Master-slave manipulators with scaling

• US 4,853,874 A
• Filed: 11/20/1987
• Issued: 08/01/1989
• Est. Priority Date: 12/12/1986
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Hiroshi, Iwamoto, Taro, Nakajima, Kichio, Aoki, Tatsu
• Primary Examiner(s): MACDONALD, ALLEN R
• Application Number:
  US07/123,276
• Time in Patent Office: 620 Days
• Field of Search: 364/513, 318/568, 414/1-5, 901/2-5, 901/8
• US Class Current: 700/249
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: G05B 19/427 Teaching successive positions by tracking the position of a joystick or handle to control the positioning servo of the tool head, master-slave control G05B19/423 takes precedence

Abstract

In a controlling apparatus of a manipulator equipped with a master arm and a slave arm, a processing device is provided for effecting scale conversion calculation of a calculation result representing the position data of the master arm for expansion or reduction, and for outputting the result of this calculation to the slave arm.

Claims

1. In a manipulator equipped with a master arm having a plurality of links connected to one another by joints to provide a terminal end which is moveable within a reference coordinate system and a slave arm having a plurality of links connected to one another by joints, a controlling apparatus for controlling said slave arm to follow the motion of said master arm comprising:

position sensors each for sensing a displacement of each of said joints of said master arm and for providing displacement data indicative thereof;

processing means for calculating the position of the terminal end of said master arm in said reference coordinate system on the basis of said displacement data, for executing expansion or reduction scale conversion of the result of said calculation and for determining a reference displacement value for each of said joints of said slave arm on the basis of a scale-converted result of calculation; and

servo controller means for controlling each of said joints of said slave arm in accordance with a reference displacement value from said processing means.

2. In a manipulator according to claim 1, wherein said processing means includes:

first calculation means for calculating the position coordinate value of said terminal end in the reference coordinate system of said master arm on the basis of the displacement data from said position sensors;

second calculation means for performing scale conversion by multiplying the position coordinate value of said terminal end of said master arm from said first calculation means by a predetermined scale conversion factor;

third calculation means for calculating the scale-converted position coordinate value of said terminal end in the reference coordinate of said slave arm; and

fourth calculation means for converting the scale-converted position coordinate value of the terminal end of said master arm from said second calculation means to reference displacement values for control of said slave arm.

3. In a manipulator according to claim 2, further including means for arbitrarily setting said predetermined scale conversion factor and wherein said second calculation means includes memory means for storing said scale conversion factor.

4. In a manipulator according to claim 2, further including means for changing a zoom ratio of a television camera for photographing a terminal of said slave arm and wherein said second calculation means includes means for setting said scale conversion factor in response to a change in the zoom ratio.

5. In a manipulator equipped with a master arm having a plurality of links connected to one another by joints and a slave arm having a plurality of links connected to one another by joints, a controlling apparatus for controlling said slave arm to follow the motion of said master arm comprising:

position sensors for detecting displacement of said joints of said master arm and for producing the displacement data indicative thereof;

differentiater means for detecting the amount of change in the displacement of each of said joints of said master arm from the displacement data produced by said position sensors;

processing means for calculating the amount of change of a terminal position of said master arm in a reference coordinate system on the basis of the amount of change in the displacement of each of said joints of said master arm detected by said differentiater means, for effecting scale conversion by expanding or reducing the result of calculation and for determining an amount of change of displacement of each of said joints of said slave arm on the basis of said scale-converted result of calculation;

incrementer means for adding the amount of change of displacement of each of said joints of said slave arm from said processing means to a present position of each of said joints of said slave arm and obtaining a reference displacement quantity; and

servo controller means for controlling each of said joints of said slave arm in accordance with the reference displacement quantity from said incrementer means.

6. In a manipulator according to claim 5, wherein said processing means includes;

first calculation means for calculating the amount of change of the coordinate value of the terminal position of the master arm in the reference coordinate system on the basis of the change in the amount of displacement of each of said joints of said master arm;

second calculation means for performing a scale conversion by multiplying the coordinate value calculated by said first calculation means by a predetermined scale conversion factor; and

third calculation means for converting the scale-converted coordinate value of said master arm from said second calculation means to a reference displacement quantity for each of said joints of said slave arm.

7. In a manipulator according to claim 6, wherein second calculation means includes memory means for storing a scale conversion factor that can be set arbitrarily.

8. In a manipulator according to claim 6, wherein said second calculation means includes means for setting a scale conversion factor in response to a change of a zooming ratio of a television camera for photographing the terminal position of said slave arm.

9. A processing device for a controlling apparatus of a manipulator, which comprises:

first calculation means for calculating a coordinate value in a reference coordinate system of a terminal position of a master arm on the basis of displacement data of said master arm;

second calculation means for performing a scale conversion by multiplying the coordinate value calculated by said first calculation means for predetermined scale conversion factor; and

third calculation means for converting a scale-converted coordinate value of said master arm received from said second calculation means to a coordinate value of a position of a slave arm.

10. A processing device for a controlling apparatus of a manipulator, which comprises:

first calculation means for calculating a coordinate value in the reference coordinate system of a terminal end of a master arm on the basis of displacement data relating to the position of said master arm;

means for changing a zoom ratio of a television camera for photographing a terminal end of a slave arm having a plurality of joints and setting a scale conversion factor;

second calculation means for producing scale conversion by multiplying the coordinate value received from said first calculation means by said scale conversion factor; and

third calculation means for converting the scale-converted coordinate value received from said second calculation means to a coordinate value of said slave arm and determining a reference displacement value for each of said joints of said slave arm.

11. A method of controlling a manipulator equipped with a master arm having plural joints and a slave arm having plural joints to control said above arm to follow the motion of said master arm, comprising the steps of:

sensing displacement of each of the joints of said master arm;

calculating the position of a terminal end of said master arm in a reference coordinate system;

executing expansion or reduction scale conversion of the result of calculation of the position of said terminal end;

determining a reference displacement value for each of said joints of said slave arm; and

controlling each of said joints of said slave arm in accordance with said determined reference displacement values.

12. A method of controlling a manipulator equipped with a master arm having plural joints and a slave arm having plural joints to control said slave arm to follow the motion of said master arm, comprising the steps of:

detecting displacement of said joints of said master arm;

detecting a change in amount of displacement in each of said joints of said master arm;

calculating an amount of change of a terminal end of said master arm in a reference coordinate system on the basis of a change in displacement of each of said joints of said master arm;

effecting scale conversion by expanding or reducing the result of calculation of the amount of change of said terminal end;

determining an amount of change in the displacement of each of said joints of said slave arm;

adding the amount of change of each of said joints of said slave arm to the position of each of said joints of said slave arm and obtaining a reference displacement quantity; and

controlling each of said joints of said slave arm in accordance with a reference displacement quantity.

13. A controlling apparatus of a manipulator having a master arm having at least one joint and a slave arm having at least one joint, which comprises:

means for sensing displacement of each of the joints of said master arm;

means for calculating a position of a terminal end of said master arm in a reference coordinate system;

means for executing an expansion or reduction scale conversion of the result of the calculation by said calculating means;

means for determining a reference displacement value for each of the joints of said slave arm in response to said executing means; and

means for controlling each of said joints of said slave arm in accordance with reference displacement values from said determining means.

14. A processing device for a controlling apparatus of a manipulator, which comprises:

means for calculating a terminal position coordinate value in a reference coordinate system of a master arm on the basis of displacement data relating to a position of said master arm;

means for effecting scale conversion by multiplying the terminal position coordinate value of said master arm received from said calculating means by a scale factor; and

means for converting the scale-converted coordinate value produced by said scale conversion means to coordinate values representing a position of a slave arm.

15. A processing device for a controlling apparatus of a manipulator, which comprises:

means for calculating a position of a control member;

means for executing expansion or reduction scale conversion of the result of the calculation by said calculating means and for determining a reference displacement value of a working member on the basis of the scale-converted result.

16. A processing device for a controlling apparatus of a manipulator, which comprises:

means for calculating an amount of change of a position of a control member in a reference coordinate system on the basis of data from a position sensor for detecting displacement of said control member;

means for executing expansion or reduction scale conversion of the result of the calculation by said calculating means and for determining an amount of change of a position of a working member on the basis of the scale-converter result.

17. In a controlling apparatus of a manipulator having a master arm and a slave arm, the improvement comprising:

means for changing a zoom ratio of a television camera for photographing a terminal of said slave arm and setting a scale conversion factor; and

means for executing a scale conversion by multiplyign a coordinate value of a position of a master arm by said scale conversion factor, so as to produce a control displacement value to control the position of said slave arm.

18. A controlling apparatus of a manipulator equipped with a master arm and a slave arm which operates while following up the motion of the master arm, comprising:

processing means for effecting conversion matrix calculation to produce expansion or reduction of the value of a calculation result representing information as to the position of the master arm; and

control means for controlling the position of said slave arm on the basis of the calculation result by said processing means.

19. A method of controlling of a manipulator equipped with a master arm and slave arm to control said slave arm to follow the motion of said master arm, comprising the steps of:

calculating a position of the master arm upon movement of the master arm;

effecting a scale conversion matrix calculation for producing predetermined expansion or reduction of the value of the result of calculation of the position of the master arm; and

outputting the result of said scale conversion matrix calculation to the slave arm to control the position thereof.