Power control system, power control method, and power control program

Abstract

A power control system is provided that is highly safe and capable of performing operations that require high positioning accuracy. [Solution] A power control system 1 comprising a working unit 12 configured to be able to perform a predetermined task, an operating unit 11 configured to be able to move the working unit 12, a position detection unit 20 that detects the working unit position X, and a control unit 30 having an impedance setting unit 31, a calculation unit 32 and a drive signal generation unit 33 and performing impedance control on the operating unit 11, wherein the impedance setting unit 31 sets an impedance value according to at least one of the position and situation of the working unit 12 and outputs the impedance value to the calculation unit 32, the calculation unit 32 calculates the drive force generated in the operating unit 11 based on the set target position Xd, working unit position X and impedance value, and the drive signal generation unit 33 outputs a drive signal to the operating unit 11 based on the drive force F.

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, a power control system that performs impedance control on an operating unit that moves a working unit is known (see, for example, Patent Document 1).

[0003] Such power control systems require high positioning accuracy for the control of the operating unit. In conventional power control systems, control with a large impedance value makes the operating unit less susceptible to external forces, thereby maintaining high positioning accuracy. Note that the "impedance value" refers to the inertia matrix M, viscosity matrix D, and stiffness matrix K in equation (1) of impedance control, which will be described later. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4243309 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when control with a large impedance value is performed, the operating part becomes less susceptible to external forces and does not move easily. Therefore, if no countermeasures are taken, there is a possibility that the working part will come into contact with an obstacle or a worker, resulting in injury to the worker or damage or breakage of the obstacle, which poses a safety issue.

[0006] However, if control is always performed to keep the impedance value small, the operating part will be susceptible to the influence of external forces, which increases safety in the event of contact with an obstacle or worker, but creates the problem that it becomes difficult to perform operations that require high positioning accuracy.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a power control system that is highly safe and capable of performing operations requiring high positioning accuracy. It also has an object to provide a power control method for performing such power control. It is still another object to provide an operation control program that can perform such power control when executed by a CPU. [Means for solving the problem]

[0008] The power control system of the present invention comprises a working unit configured to be able to perform a predetermined task, an operating unit configured to move the working unit, a position detection unit that detects the working unit position, which is the position of the working unit, and a control unit that has an impedance setting unit, a calculation unit, and a drive signal generation unit and performs impedance control on at least the operating unit, wherein the impedance setting unit sets the impedance value according to at least one of the position and situation of the working unit and outputs the impedance value to the calculation unit, the calculation unit calculates a drive force to be generated in the operating unit based on a set target position, the working unit position, and the impedance value, and the drive signal generation unit outputs a drive signal to the operating unit based on the drive force.

[0009] The power control method of the present invention is a power control method for performing impedance control on at least a working unit and an operating unit that moves the working unit, and is characterized by including a working unit position detection process for detecting the working unit position, which is the position of the working unit; an impedance value setting process for setting an impedance value according to at least one of the position and situation of the working unit; a calculation process for calculating a driving force generated in the working unit based on the set target position, the working unit position, and the impedance value; and a drive signal output process for outputting a drive signal to the operating unit based on the driving force.

[0010] The power control program of the present invention is a power control program that performs impedance control on at least the operating unit out of a working unit and an operating unit that moves the working unit, and is characterized in that it causes a CPU to execute a working unit position input process that inputs the working unit position, which is the position of the working unit; an impedance value setting process that sets an impedance value depending on at least one of the position and situation of the working unit; a calculation process that calculates a driving force generated in the working unit based on the set target position, the working unit position, and the impedance value; and a drive signal output process that outputs a drive signal to the operating unit based on the driving force.

[0011] According to the power control system, power control method, and power control program of the present invention, the impedance setting unit sets an impedance value according to at least one of the position and situation of the working unit, and outputs the impedance value to the calculation unit. The calculation unit calculates the driving force generated in the operating unit based on the set target position, working unit position, and impedance value, so that the impedance value can be switched according to the position and situation of the working unit. Therefore, for example, when the working unit is located in the work space, control is performed to increase the impedance value, making it less susceptible to external forces, thereby enabling it to perform operations that require high positioning accuracy.Also, when the working unit is located in a space other than the work space, control is performed to decrease the impedance value, making it more susceptible to external forces, thereby increasing safety in the event of contact with an obstacle or a worker. As a result, a power control system is obtained which has a high level of safety and is capable of performing operations that require high positioning accuracy.

[0012] Generally, when control is performed to produce a large impedance value and the operating unit is made less susceptible to external forces, a relatively large force is required to move the working unit, resulting in increased power consumption. According to the power control system, power control method, and power control program of the present invention, the impedance setting unit sets the impedance value in accordance with at least one of the position and situation of the working unit, so that control does not always have to be performed to produce a large impedance value. By setting a small impedance value and making the operating unit more susceptible to external forces in accordance with the position and situation of the working unit, it is possible to move the working unit with a relatively small force, thereby reducing power consumption when control with a small impedance value is being performed. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 3 is a diagram illustrating impedance control in the first embodiment. [Figure 2] 1 is a diagram for explaining a power control system 1 according to a first embodiment. [Figure 3] FIG. 2 is a diagram illustrating a computer 100 according to the first embodiment. [Figure 4] 3 is a flowchart shown to explain a power control method according to the first embodiment. [Figure 5] FIG. 1 is a schematic side view shown for explaining a power control system 1 according to a first embodiment. [Figure 6]FIG. 2 is a diagram for explaining a power control system 2 according to a second embodiment. [Figure 7] 10 is a flowchart showing an example of a power control method according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] The power control system, power control method, and power control program of the present invention will be described below based on the embodiments shown in the drawings. Note that the embodiments described below do not limit the invention according to the claims. Furthermore, not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the present invention.

[0015] [Embodiment 1] 1. Configuration of power control system 1 according to embodiment 1 (1) Impedance control First, we will explain impedance control. Impedance control is a position and force control method for setting the mechanical impedance (inertia, viscosity, rigidity, etc.) that occurs when a driving force is generated in the robot's hand (working unit) to a convenient value. Specifically, as shown in Figure 1, impedance control models the driving force F (external force vector, hereinafter simply referred to as driving force) generated in an object E (working unit) using the following equation (1) to control the position and force of the object. The first term on the left side of equation (1) is an inertia term, the second term is a viscosity term, and the third term is a rigid body term. In equation (1), M represents the inertia matrix, D represents the viscosity matrix, K represents the rigidity matrix, X represents the position and orientation vector of object E, Xd represents the target position and orientation vector (hereinafter simply referred to as the target position), and F represents the external force vector generated in object E.

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[0016] (2) Power control system Next, a power control system 1 according to embodiment 1 will be described. The power control system 1 according to embodiment 1 applies impedance control to at least the operating unit 11 of a manipulator 10 having an operating unit 11 and a working unit 12. Note that the position of the working unit 12 (hereinafter simply referred to as the working unit position) is used as the position of the target object (position and orientation vector). Furthermore, terms such as working unit position, target position, and driving force do not simply refer to quantities but also include the concept of a vector including direction.

[0017] The power control system 1 according to the first embodiment controls the operating unit 11 to perform an operation that is easily affected by external forces until the working unit 12 reaches the work space A (see FIG. 5), and when the working unit 12 is in the work space A, controls the operating unit 11 to perform an operation that is less susceptible to external forces.

[0018] 1 and 2, a power control system 1 according to the first embodiment includes a manipulator 10, a position detection unit 20, a control unit 30, and a target position information generation unit 40. In the first embodiment, the position detection unit 20 is provided in an operating unit 11 of the manipulator 10.

[0019] The manipulator 10 has an operating unit 11 and a working unit 12 provided at the tip of the operating unit 11 .

[0020] The operating unit 11 is a multi-axis controlled robot arm configured to be able to move the working unit 12. In the first embodiment, as shown in FIG. 1 , the operating unit 11 extends from a base 14 and has a first link L1, a second link L2, and a third link L3, a first joint 15 between the base (base) 14 and the first link L1, a second joint 16 between the first link L1 and the second link L2, and a third joint 17 between the second link L2 and the third link L3. Note that, although the first embodiment is a multi-axis controlled robot arm having three joints, it may also be a multi-axis controlled robot arm having two or four or more joints, or a single-axis controlled robot arm.

[0021] Each joint is provided with a motor M1 to M3, and the position of the working unit 12 can be moved by rotating the motors M1 to M3 in response to a drive signal that controls the rotational torque of the motor from the control unit 30. In the first embodiment, the operating unit 11 moves the working unit 12 toward a target position.

[0022] The working unit 12 is a hand provided at the tip of the operating unit 11, and is configured to be able to perform a predetermined task. The "predetermined task" of the working unit 12 is an action in which the working unit 12 has some effect on the object E, and examples of suitable tasks include grasping (grasping and moving) the object, drilling, and screwing. The working unit 12 performs the predetermined task in response to a signal input from the control unit 30 or a working unit control unit (not shown).

[0023] 2, the position detection unit 20 detects the working unit position, which is the position of the working unit 12, and outputs it as working unit position information to the control unit 30 (impedance setting unit 31 and calculation unit 32). In the first embodiment, the position detection unit 20 is an encoder provided at each of the first joint unit 15, the second joint unit 16, and the third joint unit 17 of the operating unit 11, and detects the rotation phase angles of the rotation shafts of the motors M1 to M3 using each encoder, and outputs this as working unit position information to the control unit 30. Note that the working unit position information may include appropriate information such as the rotation phase angle and position, as well as the rotational speed and rotational acceleration of the motors.

[0024] The control unit 30 performs impedance control on the operating unit 11. The control unit 30 also calculates the position of the working unit 12 based on the rotation phase angles of the rotation shafts of the motors M1 to M3 and the lengths of the link units L1 to L3 that have been measured in advance.

[0025] The control unit 30 has an impedance setting unit 31, a calculation unit 32, and a drive signal generation unit 33. In the first embodiment, the processing of the control unit 30 and the target position information generation unit 40 is performed by executing a program on the computer 100, but separate computers may be used, or a configuration other than a program may be used using a logic circuit or the like.

[0026] The impedance setting unit 31 sets an impedance value according to the position of the working unit 12 in the working unit position information, and outputs the impedance value to the calculation unit 32. The impedance setting unit 31 changes the impedance value depending on whether the working unit 12 is located within the set working space A (the area surrounded by the dashed line in FIG. 5).

[0027] Specifically, when working unit 12 is located in work space A, impedance setting unit 31 outputs a first impedance value having a relatively large impedance value to calculation unit 32. In this case, the operation of operating unit 11 is less susceptible to the influence of external forces, thereby maintaining high positioning accuracy. Furthermore, when working unit 12 is located in a space other than work space A, impedance setting unit 31 outputs a second impedance value having a smaller impedance value than when working unit 12 is located in work space A to calculation unit 32. In this case, the operation of operating unit 11 is more susceptible to the influence of external forces, thereby ensuring high safety.

[0028] The first impedance value and the second impedance value may each be a constant impedance value, or may be an impedance value that changes depending on the location or time, for example, an impedance value that changes in a stepwise manner.

[0029] The working space A (see FIG. 5) is a space sufficient for the working unit 12 to perform the "predetermined work," and in the first embodiment, it is set to be a space that extends from the area near the object when viewed in a plane to the area above the object when viewed from the side.

[0030] The calculation unit 32 calculates the driving force F generated in the working unit 12 using the following equation (1) based on the set target position Xd, working unit position X, and impedance value. The target position Xd is input from the target position information generation unit 40.

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[0031] As can be seen from equation (1), the greater the difference between the working unit position X and the target position Xd, the greater the driving force F generated in the working unit 112. Also, the greater the impedance values ​​(inertia matrix M, viscosity matrix D, stiffness matrix K), the greater the driving force F.

[0032] Furthermore, the calculation unit 32 controls the operation unit 11 so that the working unit 12 moves toward the target position Xd.

[0033] Drive signal generation unit 33 outputs a drive signal to operation unit 11 so that working unit 12 moves toward target position Xd based on the drive force F (and the target position) calculated by calculation unit 32. Specifically, drive signal generation unit 33 outputs a drive signal to operation unit 11 that controls the rotational torque of motors M1 to M3 provided on each axis of operation unit 11 (robot arm). In addition, drive signal generation unit 33 may output a signal to working unit 12 that causes working unit 12 to perform a predetermined task, or may cause working unit 12 to perform the predetermined task based on the drive force F calculated by calculation unit 32.

[0034] The target position information generator 40 sets the target position Xd and outputs it to the calculation unit 32 as target position information. In the first embodiment, a trajectory of movement of the working unit 12 is set in advance, and the target position Xd is set to move along the trajectory over time. The operating unit 11 then moves the working unit 12 so as to track the target position Xd. Note that in the first embodiment, the working unit 12 is positioned above the target object O, and the target position Xd is set so as to descend from there toward the target object O (see FIG. 5).

[0035] (3) About Computer 100 Next, a description will be given of a computer 100 that realizes the control unit 30 and the target position information generation unit 40 by causing the CPU 105 to execute a program in the first embodiment. As shown in Fig. 3, the computer 100 has a transmission unit 101, a reception unit 102, a BUS 103, and a CPU 105. The transmission unit 101, the reception unit 102, the output unit 50, the storage unit 60, and the input unit 70 are connected via the BUS 103. Note that a memory that stores the target position and the working unit position for each predetermined time may be provided separately from the storage unit 60, which will be described later.

[0036] The transmitter 101 outputs a drive signal to the manipulator 10 . The receiving unit 102 receives working unit position information relating to the working unit position detected by the position detecting unit 20 . The output unit 50 displays the working unit position and the target position so that the operator can understand the state of the working unit 12 and the manipulator 10 . The storage unit 60 stores a preset target position Xd, the impedance control model equation (1), the impedance value, etc. It also stores the working unit position X for each predetermined time.

[0037] The CPU 105 executes the power control program according to the first embodiment to implement the control unit 30 and the target position information generating unit 40. The power control program according to the first embodiment will be described later.

[0038] 2. Power control method according to embodiment 1 Next, a description will be given of a power control method according to embodiment 1. The power control method according to embodiment 1 is a power control method that performs impedance control on working unit 12. As shown in Fig. 4, the power control method according to embodiment 1 includes a target position setting step S11, a working unit position detection step S12, impedance value setting steps S13 to S15, a calculation step S16, and a drive signal output step S17.

[0039] (1) Target position setting step S11 First, the target position information generating unit 40 sets a target position for the working unit 12 and generates target position information (see step S11 in FIG. 4). Specifically, the target position Xd is set to move over time along a planned trajectory along which the working unit 12 is to move. In the first embodiment, the target position Xd is set so that the working unit 12 is positioned above the target object O, and then the target position Xd is set so that the working unit 12 descends from there toward the target object O (see FIG. 5). The working unit 12 is moved by the operating unit 11 toward the target position Xd.

[0040] (2) Working part position detection process S12 Next, position detection unit 20 detects working unit position X, which is the position of working unit 12, and outputs working unit position information relating to working unit position X to control unit 30 (see step S12 in FIG. 4). In the first embodiment, information on the rotational phase angles of the rotating shafts of motors M1 to M3 is output to control unit 30.

[0041] (3) Impedance value setting steps S13 to S15 Next, based on the working unit position information, an impedance value is set depending on whether or not the working unit 12 is located in a predetermined working space A. Specifically, it is determined whether or not the working unit 12 is in the working space A (see step S13 in FIG. 4). When it is determined that the working unit 12 is located within the working space A (see the Yes arrow in S13), a first impedance value is set as the impedance value (see step S14 in FIG. 4), and when it is determined that the working unit 12 is located in a space other than the working space A (see the No arrow in S13), a second impedance value smaller than the first impedance value is set as the impedance value (see step S15 in FIG. 4).

[0042] (4) Calculation process S16 Next, the driving force F generated in the working unit 12 is calculated based on the set target position Xd, working unit position X, and impedance value (see step S16 in FIG. 4). Specifically, the driving force F generated in the working unit 12 is calculated using the following equation (1).

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[0043] (5) Drive signal output step S17 Based on the drive force F calculated in the calculation step and the target position, a drive signal for performing impedance control on the working unit 12 is output (see step S17 in Figure 4). When the working unit 12 is at a predetermined location, a drive signal is output so that the working unit 12 performs a "predetermined task" rather than moving.

[0044] In this way, the working unit 12 can be moved toward the target position Xd and perform a predetermined task while performing impedance control based on the drive signal.

[0045] 3. Operation control program according to embodiment 1 Next, a description will be given of the operation control program according to embodiment 1. The power control program according to embodiment 1 causes the CPU to execute a target position setting process, a working unit position information receiving process, an impedance value setting process, a calculation process, and a drive signal output process.

[0046] (1) Target position setting process First, a target position for working unit 12 is set, and target position information is generated. Specifically, the target position Xd is set to move over time along a planned trajectory along which working unit 12 is to move. In the first embodiment, the target position Xd is set so that working unit 12 is positioned above object O from a predetermined position, and then the target position Xd is set so that working unit 12 descends from there toward object O (see FIG. 5). Working unit 12 is moved toward target position Xd by operation unit 11. Note that in the target position setting process, the target value may be input directly from an external input unit 70, or the target position Xd for each preset time may be stored in memory unit 60 and directly read by CPU 105 from memory unit 60 as needed.

[0047] (2) Work location information input processing First, working unit position information relating to the position of working unit 12 output from position detection unit 20 is input.

[0048] (3) Impedance value setting process Next, based on the working unit position information, it is determined whether or not the working unit 12 is located in a predetermined working space A, and the impedance value is set based on the determination result. Specifically, when the working unit 12 is located within the working space A, a first impedance value having a relatively large impedance value is read from the storage unit 60, and when the working unit 12 is located in a space other than the working space A, a second impedance value having an impedance value smaller than the first impedance value is read from the storage unit 60.

[0049] (4) Calculation processing Next, the drive force F generated in the working unit 12 is calculated based on the set target position Xd, working unit position X, and impedance value.

[0050] (5) Drive signal output processing Based on the drive force F calculated by the arithmetic processing, a drive signal for performing impedance control is output to the working unit 12. When the working unit 12 is in a predetermined location, a drive signal is output so that the working unit 12 performs a "predetermined task" rather than moving.

[0051] In this way, the working unit 12 can be moved toward the target position Xd and perform a predetermined task while performing impedance control based on the drive signal.

[0052] 4. Effects of the power control system 1, power control method, and power control program according to the first embodiment According to the power control system 1, power control method, and power control program of the first embodiment, the impedance setting unit 31 sets an impedance value according to the position of the working unit 12 and outputs the impedance value to the calculation unit, and the calculation unit 32 calculates the driving force F generated in the operating unit 11 based on the set target position Xd, working unit position X, and impedance value, so that the impedance value can be switched according to the position of the working unit 12. Therefore, for example, when the working unit 12 is located in the work space, control is performed to increase the impedance value, making it less susceptible to external forces, thereby enabling it to perform operations that require high positioning accuracy. On the other hand, when the working unit 12 is located in a space other than the work space, control is performed to decrease the impedance value, making it more susceptible to external forces, thereby increasing safety in the event of contact with an obstacle or a worker. As a result, a power control system is obtained which has a high level of safety and is capable of performing operations that require high positioning accuracy.

[0053] Generally, when control is performed to produce a large impedance value and the operating unit 11 is made less susceptible to external forces, a relatively large force is required to move the working unit 12, resulting in increased power consumption. According to the power control system 1, power control method, and power control program of the first embodiment, the impedance setting unit 31 sets the impedance value according to the position of the working unit 12, eliminating the need to always perform control to produce a large impedance value. By performing control to produce a small impedance value and make the operating unit 11 more susceptible to external forces according to the position and situation of the working unit 12, a relatively small force can be used to move the working unit 12, thereby reducing power consumption when control is performed to produce a small impedance value.

[0054] Furthermore, according to the power control system 1 of the first embodiment, the impedance setting unit 31 changes the impedance value depending on whether the working unit 12 is located within the set working space A. For example, when the working unit 12 is in the working space A, control is performed to increase the impedance value, thereby making the operating unit 11 less susceptible to external forces and enabling it to perform operations that require high positioning accuracy. Furthermore, when the working unit 12 is in a space other than the working space A, control is performed to decrease the impedance value for the working unit 12, making the operating unit 11 more susceptible to external forces, thereby improving safety in the event of contact with an obstacle or a worker.

[0055] Furthermore, according to the power control system 1 of the first embodiment, the impedance setting unit 31 changes the impedance value in stages, so that the working unit can be controlled more precisely.

[0056] Furthermore, according to the power control system 1 of the first embodiment, the operating unit 11 is a robot arm that performs multi-axis control, and the drive signal generation unit 33 outputs drive signals that control the rotational torque of the motors M1 to M3 provided on each axis of the robot arm, so that the working unit 12 can be moved while performing impedance control by controlling the rotational torque of the motors. Furthermore, the three-dimensional movement and drive force of the working unit 12 can be realized simply by adjusting the rotational torque of the operating unit 11.

[0057] [Embodiment 2] The power control system 2 of the second embodiment basically has the same configuration as the power control system 1 of the first embodiment, but differs from the power control system 1 of the first embodiment in that the impedance setting unit sets the impedance value according to the condition of the working unit.

[0058] As shown in FIG. 6, a power control system 2 according to the second embodiment inputs working unit status information, which is information relating to the status of the working unit 12, to the impedance setting unit 31 instead of inputting working unit position information to the impedance setting unit 31.

[0059] The impedance setting unit 31 changes the impedance value at the timing when the working unit 12 starts and finishes a predetermined task as the status of the working unit 12. Specifically, when the working unit 12 starts the predetermined task but has not yet finished it, the impedance setting unit 31 sets a first impedance value, which is a relatively high impedance value, and outputs it to the calculation unit 32, and when the working unit 12 has not started the task or has finished it, the impedance setting unit 31 outputs a second impedance value, which is a relatively small impedance value, to the calculation unit 32.

[0060] The status of the working unit 12 may be monitored by detecting that the working unit 12 receives a signal from the drive signal generating unit 33 to perform work, by providing a sensor in the working unit 12 or the operating unit 11 to detect the timing at which the working unit 12 starts or finishes work, by monitoring the working unit 12 from the outside using a camera or the like to detect the timing at which the working unit 12 starts or finishes work, or by any other appropriate method.

[0061] In the second embodiment, the impedance value is changed at the timing when the working unit 12 starts and finishes a predetermined task as the status of the working unit 12, but the impedance value may also be changed at the timing when the working unit 12 starts the predetermined task and the timing when a predetermined time (estimated time for the task to be completed) has elapsed since the working unit 12 started the predetermined task as the status of the working unit. That is, the impedance value may be changed from the normal impedance value to the working impedance value at the timing when the working unit 12 starts the predetermined task, and may be changed from the working impedance value to the normal impedance value at the timing when a predetermined time (estimated time for the task to be completed) has elapsed since the working unit 12 started the predetermined task.

[0062] Furthermore, the impedance value may be changed when an abnormal state (for example, a foreign object is detected in the work space A) is detected as the status of the working unit. That is, when no abnormal state is detected, the impedance value may be set to a relatively large value, and when an abnormal state occurs, the impedance value may be changed to a relatively small value to increase safety.

[0063] In addition, in the second embodiment, the impedance setting unit 31 may change the impedance value when the working unit 12 is located within the set working space A and starts a predetermined task, and may change the impedance value again when the working unit 12 finishes the predetermined task or when a predetermined time has elapsed since the working unit 12 started the predetermined task.

[0064] The power control method according to the second embodiment basically includes the same steps as the power control method according to the first embodiment, but differs in the impedance value setting step. That is, in the power control method according to the second embodiment, the impedance value setting step sets an impedance value according to the status of the working unit, as shown in FIG. 7. Specifically, it is determined whether working unit 12 has started working (see step S23 in FIG. 7), and if working unit 12 has not started working, a second impedance value is set (see step S25 in FIG. 7). If working unit 12 has started working, it is determined whether working has finished (see step S24 in FIG. 7), and if working has finished, a second impedance value is set (see step S25 in FIG. 7), and if working unit 12 has not finished working, a first impedance value is set (see step S26 in FIG. 7).

[0065] The power control program according to the second embodiment is basically the same as the power control program according to the first embodiment, but differs from the power control program according to the first embodiment in the content of the impedance value setting process. That is, the impedance value setting process changes the impedance value depending on the state of the working unit 12.

[0066] Thus, according to the power control system 2, power control method, and power control program of the second embodiment, the impedance setting unit differs from the power control system 1 of the first embodiment in that it sets the impedance value according to the state of the working unit. However, the impedance setting unit 31 sets the impedance value according to the state of the working unit 12 and outputs the impedance value to the calculation unit. The calculation unit 32 calculates the driving force F generated in the operating unit 11 based on the set target position Xd, working unit position X, and impedance value, so that the impedance value can be switched according to the position of the working unit 12. As a result, a power control system is obtained which has a high level of safety and is capable of performing operations that require high positioning accuracy.

[0067] According to the power control system 2, power control method, and power control program of the second embodiment, the impedance setting unit 31 changes the impedance value depending on the status of the working unit 12, that is, when the working unit 12 starts working and when it finishes working. Therefore, it is possible to switch between operations that are less susceptible to the influence of external forces and operations that are more susceptible to the influence of external forces according to the desired situation, for example, by narrowing the range of operations that are less susceptible to the influence of external forces and widening the range of operations that are highly safe.

[0068] The power control system, power control method, and power control program according to the second embodiment have the same configuration as the power control system, power control method, and power control program according to the first embodiment, except that they set the impedance value according to the status of the working unit, and therefore have the corresponding effects of the power control system, power control method, and power control program according to the first embodiment.

[0069] Although the present invention has been described above based on the above embodiment, the present invention is not limited to the above embodiment and can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0070] (1) The positions, sizes, lengths, numbers, etc. described in the above embodiments (including each modified example; the same applies below) are examples and can be changed within the scope that does not impair the effects of the present invention.

[0071] (2) In each of the above embodiments, a robot arm is used as the operating unit 11 to move the working unit 12, but the present invention is not limited to this. Any appropriate device other than a robot arm may be used as long as it can move the working unit 12. Furthermore, in each of the embodiments, a fixed base (base) is used, but a movable base (base) may also be used.

[0072] (3) In the above embodiments, the position of the working unit is detected using an encoder as the position detector, but the present invention is not limited to this. The position of the working unit may be detected using a sensor, or the position of the working unit may be detected by any other appropriate method.

[0073] (4) In the above embodiments, the target position Xd of the working unit 12 is set by the target position information generating unit, but the present invention is not limited to this. The target position Xd may be set in advance by storing it in a memory unit and reading it from the calculation unit, by inputting it from an external device, or by any other appropriate method.

[0074] (5) In each of the above embodiments, a robot arm is used as the operating unit, but the present invention is not limited to this. Devices other than a robot arm may also be used as the operating unit.

[0075] (6) In the above embodiments, when the working unit 12 is located within the working space A, a first impedance value is output to the calculation unit 32, and when the working unit 12 is located in a space other than the working space A, a second impedance value is output to the calculation unit 32. However, the present invention is not limited to this. When the working unit 12 is located within a predetermined space, a second impedance value may be output to the calculation unit 32, and when the working unit 12 is located in a space other than the predetermined space, a first impedance value may be output to the calculation unit 32.

[0076] (7) In each of the above embodiments, two spaces, namely, one workspace A and another space, are set, and impedance values ​​corresponding to the respective spaces are set, but the present invention is not limited to this. Three or more spaces may be set, and impedance values ​​corresponding to the respective spaces may be set. [Explanation of symbols]

[0077] 1, 2... power control system, 10... manipulator, 11... movable part, 12... working part, 30... control part, 31... impedance setting part, 32... calculation part, 33... drive signal generation part, 100: computer, X... working part position, Xd... target position

Claims

1. a working unit configured to be able to perform a predetermined task; an operating unit configured to be able to move the working unit; a position detection unit that detects a working unit position, which is the position of the working unit; a control unit having an impedance setting unit, a calculation unit, and a drive signal generation unit, and performing impedance control on at least the operation unit; the impedance setting unit sets an impedance value in accordance with at least one of the position and the situation of the working unit, and outputs the impedance value to the calculation unit; the calculation unit calculates a driving force generated in the operation unit based on the set target position, the working unit position, and the impedance value; the drive signal generation unit outputs a drive signal to the operation unit based on the drive force; the impedance setting unit performs control to increase a stiffness matrix in an impedance value when the working unit is located in a work space, and performs control to decrease the stiffness matrix in an impedance value when the working unit is located in a space other than the work space; The work space is narrower than a space other than the work space, A power control system, wherein the working space is an area in the vicinity of an object.

2. 2. The power control system according to claim 1, wherein the impedance setting unit changes the impedance value depending on whether the working unit is located within a set working space.

3. 2. The power control system according to claim 1, wherein the impedance setting unit changes the impedance value based on the status of the working unit, ie, when the working unit starts and finishes a predetermined task.

4. 2. The power control system according to claim 1, wherein the impedance setting unit changes the impedance value at the timing when the working unit starts a predetermined task and at the timing when a predetermined time has elapsed since the working unit started the task, as the status of the working unit.

5. A working unit configured to be able to perform a predetermined task; an operating unit configured to be able to move the working unit; a position detection unit that detects a working unit position, which is the position of the working unit; a control unit having an impedance setting unit, a calculation unit, and a drive signal generation unit, and performing impedance control on at least the operation unit; the impedance setting unit sets an impedance value in accordance with at least one of the position and the situation of the working unit, and outputs the impedance value to the calculation unit; the calculation unit calculates a driving force generated in the operation unit based on the set target position, the working unit position, and the impedance value; the drive signal generation unit outputs a drive signal to the operation unit based on the drive force; a power control system characterized in that the impedance setting unit changes the impedance value when the working unit is located within a set working space and when the working unit starts a predetermined task, and changes the impedance value again when the working unit finishes the predetermined task or when a predetermined time has elapsed since the working unit started the task.

6. 2. The power control system according to claim 1, wherein the impedance setting unit changes the impedance value when an abnormal state is detected as the state of the working unit.

7. 2. The power control system according to claim 1, wherein the impedance setting unit changes the impedance value in stages.

8. the operating unit is a robot arm, 2. The power control system according to claim 1, wherein the drive signal generating unit outputs a drive signal that controls the rotational torque of a motor provided on each axis of the robot arm.

9. A power control method for performing impedance control on at least a working unit and an operating unit that moves the working unit, comprising: a working unit position detection step of detecting a working unit position, which is the position of the working unit; an impedance value setting step of setting an impedance value in accordance with at least one of the positions of the working unit; a calculation step of calculating a driving force generated in the working unit based on the set target position, the working unit position, and the impedance value; a drive signal output step of outputting a drive signal to the operation unit based on the drive force, in the impedance value setting step, when the working unit is located in a work space, control is performed to increase the stiffness matrix in the impedance value, and when the working unit is located in a space other than the work space, control is performed to decrease the stiffness matrix in the impedance value; The work space is narrower than a space other than the work space, A power control method, wherein the working space is an area in the vicinity of an object.

10. A power control program that performs impedance control on at least a working unit and an operating unit that moves the working unit, a work unit position information input process for inputting work unit position information relating to the work unit position, which is the position of the work unit; an impedance value setting process for setting an impedance value according to at least one of the position and the situation of the working unit; a calculation process for calculating a driving force generated in the working unit based on the set target position, the working unit position, and the impedance value; a drive signal output process for outputting a drive signal to the operation unit based on the drive force; in the impedance value setting process, when the working unit is located in a work space, control is performed to increase the stiffness matrix in the impedance value, and when the working unit is located in a space other than the work space, the impedance value is set so as to decrease the stiffness matrix in the impedance value; The work space is narrower than a space other than the work space, A power control program, wherein the working space is an area in the vicinity of an object.

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