JPH1133952A - Method for controlling robot, and method for correcting position and attitude of robot and held object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease offset of the position and the attitude of an end effector even if the attitude of an object is changed, in the operation accompanying the contact of the object and the environment, to be generated by a robot arm and a compliancecontrolled end effector. SOLUTION: When the operation for pressing an object to the environment is performed by a robot arm, the target position of the object, in a hand base coordinate system, in which the hand can most easily operate the object is given to a target command determining unit 1A of the arm in the start of the operation, and a target command xd is formed. In the operation, the position in the hand base coordinate system of the gripping object and the attitude are calculated from information of the tip positions of respective fingers by a compliance calculating unit 4A and sequentially sent to the target command determining unit 1A of the arm, the difference between the position of the object, the attitude and the preset target position and attitude of the object is found, transformed into the coordinate system of the arm, the target position and attitude is added to it, and the target command xd is formed on the basis of it and sent to the compliance calculating unit 2A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling compliance of a robot arm and an end effector having compliance, and a method for correcting the position and orientation of an object held by using two or more multi-fingered hands.

[0002]

2. Description of the Related Art When an operation involving physical contact with an object or the outside world is performed by a robot, it is general that the end effector itself has compliance. In this case, it is conceivable to provide a mechanical compliance mechanism such as an RCC device in the end effector, control the compliance of the end effector itself, or control the compliance of the robot arm. The compliance control of the robot arm is a force control method for making the robot softly move using the position and posture of the robot arm tip and the force applied to the arm tip. In this method, the motion of a model in which the parameters of elasticity, viscosity, and inertia are virtually set is realized by the motion of the robot, and the apparent response characteristics of the robot can be freely set by changing the values of the parameters. be able to. Compliance control is

[0003]

(Equation 1)

[0004] This is expressed by a characteristic equation: Where M
Is a virtual inertia coefficient, D is a virtual viscosity coefficient, K is a virtual elastic coefficient, F is a force received by the tip of the arm, Fd is a target force, x is a current position of the tip of the arm, and xd is a target position. The external force F applied to the tip of the arm is measured by a force sensor, and the robot is controlled so as to satisfy the expression (1) or (2). As a generally used technique, as shown in FIG. 7 or FIG. 8, a value to be followed by a robot according to a compliance model is obtained by a compliance calculation unit 2A or 2B from equation (1) or (2), and the position of the value is calculated. Kinematics calculation unit 3 calculates the joint angles of the robot corresponding to
There is a control method that determines the position of the robot and uses it as a position command to the robot. When a multi-finger hand is considered as one of the end effectors, as shown in Japanese Patent Application Laid-Open No. 5-177566, it has been shown that cooperative control using compliance control enables stable gripping even when a disturbance is applied. I have.

When a task involving contact with an object is performed by a robot arm, a method of controlling compliance of the arm itself, a method of attaching a compliance-controlled tool to the end of the arm, and a method combining them are used to reduce environmental errors and the like. Can be expected to realize high-precision work. Here, an example is shown in which an operation of pressing a certain surface of an operation target against a certain surface of an environment is performed by a robot arm having a multi-finger hand that is compliance-controlled as an end effector. FIGS. 9 and 10 are control block diagrams of the control system, which include a target command determination unit 13, a compliance calculation unit 4A or 4B, and an inverse kinematics calculation unit 5. The pressing operation is realized by approaching the environment while maintaining the posture of the object so that the pressing surfaces are parallel to each other. Here, by setting the parameters of Equation (1) or Equation (2) so that the compliance regarding the rotation of the object becomes soft, even when the relative position and posture between the pressing environment and the object are uncertain. The pressing operation is achieved in a manner following the object.
FIG. 9 shows a case where there is an error between the expected environment surface 16 and the actual environment surface 15 in the operation of pressing the object 14 grasped by the compliance-controlled multi-finger hand 13 on the expected environment surface 16 by the robot arm 11. The object 14 and the environment 1 in a different form from the target, such as 11
5 contacts occur. The force and moment generated by the contact between the object 14 and the environment surface 15 are transmitted to the hand force sensor 12.
Is converted into a force 19 and a moment 20 at the compliance center 17 in the control system, and is used as F in the equation (1) or (2). Here, if the virtual elastic coefficient K of rotation about the compliance center 17 is set soft, the object rotates in the direction of the applied moment 20 and changes its posture. Further, the position of the compliance center 17 moves to the equilibrium point of the set K and the external force 18. Therefore, if the setting of the parameters is appropriate, the pressing of the object 14 against the environmental surface 15 is achieved as shown in FIG.

The multi-fingered hand can obtain higher responsiveness to an external force or moment than an arm. Therefore, by using the compliance control of the multi-fingered hand, it is possible to respond faster and flexibly to environmental changes and errors than when only the arm is used. An object is grasped by using a multi-fingered hand having a plurality of fingers,
In addition, the position of the object can be changed while being held. FIG. 13 shows a conceptual block diagram of this method. The multi-fingered hand 21 has two fingers 22, each finger 22 has three degrees of freedom, the position of the finger control point 23 is controlled by the finger control unit 24, and each finger control unit 24 receives a finger from the hand control unit 25. It is controlled as a hand by sending the position command of the control point 23.
The fingertip of each finger 22 has a spherical shape with a radius r around the finger control point 23. When an object is gripped by using the multi-fingered hand 21, information on the shape of the object to be gripped and the grip point on the object is given to the hand control unit 25. Hand control unit 2
In step 5, the position of each finger control point 23 for gripping the object is determined based on this information. For example, when the grip point 29 is given on the grip target object 28 as shown in FIG. 14, since the shape of the finger tip is a sphere, the finger control point of the corresponding finger is vertically r away from the object plane. Hand control unit 2
5 determines the position command of the finger control point 23. The position command is sent to each finger control unit 24, and the finger control point 23 realizes the designated position, thereby gripping the object. Further, when the position is moved while holding the object, this is realized by moving each finger control point in the same direction and the same distance as shown in FIG.

[0007]

In the above-described conventional method, most of the environmental errors are absorbed by the multi-fingered hand having higher responsiveness. As described above, the posture of the multi-fingered hand may be greatly inclined with respect to the base of the hand. Therefore, when the position and orientation of the object is further operated by the hand thereafter, there is a problem that the operable range is limited. This problem is not limited to the multi-fingered hand, and is a problem that always occurs when the compliance-controlled end effector is used.
In addition, since the equation (2) is satisfied in a state where a deviation from the target posture has occurred, the external force does not match the target. These problems are not limited to the multi-fingered hand, but always occur when using an arm having an end effector controlled in compliance.

In the conventional method, when the position of the finger is changed to move the position of the object, the posture of the finger also changes, and the position of the contact point between the finger and the object shifts accordingly. However, there is a problem that it is not possible to determine an accurate position and orientation of the object because the position and orientation of the object change. For example, for an object gripped at grip points a and b as shown in FIG.
Set the axis, y-axis, and z-axis directions. When the control position of each finger gripped in order to move this object by the distance L in the z-axis direction as shown in FIG. 17 is moved L in the z direction, the grip points are a, b, and To a ′, b ′, and an error occurs between the position of the object and the target position by the amount of change in the gripping position. Also, as shown in FIG.
When moved, the grip point changes to a ′ and b ′, and the orientation of the object changes because the direction in which the grip point changes is different. Correcting this change by calculation requires accurate geometric information of a fingertip or a grasped object, and the amount of calculation is large, making it difficult to realize.

SUMMARY OF THE INVENTION An object of the present invention is to reduce the deviation of the position and posture of the end effector even when the posture of the object changes in an operation involving contact between the robot arm and the end effector controlled by compliance with the environment of the object. To provide a robot compliance control method. Another object of the present invention is that it does not require detailed geometric information of a multi-fingered hand or a grasped object, and has a small calculation process.
An object of the present invention is to provide a position / posture compensation method for a grasped object.

[0010]

A first robot control method according to the present invention is directed to a robot control method in which an end effector is attached to a tip of an arm, wherein the end effector determines the position or posture from the tip of the arm. When there is at least one degree of freedom to change, one or more of these degrees of freedom are given mechanical or control compliance, and the operation of changing the posture of the object by external force is performed. In advance, the position and orientation of the object as viewed from the end effector, in which the end effector is the easiest to operate the object, are determined in advance, and changes in the position and orientation of the object during operation are measured by the end effector, and this is fixed. The position and posture of the arm are changed so as to maintain the position.

Therefore, the end effector changes the posture according to the external force applied to the object so that the object follows the environment by the compliance control, and at the same time, the arm is moved to its position so that the external force applied to the object becomes equal to the target force. If the posture is changed, the state where the posture of the end effector is biased due to the posture change of the object as shown in FIG. 12 is changed to the state where the external force and the target force are equal, that is, the posture where the object can be easily operated as shown in FIG. become. This facilitates the subsequent operation of the accurate position and orientation of the object by the end effector. The first robot according to the present invention includes a multi-finger hand, a force sensor attached to each arm tip, a target command of each finger tip position in the hand base coordinate system, and force information from each finger force sensor. A compliance control unit that performs compliance calculation based on each fingertip and determines a position of each fingertip, solves inverse kinematics for each finger, converts each fingertip position into a joint angle command, and sends an inverse kinematics calculation to the multi-fingered hand. When the robot arm performs the operation of pressing the target object to the environment with the hand control unit including the unit, the target position and target posture of the target object in the hand base coordinate system that makes it easy for the hand to operate the target object move Given at the start, a target command is created from these target position, target attitude, and the current position and current attitude of the object. The difference between the position and posture of the object in the hand base coordinate system and the target position and target posture of the object given in advance, obtained in the section, is converted into a value in the coordinate system of the arm, and In addition to the target position, the target attitude, a target command determination unit that generates a target command based on the target command, based on the target command and force information from the force sensor of the arm,
A compliance calculation unit that calculates a target position and a target posture of the arm, and an inverse kinematics calculation unit that calculates a joint angle of the arm that realizes the target position and the target posture and performs position control using the angle as a command to the robot arm. Including an arm control unit.

According to a second robot control method of the present invention, there is provided a robot control method having a robot arm having a plurality of degrees of freedom and an end effector having at least one degree of freedom attached to a tip of the arm. Each end effector is controlled for compliance, each compliance control center is set to the same point,
When the end effector is set to take the posture that makes it easy to operate the object when the external force and the target force are equal, and when the operation that the posture of the object changes due to the external force is performed,
A target force equal to each of the arm and the end effector is given in advance to perform compliance control, an external force applied to the object during operation is measured at the end effector and the arm, and the position of each part of the arm such that this is equal to the target force, It is to change the posture.

According to the embodiment of the present invention, the target force in the compliance control between the arm and the end effector is made to coincide. According to a second robot of the present invention, in a robot having a compliance-controlled multi-fingered hand attached to the tip of a compliance-controlled robot arm, a force sensor attached to the tip of the multi-fingered hand arm and an object are provided. Based on the target command of each finger tip position in the hand base coordinate system for grasping and the force information from the force sensor of each finger, the external force applied to the compliance center is determined, and the finger force of each finger for grasping the object is determined. A compliance calculator that performs coordination including coordination, determines a fingertip position, and solves inverse kinematics for each finger, converts each fingertip position into a joint angle command, and sends it to the multi-fingered hand. Hand control unit including tics calculation unit and target command to move the arm tip to final target position and target posture A target command determination unit that generates, based on the target command and force information from the force sensor of the arm, converts the force information into a force at the compliance center, and determines a target position and a target attitude at the compliance center. And an arm control unit including an inverse kinematics calculation unit for performing position control in which a joint angle of an arm for realizing the target position and the target posture is obtained, and the obtained angle is used as a command to the robot arm.

According to a third robot of the present invention, in a robot having a compliance-controlled multi-fingered hand attached to the tip of a compliance-controlled robot arm, a force sensor attached to the multi-fingered hand and an object are connected. Based on the target command of each finger tip position in the hand base coordinate system for grasping and the force information from the force sensor of each finger, the external force applied to the compliance center is determined, and the finger force of each finger for grasping the object is determined. A compliance calculator that performs coordination including coordination, and a compliance calculator that determines each fingertip position, solves inverse kinematics for each finger, converts each fingertip position into a joint angle command, and sends it to the multi-fingered hand. Generates a hand control unit including a tics calculation unit and a target command to move the arm tip to the final target position and target posture A target command determining unit, a coordinate system converting unit that converts an external force applied to the compliance center measured by the multi-fingered hand into a force in a robot base coordinate system, and a target command from the target command unit and a command from the coordinate converting unit. A compliance controller that calculates compliance based on force information, determines the position of each fingertip, solves the inverse kinetics for each finger, converts each fingertip position into a joint angle of the arm, and converts this to the robot arm. And an arm control unit including an inverse kinematics calculation unit that performs position control as a command of the above.

According to a fourth robot of the present invention, in a robot having an arm tip and an RCC device mechanically provided with a contour, a force sensor attached to the arm tip and an arm tip attached to a final target. position,
A target command determining unit that generates a target command for moving to a target posture, a compliance calculator that performs compliance calculation based on the target command and force information from the force sensor, and determines an arm position, a reverse kinematics To convert the arm position to the joint angle of the arm,
An arm control unit including an inverse kinematics calculation unit that performs position control using this as a command to the robot arm is provided.
The method for correcting the position and orientation of a grasped object according to the present invention is a method for correcting the position and orientation of an object grasped by using two or more multi-fingered hands, and the method of correcting an object generated when the grasped object is moved. The displacement of the position and orientation is measured in advance for a plurality of representative points, and based on this, the displacement of the position and orientation of the object when the grasped object is moved is estimated and corrected.

[0016]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the robot according to the first embodiment of the present invention. This is one in which a compliance-controlled multi-finger hand 8 is attached to the tip of a compliance-controlled robot arm. In the arm control unit, the target command determination unit 1A passes a target command xd for moving the tip of the arm to the final target position and posture to the compliance calculation unit 2A in time series. In the compliance calculation unit 2A, the target command xd
And the force information F from the force sensor 6 to calculate the target position and posture of the arm tip based on the characteristic equation (1), and calculate the joint angle of the arm for realizing the target position and posture.
And position control is performed using this as a command to the robot arm. Similarly, the hand control unit 4A also includes the compliance calculation unit 4A based on the target command xd of each finger tip position in the hand base coordinate system for gripping the target object and the force information from the force sensor 7 of each finger. The compliance calculation is performed to determine each fingertip position xd '. The inverse kinematics is solved for each finger by the inverse kinematics calculation unit 5 and
The joint angle command θ is sent to the multi-fingered hand 8.

When an operation of pressing the object to the environment is performed by the robot arm, in the present embodiment, the target position and the posture in the hand base coordinate system of the object in advance so that the hand can move the object most easily are previously operated. At the start, the target command xd is given to the target command determining section 1A of the arm, and a target command xd is created based on the target, the target position and posture of the arm, and the current position and posture information of the target object. During operation, the compliance calculation unit 4A calculates the position and orientation of the object to be grasped in the handbase coordinate system from information on the tip position of each finger. In this embodiment, the position and orientation information of the target is sequentially sent to the target command determination unit 1A of the arm. The target command determining unit 1A obtains a difference between the position and orientation of the object and a predetermined target position and orientation of the object, converts the difference into a coordinate system of the arm, and adds the result to the target position and orientation of the arm. , And sends it to the compliance calculator 2A. As a result, the position and posture of the arm are controlled so as to compensate for a deviation from the optimum posture of the hand during the pressing operation.

FIG. 2 is a block diagram of a robot according to a second embodiment of the present invention. In the hand control unit, based on a target command of each finger tip position in a hand base coordinate system for gripping an object and force information F from the force sensor 7 of each finger,
The external force applied to the compliance center is obtained, and the compliance calculation unit 4B performs the compliance calculation including the coordination of each finger for gripping the object by the specific equation (2) to determine the position of each fingertip. The reverse kinematics is solved by the reverse kinematics unit 5 for each finger, and a joint angle command is sent to the multi-finger hand 8. In the arm control unit, the target command determination unit 1B passes the target commands for moving the tip of the arm to the final target position and posture to the compliance calculation unit 2B in time series. In the compliance calculator 2B, the target command xd and the force information F from the arm force sensor 6 are obtained.
The force information F is converted into a force at the center of compliance based on the following formula, a target position and posture xd ′ at the center of compliance are calculated, and the joint angle θ of the arm for realizing this is obtained by the inverse kinematics calculation unit 3. Is performed as a command to the robot arm. The center of compliance control between the arm and the hand is set to the same coordinates. As a result, the external force applied to the compliance center required by each of the arm and the hand becomes equal.

In the present embodiment, when an operation of pressing an object to the environment is performed by the robot arm, a target force at the compliance center of the pressing operation is given to the compliance calculation unit 4B of the hand control unit in a hand base coordinate system. To the compliance control unit 2B of the unit, a value obtained by converting the target force given to the hand to the robot base coordinate system according to the change in the posture of the arm is always given. In addition, the target position and orientation of the object in the hand base coordinate system are given to the hand so that the hand can operate the object most easily when the external force and the target force are equal. In operation, the compliance calculation unit 4B obtains a force at the center of compliance based on the information on the tip position of each finger of the multi-finger hand 8 and the force information F measured by the force sensor 7 on each finger tip. The position of the object in the hand-based coordinate system,
Calculate posture. Arm compliance calculator 2B
Then, the arm position and posture are calculated from the external force applied to the center of compliance from the external force F measured by the force sensor of the arm, the target force given in advance, the current position and posture of the arm, and the target command. Here, by setting the virtual elastic coefficient of the arm to 0 or a very small value, the position and posture of the arm are controlled so that the external force and the target force are equal. Since the compliance center and the target force of the arm and the hand are set to be the same, the target force and the external force are equal in the hand during the pressing operation, and as a result, the deviation from the optimal posture of the hand is compensated.

FIG. 3 is a block diagram of a robot according to a third embodiment of the present invention. In the present embodiment, the arm does not have a force sensor, and the external force applied to the center of compliance measured by the end effector is converted into a robot base coordinate system by the coordinate system conversion unit 9 and sequentially sent to the compliance calculation unit 2C of the arm. In the compliance calculator 2C,
The position and posture of the arm are calculated from the external force applied to the object, the target force given in advance, the current position and posture of the arm, and the target command. Subsequent steps are the same as in the second embodiment.
In this example, a force sensor for the arm is not required, but a coordinate system conversion for the force information is required. FIG. 4 is a block diagram of a robot according to a fourth embodiment of the present invention. In the present embodiment, the end of the arm is not an end effector that is compliance-controlled, but has an RCC device 10 that is mechanically given compliance. In this end effector, the arm is controlled such that the compliance center mechanically determined and the compliance center of the arm coincide with each other. The relationship between the target force applied to the compliance center and the posture of the end effector is mechanically determined in advance, and the target force for optimizing the posture of the end effector is given to the compliance calculation unit 2B of the arm control unit.
In this example, the control of the end effector becomes unnecessary and the mechanism is simplified, but it becomes difficult to change the compliance of the end effector.

FIG. 6 is a block diagram of a robot according to a fifth embodiment of the present invention. The operation of grasping and moving an object using a multi-fingered hand having two fingers will be described as an example.
The position of each finger control point for gripping the object is determined from the hand control unit 25 based on the information of the shape of the grip object and the grip point on the object given in advance. 24, and each finger realizes the designated position, thereby gripping the object. The position of the object in the gripped state is set as an initial value. After the grasp of the object is completed, the hand control unit 25 starts the correction data collection operation. In this operation, first, the object is moved from the initial position to a representative point given in advance. Here, FIG.
The point moved by L in the x-axis, y-axis, and z-axis directions is a representative point. After moving the object to each position, the deviation of the position and orientation of the object is measured, and the correction value of the control position of each finger is corrected using the fingertip position input interface 26 so as to correct the deviation of the position and orientation. Enter As a method of measuring the displacement of the position and orientation of the object, a method using a visual sensor, a method of measurement by a multi-fingered hand operator, and the like can be considered. The hand control unit 25 stores the input correction value of the finger control position in the fingertip position correction value calculation unit 27. When the correction values of the positions of the finger control points for all the representative points are input, the operation of collecting the correction data ends. When actually performing the work of moving the object, a correction value of the position of each finger control point after movement is calculated in advance by the fingertip position correction calculation unit 27 using the correction data, and the hand control unit 25 calculates the correction value of the movement. By adding this correction value to the position of each finger control point for correcting the position and orientation of the grasped object after the movement. Here, it is assumed that the correction value of each finger control position by the movement of the x-axis, y-axis, and z-axis methods is proportional to the movement amount, and the movement amounts in the x-axis, y-axis, and z-axis directions at the time of work and L and , The value of each finger control position is obtained. For example,
If the correction value in the x-axis direction of the finger at the representative point where the object has been moved by L to the x-axis is a, the correction value in the x-axis direction of the finger when the amount of movement of the object in the x-axis direction is 1 b is represented by equation (3).

[0022]

## EQU2 ## b = a × 1 / L (3)

[0023]

As described above, the present invention has the following effects. 1) According to the first and second aspects of the present invention, in an operation involving contact of an operation target with the environment using a robot arm having an end effector having compliance at the tip, the target of the arm is adjusted in accordance with a change in the position and orientation of the target. By changing the command, there is an effect that the deviation of the end effector from the optimal posture can be reduced and the operability of the object by the end effector can be improved thereafter. 2) The invention according to claims 3 to 7 is directed to an operation involving contact of an operation target with an environment using a robot arm which can be divided and controlled into a tip having compliance and a plurality of degrees of freedom. By controlling the compliance of each part of the arm so that the external force applied to the object is equal to the target force of the tip, the deviation of the arm tip from the optimal posture is reduced, and the object is subsequently moved by the arm. This has the effect of improving operability.

3) In the multi-finger hand having two or more fingers, the displacement of the position and orientation of the object caused when the grasped object is moved is determined in advance for a plurality of representative points. By measuring and correcting the displacement of the object's position and orientation when moving the grasped object based on this, and correcting this, the geometric information and complex calculations of the multi-fingered hand and the grasped object are compared to the conventional method. This is advantageous in that the position and orientation of an arbitrary multi-fingered hand can be compensated for the movement of the object to be grasped without the need for the hand.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram showing the posture of an arm and a hand at the time when pressing is achieved using the present invention.

FIG. 6 is a block diagram showing a fifth embodiment of the present invention.

FIG. 7 is a block diagram of a first conventional example.

FIG. 8 is a block diagram of a second conventional example.

FIG. 9 is a block diagram of a third conventional example.

FIG. 10 is a block diagram of a fourth conventional example.

FIG. 11 is a diagram showing a force relationship at the time when an object comes into contact with an environment during a pressing operation.

FIG. 12 is a diagram showing the posture of the arm and the band at the time when the pressing is achieved.

FIG. 13 is a configuration diagram of a conventional object grasping system using a multi-fingered hand.

FIG. 14 is a diagram illustrating a method of determining a finger control point for gripping an object.

FIG. 15 is a diagram illustrating movement of a grasped object due to movement of a finger control point.

FIG. 16 is a diagram showing a grip point and a coordinate system when an object is gripped by the multi-fingered hand.

FIG. 17 is a diagram illustrating a shift in the position and orientation of an object when the object to be gripped is moved by the multi-fingered hand.

FIG. 18 is a diagram illustrating a shift in the position and orientation of an object when the object to be gripped is moved by the multi-fingered hand.

[Explanation of symbols]

 1A, 1B Target command determination unit (arm) 2A, 2B Compliance calculation unit (arm) 3 Reverse kinematics calculation unit (arm) 4A, 4B Compliance calculation unit (hand) 5 Reverse kinematics calculation unit (hand) 6,7 force Sense sensor 8 Multi-fingered hand 9 Coordinate conversion unit 10 RCC device 11 Robot arm 12 Force sensor 13 Multi-fingered hand 14 Object to be operated 15 Actual environment 16 Expected environment 17 Compliance control center 18 Object received from environment Force 19 Force at compliance center 20 Moment at compliance center 21 Multi-finger hand 22 Finger 23 Finger control point 24 Finger control unit 25 Hand control unit 26 Fingertip position input interface 27 Fingertip position correction value calculation unit 28 Grasping Object 29 Gripping point

Claims (8)

[Claims] 1. A method for controlling a robot in which an end effector is attached to an end of an arm, wherein the end effector has at least one degree of freedom for changing a position or a posture from the end of the arm. At least one of the degrees is provided with mechanical or control compliance, and when performing an operation that changes the posture of the object due to external force, the end effector is the easiest to operate the object. The position and orientation of the object viewed from the viewpoint are determined in advance, the change in the position and orientation of the object during operation is measured with an end effector, and the position and posture of the arm are changed so as to keep this constant. How to control a robot. 2. A robot in which a compliance-controlled multi-fingered hand is attached to the tip of an arm, wherein the multi-fingered hand, a force sensor attached to the tip of the arm, and the position of each finger tip in a hand base coordinate system. A compliance control is performed based on the target command and force information from the force sensor of each finger to determine the position of each fingertip, and reverse kinematics is solved for each finger, and the position of each fingertip is set to a joint angle command. And a hand control unit including an inverse kinematics calculation unit for sending the multi-fingered hand to the multi-fingered hand, and an object that allows the hand to operate the object most easily when the robot arm performs an operation of pressing the object against the environment. The target position and target attitude in the hand base coordinate system are given at the start of the operation, and these target position, target attitude, current position of the object, and The target command is created from the current posture and the current posture, and at the time of operation, the position and posture in the hand base coordinate system of the target object and the predetermined target position and target posture of the target object obtained in the compliance calculation unit of the hand control unit. And a target command determination unit for converting the difference into a value in the coordinate system of the arm to generate a target command based on the target position and the target posture of the arm, and a target command and an arm force. Based on force information from the sense sensor, a compliance calculation unit that calculates a target position and a target posture of the arm, and a joint angle of the arm that realizes the target position and the target posture are obtained, and this is set as a command to the robot arm. A robot having an arm control unit including an inverse kinematics calculation unit for performing position control. 3. A robot arm having a plurality of degrees of freedom,
In a control method of a robot having an end effector having at least one degree of freedom attached to a tip of the arm, the arm and the end effector are respectively subjected to compliance control, the respective compliance control centers are set to the same point, and the end effector is controlled by an external force. When the target force is the same as the target force, the target object is set to take the posture that is most easy to operate.When performing an operation that changes the posture of the target object due to external force, the target force equal to each of the arm and the end effector is set. Perform compliance control by giving in advance,
A robot control method characterized in that an external force applied to a target object during operation is measured by an end effector and an arm, and the position and orientation of each part of the arm are changed such that the force becomes equal to a target force. 4. The robot control method according to claim 1, wherein the target force in the compliance control between the arm and the end effector is made equal. 5. A robot having a compliance-controlled multi-fingered hand attached to the tip of a compliance-controlled robot arm, a multi-fingered hand, a force sensor attached to the tip of the arm, and a gripper for gripping an object. Based on the target command of each finger tip position in the hand base coordinate system and the force information from the force sensor of each finger, find the external force applied to the center of compliance, including the coordination of each finger to grasp the object A compliance calculator that performs compliance calculations and determines each fingertip position, and an inverse kinematics calculator that solves inverse kinematics for each finger, converts each fingertip position into a joint angle command, and sends it to the multi-finger hand. And a target command for moving the tip of the arm to a final target position and target posture. A target command determining unit, based on the target command and force information from a force sensor of the arm,
Convert force information into compliance-centric force,
A target command determination unit that calculates a target position and a target posture of the compliance center, and an inverse kinematics calculation that calculates a joint angle of an arm that achieves the target position and the target posture and performs position control using the joint angle as a command to a robot arm. A robot having an arm control unit including a unit. 6. A robot in which a compliance-controlled multi-fingered hand is attached to the tip of a compliance-controlled robot arm, a force sensor attached to the multi-fingered hand, and a hand base coordinate for gripping an object. Based on the target command of each finger tip position in the system and the force information from the force sensor of each finger, the external force applied to the compliance center is calculated, and the compliance calculation including the coordination of each finger to grasp the target object is performed. Hand control including a compliance calculator for determining each fingertip position, solving inverse kinematics for each finger, converting each fingertip position to a joint angle command, and sending the joint angle command to the multi-finger hand. A target command determining unit for generating a target command for moving the tip of the arm to the final target position and target posture; A coordinate system conversion unit that converts an external force applied to the compliance center measured by the multi-fingered hand into a force in a robot base coordinate system, and a compliance calculation based on a target command from the target command unit and force information from the coordinate conversion unit. And a compliance control unit that determines the position of each fingertip, solves the inverse kinematics for each finger, converts the position of each fingertip into a joint angle of the arm, and performs position control as a command to the robot arm. A robot having an arm control unit including an inverse kinematics calculation unit. 7. A robot having an arm tip and an RCC device mechanically provided with a conformance, wherein a force sensor attached to the arm tip and the arm tip are moved to a final target position and target posture. A target command determining unit for generating a target command for performing a compliance calculation based on force information from the target command and the force sensor, determining an arm position, solving inverse kinematics, A robot having an arm control unit including an inverse kinematics calculation unit that performs position control by converting a position into a joint angle of an arm and using the angle as a command to a robot arm. 8. A method for correcting the position and orientation of an object grasped by using two or more multi-fingered hands, wherein the displacement of the position and orientation of the object caused by moving the grasped object is calculated by a plurality of methods. A method of correcting the position and orientation of a grasped object, which measures in advance a representative point and estimates and corrects a deviation of the position and orientation of the object when the grasped object is moved based on the measurement.