Robot control device

Abstract

This robot control device includes a force control unit for performing force control based on a detection value of an external force and a predetermined force control parameter, a contact detection unit configured to detect contact between the robot and the external environment and to perform predetermined control of the robot when contact is detected, and a force control parameter adjusting unit for adjusting the predetermined force control parameter by performing a plurality of movements of the robot using force control, wherein the force control parameter adjusting unit adjusts the predetermined force control parameter and simultaneously adjusts the sensitivity of the contact detection performed by the contact detection unit.

Description

Area

[0001] The present disclosure relates to a robot control device. State of the art

[0002] Lead-through teaching, in which an operator performs teaching of a robot while directly pushing a robot arm with their hand to operate the robot, is known as a robot teaching method (see, for example, PTL 1). In lead-through teaching, control is performed to cause the robot arm to perform a movement in response to an external force applied to the robot arm by an operator.

[0003] Force control is known as a type of control method of a robot. A robot can be made to perform high-level work such as a fitting work for fitting a workpiece, held by a hand attached to a tip of a robot arm, into another workpiece, a surface alignment work, and a search work by applying force control (see, for example, PTL 2 to 4). Force control parameters that determine a relationship between a force applied to a workpiece and a behavior of a robot must be appropriately set to properly cause the robot to perform work through force control. PTL 2 describes an example of a technique for automatically adjusting a force control gain, which is one of the force control parameters. List of citationsPatent literature [PTL 1] Unexamined Japanese Patent Publication (Kokai) No. 2015-199174 A [PTL 2] Unexamined Japanese Patent Publication (Kokai) No. 2007-237312 A [PTL 3] Unexamined Japanese Patent Publication (Kokai) No. 2016-043457 A [PTL 4] Unexamined Japanese Patent Publication (Kokai) No. 2019-141937 A OverviewTechnical task

[0004] A robot that supports direct teaching, such as lead-through teaching, is generally designed to be able to detect contact between the robot and an external environment for the safety of an operator. With such a robot, it is also desirable to appropriately adjust force control parameters so that the robot can perform work appropriately through force control.

[0005] A robot control apparatus is desired that can appropriately perform adjustment of force control parameters for controlling a robot configured to be capable of detecting contact between the robot and an external environment. Technical solution

[0006] One aspect of the present disclosure is a robot control device, and the robot control device includes: a force control unit configured to perform force control based on a detected value of an external force and a predetermined force control parameter; a contact detection unit configured to detect contact between a robot and an external environment and to perform predetermined control on the robot when the contact is detected;and a force control parameter adjusting unit configured to adjust the predetermined force control parameter by causing the robot to perform operations by the force controller a plurality of times, wherein the force control parameter adjusting unit performs adjustment of the predetermined force control parameter and simultaneously adjusts a sensitivity of contact detection by the contact detection unit.;

[0007] The objects, features and advantages and other objects, features and advantages will become more apparent from the detailed description of typical embodiments of the present invention illustrated in the accompanying drawings. Short description of the drawings Fig. 1 is a diagram illustrating a configuration of a robot system according to an embodiment. Fig. 2 is a diagram illustrating a graphical functional block diagram of a robot control device. Fig. 3 is a flowchart showing an entire flow of parameter adjustment processing. Fig. 4 is a flowchart illustrating processing for automatically adjusting a force control parameter. Fig. 5 is a side view illustrating a positional error between a workpiece and a target object during automatic adjustment of a force control parameter. Fig. 6A is a plan view showing the positional error between the workpiece and the target object, which is shown in Fig. 5 are shown. Fig. Figure 6B is a plan view showing the workpiece and the target object in which a direction of the position error is 90 degrees from Fig. 6A differs. Fig. Figure 6C is a plan view showing the workpiece and the target object, in which the direction of the position error is 180 degrees from Fig. 6A differs. Fig. 6D is a top view showing the workpiece and the target object, in which the direction of the position error is 270 degrees from Fig. 6A differs. Fig. 7 is a diagram illustrating a state in which a notification screen indicating that processing for automatically setting a force control parameter is being executed is displayed together with a setting screen for setting a force control parameter. Fig. 8 is a graphical representation showing a screen for adjusting a robot sensitivity. Fig. 9 is a graphical representation illustrating a state in which a notification screen indicating that the processing for automatically adjusting a force control parameter ends is displayed. Fig. 10 is a graphical representation showing a state in which an indicator indicating an adjusted robot sensitivity is displayed on the setting screen. Fig. 11 is a graph showing a display state of a sensitivity indicator of the robot sensitivity. Description of the embodiments

[0008] Next, embodiments of the present disclosure will be described with reference to the drawings. A similar configuration area or a similar functional area is denoted by the same reference numeral in the drawings. For clarity, a scale in the drawings is appropriately changed. An aspect illustrated in the drawing is an example of implementing the present invention, and the present invention is not limited to the illustrated aspect.

[0009] Fig. 1 is a diagram illustrating a configuration of a robot system 100 according to an embodiment. The robot system 100 is configured to be capable of performing various types of work through force control. As shown in Fig. 1, the robot system 100 includes a robot 10, a robot controller 20 that controls the robot 10, a teaching pendant 40 connected to the robot controller 20, and a hand 30. As shown in Fig. 1, the robot system 100 may further include a display device 50 for displaying various types of information related to an execution of a motion program. As an example, Fig. 1 illustrates a case where a fitting work for fitting a workpiece W1 into a fitting hole MH of a workpiece W2 on a worktable 1 is performed by the robot 10.

[0010] In the present example, it is assumed that the robot 10 is a vertically articulated robot. It should be noted that a parallel linkage robot and a robot of other types can also be used as the robot 10. The robot 10 includes a base 11 and a robot arm 12 formed from a plurality of link elements. A plurality of drive axes of the robot arm 12 include an actuator 13 (see Fig. 2), which includes a servo motor.

[0011] A hand 30 is attached to an arm tip portion of the robot 10. The hand 30 is subject to drive control by the robot controller 20 to hold the workpiece WL1. In the fitting work, the workpieces include the workpiece W1 held by the hand 30 and the workpiece W2 on the worktable. The workpiece W1 has, for example, a cylindrical shape. The workpiece W2 is a target object into which the workpiece W1 is fitted by a movement of the robot 10. The workpiece W2 has the fitting hole MH for fitting the workpiece W1. The workpiece W2 is arranged on the worktable 1 such that the fitting hole MH faces upward.

[0012] The robot 10 includes an external force detector 15 that detects an external force ( Fig. 2). The external force detector 15 may be formed of a force sensor mounted on the robot 10 or may be formed of a torque sensor provided on each axis of the robot 10. Fig. 1 illustrates an example in which a force sensor 15a, which functions as an external force detector 15, is mounted on a root portion of the hand 30. The force sensor 15a is, for example, a 6-axis force sensor that can detect a force in an x-axis direction, a y-axis direction, and a z-axis direction, as well as a moment about the axes. A detected value of the external force detector 15 is output to the robot controller 20.

[0013] In such a manner, by incorporating the external force detector 15, the robot 10 is configured to be capable of performing a work (such as a passing work) by force control, and also to be capable of supporting direct teaching such as lead-through teaching.

[0014] For reference, a general robot that includes a force control function and also supports direct teaching is described herein. A robot that supports direct teaching, such as lead-through teaching, is generally designed to be able to detect contact between the robot and an external environment and, for example, stop the robot when the contact is detected to ensure the safety of an operator during direct teaching. Contact between the robot and the external environment can be detected, for example, by setting a threshold for an external force applied to the robot and determining that contact exists between the robot and the external environment when the external force exceeds the threshold.A robot's response changes according to the threshold value, and therefore, a threshold setting state is also referred to as robot sensitivity. As robot sensitivity increases (i.e., as the threshold value decreases), the robot becomes more sensitive to an external force and stops (the robot is expected to stop even with a small external force). As robot sensitivity decreases (i.e., as the threshold value increases), a robot's response to an external force becomes slower (the robot will not stop unless a large external force is applied).

[0015] In direct teaching, a threshold is usually set to a value greater than a force applied to a robot, but robot sensitivity is generally set high, preferably for safety reasons.

[0016] Implementing a force control in the robot that can detect contact with an external environment, as described above, is considered. Force control parameters must be appropriately set to properly perform the force control as described above. Adjusting the force control parameter is a high-level and difficult task, and therefore, selecting a configuration that can automatically adjust the force control parameter is beneficial to a user. When automatically adjusting the force control parameter, an adjustment value is generally acquired while causing the robot to attempt a force control movement. Meanwhile, it must also be considered that robot sensitivity may have an influence on the robot's behavior, as described above.

[0017] In view of the circumstances described above, the robot controller 20 according to the present embodiment is configured to be capable of performing adjustment of a force control parameter while adjusting the robot sensitivity, as will be described in detail below.

[0018] The robot control device 20 controls the movement of the robot 10 according to a movement program or a command from a teaching pendant 40. The robot control device 20 may have a hardware configuration as a general computer including a processor 21 ( Fig. 2), a memory (such as a ROM, a RAM and a non-volatile memory), a storage device, an operation unit, an input / output interface, a network interface and the like.

[0019] The teaching pendant 40 is used as an operating terminal for performing teaching of the robot 10 and various types of settings. A teaching device formed from a tablet computer and the like can be used as the teaching pendant 40. The teaching pendant 40 can have a hardware configuration as a general computer, including a processor, a memory (such as a ROM, a RAM, and a non-volatile memory), a storage device, an operation unit, a display unit 41 ( Fig. 2), an input / output interface, a network interface and the like.

[0020] A display device 50 provides a function for displaying various types of information related to execution of a motion program. An information processing device such as a personal computer can be used as the display device 50. The display device 50 may have a hardware configuration as a general computer, including a processor, a memory (such as a ROM, a RAM, and a non-volatile memory), a storage device, an operation unit, a display unit 51 ( Fig. 2), an input / output interface, a network interface and the like.

[0021] It should be noted that Fig. 1 illustrates the configuration in which the display device 50 and the teaching pendant 40 are provided as separate devices in the robot system 100, but the function as the display device 50 may be integrally incorporated into the teaching pendant 40.

[0022] Fig. 2 shows a graphical functional block diagram of the robot controller 20. As in Fig. 2, the robot controller 20 includes a motion control unit 121, a force control unit 122, a contact detection unit 123, an automatic parameter adjustment unit 124, a robot sensitivity adjustment unit 125, and a storage unit 126. Note that the functional blocks of the motion control unit 121, the force control unit 122, the contact detection unit 123, the automatic parameter adjustment unit 124, and the robot sensitivity adjustment unit 125 can be achieved by the processor 21 executing software.

[0023] The external force detector 15 provided in the robot 10 detects an external force applied to the robot 10 and provides the detected value to the force control unit 122 and the contact detection unit 123. The robot 10 includes a sensitivity indicator 16 that indicates robot sensitivity. A function of the sensitivity indicator 16 is described below. Each joint axis of the robot 10 includes an actuator 13.

[0024] The teaching pendant 40 includes a display unit 41. The display unit 41 includes, for example, a liquid crystal display. Various types of information related to teaching the robot 10 are displayed on the display unit 41, for example.

[0025] The display device 50 includes a display unit 51. The display unit 51 includes, for example, a liquid crystal display. Various types of information related to the execution of a movement program are displayed on the display unit 51, for example.

[0026] The force control unit 122 provides a function for performing a movement through force control by sending a command to the movement control unit 121 based on an external force detected by the external force detector 15 and force control parameters. The force control parameters are stored, for example, in the storage unit 126.

[0027] The motion control unit 121 controls a movement of the robot 10 according to a command from the force control unit 122, the contact detection unit 123, and the like. The motion control unit 121 generates a command for the actuator 13 of each joint axis through kinematic calculation to perform control of the robot 10.

[0028] The automatic parameter adjustment unit 124 provides a function for automatically adjusting force control parameters by causing the robot to perform force control operations multiple times. The force control parameters include a force control gain, a speed command value, a force command value, and the like. The force control unit 122 performs force control according to the force control parameters.

[0029] The contact detection unit 123 detects contact between the robot 10 and an external environment (such as a person) and performs predetermined control on the robot 10 when the contact is detected. For example, the contact detection unit 123 determines that contact exists between the robot 10 and an external environment (such as a person) when a magnitude of a force or moment detected by the external force detector 15 exceeds a threshold. The response of the robot 10 changes according to a magnitude of the threshold, and therefore, a setting state of the threshold represents a sensitivity of contact detection by the contact detection unit 123. As described above, the sensitivity of contact detection (the setting state of the threshold) is also referred to as robot sensitivity.The given control is a control for stopping the robot 10, for setting the robot 10 to a sufficiently low speed state, and the like. In the following, it is assumed that the given control is the control for stopping the robot 10.

[0030] The robot sensitivity adjustment unit 125 provides a function of changing a threshold value (ie, robot sensitivity) for detecting that there is contact between the robot 10 and an external environment by the contact detection unit 123. - Reducing the threshold is associated with increasing robot sensitivity. Note that when robot sensitivity is high, the robot is sensitive to external forces and will stop under a relatively small force (external force). - Increasing the threshold is associated with a decrease in robot sensitivity. Note that when robot sensitivity is low, the robot responds slowly to an external force and will not stop unless a relatively large force is applied.

[0031] With the configuration described above, both in a case where work (such as a fitting work) is performed by force control and in a case where lead-through teaching is performed in which an operator performs teaching by directly applying a force to an arm and the like of the robot 10, the robot 10 is stopped and the safety of an operator can be ensured when contact between the robot 10 and an external environment is detected. Note that in lead-through teaching, the force control unit 122 generates a movement command in such a way that the robot 10 moves in the direction of an external force detected by the external force detector 15 (a direction of a force applied to the robot 10 by the operator).

[0032] The storage unit 126 stores a motion program, force control parameters, robot sensitivity, various types of setting information, and the like. The storage unit 126 may be formed from a non-volatile memory, a storage device, and the like.

[0033] Automatic adjustment of a force control parameter may be affected by robot sensitivity. For example, when robot sensitivity is high (i.e., when the threshold described above is low), an external force is more likely to exceed a limit value (the threshold described above), and the robot tends to be sensitive to the external force, and therefore, a robot movement is more likely to be unstable. Furthermore, in this case, the robot controller cannot support force control that requires a large pushing force.Given the influence of robot sensitivity on force control parameter adjustment described above, if parameter adjustment fails, the automatic parameter adjustment unit 124 is configured to confirm and adjust the robot sensitivity and perform parameter adjustment again. In this way, appropriate automatic adjustment of the force control parameter can be achieved, and the robot sensitivity with respect to the force control parameter can also be adjusted to an optimal state.

[0034] Fig. 3 is a flowchart illustrating an entire flow of parameter adjustment processing according to the present embodiment. The automatic parameter adjustment unit 124 functions as a force control parameter adjustment unit for controlling the present parameter adjustment processing. First, a required force control parameter is taught by an operator (step S1). At this time, the operator inputs the force control parameter via a setting screen (a user interface), for example. The force control parameter input by the operator is stored in the storage unit 126.

[0035] Fig. 7 illustrates a setting screen 200 for setting the force control parameter. The setting screen 200 includes an input column 201 for inputting the force control parameter. The operator can perform force control parameter learning by entering a value into the input column 201. The automatic parameter adjustment unit 124 may have a function for displaying such a setting screen. Such a setting screen may be displayed on the display unit 51 of the display device 50 or may be displayed on the display unit 41 of the teaching pendant 40.

[0036] Next, processing for automatically adjusting a force control parameter is executed by the automatic parameter adjustment unit 124 (step S2). A column 210 for enabling the automatic force control parameter adjustment processing may be provided in the setting screen 200. In this case, the operator can enable the automatic force control parameter adjustment processing by pressing an execution button 211. When the automatic force control parameter adjustment processing is enabled, a notification screen 300 indicating that the automatic force control parameter adjustment processing is being executed may be displayed.In the present example, the notification screen 300 includes an indicator 311 indicating, in the form of a bar chart, a degree of progress of the processing for automatically adjusting a force control parameter, and a button 312 for pause instructions.

[0037] Fig. Fig. 4 is a flowchart illustrating processing for automatically adjusting a force control parameter. The processing for automatically adjusting a force control parameter by the automatic parameter adjustment unit 124 will be described with reference to the flowchart shown in Fig. 4, Fig. 5 and Fig. 6A to 6D. Automatic adjustment of a force control parameter is performed, for example, when setting up a robot system, when changing a type of workpiece, when replacing a hand, or the like. Here, a case in which a fitting motion for fitting the workpiece W1 held by the hand 30 into a fitting hole of the workpiece W2 is performed is described as an example. The automatic parameter adjustment processing is executed by the force control unit 122 and the motion control unit 121 under the control of the automatic parameter adjustment unit 124.

[0038] When the present processing is activated, first, the automatic parameter adjustment unit 124 reads an initial parameter of the force control from the storage unit 126. The force control unit 122 outputs a command to the robot 10 and executes a first operation to cause the robot 10 to perform a movement based on the initial parameter so as to fit the workpiece W1 held by the hand 30 into the fitting hole MH of the workpiece W2 (step S101).

[0039] Fig. 5 is a side view illustrating a state immediately before the workpiece W1 held by the hand 30 is fitted into the fitting hole MH of the workpiece W2 by the force control of the robot 10 by the initial parameter. Fig. Figure 6A is a top view of this state. As in Fig. 5 and Fig. As shown in Fig. 6a, when the force control based on the initial parameter is performed on the robot 10, the robot 10 has a posture in which the workpiece W1 is positioned obliquely with respect to the fitting hole MH. Specifically, an axis line W1a of the workpiece W1 is inclined by an angle E1 in the -x-axis direction (the left direction in Fig. 5 and Fig. 6A) is inclined about the y-axis with respect to an axis line W2a of the fitting hole MH of the workpiece W2.

[0040] The robot 10 must have a posture in which the axis line W1a of the workpiece W1 and the axis line W2a of the fitting hole MH coincide with each other in order to properly fit the workpiece W1 into the fitting hole MH. Therefore, the angle E1 represents a posture error that must be corrected by the robot 10 at the time of starting the fitting. The angle E1 is a change amount of a posture of the robot 10 required to properly fit the workpiece W1 into the fitting hole MH, that is, a correction amount (E) of the posture error.

[0041] Here, if a rotation matrix representing a robot posture at the time of starting the fitting is TA and a rotation matrix representing a robot posture after the fitting is TB, inv (TB) × TA is a rotation matrix representing the correction amount (E) of the posture error at the time of starting. In this case, inv represents an inverse matrix. The automatic parameter adjustment unit 124 calculates the correction amount (E) of the posture error and stores the correction amount (E) in the storage unit 126 (step S102).

[0042] Note that a threshold value of the position error correction amount is preset in the automatic parameter adjustment unit 124. When an absolute value of the position error correction amount (E) calculated in step S102 is equal to or less than the threshold value, the automatic parameter adjustment unit 124 sets the position error correction amount (E) to a predetermined value. This setting is performed to intentionally provide the position error when there is no position error or when the position error is too small. The predetermined value is, for example, the threshold value. In other words, when the threshold value is set to 0.5 degrees and the position error correction amount calculated in step S102 is equal to or less than 0.5 degrees, the position error correction amount (E) is set to 0.5 degrees.

[0043] Next, the force control unit 122 changes a direction of the posture error and executes a second passing movement at the same position as that at the time of execution of the first passing movement and with the same absolute value as that of the correction amount (E) of the posture error of the robot 10 (step S103).

[0044] In step S103, the automatic parameter adjustment unit 124 performs fitting from a position specified by a rotation matrix of TB × T (90) × inv (TB) × TA. T (90) is a matrix of a 90-degree rotation around a fitting direction (around the axis line W2a of the fitting hole MH) with respect to the first fitting movement. As shown in Fig. 6B, the robot 10 performs the fitting from a position where the axis line W1a of the workpiece W1 is inclined by the angle E1 in the +y-axis direction (the downward direction in Fig. 6B) is inclined about the x-axis with respect to the axis line W2a of the fitting hole MH of the workpiece W2.

[0045] Next, the force control unit 122 changes the direction of the posture error again and executes a third passing movement at the same position as that at the time of execution of the second passing movement and with the same absolute value as that of the correction amount (E) of the posture error of the robot 10 (step S104).

[0046] In step S104, the automatic parameter adjustment unit 124 performs fitting from a position specified by a rotation matrix of TB × T (180) × inv (TB) × TA. T (180) is a matrix of a 180-degree rotation around the fitting direction (around the axis line W2a of the fitting hole MH) with respect to the first fitting movement. As shown in Fig. 6C, the robot 10 performs the fitting from a position where the axis line W1a of the workpiece W1 is bent by the angle E1 in the +x-axis direction (the right direction in Fig. 6C) is inclined about the y-axis with respect to the axis line W2a of the fitting hole MH of the workpiece W2.

[0047] Next, the force control unit 122 changes the direction of the posture error again and executes a fourth passing movement at the same position as that at the time of execution of the third passing movement and with the same absolute value as that of the correction amount (E) of the posture error of the robot 10 (step S105).

[0048] In step S105, the automatic parameter adjustment unit 124 performs fitting from a position specified by a rotation matrix of TB × T (270) × inv (TB) × TA. T (270) is a matrix of a rotation of 270 degrees around the fitting direction (around the axis line W2a of the fitting hole MH) with respect to the first fitting movement. As shown in Fig. 6D, the robot 10 performs the fitting from a position where the axis line W1a of the workpiece W1 is inclined by the angle E1 in the -y-axis direction (the upward direction in Fig. 6D) is inclined about the x-axis with respect to the axis line W2a of the fitting hole MH of the workpiece W2.

[0049] For each passing movement from the first passing movement to the fourth passing movement, the automatic parameter adjustment unit 124 records a detected value output from the external force detector 15 via the force control unit 122. After the passing movement in the four directions (four postures) is completed, the automatic parameter adjustment unit 124 obtains an oscillation amount from the detected value of the external force detector 15 at the time of each passing movement and selects a direction (posture) in which data of the detected value oscillates the most (step S106).

[0050] As a method for obtaining a vibration amount, for example, there is a method of performing Fourier transform on a detected value of the external force detector 15 and obtaining an amplitude of a specific frequency based on the result. Furthermore, a vibration amount can be obtained by obtaining a maximum value or an average value of a change amount of a detected value of the external force detector 15.

[0051] The automatic parameter adjustment unit 124 selects the direction (posture) in which the detected value data of the external force detector 15 vibrates most in step S106, and then obtains force control parameters 1 to N adjusted only by the posture error of the selected direction (posture) (step S107), and changes each of the force control parameters to improve performance (step S108). N is the number of types of force control parameters. The types of force control parameters are a force control gain, a speed command value, a force command value, and the like. Adjustment of the force control parameter may be performed on the parameters for each type, or may be performed on a plurality of types of parameters simultaneously.

[0052] After the force control parameter has been changed in step S108, the force control unit 122 causes the robot 10 to perform a movement so that the workpiece W1 is again fitted into the fitting hole MH of the workpiece W2 with the posture error in the most swinging direction (posture) among the fitting movements in the four directions (four postures) (step S109).

[0053] If the force control parameter is changed too much in such a way as to improve the force control performance, it is more likely to cause instability of the robot 10, such as an increase in vibration. For example, if a force control gain is increased, a response to a generated force is faster, and therefore, correction of a posture error at a time of fitting is faster, and a time required for fitting is shorter. On the other hand, if the force control gain is increased too much, noise is amplified and the robot 10 may oscillate. Therefore, the automatic parameter adjustment unit 124 executes the fitting movement in step S109, and then obtains a vibration amount from the detected value of the external force detector 15 by the above-described method and decides whether the robot 10 is oscillating (step S110).It should be noted that whether the robot 10 has oscillated can be judged from a vibration amount being larger than a vibration amount at the time of previous automatic parameter adjustment, exceeding a threshold value of a preset vibration amount, or the like.

[0054] If it is judged in step S110 that the robot 10 is not oscillating (step S110: NO), the automatic parameter adjustment unit 124 returns to the processing of step S108. In other words, the automatic parameter adjustment unit 124 changes the force control parameter so as to further increase the performance of the force control parameter, and then again executes a passing motion with the most oscillating posture error. Subsequently, in step S110, it is judged again whether the robot 10 is oscillating. The processing in steps S108 and S109 is repeated until it is judged in step S110 that the robot 10 is oscillating.

[0055] On the other hand, if it is decided in step S110 that the robot 10 is oscillating (step S110: YES), the automatic parameter adjustment unit 124 resets the changed force control parameter to a previous value (step S111).

[0056] In this way, the force control parameter is set to a limit value at which the robot 10 does not oscillate. The automatic parameter adjustment unit 124 outputs and overwrites the set force control parameter to the storage unit 126, and then the force control parameter automatic adjustment processing ends.

[0057] Note that the example of performing automatic adjustment of a force control parameter by performing movement of the workpiece W1 from a plurality of position error directions is described herein, but a force control parameter may be automatically adjusted by performing movement of the workpiece W1 from a plurality of position error directions and posture error directions.

[0058] When the above-described force control parameter automatic adjustment processing from step S101 to step S111 proceeds normally and the processing ends, the automatic parameter adjustment unit 124 determines that the automatic adjustment is successful. On the other hand, when the force control parameter automatic adjustment processing does not end normally in the process from step S101 to step S111 and no automatic adjustment value of the force control parameter is detected, the automatic parameter adjustment unit 124 determines that the automatic adjustment failed and interrupts and ends the force control parameter automatic adjustment processing.

[0059] For description in Fig. 3, the automatic parameter adjustment unit 124 next confirms whether the automatic adjustment fails (step S3).

[0060] If the automatic parameter adjustment unit 124 determines that automatic adjustment fails (S3: YES), processing proceeds to step S4. In step S4, the automatic parameter adjustment unit 124 confirms the robot sensitivity.

[0061] If the robot sensitivity is not the lowest robot sensitivity (S5: NO), the automatic parameter adjustment unit 124 decreases the robot sensitivity and executes the processing for automatically adjusting a force control parameter again (step S6). When automatic adjustment of the robot sensitivity is performed, the automatic parameter adjustment unit 124 may display a sensitivity adjustment screen 310 as shown in Fig. 8 of the robot sensitivity adjustment unit 125. In this case, the operator can observe a situation in which the robot sensitivity is adjusted. Fig. The sensitivity adjustment screen 310 shown in Fig. 8 indicates a setting state of the robot sensitivity by a length of a bar 321 (a position of a button 322). Note that the sensitivity adjustment screen 310 may be displayed together with the setting screen 200 on one display screen, as shown in Fig. 7.

[0062] When the re-executed automatic adjustment of a force control parameter ends, the processing of step S3 is executed.

[0063] When the robot sensitivity is the lowest robot sensitivity (S5: YES), the operator confirms an alarm content and the like issued when the processing for automatically adjusting a force control parameter fails and ends, and performs necessary adjustment to execute the processing of step S2 (step S7).

[0064] If the processing for automatically adjusting a force control parameter is successful (S3: NO), the processing proceeds to step S8. As shown in Fig. At this time, as shown in Figure 9, a notification screen 301 indicating that the force control parameter automatic adjustment processing is ending may be displayed on the display screen. In step S8, the automatic parameter adjustment unit 124 records the adjusted robot sensitivity in, for example, the storage unit 126 (step S8).

[0065] At this time, the automatic parameter adjustment unit 124 may display an image indicating the adjusted robot sensitivity. Fig. 10 illustrates an example in which an indicator 220 indicating the adjusted robot sensitivity is displayed on the setting screen 200. In this way, the operator can visually immediately recognize how the robot sensitivity has changed as a result of the automatic adjustment.

[0066] If the robot sensitivity set during automatic adjustment is different from the robot sensitivity before automatic adjustment, the automatic parameter adjustment unit 124 resets the robot sensitivity to the robot sensitivity before automatic adjustment (step S9).

[0067] According to the parameter adjustment processing described above, the robot sensitivity can be adjusted to an appropriate value while achieving automatic adjustment of the force control parameter to an appropriate value. Therefore, the force control parameter can be efficiently acquired, achieving high performance. Furthermore, according to the configuration described above, the robot sensitivity can be adjusted to a high value within a range where automatic adjustment of the force control parameter is successful. Therefore, adjustment of the robot sensitivity with consideration of safety is achieved during automatic adjustment of the force control parameter.In other words, according to the configuration described above, appropriate adjustment of the force control parameter and the robot sensitivity can be performed efficiently, and therefore, the setup of the robot system can be performed efficiently.

[0068] The robot sensitivity recorded in step S8 is used when performing a force control work (the fitting work in the above-described example) that is a target of parameter adjustment. In other words, when the force control work (the fitting work in the above-described example) that is the target of parameter adjustment is performed in a subsequent stage, the force control unit 122 changes the robot sensitivity to the recorded robot sensitivity and executes the force control. Afterward, when the force control work is completed, the robot sensitivity is returned to an initial state before the force control work is performed. In this way, the time and effort required by the operator to manually adjust the robot sensitivity are eliminated, and the operator's workload can be reduced.

[0069] The setting screen 200 in Fig. 10 may be configured to allow an operator to adjust the robot sensitivity by pressing a button 221 of the indicator 220. For example, if a further reduction in a cycle time is required, the operator may set the robot sensitivity to a lower value to re-execute the processing for automatically adjusting a force control parameter.

[0070] The robot sensitivity adjustment unit 125 may be configured to display a current robot sensitivity in the sensitivity indicator 16 provided on the robot 10. The sensitivity indicator 16 may, for example, be an LED light. As shown in Fig. 11, in this case, the robot sensitivity adjustment unit 125 may perform control to increase the brightness of the LED light at higher robot sensitivity. The sensitivity indicator 16 may be arranged at a position, such as the base 11 of the robot 10, that the operator can easily visually recognize. The operator operating the robot 10 can immediately recognize the robot sensitivity through the sensitivity indicator 16, and thus, indicating the robot sensitivity through the sensitivity indicator 16 can contribute to improving work safety.

[0071] Note that the display of the robot sensitivity by the sensitivity indicator 16 may be performed during adjustment processing of the force control parameter or may be performed always during operation of the robot 10. As the display style of the sensitivity by the sensitivity indicator 16, a display style other than sensitivity display by brightness may be selected.

[0072] When arranging the functions in the Fig. The graphical functional block diagram shown in Figure 2 is an example, and various modification examples for the arrangement of the functional blocks are possible. For example, an example is also possible in which a part of the function blocks used in the robot controller in the graphical functional block diagram in Fig. 2 arranged function blocks in the programming handheld device or in the display device.

[0073] The Fig. The functional block of the robot controller shown in Fig. 2 can be achieved by executing various types of software stored in a storage device by the processor of the robot controller, or can be achieved by a configuration in which hardware such as an application specific integrated circuit (ASIC) is a main body.

[0074] The program for executing various types of processing such as parameter adjustment processing ( Fig. 2) and the processing for automatic parameter adjustment ( Fig.3) In the embodiment described above, it can be recorded in various computer-readable recording media (for example, a ROM, an EEPROM, a semiconductor memory such as a flash memory, a magnetic recording medium, or an optical disk such as a CD-ROM and a DVD-ROM).

[0075] As described above, according to the present embodiment, the force control parameter can be adjusted to an appropriate value and the robot sensitivity can also be adjusted appropriately.

[0076] Although the present disclosure has been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various types of addition, replacement, modification, partial deletion, and the like can be made to the embodiments without departing from the purpose of the present disclosure or departing from the content described in the claims and the scope of the present disclosure understood from their equivalents. Furthermore, the embodiments can be carried out in combination. For example, in the embodiments described above, an order of operations and an order of pieces of processing are given as an example, which is not limited to them. Furthermore, the same also applies to a case where a numerical value or a numerical expression is used in the description of the embodiments described above.

[0077] With respect to the embodiments and modification examples described above, supplementary notes are further described below. (Supplementary Note 1)

[0078] A robot control device that includes: a force control unit configured to perform force control based on a detected value of an external force and a predetermined force control parameter; a contact detection unit configured to detect contact between a robot and an external environment and to perform predetermined control on the robot when the contact is detected; and a force control parameter adjustment unit configured to adjust the predetermined force control parameter by causing the robot to perform operations by the force control multiple times, wherein the force control parameter adjustment unit performs an adjustment of the predetermined force control parameter and simultaneously adjusts the sensitivity of contact detection by the contact detection unit. (Supplementary Note 2)

[0079] The robot control device according to Supplementary Note 1, wherein the force control parameter adjustment unit decreases the sensitivity of contact detection when adjustment of the force control parameter fails, and repeats a motion for performing adjustment of the force control parameter again until adjustment of the force control parameter is successful. (Supplementary Note 3)

[0080] The robot control device according to supplementary note 1 or 2, wherein the force control parameter adjustment unit records the sensitivity of contact detection at a time of success of force control parameter adjustment. (Supplementary Note 4)

[0081] The robot control device according to any one of Supplementary Notes 1 to 3, wherein the force control parameter adjustment unit resets the sensitivity of contact detection to an original state before the force control parameter adjustment is performed after a force control parameter adjustment is successful. (Supplementary Note 5)

[0082] The robot control device according to Supplementary Note 3, wherein, when the force control is executed, the force control unit changes the sensitivity of contact detection to the recorded sensitivity of contact detection. (Supplementary Note 6)

[0083] The robot control device according to Supplementary Note 5, wherein after execution of the force control, the force control unit resets the sensitivity of the robot to a state before execution of the force control. (Supplementary Note 7)

[0084] The robot control device according to any one of Supplementary Notes 1 to 6, wherein the force control parameter adjustment unit displays a user interface screen for displaying the sensitivity of contact detection at a time of success of the force control parameter adjustment. (Supplementary Note 8)

[0085] The robot control device according to Supplementary Note 7, wherein the user interface screen is configured to accept a user operation for adjusting the sensitivity of contact detection and an instruction for performing adjustment of the force control parameter by the force control parameter adjusting unit again with the sensitivity of contact detection adjusted by the user operation. (Supplementary Note 9)

[0086] The robot control device according to any one of Supplementary Notes 1 to 8, wherein the force control parameter adjustment unit sends a signal for adjusting a brightness of a sensitivity indicator provided on the robot according to the contact detection sensitivity currently applied to the robot. List of reference symbols 10 robots 11 Base 12 Robot arm 13 Actuator 15 Detector for an external force 16 Sensitivity indicator 20 Robot control device 21 processor 30 hands 40 Programming pendant 41 Display unit 50 display device 51 Display unit 100 robot system 121 Motion control unit 122 force control unit 123 Contact detection unit 124 Unit for automatic parameter adjustment 200 Setting screen 220 Indicator 300, 301 Notification screen 310 Sensitivity adjustment screen QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2015-199174 A

[0003] JP 2007-237312 A

[0003] JP 2016-043457 A

[0003] JP 2019-141937 A

[0003]

Claims

[1] Robot control device comprising: a force control unit configured to perform force control based on a detected value of an external force and a predetermined force control parameter; a contact detection unit configured to detect contact between a robot and an external environment and to perform predetermined control on the robot when the contact is detected; and a force control parameter adjustment unit configured to adjust the predetermined force control parameter by causing the robot to perform operations by the force control multiple times, wherein the force control parameter adjustment unit performs an adjustment of the predetermined force control parameter and simultaneously adjusts a sensitivity of contact detection by the contact detection unit. [2] The robot control device according to claim 1, wherein the force control parameter adjustment unit decreases the sensitivity of contact detection when adjustment of the force control parameter fails, and repeats performing adjustment of the force control parameter until adjustment of the force control parameter is successful. [3] The robot control device according to claim 1 or 2, wherein the force control parameter adjustment unit records the sensitivity of contact detection at a time of success of adjustment of the force control parameter. [4] The robot control device according to any one of claims 1 to 3, wherein the force control parameter adjustment unit, after a success of adjustment of the force control parameter, resets the sensitivity of contact detection to an initial state before the adjustment of the force control parameter is performed. [5] The robot control device according to claim 3, wherein, when the force control is executed, the force control unit changes the sensitivity of contact detection to the recorded sensitivity of contact detection. [6] A robot control device according to claim 5, wherein after execution of the force control, the force control unit resets the sensitivity of the robot to a state before execution of the force control. [7] The robot control device according to any one of claims 1 to 6, wherein the force control parameter adjustment unit displays a user interface screen for displaying the sensitivity of contact detection at a time of success of adjustment of the force control parameter. [8] The robot control device according to claim 7, wherein the user interface screen is configured to accept a user operation for adjusting the sensitivity of contact detection and an instruction for performing adjustment of the force control parameter by the force control parameter adjusting unit again with the sensitivity of contact detection adjusted by the user operation. [9] The robot control device according to any one of claims 1 to 8, wherein the force control parameter adjusting unit sends a signal for adjusting a brightness of a sensitivity indicator provided on the robot according to the contact detection sensitivity currently applied to the robot.

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