Control device for controlling a controlled apparatus, and a control method therefor

• US 5,430,642 A
• Filed: 06/04/1991
• Issued: 07/04/1995
• Est. Priority Date: 06/04/1990
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Saito, Yutaka, Morooka, Yasuo, Hattori, Satoshi, Kawakami, Junzo, Katayama, Yasunori, Nakajima, Masaaki
• Primary Examiner(s): Gordon, Paul P.
• Application Number:
  US07/710,124
• Time in Patent Office: 1,491 Days
• Field of Search: 364/148, 364/153, 364/161-163, 364/469, 364/472, 72/203, 72/224, 72/225, 395/20, 395/21, 395/23
• US Class Current: 700/50
• CPC Class Codes: B21B 1/463 in a continuous process, i.e. the cast not being cut before rolling
• CPC Class Codes: B21B 13/147 Cluster mills, e.g. Sendzimir mills, Rohn mills, i.e. each work roll being supported by two rolls only arranged symmetrically with respect to the plane passing through the working rolls
• CPC Class Codes: B21B 2265/06 Interstand tension
• CPC Class Codes: B21B 37/28 Control of flatness or profile during rolling of strip, sheets or plates
• CPC Class Codes: B65H 2557/22 Fuzzy logic
• CPC Class Codes: B65H 43/00 Use of control, checking, or safety devices, e.g. automatic devices comprising an element for sensing a variable
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor
• CPC Class Codes: G05B 13/0285 using neural networks and fuzzy logic
• CPC Class Codes: H05B 1/00 Details of electric heating devices
• CPC Class Codes: H05B 6/067 for melting furnaces
• CPC Class Codes: H05B 6/34 Arrangements for circulation of melts

Abstract

In order to control an apparatus, such as a rolling mill, a control device may use a pre-set operation pattern to generate a preset command signal, which is then modified. That first modification may be part of a feedback loop in dependence on the variation of a variable operation device of the apparatus, on a plurality of pre-set signals may be combined by fuzzy logic. Then the relationship between the modified pre-set command signal and the variation of the variable operation device is investigated to generate a compensation signal which is used to modify further the pre-set command signal. In a feedback loop, that further modification may compensate for changes in the operating point of the loop, due to changes in the apparatus being controlled. In a fuzzy logic arrangement, the compensation signal may be a further control pattern developed by the control device itself, which is combined with the pre-set patterns by fuzzy logic. The control device may be in the form of a series of modules.

Claims

1. A system comprising a controlled apparatus and control device for controlling said controlled apparatus;

i) said controlled apparatus comprising;

at least one variable operation device;

operating means for operating said at least one variable operation device; and

detector means for detecting an operation of said at least one variable operation device and for generating a state signal corresponding to said operation;

(ii) said control device comprising;

first means for storing at least one pre-set operation pattern for said at least one variable operation device and for generating a pre-set command signal for a point value of the operation of said at least one variable operation device, said first means also being arranged for generating a pre-set state signal;

second means for generating a modification signal for modifying said pre-set command signal, thereby to generate a command signal for controlling said operation means so as to vary said point value of the operation, said second means being a feedback means for detecting a difference between said pre-set state signal and said state signal, thereby to generate said modification signal as a feedback signal; and

analysis means for;

(a) determining a relationship between said command signal and said state signal, and

(b) generating a compensation signal on the basis of said relationship,

wherein said control device is arranged further to modify said pre-set command signal on the basis of said compensation signal, and to control said operating means thereby.

2. A system according to claim 1, further including means for detecting when said modification signal exceeds a predetermined limit, and said analysis means is arranged to determine said relationship when said modification signal exceeds said predetermined limit.

3. A system according to claim 1, wherein said analysis means is arranged to generate a plurality of said compensation signals, and said second means is a fuzzy logic system for selectively combining at least some of said plurality of said compensation signals, and said system is arranged further to modify said pre-set command signal as the basis of the combination of said compensation signals by said second means.

4. A system according to claim 1, wherein said analysis means is arranged to generate a plurality of said compensation signals, includes a fuzzy logic system for selectively combining at least some of said plurality of said compensation signals, and is arranged to perform further modifying of said pre-set command signal on the basis of the combination of said compensation signals by said fuzzy logic system.

5. A system according to claim 1, wherein said first means is arranged to store a plurality of said pre-set operation patterns, and said second means is a fuzzy logic system for selectively combining at least some of said pre-set operation patterns to generate said command signal.

6. A system according to claim 5, wherein said analysis means is arranged to generate a plurality of said compensation signals, and said second means is arranged selectively to combine said plurality of compensation signals, thereby to further modify said pre-set command signals.

7. A system according to claim 1, wherein said analysis means has a plurality of modules each arranged to generate a corresponding compensation signal;

a first one of said modules being arranged to analyze said command signal and said state signal and to generate first one of said compensation signals when said state signal includes a first pattern, and having means for generating a first module signal representing said first pattern when said state signal includes said first pattern;

a second one of said modules being arranged to derive a first difference between said state signal and said first module signal, and to generate a second one of said compensation signals when said difference includes a second pattern.

8. A system according to claim 7, wherein:

said second one of said modules is arranged to generate a second module signal representing said second pattern when said difference includes said second pattern; and

a third one of said modules is arranged to derive a second difference between said first and second module signals, and to generate a third one of said compensation signal when said second difference includes a third pattern.

9. A system according to claim 1, having a plurality of said variable operation devices.

10. A system according to claim 1, wherein said controlled system is a rolling mill.

11. A system according to claim 1, wherein said controlled system is a sendzimir mill.

12. A system according to claim 1, wherein said controlled system is a heating furnace.

13. A system according to claim 1, wherein said controlled system is an elevator system.

14. A system according to claim 1, wherein said controlled system is a railroad system.

15. A system according to claim 1, wherein said controlled system is an electric car system.

16. A system according to claim 1, wherein said controlled system is an automobile system.

17. A system comprising a controlled apparatus and a control device for controlling said controlled apparatus;

i) said controlled apparatus comprising;

at least one variable operation device;

operating means for operating said at least one variable operation device; and

detector means for detecting and operation of said at least one variable operation device and for generating a state signal corresponding to said operation;

(ii) said control device comprising;

first means for storing a plurality of pre-set operation patterns for said at least one variable operation device;

a fuzzy logic system for selectively combining at least some of said plurality of pre-set operation patterns, and for generating a command signal for said operating means; and

analysis means for;

a) determining at least one relationship between said command signal and said state signal; and

b) generating at least one compensation pattern on the basis of said relationship;

wherein said fuzzy logic system is arranged selectively to combine said at least one compensation pattern and said plurality of pre-set operation patterns, thereby to modify said command signal.

18. A system comprising a controlled apparatus and a control device for controlling said controlled apparatus;

i) said controlled apparatus comprising;

at least one variable operation device;

operating means for operating said at least one variable operation device; and

detector means for detecting an operation of said at least one variable operation device and for generating a state signal corresponding to said operation;

(ii) said control device comprising;

generating means for generating a command signal for controlling said operating means;

analysis means for analyzing relationships between said command signal and said state signal, and for generating a plurality of operation patterns corresponding to said relationships; and

a fuzzy logic system for selectively combining at least some of said operation patterns, and for controlling said generation means on the basis of the combination of said at least some of said operating patterns.

19. A system comprising a controlled apparatus and a control device for controlling said controlled apparatus;

said controlled apparatus having at least one variable operation device, actuator means for actuating said at least one variable operation device, and detector means for detecting the actuation of said at least one variable operation device and for generating a state signal representing said actuation;

said control apparatus comprising;

a first control module, arranged to receive said state signal, said first control module having first analysis means for analysing said state signal and for generating a first control signal when said state signal includes a first pattern, and means for generating a first modification signal representing said first pattern when said state signal includes said first pattern;

a second control module arranged to derive difference between said state signal and said first modification signal, said second control module having second analysis means for analysing said difference and for generating a second control signal when said difference includes a second pattern; and

means for generating a sum of said first and second control signals and for controlling said actuator means on the basis of said sum.

20. A system according to claim 19, wherein:

said second control module is arranged to generate a second modification signal representing said second pattern when said difference includes said second pattern; and

said control apparatus further includes a third control module, said third control module being arranged to derive a second difference between said first and second modification signals, said third control module having third analysis means for analysing said second difference and for generating a third control signal when said second difference includes a third pattern.

21. A system comprising a controlled apparatus and a control device for controlling said controlled apparatus;

said controlled apparatus having at least one variable operation device, actuator means for actuating said at least one variable operation device, and detector means for detecting the actuation of said at least one variable operation device and for generating a state signal representing said actuation;

said control apparatus comprising;

a first control module, arranged to receive said state signal, said first control module having first analysis means for analyzing said state signal and for generating a first control signal when said state signal includes a first pattern, and means for generating a first modification signal representing said first pattern when said state signal includes said first pattern;

a second control module arranged to derive a first difference between said state signal and said first modification signal, said second control module having second analysis means for analyzing said difference and for generating a second control signal when said difference includes a second pattern;

said second control module is arranged to generate a second modification signal representing said second pattern when said difference includes said second pattern;

a third control module arranged to derive a second difference between said first and second modification signals, said third control module having third analysis means for analyzing said second difference and for generating a third control signal when said second difference includes a third pattern; and

a fuzzy logic system for selectively combining said first, second and third control signals and for controlling said actuator means on the basis of said selective combination.

22. A method of controlling a controlled apparatus, comprising the steps of:

storing at least one pre-set operation pattern for at least one variable operation device of said controlled apparatus;

detecting an operation of said at least one variable device;

generating a state signal corresponding to said operation of said at least one variable operation device;

generating a pre-set state signal;

detecting a difference between said pre-set state and said state signal;

generating a pre-set command signal for a point value of the operation of said at least one variable operation device on the basis of said pre-set operation pattern;

modifying said pre-set command signal on the basis of said difference;

determining a relationship between said pre-set command signal and said state signal;

further modifying said pre-set command signal on the basis of a compensation signal, and controlling said at least one variable operation device so as to vary said point value of the operation on the basis of said pre-set command signal as modified by said steps of modifying and further modifying.

23. A method according to claim 22, wherein a plurality of said pre-set operation patterns are stored, and at least some of said plurality of pre-set patterns are combined by fuzzy logic for generation of said pre-set command signal.

24. A method according to claim 22, wherein said step of modifying said pre-set command signal is prior to said step of further modifying said pre-set command signal, whereby said pre-set command signal is first modified by said modifying step, and the result of said modifying step is modified by said further modifying step.

25. A method according to claim 22, wherein said step of modifying said pre-set command signal is subsequent to said step of further modifying said pre-set command signal, whereby said pre-set command signal is first modified by said further modifying step and the result of said further modifying step is modified by said modifying step.

26. A method of controlling a controlled apparatus, comprising the steps of:

storing at least one pre-set operation pattern for at least one variable operation device of said controlled apparatus;

detecting an operation of said at least one variable operation device;

generating a state signal corresponding to the operation of said at least one variable operation device;

generating a pre-set command signal and a pre-set state signal on the basis of said at least one operation pattern;

detecting a difference between said pre-set state signal and said state signal;

modifying said pre-set command signal on the basis of a feedback signal derived from said difference;

detecting when said difference exceeds a predetermined limit and, when said difference exceeds said predetermined limit;

(i) determining a relationship between at least one of said command signal and said feedback signal and said difference between said state signal and said pre-set state signal, and

(ii) further modifying said pre-set command signal on the basis of said relationship; and

controlling said at least one variable operation device on the basis of said pre-set command signal as modified by said steps of modifying and further modifying.

27. A method of controlling a controlled apparatus, comprising the steps of:

storing a plurality of pre-set operation patterns for at least one variable operation device of said controlled apparatus;

detecting an operation of said at least one variable operation device;

generating a state signal corresponding to said operation of said at least one variable operation device;

determining at least one relationship between at least one of said plurality of pre-set operation patterns and said state signal, and generating at least one compensation pattern on the basis of said at least one relationship;

selectively combining at least some of said pre-set operation patterns and said at least one compensation pattern, using fuzzy logic, thereby to generate a command signal; and

controlling said at least one variable operation device on the basis of said command signal.

28. A method of controlling a controlled apparatus, comprising the steps of:

storing a plurality of pre-set operation patterns for at least one variable operation device of said controlled apparatus;

detecting an operation of said at least one variable operation device;

generating a state signal corresponding to said operation of said at least one variable operation device; and

controlling the controlled apparatus in first and second modes;

wherein, in said first mode;

(i) at least some of said pre-set operation patterns are selectively combined using fuzzy logic, to generate a first command signal;

(ii) said at least one variable operation device is operated on the basis of said first command signal; and

(iii) a relationship between said first command signal and said state signal is investigated, thereby to generate at least one compensation pattern on the basis of said relationship;

and wherein, in said second mode;

(i) said at least one compensation pattern and at least some of said plurality of pre-set operation patterns are selectively combined by fuzzy logic, to generate a second command signal; and

(ii) said at least one variable operation device is operated on the basis of said second command signal.

29. A method of controlling a controlled apparatus, comprising the steps of:

storing a plurality of pre-set operation patterns for at least one variable operation device of said controlled apparatus;

detecting an operation of said at least one variable operation device;

generating a state signal corresponding to said operation of said at least one variable operation device;

and controlling the controlled apparatus in first and second modes;

wherein, in said first mode;

(i) at least some of said pre-set operation patterns are selectively combined using fuzzy logic, to generate a first command signal;

(ii) said at least one variable operation device is operated on the basis of said first command signal; and

(iii) a plurality of relationships between said first command signal and said state signal are investigated, thereby to generate a plurality of compensation patterns on the basis of said plurality of relationship;

and wherein, in said second mode;

(i) at least some of said plurality of compensation patterns are selectively combined by fuzzy logic, to generate a second command signal; and

(ii) said at least one variable operation device is operated on the basis of said second command signal.

30. A method of controlling a controlled apparatus, comprising the steps of:

storing at least one pre-set operation pattern for at least one variable operation device of said controlled apparatus;

detecting an operation of said at least one variable operation device;

generating a state signal corresponding to said operation of said at least one variable operation device;

generating a pre-set command signal on the basis of said pre-set operation pattern;

modifying said pre-set command signal,

generating a command signal for controlling said variable operation device;

analyzing the relationships between said command signal and said state signal, and generating a plurality of operation patterns corresponding to said relationships;

combining at least some of said plurality of operation patterns using fuzzy logic; and

controlling said step of generating said command signal on the basis of the combination of said at least some of said plurality of operation patterns.

31. A method of controlling a controlled apparatus, comprising the steps of:

detecting the actuation of at least one variable operation device of said controlled system, and generating a state signal on the basis of said actuation;

analysing said state signal, generating a first control signal when said state signal includes a first pattern, and generating a first modification signal representing said first pattern when said state signal includes said first pattern;

deriving a difference between said state signal and said first modification signal;

analyzing said difference, and generating a second control signal when said difference includes a second pattern; and

controlling said actuation of said at least one variable operation device on the basis of said first and second control signals.

32. A method of controlling a controlled apparatus, comprising the steps of:

detecting an actuation of at least one variable operation device of said controlled system, and generating a state signal on the basis of said actuation;

analyzing said state signal, generating a first control signal when said state signal includes a first pattern, and generating a first modification signal representing said first pattern when said state signal includes said first pattern;

deriving a first difference between said state signal and said first modification signal;

analyzing said difference, and generating a second control signal when said difference includes a second pattern; and

generating a second modification signal representing said second pattern when said state signal difference includes said second pattern;

deriving a second difference between said difference and said modification signal;

analyzing said second difference, and generating a third control signal when said second difference includes a third pattern; and

selectively combining said first, second and third control signals by fuzzy logic, and controlling the actuation of said at least one variable operation device on the basis of said selective combination.

33. A control device for controlling a controlled apparatus, comprising:

means for storing a plurality of pre-set operation patterns for said, controlled apparatus;

a fuzzy logic system for selectively containing at least some of said plurality of pre-set operation patterns, and for generating a command signal for said controlled system; and

analysis means for;

a) determining at least one relationship between said command signal and a state signal of said controlled apparatus;

b) generating at least one compensation pattern on the basis of said relationship;

wherein said fuzzy logic system is arranged selectively to combine said at least one compensation pattern and said plurality of pre-set operation patterns, thereby to modify said command signal.

34. A control device for controlling a controlled apparatus, comprising:

a first control module arranged to receive a state signal of said controlled system;

said first control module having first analysis means for analyzing said state signal and for generating a first control signal when said state signal includes a first pattern, and means for generating a first modification signal representing said first pattern when said state signal includes said first pattern;

a second control module arranged to derive a first difference between said state signal and said first modification signal, said second control module having second analysis means for analyzing said difference and for generating a second control signal when said difference includes a second pattern; and

said second control module arranged to derive a second difference between said first and second modification signals, said third control module having third analysis means for analyzing said second difference and for generating a third control signal when said second difference includes a third pattern; and

a fuzzy logic system for selectively combining said first, second and third control signals.