Robotic system and robot control device

Abstract

In force control at the time of production, optimal force control parameters that do not cause oscillation of a robot, work failure can be automatically adjusted. A robot arm has a hand that holds a workpiece at a front end of the robot arm; a force detector that detects a force and a moment that the workpiece held by the hand receives; and a control device that moves the workpiece held by the hand relative to a target object while performing force control of the robot arm based on a prescribed force control parameter and a detection value of the force detector to correct a positional error and a posture error of the workpiece. The control device has a parameter automatic adjustment section that automatically adjusts the force control parameter by performing movement of the workpiece relative to the target object a plurality of times. The parameter automatic adjustment section automatically adjusts the force control parameter by performing movement of the workpiece relative to the target object from at least a plurality of posture error directions among a plurality of positional error directions and a plurality of posture error directions.

Description

Technical Field

[0001] This disclosure relates to a robot system and a robot control device. Background Technology

[0002] In the assembly process of components using robots, the workpiece held by the end of the robot arm undergoes fitting, alignment, and searching operations. Fitting involves inserting the held workpiece into the fitting hole of the target object. Alignment involves bringing the held workpiece into contact with the plane of the target object. Searching involves locating the held workpiece in a way that aligns it with the shape and phase of the holes in the target object.

[0003] Previously, to perform robot-driven component assembly operations with high precision, force detectors were installed in the robot arm to detect the forces and torques acting on the workpiece held by the hand. During assembly, the robot's force control was based on the detection values ​​of these force detectors to ensure that the force applied to the workpiece matched the target force set by the operator. Types of force control known include impedance control, damping control, and hybrid control.

[0004] In order for a robot to perform tasks appropriately through force control, it is important to properly set force control parameters that determine the relationship between the force applied to the workpiece and the robot's behavior. In recent years, a technique for automatically adjusting force control parameters by automatically performing force control multiple times has also been known (see, for example, Patent Document 1).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2014-128857 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, sometimes even after automatic adjustment of the force control parameters, the adjusted parameters are not optimal. This is believed to be because the force control conditions differ between when adjusting the force control parameters and during actual production, resulting in different directions of error in the robot's position and posture.

[0010] Furthermore, the optimal value of the force control gain, which represents the responsiveness of force control, sometimes depends on the direction of position and posture correction, depending on factors such as the robot's position and posture. Therefore, if the force control parameters are adjusted to accommodate high position and posture errors, the robot may oscillate during production. If the robot oscillates, it can potentially affect product quality. In the worst-case scenario, the robot itself, its hand, and peripheral equipment may be damaged.

[0011] Furthermore, for the search operation, when adjusting the force control parameters, it is necessary to verify whether the correct position and posture can be found using multiple position and posture error conditions. If this verification is not performed using multiple error conditions during production, the search may fail during production.

[0012] Therefore, in force control during production, it is desirable to automatically adjust to obtain the optimal force control parameters that will not cause robot oscillation or operation failure.

[0013] Solution for solving the problem

[0014] One aspect of this disclosure is a robot system comprising: a robot arm having a hand at its forehead for grasping a workpiece; a force detector for detecting the force and torque acting on the workpiece grasped by the hand; and a control device that, while performing force control of the robot arm based on predetermined force control parameters and the detection values ​​of the force detector to correct position and posture errors of the workpiece, moves the workpiece grasped by the hand relative to a target object, wherein the control device has an automatic parameter adjustment unit that automatically adjusts the force control parameters by repeatedly executing the movement of the workpiece relative to the target object, the automatic parameter adjustment unit automatically adjusting the force control parameters by executing the movement of the workpiece relative to the target object from at least one of a plurality of position error directions and a plurality of posture error directions.

[0015] Another aspect of this disclosure is a robot control device that controls the movement of a robot arm with a hand at its front end that holds a workpiece to move the workpiece toward a target object. The robot arm's force control is based on predetermined force control parameters and force detector values ​​to correct positional and posture errors of the workpiece relative to the target object. The force detector detects the force and torque acting on the workpiece held by the hand. The robot control device includes an automatic parameter adjustment unit that automatically adjusts the force control parameters by repeatedly executing the movement of the workpiece relative to the target object. The automatic parameter adjustment unit automatically adjusts the force control parameters by executing the movement of the workpiece relative to the target object from at least one of multiple positional error directions and multiple posture error directions.

[0016] The effects of the invention

[0017] According to one method, during force control in production, the optimal force control parameters can be automatically adjusted to avoid causing robot oscillations or operational failures. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing a robot system performing interlocking operations.

[0019] Figure 2 This is a functional block diagram showing the internal structure of the robot and its control device.

[0020] Figure 3 This is a flowchart showing the automatic adjustment process of force control parameters.

[0021] Figure 4 This is a side view showing the posture error between the workpiece and the target object when the force control parameters are automatically adjusted.

[0022] Figure 5A It is shown Figure 4 The top view shows the posture error between the workpiece and the target object.

[0023] Figure 5B This shows that the orientation error direction is relative to... Figure 5A The top view of the workpiece and target object was changed by 90 degrees.

[0024] Figure 5C This shows that the orientation error direction is relative to... Figure 5A The top view of the workpiece and target object was changed by 180 degrees.

[0025] Figure 5D This shows that the orientation error direction is relative to... Figure 5AThe top view of the workpiece and target object was changed by 270 degrees.

[0026] Figure 6 This is a side view showing the positional error between the workpiece and the target object when the force control parameters are automatically adjusted.

[0027] Figure 7 This is a schematic diagram illustrating a robotic system performing a face-alignment operation.

[0028] Figure 8 This is a schematic diagram showing a robotic system performing a search operation. Detailed Implementation

[0029] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Figure 1 This is a schematic diagram showing a robot system 1 performing interlocking operations. The robot system 1 includes a robot 2, a robot control device 3 for controlling the robot 2, and a teach pendant 4 for an operator to manually operate the robot 2 via the robot control device 3.

[0030] Robot 2 is a vertical multi-joint robot with multiple robotic arms 21. The multiple robotic arms 21 are rotatably connected via multiple drive axes. The drive axes are controlled by actuators 24 (see reference 3) controlled by the robot control unit 3. Figure 2 The actuators 24, consisting of servo motors, are driven to rotate. A hand 22 and a force detector 23 are mounted at the front end of the robot arm 21.

[0031] Hand 22 holds the workpiece by drive control via robot control device 3. In the fitting operation, the workpiece consists of workpiece W1 held by hand 22 and workpiece W2 on worktable 100. Workpiece W1 has, for example, a cylindrical shape. Workpiece W2 is the target object into which workpiece W1 is fitted by the action of robot 2. Workpiece W2 has a cylindrical fitting hole MH that allows workpiece W1 to fit. Workpiece W2 is placed on worktable 100 with the opening of fitting hole MH facing upward.

[0032] Force detector 23 is positioned near the base of hand 22. Force detector 23 detects the force and torque acting on the workpiece W1 held by hand 22. Specifically, force detector 23 is composed of a force sensor. More specifically, force detector 23 can use a 6-axis sensor capable of detecting translational forces in the X, Y, and Z axes, as well as torques about these axes. The detection values ​​of force detector 23 are output to the control unit 31 of robot control device 3.

[0033] like Figure 2As shown, the robot control device 3 is configured to include a control unit 31, an arm drive unit 32, an automatic parameter adjustment unit 33, and a storage unit 34. In addition to the general functions of a control device for controlling the motion of the robot 2, the robot control device 3 also includes the functions of a control device for automatically adjusting force control parameters. In this specification, the function for automatically adjusting force control parameters in the robot control device 3 will be described, while detailed descriptions of the general functions for controlling the motion of the robot 2 will be omitted.

[0034] The control unit 31 is a control device that outputs movement commands based on the prescribed operation to the arm drive unit 32 to control the movement of the robot 2. The control unit 31 controls the force of the robot arm 21 based on the prescribed force control parameters stored in the storage unit 34 and the detection value of the force detector 23 to correct the position and posture errors of the workpiece W1 held by the hand 22, while moving the workpiece W1 relative to the workpiece W2.

[0035] The arm drive unit 32 applies driving current to the actuators 24 of each drive axis of the robot 2 based on movement commands from the control unit 31. As a result, each robot arm 21 of the robot 2 is driven, and the robot 2 changes various postures. Figure 2 As shown, robot 2 has a torque sensor 25 for detecting the torque of actuator 24. The torque sensor 25 outputs the detected torque value of actuator 24 to force detector 23. Figure 2 Only one actuator 24 and one torque sensor 25 are shown in the diagram. However, combinations of actuators 24 and torque sensors 25 are respectively arranged on multiple drive axes of robot 2.

[0036] The automatic parameter adjustment unit 33 controls the movement of the robot 2 via the control unit 31 to automatically adjust the force control parameters. The force control parameters include force control gain, speed command value, and force command value, which represent the responsiveness of the robot 2's force control. The automatically adjusted force control parameters overwrite the force control parameters (initial parameters) stored in the storage unit 34. Details of the specific adjustment actions of the force control parameters performed by the automatic parameter adjustment unit 33 will be described later.

[0037] The teach pendant 4 is connected to the control unit 31 of the robot control device 3. The teach pendant 4 allows the operator to manually instruct various actions, such as reproducing the robot 2's motion program, teaching the robot 2 via jog operation, and automatically adjusting force control parameters. Figure 2 In this system, the teaching control panel 4 is connected to the control unit 31 via a wired connection, but it can also be connected wirelessly.

[0038] Next, based on Figure 3 The flowchart shown Figure 4 and Figures 5A to 5D To further explain the automatic adjustment of force control parameters performed by the parameter automatic adjustment unit 33 of the robot control device 3. The automatic adjustment of force control parameters performed by the parameter automatic adjustment unit 33 shown below is performed, for example, when the robot system 1 is initially started, when the type of workpiece is changed, and when the hand 22 at the front end of the robot arm 21 is replaced with a hand with a different structure, by instructions from the operator via the teach pendant 4.

[0039] First, the control unit 31 executes multiple times, according to the prescribed automatic parameter adjustment process performed by the automatic parameter adjustment unit 33, the action of moving the workpiece W1 held by the hand 22 relative to the workpiece W2, which is the target object, to fit the workpiece W1 into the fitting hole MH of the workpiece W2. Specifically, when the robot 2 is moved by the operator manually operating the teaching pendant 4, the automatic parameter adjustment unit 33 reads the initial parameters of the force control parameters from the storage unit 34. Based on these initial parameters, the control unit 31 outputs a movement command to the arm drive unit 32 to execute the first fitting action (step S1) in which the robot 2 moves to fit the workpiece W1 held by the hand 22 into the fitting hole MH of the workpiece W2.

[0040] Figure 4 This is a side view showing the state in which the workpiece W1 held by hand 22 is about to be fitted into the fitting hole MH of workpiece W2 through force control of robot 2 based on initial parameters. Figure 5A This is a top view of the current state. For example... Figure 4 and Figure 5A As shown, when force control is applied to robot 2 based on initial parameters, robot 2 exhibits a posture in which workpiece W1 is tilted relative to the mating hole MH. Specifically, the axis W1a of workpiece W1 is tilted relative to the axis W2a of the mating hole MH of workpiece W2 around the Y-axis in the -X-axis direction. Figure 4 and Figure 5A The angle E1 is tilted to the left.

[0041] In order for workpiece W1 to fit properly into the fitting hole MH, robot 2 needs to exhibit an orientation that aligns the axis W1a of workpiece W1 with the axis W2a of fitting hole MH. Therefore, angle E1 represents the orientation error that robot 2 should correct at the start of fitting. This angle E1 is the amount of change in robot 2's orientation required to properly fit workpiece W1 into fitting hole MH, i.e., the correction amount (E) for the orientation error.

[0042] Here, when the rotation matrix representing the robot posture at the start of engagement is set as TA, and the rotation matrix representing the robot posture after engagement is set as TB, inv(TB)×TA is the rotation matrix representing the correction amount (E) of the posture error. inv is the inverse matrix. The parameter automatic adjustment unit 33 calculates the correction amount (E) of the posture error and stores it in the storage unit 34 (step S2).

[0043] Furthermore, a threshold for the correction amount of posture error is preset in the parameter automatic adjustment unit 33. If the absolute value of the posture error correction amount (E) calculated in step S2 is below the threshold, the parameter automatic adjustment unit 33 sets the posture error correction amount (E) to a predetermined value. This is because a posture error is intentionally assigned when there is no posture error or when the posture error is too small. The predetermined value is, for example, the threshold. That is, if the threshold is set to 0.5 degrees, and the posture error correction amount calculated in step S2 is below 0.5 degrees, the posture error correction amount (E) is set to 0.5 degrees.

[0044] Next, the control unit 31, at the same position as when the first engagement action was performed, changes the direction of the posture error according to the same absolute value as the correction amount (E) of the posture error of the robot 2, and then performs the second engagement action (step S3).

[0045] In step S3, the automatic parameter adjustment unit 33 performs engagement based on the posture represented by the rotation matrix TB×T(90)×inv(TB)×TA. T(90) is a matrix that rotates 90 degrees relative to the first engagement action about the engagement direction (about the axis W2a of the engagement hole MH). Thus, as Figure 5B As shown, robot 2 moves from the axis W1a of workpiece W1 relative to the axis W2a of the mating hole MH of workpiece W2 around the X-axis and +Y-axis direction. Figure 5B The lower direction) is tilted at an angle E1 for fitting.

[0046] Next, at the same position as when the second engagement action was performed, the control unit 31 changes the direction of the posture error again based on the same absolute value as the correction amount (E) of the posture error of the robot 2, and then performs the third engagement action (step S4).

[0047] In step S4, the automatic parameter adjustment unit 33 performs engagement based on the posture represented by the rotation matrix TB×T(180)×inv(TB)×TA. T(180) is a matrix that rotates 180 degrees relative to the first engagement action about the engagement direction (about the axis W2a of the engagement hole MH). Thus, as Figure 5C As shown, robot 2 moves from the axis W1a of workpiece W1 relative to the axis W2a of the mating hole MH of workpiece W2, around the Y-axis and +X-axis direction. Figure 5C The position is tilted at an angle E1 to the right for fitting.

[0048] Next, at the same position as when the third engagement action was performed, the control unit 31 changes the direction of the posture error again based on the same absolute value as the correction amount (E) of the posture error of the robot 2, and then performs the fourth engagement action (step S5).

[0049] In step S5, the automatic parameter adjustment unit 33 performs engagement based on the posture represented by the rotation matrix TB×T(270)×inv(TB)×TA. T(270) is a matrix that rotates 270 degrees relative to the first engagement action about the engagement direction (about the axis W2a of the engagement hole MH). Thus, as Figure 5D As shown, robot 2 moves from the axis W1a of workpiece W1 relative to the axis W2a of the mating hole MH of workpiece W2 around the X-axis and the Y-axis direction. Figure 5D The upper direction is tilted at an angle E1 for fitting.

[0050] In each engagement action from the first engagement action to the fourth engagement action, the parameter automatic adjustment unit 33 records the detection value output from the force detector 23 via the control unit 31. After the engagement action in the four directions (four postures) is completed, the parameter automatic adjustment unit 33 calculates the vibration amount based on the detection value of the force detector 23 during each engagement action, and selects the direction (posture) with the largest data fluctuation of the detection value (step S6).

[0051] One method for determining the amount of vibration is to perform a Fourier transform on the detected value of the force detector 23 and determine the amplitude at a specific frequency based on the result. Alternatively, the amount of vibration can be determined by finding the maximum or average value of the change in the detected value of the force detector 23.

[0052] In step S6, the automatic parameter adjustment unit 33 selects the direction (posture) with the largest fluctuation in the data detected by the force detector 23, calculates the force control parameters 1 to N obtained by adjusting the posture error using only that direction (posture) (step S7), and changes each force control parameter to improve performance (step S8). N is the number of types of force control parameters. The types of force control parameters include force control gain, speed command value, force command value, etc. The force control parameters can be adjusted either by each type of parameter or by multiple types of parameters simultaneously.

[0053] After the force control parameters are changed in step S8, the control unit 31, based on the posture error of the direction (posture) with the greatest fluctuation in the four directions (four postures) of the fitting action, makes the robot 2 move again in a way that makes the workpiece W1 fit into the fitting hole MH of the workpiece W2 (step S9).

[0054] When force control parameters are excessively altered to improve force control performance, it can easily lead to instability in robot 2, such as increased vibration. For example, increasing the force control gain speeds up the response to the generated force, thus accelerating the correction of posture errors during engagement and reducing the engagement time. Conversely, excessively increasing the force control gain can sometimes amplify noise and cause robot 2 to oscillate. Therefore, after performing the engagement operation in step S9, the parameter automatic adjustment unit 33 calculates the vibration amount based on the detection value of the force detector 23 using the method described above, and determines whether robot 2 has oscillated (step S10). Furthermore, whether robot 2 has oscillated can be determined by whether the vibration amount is larger than the vibration amount during the previous parameter automatic adjustment, or whether it exceeds a preset vibration amount threshold.

[0055] In step S10, if it is determined that robot 2 is not oscillating (step S10: "No"), the automatic parameter adjustment unit 33 returns to the processing from step S8. That is, the automatic parameter adjustment unit 33 changes the force control parameters to further improve their performance, and then performs the engagement action again based on the posture error with the largest fluctuation. Then, in step S10, it is determined again whether robot 2 is oscillating. The processing of steps S8 and S9 is repeated until it is determined in step S10 that robot 2 is oscillating.

[0056] On the other hand, in step S10, if it is determined that the robot 2 has oscillated (step S10: "Yes"), the parameter automatic adjustment unit 33 returns the changed force control parameter to the previous value (step S11).

[0057] Therefore, the force control parameters are set to the limit value at which the robot 2 does not oscillate. After the parameter automatic adjustment unit 33 outputs the set force control parameters to the storage unit 34 and overwrites and saves them, the automatic adjustment operation of the force control parameters ends.

[0058] In the case of a vertical multi-joint robot like Robot 2, the vibration situation varies depending on the direction of motion. Furthermore, depending on the shape of the hand 22 located at the tip of the robot arm 21, there are sometimes movements prone to vibration. When Robot 2 vibrates, the performance of force control changes. However, as described above, in this robot system 1, the automatic parameter adjustment unit 33 automatically adjusts the force control parameters by moving the workpiece W1 from multiple posture error directions. The automatic parameter adjustment unit 33 adjusts the force control parameters based on the posture error with the largest fluctuation among the multiple posture error directions. Therefore, Robot 2 performs the fitting action based on force control parameters that enable stable fitting action even under the most severe posture error conditions, and thus, it can also stably perform the fitting action under other less severe posture error conditions. Therefore, according to this robot system 1 and robot control device 3, optimal force control parameters that do not cause oscillation of Robot 2 or failure of the fitting operation can be automatically adjusted during production force control.

[0059] The robotic arm 21 includes: an actuator 24 for driving the robotic arm 21; and a torque sensor 25 for detecting the torque of the actuator 24. A force detector 23 detects the force and torque acting on the workpiece W1 based on the detection value from the torque sensor 25. Therefore, the force and torque acting on the workpiece W1 can be easily detected based on the torque of the actuator 24.

[0060] Furthermore, the force detector 23 can also detect the force and torque acting on the workpiece W1 based on the current value applied to the actuator 24. Therefore, the torque sensor 25 is not required, thus simplifying the structure of the robot 2.

[0061] In the above embodiment, the automatic parameter adjustment unit 33 automatically adjusts the force control parameters by moving the workpiece W1 from multiple orientation error directions. However, the automatic parameter adjustment unit 33 can also be as follows: Figure 6 As shown, the force control parameters are automatically adjusted by moving the workpiece W1 from both multiple positional error directions and posture error directions. Figure 6 In the scenario shown, when force control is applied to robot 2 based on initial parameters, robot 2 exhibits a posture in which workpiece W1 is tilted relative to the fitting hole MH, and slightly offset to the side from the center of the fitting hole MH. Specifically, the axis W1a of workpiece W1 is tilted relative to the axis W2a of the fitting hole MH of workpiece W2 around the Y-axis in the -X-axis direction. Figure 6 The workpiece W1 is tilted at an angle E1 to the left, and the workpiece W1 is offset by a distance E2 relative to the axis W2a of the fitting hole MH in the -X direction.

[0062] In the above embodiment, it was described that the movement of workpiece W1 relative to workpiece W2 performed by robot 2 is a fitting action in which workpiece W1 is fitted into the fitting hole MH of workpiece W2. However, the movement of workpiece W1 relative to workpiece W2 performed by robot 2 can also be as follows: Figure 7 As shown in the robot system 1A, the workpiece W1 held by the hand 22 is aligned with the plane SF of the workpiece W2. Furthermore, the movement of workpiece W1 relative to workpiece W2 performed by the robot 2 can also be as follows: Figure 8 The robot system 1B shown performs a search operation that makes workpiece W1 search in a manner that matches the shape and phase of the engagement hole EH of workpiece W2.

[0063] In the above implementation, the movement of workpiece W1 relative to workpiece W2 was performed from four directions (four postures) that changed by 90 degrees each time, while the force control parameters were automatically adjusted. However, the changed directions (postures) are not limited to four; any two or more directions (postures) are acceptable. Furthermore, the changed angles are not limited to 90 degrees.

[0064] In the above embodiment, the automatic parameter adjustment unit 33, which automatically adjusts the force control parameters, is installed in the robot control device 3, which is electrically connected to the robot 2, to control the movement of the robot 2. However, the function or all functions of the automatic parameter adjustment unit 33 of the robot control device 3 can also be implemented through an external terminal such as a PC (personal computer) or a tablet terminal.

[0065] Explanation of reference numerals in the attached figures

[0066] 1, 1A, 1B: Robot system; 2: Robot; 21: Robot arm; 22: Hand; 23: Force detector; 24: Actuator; 25: Torque sensor; 3: Robot control device; 31: Control unit; 33: Automatic parameter adjustment unit; W1: Workpiece; W2: Workpiece (target object); MH: Fitting hole; SF: Plane; EH: Engaging hole.

Claims

1. A robot system comprising: A robotic arm, with a hand at its front end for holding a workpiece; A force detector that detects the force and torque acting on the workpiece held by the hand; as well as The control device, based on predetermined force control parameters and the detection values ​​of the force detector, performs force control on the robot arm to correct the position and posture errors of the workpiece, while simultaneously moving the workpiece held by the hand relative to the target object. The control device includes an automatic parameter adjustment unit that automatically adjusts the force control parameters by repeatedly executing the movement of the workpiece relative to the target object. And a storage unit that stores the force control parameters. The automatic parameter adjustment unit automatically adjusts the force control parameters by moving the workpiece relative to the target object from at least one of multiple position error directions and multiple posture error directions, and then overwrites and saves them to the storage unit. The automatic parameter adjustment unit performs movement of the workpiece relative to the target object from at least one of the multiple position error directions and multiple posture error directions, and automatically adjusts the force control parameters according to the condition of the direction in which the detection value of the force detector fluctuates the most among the multiple posture error directions.

2. The robot system according to claim 1, wherein, The movement of the workpiece relative to the target object is any one of the following actions: fitting action, alignment action, and searching action. The fitting action is the action of fitting the workpiece into the fitting hole of the target object. The alignment action is the action of aligning the workpiece with the plane of the target object. The searching action is the action of searching for the workpiece in a manner that matches the shape of the locking hole of the target object.

3. The robot system according to claim 1 or 2, wherein, The force detector is a force sensor.

4. The robot system according to claim 1 or 2, wherein, The robotic arm has an actuator for driving the robotic arm and a torque sensor for detecting the torque of the actuator. The force detector detects the force and torque acting on the workpiece based on the detection value of the torque sensor.

5. The robot system according to claim 3, wherein, The robotic arm has an actuator for driving the robotic arm and a torque sensor for detecting the torque of the actuator. The force detector detects the force and torque acting on the workpiece based on the detection value of the torque sensor.

6. The robot system according to claim 1 or 2, wherein, The robotic arm has actuators for driving the robotic arm. The force detector detects the force and torque acting on the workpiece based on the current value applied to the actuator.

7. The robot system according to claim 3, wherein, The robotic arm has actuators for driving the robotic arm. The force detector detects the force and torque acting on the workpiece based on the current value applied to the actuator.

8. A robot control device for controlling the movement of a robot arm having a hand at its front end that grasps a workpiece to move the workpiece toward a target object, wherein the robot arm is force-controlled based on predetermined force control parameters and detection values ​​from a force detector to correct positional and posture errors of the workpiece relative to the target object, the force detector detecting the force and torque acting on the workpiece grasped by the hand, wherein in the robot control device, It includes: an automatic parameter adjustment unit that automatically adjusts the force control parameters by repeatedly performing movement of the workpiece relative to the object; and a storage unit that stores the force control parameters. The automatic parameter adjustment unit automatically adjusts the force control parameters by moving the workpiece relative to the target object from at least one of multiple position error directions and multiple posture error directions, and then overwrites and saves them to the storage unit. The automatic parameter adjustment unit performs movement of the workpiece relative to the target object from at least one of the multiple position error directions and multiple posture error directions, and automatically adjusts the force control parameters according to the condition of the direction in which the detection value of the force detector fluctuates the most among the multiple posture error directions.

9. The robot control device according to claim 8, wherein, The movement of the workpiece relative to the target object is any one of the following actions: fitting action, alignment action, and searching action. The fitting action is the action of fitting the workpiece into a hole in the target object. The alignment action is the action of aligning the workpiece with the plane of the target object. The searching action is the action of searching for the workpiece in a manner that matches the shape of the engaging hole in the target object.

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