JP2018144130A - Robot hand device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot hand device that can improve control accuracy in controlling, by feedback control, operation of a finger member of a robot hand in which a relation between an operation state parameter relating to a driving part and an operation state parameter relating to the finger member to be operated by the driving part is a non-linear relation.SOLUTION: A robot hand control device 20 outputs a result obtained by multiplying an inverse matrix of products in a first matrix and in a second matrix to a calculated value to be obtained by feedback control to a driver 12 of a driving motor 60. The first matrix is set to be a Jacobian matrix of an operation state parameter of a linear moving body which transmits power to the finger member via a link mechanism and an operation state parameter of a joint of the finger member. The second matrix is set to be a Jacobian matrix of an operation state parameter of the driving motor and the operation state parameter of the linear moving body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a robot hand device.

  The present applicant has proposed the robot hand of Patent Document 1. FIG. 2 is a principle diagram of a configuration in which each finger constituting the robot hand is operated. As shown in the figure, the base end of the finger member 50 is rotatably supported by the adjacent finger support member 54 by a joint shaft 52 serving as a joint. The finger support member 54 is another adjacent finger member or a palm member. The finger member 50 is operated by a drive motor 60 that is a rotary motor provided on the finger support member 54 and a transmission mechanism 70 that transmits the power of the drive motor 60.

  The transmission mechanism 70 includes a gear head 72, a spur gear train 74 provided between the input shaft of the gear head 72 and the output shaft of the drive motor 60, and a spur gear train 76 provided between the output shaft of the gear head 72 and the input shaft of the ball screw 78. , A linear moving body (for example, a nut body) 80 that linearly moves by the ball screw 78, and a pair of links 81 and 82 connected between the linear moving body 80 and the joint shaft 52. The links 81 and 82, the ball screw 78, and the linear moving body 80 constitute a slider crank mechanism. When the drive motor 60 rotates, the spur gear train 74, the gear head 72, and the spur gear train 76 are operated to rotate the ball screw 78, and the rotation of the ball screw 78 moves the linear motion body 80, whereby a pair of links 81, The finger member 50 rotates via 82 and the joint shaft 52.

A conventional control method of the robot hand having the finger member 50 (finger) configured as described above will be described. First, various parameters related to this control method will be described. The movement amount _xb of the linear moving body 80 generated by the ball screw 78 is as follows.

Shown in thrust _{F b} type ball screw 78 caused by the motor torque τ _M (2). Note that the efficiency below is not included in the formula below.

Next, the joint angle θ _j generated by the movement amount _xb of the linear motion body 80 is shown in Expression (3). The subscript “j” is the number of joints of the robot hand 10 (see FIG. 7).

The joint torque τ _j generated by the thrust F _b of the linear motion body 80 is shown in Expression (9).

The fingertip position x _f generated by the joint angle θ _j is shown in Expression (10). The subscript “f” is the number of fingertips of the robot hand 10.

The fingertip force F _f generated by the joint torque τ _j is shown in Expression (11).

The relationship between the rotational angle theta _M and the fingertip position x _f of the drive motor 60, by the equation (10), is found to be non-linear. It can also be seen that the relationship between the motor torque τ _M of the drive motor 60 and the fingertip force F _f is also non-linear according to equation (12).

<Control of joint angle>
As shown by the control block in FIG. 7, conventional general joint angle feedback control is performed by, for example, PID control.

Explaining this PID control, as shown in FIG. 7, a subtractor 100 calculates a deviation between θ _jd , which is a target value output from a _host controller (not shown), and a joint angle θ _j, and the deviation is The proportional calculation unit 110 multiplies the proportional gain and outputs the calculation result to the adder 160.

The joint angle θ _j is calculated by the calculator 180 based on the formula (1), the formula (3), and the like. In addition, the rotation angle θ _M is detected by a detection unit (rotary encoding or the like) (not shown) provided in the drive motor 60. Expression (1), Expression (3), and parameters related to these expressions are fixed values or values calculated by Expressions (5) to (8). The fixed value is stored in a storage unit of a control device (not shown) that realizes the control block. The same applies to formulas and fixed values used in other controls. The deviation is calculated by the integrator 120 and the integral gain calculation unit 130, and the calculation result is output to the adder 160. The deviation is calculated by the differentiator 140 and the differential gain calculation unit 150, and the calculation result is output to the adder 160. The adder 160 adds a torque command u _M obtained by adding the output values of the proportional calculation unit 110, the integral gain calculation unit 130, and the differential gain calculation unit 150 to the drive motor 60 that drives each finger of the robot hand 10, respectively. Is output to a driver (not shown).

The torque command u _M obtained by the joint angle control (PID control) shown in FIG. 7 can be expressed by Expression (13).

<Control of fingertip position>
Next, conventional fingertip position control will be described. As shown by the control block in FIG. 8, the conventional general fingertip position feedback control is performed by, for example, PID control. Explaining this PID control, as shown in FIG. 8, a subtractor 200 calculates a deviation between x _fd , which is a target value output from a host controller (not shown), and the fingertip position x _f of the robot hand 10. The

Incidentally, the fingertip position x _f, associated with detection unit (not shown) provided to the drive motor 60 (10) by the arithmetic unit 280 (rotary encoding, etc.) enters the rotational angle theta _M detected, and the formula (10) It is calculated based on the equations (3) to (8) for calculating the parameters.

  The deviation is multiplied by the proportional gain and torque converted by the proportional calculation unit 210, and the calculation result is output to the adder 260. The deviation is integrated by an integrator 220, multiplied by an integral gain by an integral gain calculation unit 230, and torque converted, and the calculation result is output to an adder 260. The deviation is differentiated by a differentiator 240, multiplied by a differential gain by a differential gain calculation unit 250 and torque-converted, and the calculation result is output to an adder 260.

The adder 260 is a drive motor 60 that drives each finger of the robot hand 10 using the torque command u _M obtained by adding the output values of the proportional calculation unit 210, the integral gain calculation unit 230, and the differential gain calculation unit 250. Is output to a driver (not shown).

The torque command u _M obtained by the joint angle control (PID control) shown in FIG. 8 can be expressed by Expression (14).

<Control of joint torque>
Conventional control of joint torque will be described. As shown in the control block of FIG. 9, conventional general joint torque feedback control is performed by, for example, PI control. As shown in FIG. 9, a subtractor 300 calculates a deviation between τ _jd that is a target value output from a _host control unit (not shown) and the joint torque τ _j . The joint torque τ _j is calculated by a calculator 380 that inputs a motor torque τ _M output from a motor torque detector (not shown) (for example, a motor current detector). Specifically, the calculator 380 calculates the joint torque τ _j based on the equations (2) to (8) for calculating the parameters in the equations (9) and (9).

The proportional calculation unit 310 multiplies the deviation by the proportional gain and outputs the calculation result to the adder 360. The deviation is calculated by the integrator 320 and the integral gain calculation unit 330, and the calculation result is output to the adder 360. The adder 360 outputs the torque command u _M obtained by adding the output values of the proportional calculation unit 310 and the integral gain calculation unit 330 to a driver (not shown) of the drive motor 60 that drives each finger of the robot hand 10. To do.

The torque command u _M obtained by the joint angle control (PI control) shown in FIG. 9 can be expressed by Expression (15).

<Control of fingertip force>
The conventional fingertip force control will be described. As shown by the control block in FIG. 10, the conventional general fingertip force feedback control is performed by, for example, PI control. As shown in FIG. 10, the subtracter 400 calculates a deviation between F _fd , which is a target value output from a host controller (not shown), and fingertip force F _f . The fingertip force F _f is calculated by a calculator 480 that inputs a motor torque τ _M output from a motor torque detector (not shown) (for example, a motor current detector). Specifically, the calculator 480 calculates the joint torque τ _j based on the equations (2) and (9) for calculating the parameters in the equations (12) and (12). The proportional calculation unit 410 multiplies the deviation by a proportional gain and converts the torque, and the calculation result is output to the adder 460.

The deviation is integrated by an integrator 420, multiplied by an integral gain by an integral gain calculation unit 430 and torque-converted, and the calculation result is output to an adder 460. Further, the target value F _fd is torque-converted by the torque converter 440, and the calculation result is output to the adder 460. The adder 460 shows the torque command u _M obtained by adding the output values of the proportional calculation unit 410, the integral gain calculation unit 430, and the torque conversion unit 440 to the drive motor 60 that drives each finger of the robot hand 10, respectively. Output to the driver that does not.

The torque command u _M obtained by the joint angle control (PI control) shown in FIG. 10 can be expressed by Expression (16).

JP 2014-54720 A

Incidentally, when performing the feedback control described above the operation of the finger member of the robot hand, as described above, the relationship between the rotational angle theta _M and the fingertip position x _f of the drive motor 60, by the equation (10), a nonlinear .

Further, the relationship between the motor torque τ _M of the drive motor 60 and the fingertip force F _f is also non-linear by the equation (12). For this reason, the conventional control method described above corresponds to the nonlinear relationship between the operational state parameter related to the drive unit such as a motor and the operational state parameter related to the finger member operated by the drive unit. As a result, the control accuracy is poor.

  An object of the present invention is to control the operation of a finger member of a robot hand in which the relationship between an operation state parameter related to a drive unit and an operation state parameter related to a finger member operated by the drive unit is non-linear by feedback control. Another object of the present invention is to provide a robot hand device capable of improving the control accuracy.

  The robot hand device of the present invention includes a finger member and a finger support member that swingably supports the finger member by a joint, and the finger support member includes a linear motion body that is provided so as to freely move. A parameter that indicates the operating state of the finger member or the joint; a transmission mechanism that transmits the power of the linear motion body to the finger member in a non-linear manner to impart swinging; a drive unit that applies power to the linear motion body; A robot hand device comprising: a robot hand having an operation state acquisition unit that acquires the control unit; and a control unit that feedback-controls the operation of the finger member via the drive unit based on the parameter. The control unit outputs a result obtained by multiplying the operation value obtained by the feedback control by the inverse matrix of the product of the first matrix and the second matrix to the driver of the drive unit. And The first matrix is a Jacobian matrix of the operation state parameters of the linear motion body and the operation state parameters of the joint, and the second matrix is a Jacobian matrix of the operation state parameters of the drive unit and the operation state parameters of the linear motion body. .

  The drive unit may be a rotary motor, the linear motion body may be linearly moved by a ball screw operatively connected to the rotary motor, and the transmission mechanism may be a link mechanism.

The drive unit may be a linear motion motor that linearly moves the linear motion body, and the transmission mechanism may be a link mechanism.
The operating state acquisition unit is configured to detect or calculate a joint angle of the joint as a parameter indicating the operating state of the joint, and the operating state parameter of the driving unit is an operating amount of the driving unit. In addition, the operating state parameter of the linear moving body may be a movement amount of the linear moving body, and the operating state parameter of the joint may be a joint angle.

  The operating state acquisition unit is configured to acquire or calculate the tip position of the finger member as a parameter indicating the operating state of the finger member, and the operating state parameter of the driving unit is an operation of the driving unit. The operating state parameter of the linear moving body may be a movement amount of the linear moving body, and the operating state parameter of the joint may be a joint angle.

  In addition, the operating state acquisition unit acquires or calculates the joint torque of the joint as a parameter indicating the operating state of the joint, and the operating state parameter of the driving unit is a driving unit torque, The operating state parameter of the linear moving body may be a thrust of the linear moving body, and the operating state parameter of the joint may be a joint torque.

  In addition, the operating state acquisition unit acquires the tip force of the finger member as a parameter indicating the operating state of the finger member by detection or calculation, and the operating state parameter of the driving unit is a driving unit torque. The operating state parameter of the linear moving body may be a thrust of the linear moving body, and the operating state parameter of the joint may be a joint torque.

  According to the present invention, when the operation of the finger member of the robot hand in which the relationship between the operation state parameter related to the drive unit and the operation state parameter related to the finger member operated by the drive unit is nonlinear is controlled by feedback control. In addition, the control accuracy can be improved.

The whole robot hand apparatus schematic. The operation principle figure of the finger member of a robot hand. The control block diagram of the robot hand of 1st Embodiment. The control block diagram of the robot hand of 2nd Embodiment. The control block diagram of the robot hand of 3rd Embodiment. The control block diagram of the robot hand of 4th Embodiment. The control block diagram of the conventional robot hand. The control block diagram of the conventional robot hand. The control block diagram of the conventional robot hand. The control block diagram of the conventional robot hand. The operation principle figure of the finger member of the robot hand of the 5th-8th embodiments. Explanatory drawing of the design parameter of a slider crank mechanism.

(First embodiment)
Hereinafter, a robot hand device according to a first embodiment embodying the present invention will be described with reference to FIGS. 1, 2, and 3. This embodiment is an example for controlling the joint angle.

As shown in FIG. 1, the robot hand device includes a robot hand 10 and a robot hand control device 20 that controls the robot hand 10. The robot hand control device 20 corresponds to a control unit. Since the structure which operates each finger which comprises the robot hand 10 of this embodiment is the same as FIG. 2 demonstrated by background art, detailed description of each member is abbreviate | omitted. The links 81 and 82 correspond to a link mechanism, and the transmission mechanism 70 has a link mechanism. Thus, the relationship between the rotational angle theta _M and the fingertip position x _f of the drive motor 60 is a non-linear, and has a non-linear the relationship between the motor torque tau _M and the fingertip force F _f of the drive motor 60.

As shown in FIG. 1, the robot hand control device 20 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown). In the present embodiment, the upper control unit 30 and the motor control unit 40 are configured by the CPU. The host control unit 30 outputs various command values (that is, target values) for controlling the robot hand 10 to the motor control unit 40. The motor control unit 40, based on the various command value, a torque command u _M, and outputs to the driver 12 of the driving motor 60 as a driving unit. The driver 12 drives the drive motor 60 based on the torque command _{u M.}

1, the driving motor 60 as shown in FIG. 2, a detector 62 and a detector 64 for detecting a motor torque tau _M, detects the rotational angle theta _M of the motor. The detection part 62 consists of rotary encoding etc., for example. The detection unit 64 may be configured by, for example, a torque sensor, or detects a motor current applied to the drive motor 60 applied from the driver 12 and detects torque based on the motor current. It may be.

<Control of joint angle>
Next, feedback control of the joint angle of the robot hand 10 by the robot hand control device 20 will be described.

  As shown in FIG. 3, the feedback control of the joint angle according to the present embodiment is PID control. In the present embodiment, the configuration of the control block of FIG. 7 described in the background art is different in that the multiplier 170 is provided on the output side of the adder 160. Therefore, each control block described in the background art is different. The same or corresponding components are denoted by the same reference numerals and description thereof is omitted.

The multiplier 170 multiplies the operation value output from the adder 160 by (J ₂ J ₁ ) ⁻¹ and outputs the obtained value to the driver 12 shown in FIG. 1 as the torque command u _M.
The torque command u _M obtained by the joint angle control (PID control) shown in FIG. 3 can be expressed by Expression (17).

Here, _{J 2} and _{J 1} is represented by the formula (19) and (18).

Incidentally, J ₁ is a fixed value (i.e., constant) since the advance gain (proportional gain, integral gain, differential gain) may be included in. J ₂ is a variable value and is calculated by the multiplier 170.

J ₁ is a Jacobian matrix of the rotation angle θ _M (actuation amount) of the drive motor 60 (drive unit) and the movement amount of the linear motion body, and corresponds to the second matrix. The rotation angle corresponds to an operation amount of the drive unit and an operation state parameter of the drive unit.

Meanwhile, J ₂ is a Jacobian matrix of movement and joint angle of the linear motion body, corresponding to the first matrix. The joint angle corresponds to a joint operating state parameter. The computing unit 180 corresponds to an operating state acquisition unit.

This embodiment has the following features.
(1) As described above, in this embodiment, the driver 12 uses the result obtained by multiplying the operation value obtained by the feedback control of the joint angle by the inverse matrix of the product of the first matrix and the second matrix. Output to. For this reason, even if it has a transmission mechanism that non-linearly transmits the power of the linear moving body 80 to the finger member 50 and imparts swinging, the operation of the finger member of the robot hand, that is, the joint angle is feedback-controlled. When controlling with, the control accuracy can be improved.

(Second Embodiment)
With reference to FIG. 4, the robot hand apparatus of the second embodiment, that is, the robot hand apparatus that controls the fingertip position will be described. In the following embodiments including this embodiment, the hardware configuration of the robot hand apparatus is the same as that of the first embodiment, and thus the description of the hardware configuration is omitted.

<Control of fingertip position>
Next, feedback control of the fingertip position will be described.
As shown in FIG. 4, the feedback control of the fingertip position according to the present embodiment is PID control. In the present embodiment, the configuration of the control block of FIG. 8 described in the background art is different in that the multiplier 270 is provided on the output side of the adder 260. The same or corresponding components are denoted by the same reference numerals and description thereof is omitted.

Multiplier 270 multiplies the operation value output from adder 260 by (J ₂ J ₁ ) ⁻¹ and outputs the obtained value to driver 12 shown in FIG. 1 as torque command u _M. The multiplier 270 has the same configuration as that of the multiplier 170 of the above embodiment.

Torque command u _M obtained by joint angle control (PID control) shown in FIG. 4 can be expressed by equation (20).

In the present embodiment, the calculator 280 corresponds to an operating state acquisition unit.

This embodiment has the following features.
(1) In this embodiment, the result obtained by multiplying the calculated value obtained by the feedback control of the fingertip position by the inverse matrix of the product of the first matrix and the second matrix is output to the driver 12. For this reason, even if it has a transmission mechanism that transmits the power of the linear moving body 80 to the finger member 50 in a non-linear manner to impart swing, the operation of the finger member of the robot hand, that is, the fingertip position is feedback-controlled. When controlling with, the control accuracy can be improved.

(Third embodiment)
With reference to FIG. 5, a robot hand apparatus according to a third embodiment, that is, a robot hand apparatus that controls joint torque will be described.

<Control of joint torque>
As shown in FIG. 5, the feedback control of the joint torque of this embodiment is PI control. In the present embodiment, since the multiplier 370 is provided on the output side of the adder 360 in the configuration of the control block of FIG. 9 described in the background art, each control block described in the background art is different. The same or corresponding components are denoted by the same reference numerals and description thereof is omitted.

The multiplier 370 multiplies the operation value output from the adder 360 by (J ₄ J ₃ ) ⁻¹ and outputs the obtained value as a torque command u _M to the driver 12 shown in FIG.
Torque command u _M obtained by joint torque control (PI control) shown in FIG. 5 can be expressed by equation (21).

Here, _{J 3} and _{J 4} are represented by the formula (22) and (23).

Incidentally, J ₃ is, to become a fixed value, it may be included in the pre-gain (proportional gain, integral gain).

J ₃ is, and the motor torque tau _M of the driving motor 60 (driving unit), a Jacobian matrix of the thrust of the linear motion body, corresponding to the second matrix. Here, the motor torque τ _M corresponds to the operating state parameter of the driving unit and the driving unit torque. The thrust of the linear moving body corresponds to the operating state parameter of the thrust of the linear moving body.

Meanwhile, J ₄ is a Jacobian matrix of the thrust and joint torque translatory bodies, corresponding to the first matrix. The joint torque corresponds to a joint operating state parameter. The computing unit 380 corresponds to an operation state acquisition unit.

This embodiment has the following features.
(1) As described above, in the present embodiment, the driver 12 uses the result obtained by multiplying the calculated value obtained by the feedback control of the joint torque by the inverse matrix of the product of the first matrix and the second matrix. Output to. For this reason, even if it has a transmission mechanism that non-linearly transmits the power of the linear moving body 80 to the finger member 50 and imparts swinging, the operation of the finger member of the robot hand, that is, the joint torque is feedback-controlled. When controlling with, the control accuracy can be improved.

(Fourth embodiment)
With reference to FIG. 6, the robot hand apparatus of 4th Embodiment, ie, the robot hand apparatus which controls fingertip force, is demonstrated.

<Control of fingertip force>
As shown in FIG. 6, the feedback control of the fingertip force of the present embodiment is PI control.
In the present embodiment, since the multiplier 470 is provided on the output side of the adder 460 in the configuration of the control block of FIG. 9 described in the background art, each control block described in the background art is different. The same or corresponding components are denoted by the same reference numerals and description thereof is omitted.

The multiplier 470 multiplies the operation value output from the adder 460 by (J ₄ J ₃ ) ⁻¹ and outputs the obtained value to the driver 12 shown in FIG. 1 as a torque command u _M.
Torque command u _M obtained by fingertip force control (PI control) shown in FIG. 6 can be expressed by equation (24).

The calculator 480 corresponds to an operating state acquisition unit.

This embodiment has the following features.
(1) In this embodiment, the result obtained by multiplying the calculated value obtained by the feedback control of the fingertip force by the inverse matrix of the product of the first matrix and the second matrix is output to the driver 12. For this reason, even if it has a transmission mechanism that transmits the power of the linear moving body 80 to the finger member 50 in a non-linear manner to impart swing, the operation of the finger member of the robot hand, that is, the fingertip force is feedback-controlled. When controlling with, the control accuracy can be improved.

Next, fifth to eighth embodiments will be described.
As shown in FIG. 11, in the robot hand apparatus of the fifth to eighth embodiments, the ball screw 78 and the transmission mechanism 70 (gear head 72, spur gear trains 74 and 76) are omitted in the hardware configuration of the first to fourth embodiments. In addition, the drive motor 60 that is a rotary motor of the linear motion body 80 is changed to a linear motion motor (for example, a linear motor). That is, the configuration of the slider crank mechanism is changed. In FIG. 11, the linear motion motor 90 is a flat type linear motor, and the movable element 94, which is the linear motion body, is directly connected to the stator 92 in which NS magnet rows (not shown) are alternately arranged in the movable direction. It is supposed to move. Other configurations of the robot hand device are configured in the same manner as in the first to fourth embodiments. The linear motor is not limited to the flat type, and may be of other types.

(Fifth embodiment)
5th Embodiment is an example for the robot hand apparatus shown in FIG.1 and FIG.11 to control a joint angle.

<Control of joint angle>
3, in the present embodiment, the multiplier 170 multiplies the operation value output from the adder 160 by (J ₂ J ₁ ) ⁻¹ and uses the obtained value as the torque command u _M as shown in FIG. , Output to the driver 12.

In the present embodiment, since the movable element 94 (linear motion body) is driven by the linear motion motor 90 as described above, the Jacobian matrix J ₁ = 1. From this fact, the multiplier 170 substantially multiplies (J ₂ ) ⁻¹ .

The torque command u _M obtained by the joint angle control (PID control) shown in FIG. 3 can be expressed by Expression (25).

(Sixth embodiment)
The sixth embodiment is an example for the robot hand device shown in FIGS. 1 and 11 to control the fingertip position.

<Control of fingertip position>
4, in the present embodiment, the multiplier 270 multiplies the operation value output from the adder 260 by (J ₂ ) ^−1, and uses the obtained value as the torque command u _M, as shown in FIG. 12 is output.

Similar to the fifth embodiment, in this embodiment, the multiplier 170 multiplies (J ₂ ) ^−1, which is different from the first embodiment that multiplies (J ₂ J ₁ ) ^−1. However, since the movable element 94 (linear motion body) is driven by the linear motion motor 90 as described above, the Jacobian matrix J ₁ = 1. From this, it is synonymous to multiply (J ₂ J ₁ ) ⁻¹ .

Torque command u _M obtained by fingertip position control (PID control) shown in FIG. 4 can be expressed by equation (26).

(Seventh embodiment)
7th Embodiment is an example for the robot hand apparatus shown in FIG.1 and FIG.11 to control a joint torque.

<Control of joint torque>
3, in this embodiment, the multiplier 370 multiplies the operation value output from the adder 360 by (J ₄ J ₃ ) ⁻¹ and uses the obtained value as the torque command u _M as shown in FIG. , Output to the driver 12.

In the present embodiment, since the movable element 94 (linear motion body) is driven by the linear motion motor 90 as described above, the Jacobian matrix J ₃ = 1. From this, the multiplier 370 substantially multiplies (J ₄ ) ⁻¹ .

Torque command u _M obtained by joint torque control (PI control) shown in FIG. 5 can be expressed by equation (27).

(Eighth embodiment)
The eighth embodiment is an example for the robot hand apparatus shown in FIGS. 1 and 11 to control the fingertip force.

<Control of fingertip force>
In FIG. 6, in the present embodiment, the multiplier 470 multiplies the operation value output from the adder 460 by (J ₄ J ₃ ) ⁻¹ and uses the obtained value as the torque command u _M as shown in FIG. , Output to the driver 12.

In the present embodiment, since the movable element 94 (linear motion body) is driven by the linear motion motor 90 as described above, the Jacobian matrix J ₃ = 1. From this, the multiplier 370 substantially multiplies (J ₄ ) ⁻¹ .

Torque command u _M obtained by fingertip force control (PID control) shown in FIG. 6 can be expressed by equation (28).

In addition, embodiment of this invention is not limited to the said embodiment, You may change as follows.

In the first embodiment and the fifth embodiment, the joint angle θ _j is calculated by the calculator 180. However, the angle detector that detects the joint angle θ _j is provided on the joint shaft 52 as an operation state acquisition unit, and the calculator 180 may be omitted.

· In the second embodiment and the sixth embodiment, the fingertip position x _f calculated in calculator 280, is provided to the finger member 50 to the position detector for detecting a fingertip position x _f as the operating state acquisition unit, the arithmetic unit 280 may be omitted.

-In 3rd Embodiment and 7th Embodiment, although the joint torque (tau) _j was computed with the calculator 380, the joint torque detection part which detects joint torque (tau) _j is provided in the joint shaft 52 as an operation state acquisition part, and is calculated. The device 380 may be omitted.

· In the fourth embodiment and the eighth embodiment, the finger force F _f is calculated by the arithmetic unit 480, is provided at the tip of the finger member 50 for detecting the finger force F _f, it may be omitted calculator 180 . For example, as the working state acquiring unit and the pressure sensor, provided in the finger tip of the finger member to grip an object, may be detected fingertip force F _f by pressure sensor.

-You may change embodiment (1st Embodiment, 2nd Embodiment, 5th Embodiment, 6th Embodiment) demonstrated by PID control to PI control, PD control, or P control.
-You may change embodiment (3rd Embodiment, 4th Embodiment, 7th Embodiment, and 8th Embodiment) demonstrated by PI control into PID control, PD control, or P control.

-In the said 2nd Embodiment and 6th Embodiment, it was set as control of the fingertip position, However, It is also possible to make it feedback control of the front-end | tip position of finger members other than a fingertip.
The transmission mechanism 70 is not limited to a link mechanism, and may be another mechanism that transmits power in a non-linear manner.

<Robot hand design method>
A robot hand design method will be described with reference to FIG.
The design parameters of the robot hand using the slider crank mechanism are the finger length r of the finger member, the design parameters l ₁ , l ₂ , l ₃ , x of the slider crank mechanism, the fingertip force F _f , and the joint torque τ _j .

The design method of these design parameters is as follows: (1) fingertip force F _f , finger length r, (2) joint torque τ _j , (3) slider crank mechanism design parameters l ₁ , l ₂ , l ₃ , x, ( 4) It is necessary to determine each of the design parameters regarding the speed reduction mechanism between the ball screw (screw member) and the drive motor (drive unit), and (5) motor characteristics.

Generally, the design parameters (3) to (5) are obtained by trial and error based on the determined design parameter (1). Note that the joint torque τ _j in (2) is generally uniquely determined based on Expression (11) if the parameter in (1) is determined.

However, for example, even if the design parameters (4) and (5) are determined and these are used as conditions, (3) cannot be uniquely determined because there are a plurality of parameter candidates. In the first embodiment, the speed reduction mechanism between the ball screw 78 and the drive motor 60 (drive unit) is composed of spur gear trains 74 and 76 and a gear head 72. Therefore, (4), and the parameters related to the reduction mechanism between a ball screw and a motor (drive unit), gearhead reduction ratio G _h, mechanism reduction ratio (spur gear, etc.) is a G _b, Horuneji lead P _h.

  Here, when miniaturization of the robot finger, and hence miniaturization of the robot hand, is one of the issues, the options for miniaturizing the drive motor and ball screw are limited for the design parameters (4) and (5). The

Therefore, (4) and (5) are determined on the assumption that the downsizing is an issue, and on this condition, design parameters l ₁ , l ₂ , l of the slider crank mechanism as shown in FIG. _{3 If} the area (or sum) surrounded by x is determined to be the smallest, the problem of miniaturization can be solved. Note that the design parameters (4) and (5) may be set before, after, or simultaneously with the settings (1) and (2).

From the above, the following technical idea can be found as a design method of design parameters of the robot hand that solves the problem of miniaturization of the robot hand with the robot finger.
<Technical ideas other than the present invention>
A finger member, and a finger support member that swingably supports the finger member by a joint,
The finger support member includes a drive unit, a deceleration mechanism that decelerates the rotation of the drive unit, and a transmission mechanism that transmits the power of the drive unit to the joint via the deceleration mechanism.
The transmission mechanism includes a screw member, a linear motion body that linearly moves by the screw member, and a plurality of links that transmit the linear motion of the linear motion body to the joint in a non-linear manner to impart swinging to the finger member. In a robot hand design method including a slider crank mechanism, a first step of determining a finger length and a fingertip force of the finger member, a second step of calculating a joint torque based on the fingertip force, This is a third stage that is performed before, after, or simultaneously with the order of the stage and the second stage, and selects design parameters relating to the speed reduction mechanism and characteristics of the drive unit for the purpose of minimizing the robot hand. When determining the design parameters of the third stage and the slider crank mechanism, the area of the shape that is two-dimensionally surrounded by the design parameters of the slider crank mechanism is minimized. , A method of designing a robot hand comprising a fourth step of calculating the design parameters of the slider crank mechanism.

10 ... Robot hand, 12 ... Driver,
20 ... Robot hand control device (control unit),
30 ... Host control unit, 40 ... Motor control unit, 50 ... Finger member,
52 ... Joint shaft (joint), 54 ... Finger support member, 60 ... Drive motor,
62, 64 ... detector, 70 ... transmission mechanism, 72 ... gear head,
74, 76 ... spur gear train, 78 ... ball screw, 80 ... linear motion body,
81, 82 ... Link (link mechanism), 90 ... Linear motion motor, 92 ... Stator,
94: Movable element (linear motion body), 100: Subtractor, 110: Proportional calculation unit,
120 ... integrator, 130 ... integral gain calculation unit, 140 ... differentiator,
150 ... differential gain calculation unit, 160 ... adder, 170 ... multiplier,
180 ... arithmetic unit (operation state acquisition unit), 200 ... subtractor,
210 ... Proportional calculation unit, 220 ... Integrator, 230 ... Integral gain calculation unit,
240 ... differentiator, 250 ... differential gain calculator, 260 ... adder,
270 ... multiplier, 280 ... operator (operation state acquisition unit),
300 ... Subtractor, 310 ... Proportional calculation unit, 320 ... Integrator,
330 ... integral gain calculation unit, 360 ... adder, 370 ... multiplier,
380 ... Calculator (operating state acquisition unit), 400 ... Subtractor,
410 ... proportional calculation unit, 420 ... integrator, 430 ... integral gain calculation unit,
440 ... Torque converter, 460 ... Adder, 470 ... Multiplier,
480... Arithmetic unit (operation state acquisition unit).

Claims (7)

A finger member; and a finger support member that swingably supports the finger member by a joint. The finger support member includes a linear motion body that is provided so as to be linearly movable, and power of the linear motion body is transmitted to the finger. A transmission mechanism for nonlinearly transmitting the member to impart swinging, a drive unit for applying power to the linear motion body, and an operation state acquisition unit for acquiring a parameter indicating an operation state of the finger member or the joint; A robot hand having,
A robot hand device including a control unit that feedback-controls the operation of the finger member via the drive unit based on the parameter,
The control unit outputs a result obtained by multiplying an arithmetic value obtained by the feedback control by an inverse matrix of a product of a first matrix and a second matrix to the driver of the driving unit,
The first matrix is a Jacobian matrix of the operating state parameter of the linear motion body and the operating state parameter of the joint,
The second matrix is a robot hand device that is a Jacobian matrix of operating state parameters of the drive unit and operating state parameters of the linear motion body.   2. The robot hand apparatus according to claim 1, wherein the drive unit is a rotary motor, the linear moving body is linearly moved by a ball screw operatively connected to the rotary motor, and the transmission mechanism is a link mechanism.   The robot hand apparatus according to claim 1, wherein the drive unit is a linear motion motor that linearly moves the linear motion body, and the transmission mechanism is a link mechanism. The operating state acquisition unit detects or calculates the joint angle of the joint as a parameter indicating the operating state of the joint,
The operating state parameter of the driving unit is an operating amount of the driving unit,
The operating state parameter of the linear moving body is a movement amount of the linear moving body,
The robot hand apparatus according to claim 2, wherein the joint operation state parameter is a joint angle. The operating state acquisition unit detects or calculates the tip position of the finger member as a parameter indicating the operating state of the finger member,
The operating state parameter of the driving unit is an operating amount of the driving unit,
The operating state parameter of the linear moving body is a movement amount of the linear moving body,
The robot hand apparatus according to claim 2, wherein the joint operation state parameter is a joint angle. The operating state acquisition unit detects or calculates the joint torque of the joint as a parameter indicating the operating state of the joint,
The operating state parameter of the driving unit is a driving unit torque,
The operating state parameter of the linear moving body is a thrust of the linear moving body,
The robot hand apparatus according to claim 2, wherein the joint operation state parameter is joint torque. The operating state acquisition unit acquires the tip force of the finger member as a parameter indicating the operating state of the finger member by detection or calculation,
The operating state parameter of the driving unit is a driving unit torque,
The operating state parameter of the linear moving body is a thrust of the linear moving body,
The robot hand apparatus according to claim 2, wherein the joint operation state parameter is joint torque.