shape of the second workpiece, and assembly can be performed by moving the second workpiece to the determined position and orientation.

However, in reality, when the hand grasps the first workpiece, there is a deviation between the target trajectory and the actual trajectory, and there is also a deviation in the grasping position and posture due to a deviation between the simulation model and the actual machine. As a result, it may not be possible to carry out the planned assembly work by simply moving the position and posture of the second workpiece, as with the technology described in Patent Document 1.

The present invention has been made in consideration of the above points, and aims to prevent assembly work failures caused by deviations in the gripping position or posture that occur when the workpiece is actually gripped.

This application includes multiple means for solving at least some of the above problems, examples of which are as follows:

In order to solve the above problem, a robot system according to one aspect of the present invention is a robot system including a robot that performs an assembly operation of a workpiece and a control device that controls the robot, the control device being characterized by having: a motion planning unit that determines a trajectory from a start point to an end point of the operation of the robot to generate trajectory information; a grip adjustment unit that estimates an error from the planned time for at least one of the grip position, posture, and grip force of the robot when the robot actually grips the workpiece based on the trajectory information; a simulation execution unit that adjusts at least one of the grip position, posture, and grip force of the robot in a direction to eliminate the estimated error and then executes a motion simulation of the assembly operation to generate a new trajectory; and a re-grasp determination unit that determines whether the assembly operation can be performed based on whether a trajectory has been generated by the simulation execution unit.

The present invention makes it possible to prevent assembly work failures caused by misalignment of the gripping position or posture that occurs when the workpiece is actually gripped.

Problems, configurations, and advantages other than those described above will become clear from the description of the embodiments below.

FIG. 1 is a diagram showing an example of the configuration of a robot system according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining an example of a process performed by the operation planning unit. FIG. 3 is a diagram illustrating a configuration example of the grip adjustment unit. Figures 4(A) and (B) are diagrams for explaining an example of processing by the simulation execution unit and the re-grasping judgment unit, in which Fig. 4(A) shows a case in which a trajectory can be generated because the interference area is small, and Fig. 4(B) shows a case in which a trajectory cannot be generated because the interference area is large. FIG. 5 is a flowchart illustrating an example of a control process performed by the robot system of FIG. FIG. 6 is a diagram showing an example of the configuration of a robot system according to the second embodiment of the present invention. FIG. 7 is a flowchart illustrating an example of a control process performed by the robot system of FIG. FIG. 8 is a diagram showing an example of the configuration of a robot system according to the third embodiment of the present invention. FIG. 9 is a flowchart illustrating an example of a control process performed by the robot system of FIG.

In the following, several embodiments of the present invention will be described with reference to the drawings. In all the drawings for describing each embodiment, the same components are generally given the same reference numerals, and the repeated description will be omitted. In the following embodiments, the components (including element steps, etc.) are not necessarily essential, unless otherwise specified or considered to be obviously essential in principle. In addition, when it is said that "consists of A," "consists of A," "has A," or "includes A," it is needless to say that it does not exclude other elements, except when it is specifically specified that it is only that element. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc. of components, etc., it is intended to include those that are substantially similar or similar to the shape, etc., except when it is specifically specified or considered to be obviously not essential in principle.

<Configuration Example of Robot System 11 According to First Embodiment of the Present Invention>
FIG. 1 shows an example of the configuration of a robot system 11 according to a first embodiment of the present invention.

The robot system 11 includes a control device 20, a controller 30, and a robot 40.

The control device 20 controls the operation of the robot 40 via the controller 30. The control device 20 is composed of a general computer such as a personal computer equipped with a processor such as a CPU (Central Processing Unit), a memory such as an SDRAM (Static Random Access Memory), a storage such as an HDD (Hard Disc Drive) or SSD (Solid State Drive), a communication module, an input device, and a display device.

The control device 20 includes a calculation unit 21, a memory unit 22, a display unit 23, an input unit 24, and a communication unit 25.

The calculation unit 21 is realized by a computer processor. The calculation unit 21 has the following functional blocks: a motion planning unit 211, a grip adjustment unit 212, a simulation execution unit 213, a re-grasp determination unit 214, and a display control unit 218. These functional blocks are realized by the computer processor executing a predetermined program.

The motion planning unit 211 determines the trajectory that the robot 40 will take to grasp the workpiece and perform the assembly work based on the robot configuration information 221, trajectory start and end point information 222, interference object configuration information 223, and grasped object information 224 (all of which will be described later) stored in the memory unit 22, and stores the trajectory information 225 in the memory unit 22.

Figure 2 is a diagram for explaining an example of processing by the motion planning unit 211, and shows a coordinate space (hereinafter referred to as a configuration space) in which each joint angle of the robot 40 is a spatial axis. However, the configuration space in the figure shows a case in which the robot 40 has two degrees of freedom.

The motion planning unit 211 calculates the position of an interference area where surrounding structures that may interfere with the motion of the robot 40 exist, by motion simulation based on the robot configuration information 221, the interference object configuration information 223, and the grasped object information 224. The motion planning unit 211 generates multiple trajectory candidates from a start point S, which represents a state in which the robot 40 grasps a workpiece, via one or more waypoints (not shown), to an end point G, which represents a state in which the workpiece is assembled, and selects a trajectory P from the trajectory candidates that does not pass through the interference area. There are many known algorithms for generating the trajectory candidates and selecting the trajectory P, so it is sufficient to use any of them. The trajectory information generated by the motion planning unit 211 includes information representing the positions of the start point S of the motion, one or more waypoints, and the end point G, and the posture of the robot 40 at each of them.

Returning to FIG. 1, the gripping adjustment unit 212 adjusts the gripping operation of the hand unit 42 of the robot 40 on the workpiece.

Figure 3 shows a detailed configuration example of the grip adjustment unit 212. The grip adjustment unit 212 has a feature extraction unit 51, an error estimation unit 52, and a grip force adjustment unit 53.

The feature extraction unit 51 acquires sensor data representing the results detected by the tactile sensor 43 and the visual sensor 44 when the hand unit 42 grasps the workpiece, and extracts the feature values. The error estimation unit 52 inputs the extracted feature values into the trained model 226, thereby estimating the error between the planned state and the actual state when the workpiece is grasped by the hand unit 42 for at least one of the grasping position, the grasping posture, and the grasping force of the workpiece.

Here, the gripping position is represented, for example, by a position vector on the Cartesian coordinate system when the hand unit 42 grips the workpiece. The gripping posture is represented by the rotation (roll, pitch, yaw) of the hand unit 42 around the Cartesian coordinate system axis when gripping the workpiece. The gripping force is represented by the rotation angle of the joint that controls the degree of opening and closing of the hand unit 42.

The gripping force adjustment unit 53 adjusts the gripping force of the gripping operation performed on the workpiece by the hand unit 42 of the robot 40.

Returning to FIG. 1, the simulation execution unit 213 adjusts at least one of the current position, posture, and gripping force of the hand unit 42 in a direction that eliminates the error estimated by the error estimation unit 52. Specifically, the simulation execution unit 213 moves the gripping position of the workpiece by the hand unit 42, or changes the posture or gripping force. Note that the adjustment of the hand unit 42 to eliminate the error may be performed by actually operating the hand unit 42, or may be performed as a simulation without operating the hand unit 42. Furthermore, the simulation execution unit 213 executes a simulation similar to that of the motion planning unit 211, assuming that the hand unit 42 has been adjusted, to search for a trajectory from the start point to the end point of the assembly work.

The re-gripping determination unit 214 determines whether or not the assembly work can be performed by re-gripping after adjusting at least one of the position, posture, and gripping force of the hand unit 42 based on the simulation results by the simulation execution unit 213. If it is determined that the assembly work can be performed by re-gripping, the re-gripping determination unit 214 generates a control target value for adjusting the hand unit 42 in a direction that eliminates the error. This control target value is transmitted to the controller 30 by the communication unit 25.

Figure 4 is a diagram for explaining an example of processing by the simulation execution unit 213 and the re-grasping judgment unit 214, showing the configuration space of the robot 40. Figure (A) shows a trajectory in the configuration space after the hand unit 42 is adjusted in a direction that eliminates the error when it is judged that assembly is possible by re-grasping. Here, the starting point S represents the combination of each joint angle of the robot 40 after adjustment. The end point G is the same position as when planned by the motion planning unit 211.

Note that the start point S after adjustment is different from the start point S at the time of planning by the motion planning unit 211 (Figure 2), and therefore the interference region is also different from that at the time of planning (Figure 2). Figure (A) shows a case where the amount of adjustment is relatively small, resulting in a small change in the interference region, and a trajectory P from the start point S to the end point G can be generated without passing through the interference region. On the other hand, Figure (B) shows a case where the amount of adjustment is relatively large, resulting in a large change in the interference region, and therefore a trajectory from the start point S to the end point G cannot be generated without passing through the interference region.

Returning to FIG. 1, the display control unit 218 controls various displays on the display unit 23.

The memory unit 22 is realized by the memory and storage of a computer. The memory unit 22 stores robot configuration information 221, trajectory start point/end point information 222, interference object configuration information 223, grasp target object information 224, trajectory information 225, and learned model 226.

The robot configuration information 221 is information including the shapes and connection states of the arm unit 41 and hand unit 42 that constitute the robot 40. Specifically, it is 3D CAD (Computer Aided Design) data and URDF (Unified Robot Description Format) data of the robot 40. The robot configuration information 221 is stored in advance in the memory unit 22.

The trajectory start point/end point information 222 is information that represents the coordinates and posture of the start point, intermediate point, and end point of the movement of the robot 40. The trajectory start point/end point information 222 is, for example, input in advance by the user and stored in the memory unit 22.

The interference object configuration information 223 is information on structures present around the robot 40 that may interfere with the operation of the robot 40. Specifically, it is, for example, 3D CAD data of jigs used in assembly and stalls around the robot 40. The interference object configuration information 223 is stored in advance in the memory unit 22.

The grasp target information 224 is information that represents the shape of the workpiece to be grasped. Specifically, it is 3D CAD data of the workpiece, etc. The grasp target information 224 is stored in advance in the memory unit 22.

The trajectory information 225 is information that represents the time series changes in the combination of each joint angle of the robot 40. The trajectory information 225 is generated by the motion planning unit 211 and stored in the memory unit 22.

The trained model 226 is a machine learning model such as a neural network. The trained model 226 has learned the relationship between the feature amounts of sensor data from the tactile sensor 43 and the visual sensor 44 in a past gripping operation of a certain workpiece, and the error between the planned and actual gripping position, posture, and gripping force when the hand unit 42 grips the workpiece. The trained model 226 takes the feature amounts of the sensor data as input, and outputs the error between the planned and actual gripping position, posture, and gripping force. The trained model 226 is stored in advance in the memory unit 22.

The display unit 23 is realized by a computer display device. The display unit 23 displays, for example, a screen such as a GUI (Graphical User Interface) that allows the user to input various information, shows the operating status of the robot 40, and notifies the user that the robot 40 is unable to perform the assembly work as planned.

The input unit 24 is realized by an input device of a computer. The input unit 24 accepts various input operations from the user.

The communication unit 25 is realized by a communication module of a computer. The communication unit 25 connects to the controller 30 via a network (not shown) such as the Internet or a mobile phone communication network, and communicates various types of data.

The controller 30 performs assembly work by operating the arm unit 41 and hand unit 42 that constitute the robot 40 according to the control input from the control device 20.

The robot 40 has an arm unit 41, a hand unit 42, a tactile sensor 43, and a visual sensor 44. The robot 40 operates the arm unit 41 and the hand unit 42 according to the control from the controller 30.

The arm unit 41 is a structure that supports the hand unit 42, and is a movable part of the robot 40. The hand unit 42 is an end effector such as a gripper. The tactile sensor 43 is installed on the hand unit 42. The tactile sensor 43 detects the shape and stress of the contact surface between the gripping surface of the hand unit 42 and the workpiece. The visual sensor 44 is installed somewhere on the robot 40. The visual sensor 44 is, for example, a camera, and detects workpieces, obstructions, etc. that exist around the robot 40. Note that the visual sensor 44 may be installed in a location other than the robot 40 (for example, the ceiling, etc.) as long as it can detect workpieces, obstructions, etc. that exist around the robot 40.

Next, FIG. 5 is a flowchart illustrating an example of robot control processing by the robot system 11.

The robot control process is started, for example, in response to a predetermined operation by the user. First, the motion planning unit 211 determines the trajectory that the robot 40 will take to grasp the workpiece and perform the assembly work based on the robot configuration information 221, trajectory start and end point information 222, interference object configuration information 223, and grasped object information 224 stored in the memory unit 22, and generates trajectory information 225 and stores it in the memory unit 22 (step S1).

Next, the grip adjustment unit 212 refers to the trajectory information 225 and causes the robot 40 to actually grip the workpiece (step S2). Specifically, the grip adjustment unit 212 controls the controller 30 via the communication unit 25 to cause the robot 40 to perform the gripping operation.

Next, the feature extraction unit 51 of the grip adjustment unit 212 acquires sensor data detected by the tactile sensor 43 and the visual sensor 44 when the robot 40 is performing a gripping operation from the controller 30 and extracts features (step S3).

Next, the error estimation unit 52 inputs the extracted features into the trained model 226 to estimate the error between the planned and actual gripping position, gripping posture, and gripping force of the workpiece by the hand unit 42 (step S4).

Next, the simulation execution unit 213 executes a simulation similar to that of the motion planning unit 211, which is based on the assumption that the hand unit 42 is adjusted in a direction that eliminates the estimated error, and searches for a trajectory that reaches the end point from the changed starting point without passing through the interference area (step S5).

Next, the re-gripping determination unit 214 determines whether the assembly work is possible based on whether a trajectory has been searched for based on the results of the simulation performed by the simulation execution unit 213 (step S6). If it is determined that the assembly work is possible because a trajectory has been searched for (YES in step S6), the re-gripping determination unit 214 generates a control target value for adjusting the hand unit 42 in a direction that eliminates the error, and transmits this to the controller 30 via the communication unit 25, thereby causing the robot 40 to perform the workpiece gripping operation again (step S7).

Next, the grip adjustment unit 212 controls the controller 30 via the communication unit 25 to operate the robot 40 along the trajectory that was searched for in step S5 and that was determined to be suitable for assembly work in step S6 (step S8). This ends the robot control process.

On the other hand, if the re-grasp determination unit 214 determines that the assembly work cannot be performed because the trajectory could not be found (NO in step S6), the display control unit 218 causes the display unit 23 to display an alert screen indicating that the assembly work cannot be performed (step S9). This ends the robot control process.

According to the robot control process by the robot system 11 described above, even if a shift in the gripping position or posture occurs when gripping a workpiece, a simulation is performed to determine whether or not re-gripping and assembly is possible, thereby making it possible to improve the success rate of assembly work.

<Configuration Example of Robot System 12 According to Second Embodiment of the Present Invention>
Next, FIG. 6 shows an example of the configuration of a robot system 11 according to a second embodiment of the present invention.

The robot system 12 is obtained by adding a threshold determination unit 215 as a functional block of the calculation unit 21 of the robot system 11 (FIG. 1), and adding error threshold information 227 as information stored in the memory unit 22. Among the components of the robot system 12, those that are common to the components of the robot system 11 are given the same reference numerals and their description is omitted.

The threshold determination unit 215 refers to the error threshold information 227, which represents the thresholds of the allowable errors of the gripping position, gripping posture, and gripping force set for each workpiece, and determines whether the error estimated by the error estimation unit 52 is equal to or smaller than the threshold.

Next, FIG. 7 is a flowchart illustrating an example of robot control processing by the robot system 12.

The robot control process is started, for example, in response to a predetermined operation by the user. Note that the processes in steps S11 to S14 are similar to the processes in steps S1 to S4 in the robot control process by the robot system 11 (FIG. 5), and therefore a description thereof will be omitted.

After the error is estimated in step S14, the threshold determination unit 215 then refers to the error threshold information 227 and determines whether the estimated error is equal to or less than the threshold (step S15). If it is determined that the estimated error is not equal to or less than the threshold (NO in step S15), the simulation execution unit 213 executes a simulation similar to that of the motion planning unit 211 on the premise that the hand unit 42 has been adjusted in a direction that eliminates the estimated error, and searches for a trajectory that reaches the end point from the changed starting point without passing through the interference area (step S16).

Next, the re-gripping determination unit 214 determines whether or not the assembly work is possible based on whether or not a trajectory has been found based on the results of the simulation performed by the simulation execution unit 213 (step S17). If it is determined that the assembly work is possible because a trajectory has been found (YES in step S17), the re-gripping determination unit 214 generates a control target value for adjusting the hand unit 42 in a direction that eliminates the error, and transmits this to the controller 30 via the communication unit 25, thereby causing the robot 40 to perform the workpiece gripping operation again (step S18). After this, the process returns to step S13, and steps S13 and onward are repeated.

On the other hand, if the re-grasp determination unit 214 determines that the assembly work cannot be performed because the trajectory could not be found (NO in step S17), the display control unit 218 causes the display unit 23 to display an alert screen indicating that the assembly work cannot be performed (step S19). This ends the robot control process.

If the threshold determination unit 215 determines that the estimated error is equal to or less than the threshold (YES in step S15), no further error adjustment is required, and the grip adjustment unit 212 controls the controller 30 via the communication unit 25 to operate the robot 40 along the latest trajectory (step S20). This ends the robot control process.

According to the robot control process by the robot system 12 described above, except when the trajectory cannot be searched, the re-gripping operation and trajectory search are repeated until the estimated error falls below the threshold value, which makes it possible to further improve the success rate of the assembly work compared to the first embodiment.

<Configuration Example of Robot System 13 According to Third Embodiment of the Present Invention>
Next, FIG. 8 shows an example of the configuration of a robot system 13 according to a third embodiment of the present invention.

The robot system 13 is a robot system 11 (FIG. 1) to which an interference identification unit 216 has been added as a functional block of the calculation unit 21. Among the components of the robot system 13, the components common to the components of the robot system 11 are given the same reference numerals and their description is omitted.

When the re-gripping determination unit 214 determines that the assembly work is impossible because the trajectory after re-gripping could not be found, the interference identification unit 216 identifies the interference that caused the trajectory to be unable to be searched for, and outputs the information to the display control unit 218. The display control unit 218 causes the display unit 23 to display the position, shape, etc. of the interference, for example, by using a character string or an image.

Next, FIG. 9 is a flowchart illustrating an example of robot control processing by the robot system 13.

The robot control process is started, for example, in response to a predetermined operation by the user. Note that the processes in steps S31 to S38 are similar to the processes in steps S1 to S8 in the robot control process by the robot system 11 (FIG. 5), and therefore will not be described here.

In step S36, if the re-grasp judgment unit 214 judges that the assembly work is impossible (NO in step S36), the interference object identification unit 216 identifies the interference object that caused the trajectory to be unable to be searched and outputs the information to the display control unit 218, and the display control unit 218 displays the position, shape, etc. of the interference object on the display unit 23, for example, by using a character string or an image (step S39).

Next, the display control unit 218 causes the display unit 23 to display an alert screen indicating that the assembly work cannot be performed (step S40). This ends the robot control process.

The robot control process by the robot system 13 described above can achieve the same effects and advantages as the robot control process by the robot system 11 (FIG. 5). Furthermore, the robot control process by the robot system 13 allows the user to identify any obstructions that are impeding the trajectory, making it easier for the user to plan countermeasures, such as moving the obstructions.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to having all of the configurations described. Also, it is possible to replace part of the configuration of one embodiment with or add to the configuration of another embodiment. Note that an interference object identification unit 216 may be added to the robot system 12 (Figure 6).

In addition, the above-mentioned configurations, functions, processing units, processing means, etc. may be realized in part or in whole in hardware, for example by designing them as integrated circuits. In addition, the above-mentioned configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. Information such as programs, tables, files, etc. that realize each function can be stored in memory, a recording device such as a hard disk or SSD, or a recording medium such as an IC card, SD card, or DVD. In addition, the control lines and information lines shown are those that are considered necessary for explanation, and do not necessarily show all control lines and information lines in the product. In reality, it can be considered that almost all configurations are connected to each other.

11-13: Robot system, 20: Control device, 21: Calculation unit, 211: Motion planning unit, 212: Grasping adjustment unit, 213: Simulation execution unit, 214: Re-grasping judgment unit, 215: Threshold judgment unit, 216: Interference object identification unit, 218: Display control unit, 22: Storage unit, 221: Robot configuration information, 222: Trajectory start point/end point information, 223: Interference object configuration information, 224: Grasping object information, 225: Trajectory information, 226: Learned model, 227: Error threshold information, 23: Display unit, 24: Input unit, 25: Communication unit, 30: Controller, 40: Robot, 41: Arm unit, 42: Hand unit, 43: Tactile sensor, 44: Visual sensor, 51: Feature extraction unit, 52: Error estimation unit, 53: Grasping force adjustment unit

Claims (9)

A robot system including a robot that performs an assembly operation of a workpiece and a control device that controls the robot,
The control device includes:
A motion planning unit that determines a trajectory of the motion of the robot from a start point representing a state in which the workpiece is gripped in a configuration space to an end point representing a state in which the workpiece is assembled, and generates trajectory information;
a grip adjustment unit that estimates an error at the starting point from a planned time for at least one of a grip position, a posture, and a grip force of the hand unit of the robot when the hand unit of the robot actually grips the workpiece based on the trajectory information ;
a simulation execution unit that adjusts at least one of a gripping position, an attitude, and a gripping force of the hand unit in a direction to eliminate the estimated error, and generates a new trajectory from a start point changed by the adjustment to the end point ;
a re-grasp determination unit that determines whether or not the assembly work can be performed based on whether or not the new trajectory has been generated by the simulation execution unit. The robot system according to claim 1 ,
the simulation execution unit generates the new trajectory from the starting point changed by the adjustment to the end point without passing through an interference area that is different from that at the time of the plan due to the adjustment . The robot system according to claim 1 ,
the robot has at least one of a tactile sensor and a visual sensor;
the grip adjustment unit estimates the error of the hand unit based on sensor data output by at least one of the tactile sensor and the visual sensor. The robot system according to claim 3,
the grip adjustment unit estimates the error by using a learning model that receives a feature of the sensor data as an input and outputs the error. The robot system according to claim 1 ,
The control device includes:
a display control unit that causes a result of the determination made by the re-gripping determination unit as to whether or not the assembly work can be completed to be displayed on a display unit. The robot system according to claim 1 ,
The control device includes:
a threshold determination unit that determines whether the estimated error is equal to or smaller than a predetermined threshold,
the simulation execution unit and the re-grasp determination unit repeatedly execute their respective processes when the threshold determination unit determines that the error is not equal to or less than a predetermined threshold. The robot system according to claim 1 ,
The control device includes:
an interference identifying unit that identifies an interference that has hindered the simulation execution unit from generating a trajectory when the re-gripping determination unit determines that the assembly work is impossible because the simulation execution unit has not generated a trajectory; and
a display control unit that causes information regarding the identified interfering object to be displayed on a display unit;
A robot system comprising: A control device for controlling a robot that performs an assembly operation of a workpiece,
A motion planning unit that determines a trajectory of the motion of the robot from a start point representing a state in which the workpiece is gripped in a configuration space to an end point representing a state in which the workpiece is assembled, and generates trajectory information;
a grip adjustment unit that estimates an error at the starting point from a planned time for at least one of a grip position, a posture, and a grip force of the hand unit of the robot when the hand unit of the robot actually grips the workpiece based on the trajectory information ;
a simulation execution unit that adjusts at least one of a gripping position, an attitude, and a gripping force of the hand unit in a direction to eliminate the estimated error, and generates a new trajectory from a start point changed by the adjustment to the end point ;
a re-gripping determination unit that determines whether or not the assembly work can be performed based on whether or not the new trajectory has been generated by the simulation execution unit;
A control device comprising: A control method by a control device that controls a robot that performs an assembly operation of a workpiece, comprising:
Determining a trajectory of the operation of the robot from a start point representing a state in which the workpiece is gripped in a configuration space to an end point representing a state in which the workpiece is assembled, and generating trajectory information;
estimating an error at the starting point from a planned time for at least one of a gripping position, a posture, and a gripping force of the hand unit when the hand unit of the robot actually grips the workpiece based on the trajectory information;
adjusting at least one of the grip position, the attitude, and the grip force of the hand unit in a direction to eliminate the estimated error, and generating a new trajectory from the start point changed by the adjustment to the end point ;
a step of determining whether or not the assembly work can be performed based on whether or not the new trajectory has been generated.

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