Process control system with on-line reconfigurable modules

• US 4,965,742 A
• Filed: 09/30/1987
• Issued: 10/23/1990
• Est. Priority Date: 09/30/1987
• Status: Expired due to Term

• Current Assignee: Pavilion Technologies Incorporated (Rockwell Automation, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Skeirik, Richard D.
• Primary Examiner(s): MACDONALD, ALLEN R
• Application Number:
  US07/103,047
• Time in Patent Office: 1,119 Days
• Field of Search: 364/513, 364/468, 364/469, 364/148-152, 364/191, 364/138-139
• US Class Current: 700/86
• CPC Class Codes: G05B 13/028 using expert systems only
• CPC Class Codes: G06N 5/04 Inference or reasoning models
• CPC Class Codes: Y10S 706/906 Process plant

Abstract

An integrated system for process control in which a process supervisor procedure (which is preferably the top-level procedure) is configured as a modular software structure with modules which can be revised by a user at any time, without significantly interrupting the operation of the process supervisor. Users can define or redefine modules by editing highly constrained templates. These templates use a standardized data interface (as seen by the user), which facilitates communications with an extremely wide variety of systems. The template set preferably contains highly constrained portions (which are optimized for the most common functions), and also contains pointers to user-customized functions. Thus, rapid set-up and modification are possible, but sophisticated users still have full flexibility to do customization.

Claims

1. A computer-based method for operating a substantially continuous process, comprising the steps of:

(1) operating the process with one or more sensors connected to sense conditions in materials being processed, and one or more actuators connected to change conditions in the process;

(2) controlling one or more of said actuators with a process controller in accordance with signals received from said sensors and in accordance with one or more control parameters;

(3) running a process supervisor procedure comprising one or more software modules, for selectively defining one or more of said control parameters for said process controller;

(4) selectively presenting a functional structure to a user, for a new software module for said process supervisor procedure and/or a functional structure corresponding to the user input from which a current software module of said process supervisor procedure was generated, and selectively loading the user input from said functional structure to be used by said process supervisor procedure;

wherein step (4) of presenting a functional structure includes presenting standardized data interface definitions further comprising the step (5) of enabling each said software module to perform the steps of

getting data from any one of a plurality of data collection and/or process control systems

and/or sending process control parameters to any one of a plurality of data collection and/or process controls systems

without the user explicitly defining any custom data interfacing procedures.

4. The method of claim 1, wherein said process controller of step (2) uses a cycling step, and wherein said process supervisor procedure of step (3) uses a cycling step.

5. The method of claim 1, wherein said process supervisor procedure of step (3) uses a cycling step, and said process controller of step (2) operates in substantially real-time.

6. The method of claim 1, wherein step (4) comprises the step of presenting functional structures in a substantially natural language format which is readily understandable by a user who is technically skilled in a predetermined art but who is not necessarily competent in any computer language.

7. The method of claim 1, wherein step (4) comprises the step of allowing the user to alter only restricted portions of said functional structures.

8. The method of claim 1, wherein step (4) comprises the step of presenting user-alterable portions of said functional structure which appear differently to said user than do other portions of said functional structure.

9. The method of claim 1, wherein step (4) comprises the step of presenting said functional structure in a substantially natural language format.

10. The method of claim 1, wherein said process supervisor procedure of step (3) comprises the step of calling on at least one expert subprocedure which uses a knowledge base and inference structure relevant to the process.

11. The method of claim 1, wherein, for each of said control parameters of step (2), said process supervisor procedure of step (3) comprises the step of being constrained not to make changes unless the indicia for the change exceed a certain threshold;

and wherein said process supervisor procedure further comprises the step of reporting every instance where it changes one of said control parameters.

12. The method of claim 1, wherein, for each of said control parameters of step (3), said process supervisor procedure of step (3) comprises the step of being constrained not to make changes unless the amount of the change exceeds a certain threshold.

13. The method of claim 1, wherein said process supervisor procedure of step (3) comprises the steps of following a feedback control relation including a supervisor goal condition, and a deadband on said supervisor goal condition, and/or of following a feedforward control relation on input of said sensors, and including a deadband on said input.

14. The method of claim 1, wherein said functional structure of step (4) comprise the step of allowing the user to define timing and sequencing parameters for respective ones of said software modules which include at least the following options:

become active if another specified software module has become active;

become active if a new value has been entered for a specified data source;

or become active if a specified time of inactivity has elapsed.

15. The method of claim 1, wherein said process supervisor procedure of step (3) comprises the step of using a maximum iteration period significantly longer than the maximum iteration period of said process controller.

16. The method of claim 1, wherein said process controller of step (2) uses analog logic for controlling.

17. The method of claim 1, wherein step (3) comprises the step of defining said software modules by respective data definitions, including

pointers to procedures which will carry out a respective function,

and, for at least some of said software modules, parameters to be passed to said procedure pointed to.

18. The method of claim 1, wherein step (3) comprises the step of defining said software modules by respective data definitions, including

pointers to procedures which will carry out a respective function, most of said procedures pointed to corresponding generally to one of a limited number of procedure types,

and, for at least some of said software modules, parameters to be passed to said procedures pointed to.

19. The method of claim 1, wherein step (3) comprises the step of defining said software modules by respective data definitions, including

pointers to procedures which will carry out a respective function,

wherein most of said procedures pointed to correspond generally to one of a limited number of procedure types,

and wherein at least some of said procedures pointed to also contain further pointers to procedures which do not correspond generally to any one of said limited number of procedure types,

and, for at least some of said software modules, parameters to be passed to said procedures pointed to.

20. The method of claim 1, wherein one or more of said control parameters of step (3) comprise the step of including goals of said process controller.

21. The method of claim 1, wherein said step of presenting functional structures includes presenting standardized data interface definitions such that the user can specify data having one of plural pre-defined temporal characteristics.

22. The method of claim 1, wherein said step of presenting functional structures includes presenting standardized data interface definitions such that the user can specify data having one of plural pre-defined temporal characteristics, and said pre-defined temporal characteristics include both current values and also time-averaged values.

23. The method of claim 1, wherein said step of presenting functional structures includes presenting standardized data interface definitions such that the user can specify data from any one of several different types of control systems having different respective data standards.

24. The method of claim 1, wherein said functional structure of step (4) comprise the step of using a limited set of standard functional control relationships and a pointer to optional user-customized programming.

25. The method of claim 1, wherein said process controller and said process supervisor procedure of step (3) comprise the step of using processes running on the same computer system.

26. The method of claim 1, wherein said process controller of step (2) and said process supervisor procedure of step (3) comprise the step of both using respective parts of the same software system.

27. The method of claim 1, wherein some of said software modules of step (3) in said process supervisor procedure of step (3) comprise the step of not defining a control relation among said sensors and actuators.

28. The method of claim 1, wherein said input from said functional structures of step (4) comprise the step of being operationally accessible by said process supervisor procedure.

37. The system of claim 27, wherein, for each or said goal conditions of element (b), said process supervisor means of element (c) is constrained not to make changes unless the indicia for the change exceed a certain threshold;

and wherein said process supervisor means reports every instance where it changes a goal condition.

2. A computer-based method for operating a substantially continuous process, comprising the steps of:

(1) operating the process with one or more sensors connected to sense conditions in materials being processed, and one or more actuators connected to change conditions in the process;

(2) controlling one or more of said actuators with a process controller in accordance with signals received from said sensors and in accordance with one or more control parameters;

(3) running a process supervisor procedure comprising one or more software modules, for selectively defining one or more of said control parameters for said process controller;

(4) selectively presenting a functional structure to a user, for a new software for said process supervisor procedure and/or a functional structure corresponding to the user input from which a current software module of said process supervisor procedure was generated, and selectively loading the user input from said functional structure to be used by said process supervisor procedure;

wherein step (4) of presenting a functional structure includes presenting standardized data interface definitions.

3. A computer-based process control system, comprising:

(a) one or more sensors connected to sense conditions in the process, and one or more actuators connected to change conditions in the process;

(b) process control means, comprising one or more software modules for controlling the process, respective ones of said software modules defining a control relation among one or more of said sensors and acutators;

(c) build means which is configured to;

(1) present to a user a template for a new software module for said process control means;

(2) present to a user a template including data corresponding to the user input from which a current software module of said process control means was generated; and

(3) selectively to load user inputs from said template to be operationally accessible by said process control means.

29. A computer-based process control system, comprising:

(a) one or more sensors connected to sense conditions in the process, and one or more actuators connected to change conditions in the process;

(b) a process controller connected to control one or more of said actuators in accordance with deviations between one or more of said sensors and a respective goal condition;

(c) process supervisor means, running on a digital computer separate from said process controller, and comprising one or more software modules, connected for communicating one or more of said respective goal conditions to said process controller;

(d) build-supervisor means configured for;

(1) selectively presenting to a user a functional structure for a new software module for said process supervisor means;

(2) upon command, presenting to a user a functional structure corresponding to the user input from which a current of said software modules of said process supervisor means was generated; and

(3) selectively loading the user input from said functional structure to be used by said process supervisor means;

wherein said process supervisor means has a maximum iteration period significantly longer than the maximum iteration period of said process controller.

30. The system of claim 29, wherein said build-supervisor means of element (d) does not allow data corresponding to fresh user inputs to become actively accessed by said process supervisor means until a validation run has been performed.

31. The system of claim 29, wherein said process controller of element (c) uses means for cycling, and said process supervisor means of element (c) uses means for cycling.

32. The system of claim 29, wherein said process supervisor means of element (c) uses means for cycling, and said process controller of element (c) operates in substantially real-time.

33. The system of claim 29, wherein only restricted portions of said functional structure of said build-supervisor means of element (d) are user-alterable.

34. The system of claim 29, wherein portions of said functional structure of said build-supervisor means of element (d) are user-alternable, and appear different to said user than do other portions of said functional structure.

35. The system of claim 29, wherein said functional structure of said build-supervisor means of element (d) have a substantially natural language format.

36. The system of claim 29, wherein said process supervisor means of element (c) also calls on at least one expert subprocedure means which includes a knowledge base and inference structure relevant to the process.

38. The system of claim 29, wherein, for each of said goal conditions of element (b), said process supervisor means of element (c) is constrained not to make changes unless the amount of the change would exceed a certain threshold.

39. The system of claim 29, wherein said process supervisor means of element (c) implements at least one feedback control relation including a supervisor goal condition, and a deadband on said supervisor goal condition, and also at least one feedforward control relation on input of said sensor, and including a deadband on said input.

40. The system of claim 29, wherein said functional structure of said build-supervisor means of element (d) permit the user to define timing and sequencing parameters for respective ones of said software modules which include at least the following options:

become active in another specified software module has become active;

become active if a new value has been entered for a specified data source;

or become active if a specified time of inactivity has elapsed.

41. The system of claim 29, wherein said process supervisor means of element (c) has a maximum iteration period significantly longer than the maximum iteration period of said process controller of element (b).

42. The system of claim 29, wherein said process controller uses analog logic for controlling.

43. The system of claim 29, wherein said software modules of element (c) are defined by respective data definitions, including

pointers to means which will carry out a respective function,

and (for at least some of said software modules) parameters to be passed to said means pointed to.

44. The system of claim 29, wherein said software modules of element (c) are defined by respective data definitions, including

pointers to means which will carry out a respective function, most of said means pointed to corresponding generally to one of a limited number of procedure types,

and (for at least some of said software modules) parameters to be passed to said means pointed to.

45. The system of claim 29, wherein said software modules of element (c) are defined by respective data definitions, including

pointers to means for carrying out a respective function,

wherein most of said means pointed to correspond generally to one of a limited number of procedure types,

and wherein at least some of said means pointed to also contain further pointers to means which do not correspond generally to any one of said limited number of procedure types,

and, for at least some of said software modules parameters to be passed to said means pointed to.

46. The system of claim 29, wherein said presentation of functional structure of said build-supervisor means of element (d) includes presenting standardized data interface definitions such that the user can specify data having one of plural pre-defined temporal characteristics.

47. The system of claim 29, wherein said functional structure of said build-supervisor means of element (d) include standardized data interface definitions such that the user can specify data having one of plural pre-defined temporal characteristics, and said pre-defined temporal characteristics include both current values and also time-averaged values.

48. The system of claim 29, wherein said functional structure of said build-supervisor means of element (d) include standardized data interface definitions such that the user can specify data from any one of several different types of control systems having different respective data standards.

49. The system of claim 29, wherein said functional structure of said build-supervisor means of element (d) include a limited set of standard functional control relationships and a pointer to optional user-customized programming.

50. The system of claim 29, wherein said process controller of element (b) and said process supervisor means of element (c) comprise processes running on the same computer system.

51. The system of claim 29, wherein said process controller of element (b) and said process supervisor means of element (c) are both respective parts of the same software system.

52. The system of claim 29, wherein some of said software modules of element (c) in said process control means do not define a control relation among said sensors and actuators.

53. The system of claim 29, wherein said input from said functional structures of element (2) is operationally accessible by said process supervisor means.

54. A computer-based process control system, comprising:

(a) one or more sensors connected to sense conditions in the process, and one or more actuators connected to change conditions (1) the process;

(b) process control means, comprising one or more software modules for controlling the process, respective ones of said software modules defining a control relation among one or more of said sensors and actuators;

(c) build means which is configured to;

(1) present to a user a template for a new software module for said process control means;

(2) present to a user a template including data corresponding to the user input from which a current software module of said process control means was generated; and

(3) selectively loading user input from said template be used by said process control means;

wherein each said template presented by said build means includes

(i) a standard functional control relationship selected from a limited set, and

(ii) a pointer to optional user-customized programming.

55. The system of claim 54, wherein said build means of element (c) does not allow data corresponding to fresh user inputs to become actively accessed by said process control means of element (b) until a validation run has been performed.

56. The system of claim 54, wherein said template of said build means of element (c) is user-alterable, and appears differently to said user than do other portions of said template.

57. The system of claim 54, wherein said template of said build means of element (c) have a substantially natural language format.

58. The system of claim 54, wherein said process control means of element (b) uses analog logic for controlling.

59. The system of claim 54, wherein said limited set of standard functional control relationships of said build means of element (c) comprises feedback, feedforward, statistical filtering, and/or null control relationships.

60. The system of claim 54, wherein said process control means of element (b) and said build means of element (c) comprise processes running on the same computer system.

61. The system of claim 54, wherein said process control means of element (b) and said build means of element (c) are both respective parts of the same software system.

62. The system of claim 54, wherein said input from said templates of element (2) are optionally accessible by said process control means.

63. A computer-based process control system, comprising:

(a) one or more sensors connected to sense conditions in the process, and one or more actuators connected to change conditions i the process;

(b) process control means, comprising one or more software modules for controlling the process, respective ones of said software modules defining a control relation among one or more of said sensors and actuators;

wherein each said software modules includes

(i) a standard functional control relationship selected from a limited set, and

(ii) a pointer to optional user-customized programming.

64. A computer-based process control system, comprising:

(a) one or more sensors connected to sense conditions in the process, and one or more actuators connected to change conditions the process;

(b) process control means, comprising one or more software modules for controlling the process, respective ones of said software moduless defining a control relation among one or more of said sensors and actuators;

(c) build means which is configured to;

(1) present to a user a functional structure for a ne, software module for said process control means;

(2) present to a user a functional structure including data corresponding to the user input from which a current software module of said process control means was generated; and

(3) selectively loading the user inputs from said functional structure to be used by said process control means;

wherein each said functional structure presented by said build means includes

(i) a standard functional control relationship selected from a limited set, and

(ii) a pointer to optional user-customized programming.