Manipulator

• US 5,047,701 A
• Filed: 06/12/1990
• Issued: 09/10/1991
• Est. Priority Date: 06/12/1989
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Mohri, Satoshi, Takarada, Shinichi
• Primary Examiner(s): Ip, Paul
• Application Number:
  US07/536,801
• Time in Patent Office: 455 Days
• Field of Search: 318/560-646, 364/513, 364/424.1, 364/424.01, 364/424.06, 901/9, 901/13, 901/15-22, 901/40, 901/47
• US Class Current: 700/246
• CPC Class Codes: B25J 9/161 Hardware, e.g. neural networks, fuzzy logic, interfaces, processor
• CPC Class Codes: G05B 19/19 characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
• 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
• CPC Class Codes: G05B 2219/34065 Fuzzy logic, controller
• CPC Class Codes: G05B 2219/37357 Force, pressure, weight or deflection
• CPC Class Codes: G05B 2219/37425 Distance, range
• CPC Class Codes: G05B 2219/37572 Camera, tv, vision
• CPC Class Codes: Y10S 706/90 Fuzzy logic

Abstract

A manipulator having a plurality of articulations to be controlled with a given destination value of position and orientation, has a finite difference unit for obtaining a finite difference between the destination value and a present value for each articulation, and a fuzzy inference determination unit for executing a fuzzy inference for each articulation by using the finite difference and determining a command value for each articulation. The position of the manipulator terminal may be obtained on the basis of each articulation angle data, video data from a TV camera, or data from an ultrasonic sensor.

Claims

1. A manipulator system having a plurality of articulations, comprising:

destination coordinate means for giving a destination coordinate value of the position and orientation of the terminal of a manipulator;

present coordinate means for giving a present coordinate value of the position and orientation of the terminal of said manipulator;

finite difference generating means connected to said destination coordinate means and said present coordinate means for generating finite differences between said destination coordinate value and said present coordinate value; and

fuzzy inference means connected to said finite difference generating means for executing a fuzzy inference of said finite differences data for at least one of said plurality of articulations.

2. A manipulator system according to claim 1, further comprising angle sensor means for detecting the angle of each of said plurality of articulations of said manipulator and supplying said angle to said present coordinate means.

3. A manipulator system according to claim 2, wherein the number of said plurality of articulations of said manipulator is seven.

4. A manipulator system according to claim 1, wherein said present coordinate means includes a plurality of TV camera means for measuring the present coordinate value of the position and orientation of the terminal of said manipulator.

5. A manipulator system according to claim 1, wherein said fuzzy inference means includes weighting means for weighting, with respect to the position of said terminal of said manipulator, articulations near the base of said manipulator greater than articulations near the terminal of said manipulator.

6. A manipulator system according to claim 1, wherein said present coordinate means includes ultrasonic measurement means for measuring the present coordinate value of the position and orientation of said terminal of said manipulator.

7. A manipulator system according to claim 1, wherein said manipulator has a master-slave manipulator function.

8. A controller for a manipulator having a plurality of articulations, comprising:

means for giving a finite difference set between a destination value and a present value of the position and orientation of the terminal of said manipulator; and

means for determining a command value for each articulation angle by executing a fuzzy inference of said articulations with respect to at least one articulation.

9. A controller according to claim 8, further comprising a sensor for giving a present value of the position and orientation of said terminal of said manipulator.

10. A controller according to claim 9, wherein said sensor is a TV camera.

11. A controller according to claim 9, wherein said sensor is an ultrasonic sensor.

12. A controller according to claim 10, wherein said manipulator is a manipulator having a redundant degree of freedom.

13. A controller according to claim 11, wherein said manipulator is a master-slave manipulator.

14. A control method for a manipulator having a plurality of articulations, comprising:

a step of giving a finite difference set between a destination value and a present value of the position and orientation of the terminal of said manipulator; and

a step of executing a fuzzy inference of said articulations with respect to at least one articulation and determining a command value for each articulation angle.

15. A control method according to claim 14, further comprising a step of using a fuzzy rule which executes a fuzzy inference of an articulation near the base of said manipulator while giving an emphasis on the finite differences of the position of said manipulator terminal greater than the finite differences of the orientation.

16. A control method according to claim 14, further comprising a step of obtaining a present value of the position and orientation of said manipulator terminal by subjecting each manipulator articulation angle to coordinate transformation.