Robot, robot control method, and robot system

Abstract

The tool executes a process depending on whether it is in contact with the target surface. [Solution] A robot arm equipped with a working part having different rigidity characteristics, moves the robot arm to bring the working part into contact with a target surface, determines the state in which the working part is in contact with the target surface, and if the determination is unsatisfactory, notifies that the state is unsatisfactory. Since the robot determines the state in which the working part is in contact with the target surface and notifies that the state is unsatisfactory if the determination is unsatisfactory, processing can be performed according to the state in which the working part is in contact with the target surface.

Description

Technical Field

[0001] The technology of the present disclosure relates to a robot, a method for controlling the robot, and a robot system.

Background Art

[0002] When operating a master robot to clean the surface of a desk with a brush attached to the tip of the arm of a slave robot, the quality of the work varies depending on the magnitude of the pressing force with which the brush presses against the surface of the desk. For example, if the pressing force is large, the surface of the desk will be damaged, and if the pressing force is small, the surface of the desk will not be properly cleaned. Therefore, in order to clean with an appropriate pressing force, a technique for impedance control is disclosed in Non-Patent Document 1. In Non-Patent Document 1, the impedance (force-displacement impedance) determined by the position of the brush and the reaction force from the surface of the desk is made to be a predetermined impedance. Specifically, the position of each robot arm is controlled so that the slope of the reaction force from the surface of the desk with respect to the position of the brush becomes a predetermined slope. In impedance control, the position of the brush is adjusted according to the reaction force received by the slave robot arm, and an attempt is made to maintain the set force-displacement impedance (the relationship between the degree of force application and the change in position). Thereby, the position of the robot arm is changed while finely adjusting it so that the surface of the desk can be cleaned with an appropriate pressing force.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, if the operator intentionally avoids contact between the brush and the target surface, for example, after cleaning a first area and moving to a second area away from the first, the operator may attempt to move the brush without touching the target surface. In conventional technology, impedance control is performed even in such cases, resulting in irregular or abrupt changes in the reaction force received by the robot arm, which differs from the intended cleaning motion. As a result, the robot attempts to adjust the brush position in response to these changes in reaction force, leading to unnecessarily small movements. Specifically, it attempts to maintain the appropriate pressure between the brush and the desk by moving backward when the reaction force increases and forward when the reaction force decreases. Consequently, the brush tries to remain in the first area and does not move smoothly to the second area. This results in a longer overall cleaning time.

[0005] The reason the overall cleaning time is longer is that the system uses impedance control, treating brushes and other tools as if they were in contact with the desk surface (target surface) even when they are not.

[0006] The present invention aims to provide a robot, a robot control method, and a robot system that can perform processing according to the state in which the working part is in contact with a target surface. [Means for solving the problem]

[0007] To achieve the above objective, a first aspect of the technology of this disclosure is a robot equipped with a robot arm to which working parts having different rigidity characteristics are attached, and which moves the robot arm to bring the working parts into contact with a target surface. This robot determines the state in which the working parts are in contact with the target surface.

[0008] A second embodiment is a robot equipped with a robot arm to which a working part having different rigidity characteristics is attached, and the robot arm is moved to bring the working part into contact with a target surface. In this robot, when the working part is in contact with the target surface, the position of the robot arm is controlled so that the relationship between the position of the robot arm and the reaction force that the robot arm receives from the target surface is a predetermined relationship. When the working part is not in contact with the target surface, the position of the robot arm is controlled without considering the aforementioned relationship. [Effects of the Invention]

[0009] A first aspect of the technology of this disclosure determines the state in which a working part having different rigidity characteristics is in contact with the target surface, and therefore can perform processing according to the state in which the working part is in contact with the target surface.

[0010] In the second embodiment, when the working part is in contact with the target surface, the position of the robot arm is controlled so that the relationship between the position of the robot arm and the reaction force received by the robot arm from the target surface is a predetermined relationship. When the working part is not in contact with the target surface, the position of the robot arm is controlled without considering the relationship. Thus, processing can be performed according to whether the working part is in contact with the target surface. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a block diagram of an example of a robot system 100. [Figure 2] Figure 2 shows an example of the postures of the master robot arm 10 and the slave robot arm 20 when the slave robot 2040 is remotely controlled by an operator operating the master robot arm 10. [Figure 3A] Figure 3A shows an example of how the pressing force is distributed when the pressing force applied to the target surface 5 by the brush 20p6B of the arm portion 20p6 at the tip of the slave robot arm 20 is appropriate. [Figure 3B]Figure 3B shows an example of how the pressing force concentrates when the pressing force applied by the arm portion 20p6 to the target surface 5 is too strong. [Figure 4] Figure 4 is a block diagram of an example of the electrical system of the slave robot 2040. [Figure 5] Figure 5 shows an example of the processing performed by the control unit 52A, calculation unit 52B, recording unit 52C, determination unit 52D, setting unit 52E, and display processing unit 52F. [Figure 6] Figure 6 shows an example of the slave robot arm attitude control program 54P. [Figure 7] Figure 7 is a graph showing the slope of the reaction force that the brush 20p6B receives from the target surface 5 with respect to the position of the tip of the slave robot arm 20. [Figure 8] Figure 8 is a graph showing the second partial derivative of the reaction force with respect to the position of the tip of the slave robot arm 20. [Figure 9] Figure 9 shows an example of the slave robot arm attitude control program 54P according to the second embodiment. [Modes for carrying out the invention]

[0012] [Embodiment] Embodiments of the technology of this disclosure will be described below with reference to the drawings.

[0013] [First Embodiment] (composition) The configuration of the robot system 100 of this embodiment will now be described. Figure 1 is a block diagram of an example of the robot system 100. As shown in Figure 1, the robot system 100 comprises a master robot 1030 and a slave robot 2040 whose posture changes according to a command value determined in accordance with the posture change of the master robot 1030. The master robot 1030 comprises a master robot arm 10 and a master robot controller 30. The slave robot 2040 comprises a slave robot arm 20 and a slave robot controller 40.

[0014] When remotely operating the slave robot 2040, the operator operates the master robot arm 10. The master robot controller 30 transmits, as command values, the angle and torque information of the master robot arm 10 at that time to the slave robot controller 40 via wireless or wired communication. Then, the slave robot controller 40 controls the slave robot arm 20 so that its posture changes according to the received command values. Thereby, the slave robot arm 20 acts on the object.

[0015] The robot system 100 of the present embodiment is applicable to a remote operation robot that performs work following the surface of an object while applying a constant force to the object, and the surface of the object may be flat or curved. For example, it is a processing robot (i.e., an industrial robot) such as a polishing or grinding robot, or a cleaning robot such as a floor cleaning robot. The case of cleaning the target surface of the following floor (see also FIG. 2) will be described as an example.

[0016] FIG. 2 is a diagram showing an example of the postures of the master robot arm 10 and the slave robot arm 20 when the slave robot 2040 is remotely operated by the operator operating the master robot arm 10. As shown in FIG. 2, the master robot arm 10 includes arm portions 10p1 to 10p6 connected by a plurality of joints J11 to J15. The slave robot arm 20 includes arm portions 20p1 to 20p6 connected by a plurality of joints J21 to J25. In the present embodiment, the arm portion 10p1 on the proximal end side of the master robot arm 10 is fixed to a fixing body 10K fixed to the floor. The arm portion 20p1 on the proximal end side of the slave robot arm 20 is fixed to a fixing body 20K fixed to the floor.

[0017] The arm portion 20p6 at the tip of the slave robot arm 20 is a tool for cleaning the surface of the floor, and includes a handle 20p6A having one end connected to the arm portion 20p5 and a brush 20p6B connected to the other end of the handle 20p6A. These have different rigidities. That is, the tool (arm portion 20p6) has characteristics with different rigidities. The tool (arm part 20p6) is an example of the "working part" of the technology of the present disclosure.

[0018] The operator grasps the arm part 10p6 at the tip of the master robot arm 10 and applies a predetermined force to the master robot arm 10. As a result, the above command value is transmitted to the slave robot controller 40, and the slave robot controller 40 controls the posture of the slave robot arm 20. Thereby, the arm part (tool) 20p6 at the tip of the slave robot arm 20 applies a pressing force to the target surface 5 to be contacted.

[0019] FIG. 3A shows an example of a state in which the pressing force is dispersed when the pressing force of the brush 20p6B of the arm part (tool) 20p6 at the tip of the slave robot arm 20 against the target surface 5 is appropriate. As shown in FIG. 3A, when the pressing force is appropriate, the pressing force acts evenly on the brush 20p6B. When the pressing force acts evenly on the brush 20p6B in this way, as shown in FIG. 7, the inclination of the reaction force received by the brush 20p6B from the target surface 5 with respect to the position of the tip of the slave robot arm 20 (that is, the brush 20p6B) is constant between the positions x0 to x2.

[0020] FIG. 3B shows an example of a state in which the pressing force concentrates when the pressing force of the arm part (tool) 20p6 against the target surface 5 is too strong. As shown in FIG. 3B, when the pressing force of the arm part (tool) 20p6 against the target surface 5 is too strong, the pressing force concentrates in a relatively narrow area on the brush 20p6B of the arm part (tool) 20p6. When the pressing force is too large, as shown in FIG. 7, the inclination of the reaction force received by the brush 20p6B from the target surface 5 with respect to the position of the tip of the slave robot arm 20 becomes larger by a predetermined value K at the position x2 than the inclination between the positions x0 to x2.

[0021] FIG. 4 is a block diagram of an example of the electrical system of the slave robot 2040. As shown in FIG. 4, each joint J21 to J25 of the slave robot arm 20 is provided with a motor 22, an encoder 24, and a torque sensor 26.

[0022] The slave robot controller 40 comprises a computer 50, a display device 62, and a communication device 64. The computer 50 includes a processor 52, an NVM (Non-volatile memory) 54, a RAM (Random Access Memory) 56, and an input / output (I / O) port 58. The processor 52, NVM 54, RAM 56, and input / output (I / O) port 58 are interconnected by a bus 60. The motors 22, encoders 24, and torque sensors 26 of each joint J21 to J25 of the slave robot arm 20, as well as the display device 62 and the communication device 64, are connected to the input / output (I / O) port 58.

[0023] The processor 52 is a processing unit that includes a DSP (Digital Signal Processor), a CPU (Central Processing Unit), and a GPU (Graphics Processing Unit). The DSP and GPU operate under the control of the CPU and are responsible for executing the processes described later. Here, a processing unit including a DSP, CPU, and GPU is given as an example of the processor 52, but this is only an example. The processor 52 may be one or more CPUs and DSPs with integrated GPU functionality, or one or more CPUs and DSPs without integrated GPU functionality, or it may be equipped with a TPU (Tensor Processing Unit).

[0024] The functional section of the processor 52 includes a control unit 52A, a calculation unit 52B, a recording unit 52C, a decision unit 52D, a setting unit 52E, and a display processing unit 52F.

[0025] NVM54 is a non-volatile memory device that stores programs and various parameters. An example of NVM54 is flash memory (e.g., EEPROM (Electrically Erasable and Programmable Read Only Memory)). The NVM54 stores the slave robot arm attitude control program 54P.

[0026] RAM56 is memory that temporarily stores information and is used as work memory by the processor 52. Examples of RAM56 include DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory).

[0027] When the slave robot arm attitude control program 54P is read from NVM 54 to RAM 56 and executed by processor 52 in RAM 56, processor 52 functions as a control unit 52A, a calculation unit 52B, a recording unit 52C, a decision unit 52D, a setting unit 52E, and a display processing unit 52F.

[0028] The electrical system of master robot 1030 is the same as that of slave robot 2040, so its explanation will be omitted. Master robot 1030 and slave robot 2040 communicate with each other via a communication device.

[0029] Figure 5 shows an example of the processing performed by the control unit 52A, calculation unit 52B, recording unit 52C, determination unit 52D, setting unit 52E, and display processing unit 52F.

[0030] The control unit 52A controls the slave robot arm 20 and presses the arm (tool) 20p6 against the target surface 5. The calculation unit 52B acquires the values ​​from the torque sensors 26 of each joint J21, J22, ... and calculates the reaction force that the arm (tool) 20p6 receives from the target surface 5 from these values. The calculation unit 52B acquires the values ​​from the encoders 24 of each joint J21, J22, ... and calculates the position of the tip of the slave robot arm 20 from these values. The recording unit 52C records the relationship between the position of the tip of the slave robot arm 20 and the reaction force that the arm (tool) 20p6 receives from the target surface 5. The judgment unit 52D determines whether the above relationship has changed abruptly. The setting unit 52E sets the reaction force when the relationship has changed abruptly to the limit value RF of the pressing force.

[0031] The control unit 52A controls the slave robot arm 20 so that its posture changes. The calculation unit 52B calculates the pressing force DF that presses the arm (tool) 20p6 against the target surface 5 from the values ​​of the torque sensors 26 of each joint J21, J22, ... The judgment unit 52D determines whether the pressing force DF that presses the arm (tool) 20p6 against the target surface 5 exceeds the limit value RF (DF > RF). If it is determined that the pressing force DF has exceeded the limit value RF (indicating a poor judgment result), the display processing unit 52F displays on the display device that the working state is poor. The control unit 52A controls the motors 22 of each joint J21, J22, ... to control the position of the slave robot arm so that the pressing force DF is less than or equal to the limit value RF.

[0032] (action) Next, the operation of this embodiment will be explained.

[0033] Figure 6 shows an example of the slave robot arm attitude control program 54P. Figure 7 is a graph showing the slope of the reaction force that the brush 20p6B receives from the symmetric surface 5 with respect to the position of the tip of the slave robot arm 20. Figure 8 is a graph showing the result of the second partial derivative of the reaction force with respect to the position of the tip of the slave robot arm 20.

[0034] The slave robot arm attitude control program 54P starts when a start button (not shown) is turned on. The processor 52 executes the slave robot arm attitude control program 54P, thereby executing the slave robot arm attitude control process and the slave robot arm attitude control process method.

[0035] In the slave robot arm posture control process, the slave robot 2040 is remotely controlled to clean the target surface 5 of the desk, but in steps 82 to 92, limit values ​​are set first.

[0036] The operator operates the master robot arm 10 by pressing it against the slave robot controller 40. The master robot controller 30 then transmits the angle and torque information of the master robot arm 10 as command values ​​to the slave robot controller 40 via wireless or wired communication.

[0037] In step 82, the control unit 52A controls the slave robot arm 20 according to the received command value and presses the arm (tool) 20p6 against the target surface 5.

[0038] In step 84, the calculation unit 52B acquires the values ​​from each torque sensor 26 of each joint J21, J22, ... and calculates the reaction force that the arm (tool) 20p6 receives from the target surface 5 from these values.

[0039] In step 86, the calculation unit 52B acquires the values ​​from each encoder 24 of each joint J21, J22, ... and calculates the position of the tip of the slave robot arm 20 from these values.

[0040] In step 88, the recording unit 52C records (i.e., stores) the relationship between the position of the tip of the slave robot arm 20 and the reaction force that the arm (tool) 20p6 receives from the target surface 5 in the NVM 54.

[0041] Figure 7 is a graph showing the relationship between the position of the tip of the slave robot arm 20 and the reaction force that the arm (tool) 20p6 receives from the target surface 5. In step 88, the position of the tip of the slave robot arm 20 and the reaction force that the arm (tool) 20p6 receives from the target surface 5 are plotted when the arm (tool) 20p6 is pressed against the target surface 5.

[0042] In step 90, the determination unit 52D determines whether the relationship obtained from the plot has changed sharply or not.

[0043] Figure 8 shows the second-order partial derivative of the reaction force received by the arm (tool) 20p6 from the target surface 5 with respect to the position of the tip of the slave robot arm 20. As shown in Figure 8, the determination unit 52D determines that the above relationship has changed sharply when the second-order partial derivative value exceeds a predetermined threshold.

[0044] If it is not determined that the above relationship has changed abruptly, the slave robot arm attitude control process returns to step 82 and executes the above processes (steps 82 to 90).

[0045] If it is determined that the above relationship has changed abruptly, it is determined that the pressing force applied to the arm (tool) 20p6 against the target surface 5 is too large and exceeds the allowable value ff, which is a predetermined value K smaller than the predetermined limit value fr.

[0046] The above threshold for the second-order partial derivative is the threshold at which it is determined that the pressing force applied by the arm (tool) 20p6 to the target surface 5 is too large and exceeds a predetermined tolerance value ff that is a predetermined value K smaller than the limit value fr.

[0047] If it is determined that the above relationship has changed abruptly, the slave robot arm attitude control process proceeds to step 92.

[0048] The acceptable value ff may be defined as follows:

[0049] ff = (limit value fr) - (robot tracking error / arm compliance) Robot tracking error refers to the discrepancy between the command value (target value) from the master robot and the actual movement (measured value) of the slave robot. Ideally, the slave robot is expected to operate precisely according to the command value, but errors can occur due to factors such as load, external interference, and the precision of the mechanism.

[0050] Arm compliance is an indicator that represents how flexibly a robot arm can respond to external forces or how easily it deforms. The higher the compliance, the more flexibly the robot arm can respond to external shocks and forces, contributing to shock absorption and protection of the object. Compliance is set so that the tip of the robot arm does not apply excessive force when contacting the object surface.

[0051] In step 92, the setting unit 52E sets the reaction force when the relationship changes abruptly to the limit value RF of the pressing force.

[0052] Subsequently, the operator cleans the target surface 5 of the desk with the arm (tool) 20p6. Specifically, the operator operates the master robot arm 10 to remotely control the slave robot 2040 to clean the target surface 5 of the desk. The master robot controller 30 transmits the angle and torque information of the master robot arm 10 at that time as command values ​​to the slave robot controller 40 via wireless or wired communication.

[0053] In step 94, the control unit 52A controls the slave robot arm 20 so that its posture changes according to the received command value.

[0054] In step 96, the calculation unit 52B calculates the pressing force DF applied to the arm (tool) 20p6 against the target surface 5 from the values ​​of the torque sensors 26 at each joint J21, J22, ... Alternatively, the pressing force may be directly measured by installing a sensor between the arm 20p5 and the handle 20p6A of the slave robot arm 20.

[0055] In step 98, the judgment unit 52D determines whether the pressing force DF applied to the arm (tool) 20p6 against the target surface 5 exceeds the limit value RF (DF > RF). In other words, it determines whether the state in which the arm (tool) 20p6 is pressed against the target surface 5 is defective due to excessive pressure.

[0056] If the pressing force DF is not determined to have exceeded the limit value RF (i.e., the working state is such that the arm (tool) 20p6 is properly pressed against the target surface 5 (i.e., the judgment result is good)), the slave robot arm attitude control process returns to step 92 and executes the above process (steps 92 to 98).

[0057] If it is determined that the pressing force DF exceeds the limit value RF (i.e., the working condition is such that the arm (tool) 20p6 is being pressed too hard against the target surface 5 (i.e., the judgment result is poor)), the slave robot arm attitude control process proceeds to step 100.

[0058] In step 100, the display processing unit 52F displays on the display device that the work status is poor. Specifically, it transmits data indicating that the work status is poor to the master robot controller 30 via the communication device 64. Based on the received information, the processor 52 of the master robot controller 30 displays on the display device 62 of the master robot controller 30 that the work status is poor. Alternatively, a warning sound may be generated instead of, or in conjunction with, displaying that the work status is poor.

[0059] In step 102, the control unit 52A controls the motors 22 of each joint J21, J22, ... to control the position of the slave robot arm so that the pressing force DF is less than or equal to the limit value RF.

[0060] In step 104, the determination unit 52D determines whether or not the slave robot arm posture control process (specifically, cleaning the target surface 5 of the desk) has been instructed to end by determining whether or not an exit button (not shown) has been turned on.

[0061] If it is not determined that the slave robot arm attitude control process has been instructed to terminate, the slave robot arm attitude control process returns to step 92 and executes the above processes (steps 92 to 104).

[0062] If it is determined that the slave robot arm posture control process has been instructed to end, it is determined that the slave robot arm posture control process, i.e., the cleaning of the target surface 5 of the desk, has been instructed to end, and the slave robot arm posture control process ends.

[0063] (effect) As described above, in this embodiment, it is determined whether the pressing force DF applied to the arm (tool) 20p6 against the target surface 5 exceeds the limit value RF. That is, it is determined whether the state in which the arm (tool) 20p6 is pressed against the target surface 5 is defective, such as being pressed too hard. If the determination result is defective, the display device 62 of the master robot controller 30 displays that the work state is defective. Therefore, in this embodiment, processing can be performed according to the state in which the arm (tool) 20p6 is in contact with the target surface 5.

[0064] Upon seeing the message on the display device 62 indicating that the work status is poor, the operator realizes that they are pressing the arm (tool) 20p6 too hard against the target surface 5. Therefore, the operator operates the master robot arm 10 to reduce the force with which the arm (tool) 20p6 is pressed against the target surface 5. This allows for proper cleaning, specifically, preventing damage to the target surface 5 of the desk. Conversely, if the display device 62 does not indicate that the work status is poor, the operator can freely operate the master robot arm 10, and the slave robot arm 20 moves freely accordingly. In other words, the slave robot arm 20 is controlled to move without considering the inclination of the reaction force that the slave robot arm 20 receives from the target surface 5 relative to its position. Consequently, the operator may intentionally avoid contact between the arm (tool) 20p6 and the target surface 5. For example, when cleaning a first area is finished and the arm (tool) 20p6 is to be moved to a second area away from the first area without contacting the target surface 5, the arm (tool) 20p6 moves smoothly. In contrast, in the conventional technology, impedance control is performed even when the arm (tool) 20p6 is not in contact with the target surface 5, so it tries to stay in the first area and does not move smoothly to the second area. As a result, the overall cleaning time becomes longer. Thus, in this embodiment, even when the arm (tool) 20p6 is not in contact with the target surface 5, the arm (tool) 20p6 can be moved smoothly, and the overall cleaning time can be shortened compared to the conventional technology.

[0065] In this embodiment, the limit value RF for the pressing force is set based on the reaction force when the relationship between the position of the tip of the slave robot arm 20 and the reaction force that the arm (tool) 20p6 receives from the target surface 5 changes abruptly. Therefore, the limit value can be set in accordance with the actual target surface 5, making the cleaning work more appropriate.

[0066] [Second Embodiment] (composition) The robot system 100 of this embodiment has the same configuration as that of the first embodiment, so its description will be omitted.

[0067] (action) Since the operation of the robot system 100 in this embodiment is substantially the same as that of the first embodiment, we will mainly describe the different operational parts.

[0068] In the first embodiment described above, instead of impedance control, it is determined whether the pressing force DF applied to the arm (tool) 20p6 against the target surface 5 exceeds the limit value RF.

[0069] In contrast, the second embodiment performs impedance control, but differs in that it releases the impedance control when the arm (tool) 20p6 does not come into contact with the target surface 5. The specifics will be explained below.

[0070] Figure 9 shows an example of a slave robot arm attitude control program 54P according to the second embodiment. The slave robot arm attitude control program 54P starts when a start button (not shown) is turned on. The processor 52 executes the slave robot arm attitude control program 54P, thereby executing the slave robot arm attitude control process and the slave robot arm attitude control process method.

[0071] In step 122, the calculation unit 52B acquires the values ​​from the torque sensors 26 of each joint J21, J22, ... and calculates the reaction force that the arm (tool) 20p6 receives from the target surface 5 from these values.

[0072] In step 124, the determination unit 52D determines from the calculated reaction force value whether or not the arm portion (tool) 20p6 is in contact with the target surface 5.

[0073] If it is determined that the arm (tool) 20p6 is in contact with the target surface 5, the slave robot arm attitude control process proceeds to step 126. If it is not determined that the arm (tool) 20p6 is in contact with the target surface 5, the slave robot arm attitude control process proceeds to step 132.

[0074] In step 126, the calculation unit 52B acquires the values ​​from the encoders 24 of each joint J21, J22, ... and calculates the position of the tip of the slave robot arm 20 from these values.

[0075] In step 128, the control unit 52A controls the motors 22 of each joint J21, J22, ... to control the position of the slave robot arm 20 so that the relationship between the position of the tip of the slave robot arm 20 and the reaction force that the arm (tool) 20p6 receives from the target surface 5 is a predetermined relationship. Specifically, the control unit 52A controls the position of the slave robot arm 20 so that the inclination of the reaction force that the arm (tool) 20p6 receives from the target surface 5 relative to the position of the tip of the slave robot arm 20 is a predetermined inclination that occurs when the arm (tool) 20p6 is properly pressing against the target surface 5.

[0076] In step 130, the determination unit 52D determines whether or not the slave robot arm posture control process (specifically, cleaning the target surface 5 of the desk) has been instructed to end by determining whether or not an exit button (not shown) has been turned on.

[0077] If it is not determined that the slave robot arm attitude control process has been instructed to end, the slave robot arm attitude control process returns to step 122 and executes the above processes (steps 122 to 130).

[0078] If, in step 124, it is determined that the arm (tool) 20p6 is not in contact with the target surface 5, then in step 132, the control unit 52A controls the slave robot arm 20 according to the command value without considering the above relationship.

[0079] After the processing in step 124, the slave robot arm attitude control process proceeds to step 130.

[0080] If it is determined in step 130 that the slave robot arm attitude control process has been instructed to end, it is determined that the slave robot arm attitude control process, i.e., the cleaning of the target surface 5 of the desk, has been instructed to end, and the slave robot arm attitude control process ends.

[0081] (effect) As described above, in the second embodiment, impedance control is performed when the arm (tool) 20p6 is in contact with the target surface 5, and impedance control is released when the arm (tool) 20p6 is not in contact with the target surface 5.

[0082] Therefore, when the arm (tool) 20p6 is in contact with the target surface 5, the position of the slave robot arm 20 is controlled so that the arm (tool) 20p6 properly presses against the target surface 5. On the other hand, when the arm (tool) 20p6 is not in contact with the target surface 5, the slave robot arm 20 is controlled according to the command value without considering the above relationship. Therefore, for example, when cleaning a first area is finished and the arm (tool) 20p6 is to be moved to a second area away from the first area without contacting the target surface 5, the arm (tool) 20p6 can be moved smoothly. Therefore, the overall cleaning time can be shortened compared to conventional technology. [Explanation of symbols]

[0083] 5. Target surface 10 Master Robot Arm 20 Slave Robot Arms 20p6 Arm section (tool) 20p6A pattern 20p6B brush 22 motors 24 IOS 26 Torque Sensor 30 Master Robot Controllers 40 Slave Robot Controllers 50 Computers 52 processors 52A Control Unit 52B Calculation section 52C Recording Section 52D Judgment Department 52E Settings Section 52F Display Processing Unit 52G Display Processing Unit 54P Slave Robot Arm Attitude Control Program 58 Input / Output (I / O) Ports 60 bus 62 Display device 64 Communication equipment 100 Robot Systems 1030 Master Robot 2040 Slave Robot DF force ff tolerance fr limit value RF limit

Claims

1. A robot comprising a robot arm to which a working part having different rigidity characteristics is attached, and which moves the robot arm to bring the working part into contact with a target surface, The working part determines the state in which it is in contact with the target surface. robot.

2. If the result of the above determination is not poor, the position of the robot arm is moved without considering the reaction force that the robot arm receives from the target surface relative to the position of the robot arm. If the result of the above determination is unfavorable, the position of the robot arm is controlled so that the reaction force received by the robot arm from the target surface is within a predetermined limit value. The robot according to claim 1.

3. The aforementioned limit value is predetermined based on the value of the reaction force at which the inclination of the reaction force received by the robot arm from the target surface changes by a predetermined value or more relative to the position of the robot arm. The robot according to claim 2.

4. A robot comprising a robot arm to which a working part having different rigidity characteristics is attached, and which moves the robot arm to bring the working part into contact with a target surface, When the working part is in contact with the target surface, the position of the robot arm is controlled so that the relationship between the position of the robot arm and the reaction force received by the robot arm from the target surface is a predetermined relationship. If the work unit is not in contact with the target surface, the position of the robot arm is controlled without considering the relationship. robot.

5. A robot control method comprising a robot arm to which a working part having different rigidity characteristics is attached, wherein the robot arm is moved to bring the working part into contact with a target surface, The system determines whether the working part is in contact with the target surface, and if the determination is unsatisfactory, it notifies that the condition is unsatisfactory. Robot control methods.

6. A robot control method comprising a robot arm to which a working part having different rigidity characteristics is attached, wherein the robot arm is moved to bring the working part into contact with a target surface, When the working part is in contact with the target surface, the position of the robot arm is controlled so that the relationship between the position of the robot arm and the reaction force received by the robot arm from the target surface is a predetermined relationship. If the work unit is not in contact with the target surface, the position of the robot arm is controlled without considering the relationship. Robot control methods.

7. A robot system comprising a master robot and a slave robot whose posture changes according to a command value determined in response to a change in the posture of the master robot, The slave robot comprises a robot arm to which a work section having different rigidity characteristics is attached, and moves the robot arm according to the command value to bring the work section into contact with the target surface. The system determines whether the working part is in contact with the target surface, and if the determination is unsatisfactory, it notifies that the condition is unsatisfactory. Robot system.

8. A robot system comprising a master robot and a slave robot whose posture changes according to a command value determined in response to a change in the posture of the master robot, The slave robot comprises a robot arm to which a work section having different rigidity characteristics is attached, and moves the robot arm according to the command value to bring the work section into contact with the target surface. When the working part is in contact with the target surface, the position of the robot arm is controlled so that the relationship between the position of the robot arm and the reaction force received by the robot arm from the target surface is a predetermined relationship. If the work unit is not in contact with the target surface, the position of the robot arm is controlled without considering the relationship. Robot system.

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