Control system for unmanned carrier vehicle

• US 5,218,542 A
• Filed: 04/01/1991
• Issued: 06/08/1993
• Est. Priority Date: 03/30/1990
• Status: Expired due to Fees

• Current Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Inventors: Toda, Masaaki, Endo, Shinichiro, Kanazawa, Junpei, Egawa, Takami
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/678,598
• Time in Patent Office: 799 Days
• Field of Search: 364/424.02, 364/424.01, 364/443, 364/424.05, 180/167-169, 358/103
• US Class Current: 701/27
• CPC Class Codes: G05D 1/0221 involving a learning process
• CPC Class Codes: G05D 1/0223 involving speed control of the vehicle vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00
• CPC Class Codes: G05D 1/0263 using magnetic strips
• CPC Class Codes: Y10S 706/90 Fuzzy logic

Abstract

A control system for an unmanned carrier vehicle, capable of automatically and independently traveling along a guiding line laid on a floor, provides a steering angle control unit and/or a velocity control unit. Herein, when the unmanned carrier vehicle is deviated from the guiding line, its deviation is detected. By performing a time-differentiation on the deviation, a deviation direction of the unmanned carrier vehicle is computed. In addition, a steering angle of a steering wheel of the unmanned carrier vehicle is detected by a sensor provided at a wheel of the unmanned carrier vehicle. Based on a result of a fuzzy inference to be performed on the deviation, deviation direction and steering angle, the steering angle control unit controls the steering angle of the unmanned carrier vehicle. Similarly, the velocity control unit controls a traveling velocity of the unmanned carrier vehicle. Incidentally, the fuzzy inference is performed in accordance with the predetermined fuzzy control regulation.

Claims

1. In a steering angle control unit for an unmanned carrier vehicle capable of automatically traveling along a guiding line laid on a floor by itself, said steering angle control unit comprising:

detection means for detecting a deviation of said unmanned carrier vehicle to be deviated from said guiding line, thereby outputting a deviation signal;

computation means for performing a time-differentiation on said deviation signal to thereby compute a deviation direction of said unmanned carrier vehicle;

steering angle detecting means for detecting a steering angle of a wheel of said unmanned carrier vehicle; and

control means for performing a fuzzy inference on said deviation, said deviation direction and said steering angle at a current timing, thereby controlling said steering angle of the wheel of said unmanned carrier vehicle based on a result of the fuzzy inference.

2. In a velocity control unit for an unmanned carrier vehicle capable of automatically traveling along a guiding line laid on a floor by itself, said velocity control unit comprising:

control signal generating means for generating a first control signal which value is proportional to a positional deviation of said unmanned carrier vehicle to be deviated from said guiding line, and also generating a second control signal which is obtained by performing a time-differentiation on said positional deviation; and

control means, responsive to said first and second control signals, for performing a fuzzy inference on a fuzzy set defined by a plurality of membership functions in accordance with a predetermined fuzzy control regulation, thereby controlling a traveling velocity of said unmanned carrier vehicle based on a result of the fuzzy inference.

3. In a velocity control unit for an unmanned carrier vehicle capable of automatically traveling along a guiding line laid on a floor by itself, said velocity control unit comprising:

control signal generating means for generating a first control signal which value is proportional to a steering angle by which said unmanned carrier vehicle is steered along the guiding line, and also generating a second control signal which is obtained by performing a time-differentiation on the steering angle; and

control means, responsive to said first and second control signals, for performing a fuzzy inference on a fuzzy set defined by a plurality of membership functions in accordance with a predetermined fuzzy control regulation, thereby controlling a traveling velocity of said unmanned carrier vehicle based on a result of the fuzzy inference.

4. In a control unit for an unmanned carrier vehicle capable of automatically traveling along a guiding line laid on a floor by itself, said control unit comprising:

detection means for detecting a deviation of said unmanned carrier vehicle to be deviated from said guiding line, thereby outputting a deviation signal;

computation means for performing a time-differentiation on said deviation signal to thereby compute a deviation direction of said unmanned carrier vehicle;

steering angle detecting means for detecting a steering angle of a wheel of said unmanned carrier vehicle;

traveling velocity detecting means for detecting a traveling velocity of said unmanned carrier vehicle; and

control means for performing a fuzzy inference on said deviation, said deviation direction and said steering angle at a current timing, thereby controlling said steering angle and said traveling velocity based on a result of the fuzzy inference.