Integrated advanced control blocks in process control systems

• US 6,445,963 B1
• Filed: 10/04/1999
• Issued: 09/03/2002
• Est. Priority Date: 10/04/1999
• Status: Expired due to Term

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Thiele, Dirk, Blevins, Terrence L., Wojsznis, Wilhelm K., Tzovla, Vasiliki
• Primary Examiner(s): PATEL, RAMESH B
• Application Number:
  US09/412,078
• Time in Patent Office: 1,065 Days
• Field of Search: 700/7, 700/11, 700/19, 700/23, 700/28, 700/29-31, 700/34, 700/41-46, 700/48-54, 700/67, 700/73-74, 703/13, 703/14, 703/15, 706/5, 706/14-15, 706/920, 706/21-23
• US Class Current: 700/44
• CPC Class Codes: G05B 11/32 with inputs from more than one sensing element; with outputs to more than one correcting element
• CPC Class Codes: G05B 13/0285 using neural networks and fuzzy logic
• CPC Class Codes: G05B 13/048 using a predictor
• CPC Class Codes: Y10S 706/92 Simulation

Abstract

An advanced control block that implements multiple-input/multiple-output control, such as model predictive control, within a process control system is initiated by creating an initial control block having generic control logic and desired control inputs and control outputs communicatively connected to process outputs and process inputs within a process control routine. A waveform generator within the control block systematically upsets each of the process inputs via the control block outputs using excitation waveforms designed for use in developing a process model. At the same time, a data collection routine collects data indicating the response of each of the process outputs to the waveforms delivered at each of the process inputs. After sufficient data has been collected, a process modeling routine generates a process model from the collected data and a control logic parameter creation routine creates control logic parameters for the control logic from the process model. The control logic parameters and the process model are then downloaded to the control block to complete formation of the advanced control block. Thereafter, the advanced control block is used to provide advanced process control within the process control routine. Likewise, the process model is used to provide simulation of the process or to produce virtual process outputs.

Claims

1. A process control element adapted to be used as a portion of a process control routine implemented on a processor to control a process, the process control element comprising:

a computer readable medium;

an advanced control function block stored on the computer readable medium and adapted to be executed on the processor to implement multiple-input/multiple output control of a process, the advanced control function block including,

a first plurality of inputs, wherein each input is adapted to receive a different one of a set of process parameters;

a second plurality of outputs, wherein each output is adapted to be communicatively coupled to a different process input for controlling the set of process parameters; and

control logic responsive to the first plurality of inputs to produce a control signal at each of the second plurality of outputs.

2. The process control element of claim 1, wherein the advanced control function block includes parameter storage adapted to accept control parameters used by the control logic.

3. The process control element of claim 2, wherein the parameter storage is adapted to receive model predictive control logic coefficients.

4. The process control element of claim 2, wherein the advanced control function block includes a process model for the process that is used by the control logic to produce the control signals at the second plurality of outputs.

5. The process control element of claim 1, wherein the control logic is model predictive control logic.

6. The process control element of claim 1, wherein the control logic is neural network logic.

7. The process control element of claim 1, wherein the control logic is developed from a process model.

8. The process control element of claim 1, wherein the control logic includes a process model for the process.

9. The process control element of claim 1, wherein the advanced control function block is a Fieldbus function block corresponding to the Fieldbus protocol.

10. The process control element of claim 1, wherein the advanced control function block further includes a waveform generator adapted to generate process excitation waveforms at each of the plurality of outputs.

11. The process control element of claim 10, wherein the advanced control function block further includes a data collection unit adapted to coordinate the collection of data representing signal values at each of the plurality of inputs when the waveform generator generates the process excitation waveforms at each of the plurality of outputs.

12. The process control element of claim 10, wherein the waveform generator generates a series of pulses of pseudo-random length as the excitation waveforms.

13. The process control element of claim 10, wherein the waveform generator generates excitation waveforms adapted to develop a process model for the process for use in producing a model predictive controller.

14. The process control element of claim 1, wherein the advanced control function block includes a graphical view adapted to display information pertaining to operation of the advanced control function block via a user interface.

15. The process control element of claim 1, further including a process simulation function block communicatively coupled to the advanced control function block.

16. The process control element of claim 15, wherein the process simulation function block includes a process model that simulates the operation of the process.

17. A process control element adapted to be used as a portion of a process control routine implemented on a processor to control a process, the process control element comprising:

a computer readable medium;

an advanced control function block stored on the computer readable medium and adapted to be executed on the processor including,

a first plurality of inputs, wherein each input is adapted to receive a different one of a set of process parameters;

a second plurality of outputs, wherein each output is adapted to be communicatively coupled to a different process input for controlling the set of process parameters;

a waveform generator adapted to generate process excitation waveforms at each of the plurality of outputs; and

a data collection unit adapted to coordinate the collection of data representing signal values at each of the plurality of inputs when the waveform generator generates the process excitation waveforms at each of the plurality of outputs.

18. The process control element of claim 17, wherein the waveform generator generates a series of pulses of pseudo-random length as the excitation waveforms.

19. The process control element of claim 17, wherein the waveform generator generates excitation waveforms adapted to excite the process to develop a process model for use in producing a model predictive controller.

20. The process control element of claim 17, wherein the advanced control function block includes a graphical view adapted to display information pertaining to operation of the advanced control function block via a user interface.

21. The process control element of claim 17, wherein the advanced control function block includes control logic responsive to the first plurality of inputs to produce a control signal at each of the second plurality of outputs and includes parameter storage adapted to accept control parameters used by the control logic.

22. The process control element of claim 21, wherein the parameter storage is adapted to receive model predictive control logic coefficients.

23. The process control element of claim 20, wherein the advanced control function block includes a process model storage adapted to store a process model for the process, and wherein the control logic is adapted to use the control parameters stored in the parameter storage and the process model stored in the process model storage to produce the control signals at the second plurality of outputs.

24. A method of developing an advanced control element for use in a process control routine that controls a process, the method comprising the steps of:

providing an advanced control element having a first plurality of control inputs adapted to receive process outputs of the process and having a second plurality of control outputs adapted to provide control signals to process inputs of the process;

communicatively connecting the advanced control element within the process control routine;

using the advanced control element to provide excitation waveforms to each of the process inputs;

using the advanced control element to collect data reflecting the response of each of the process outputs to the excitation waveforms;

creating a process model from the collected data;

developing advanced control logic parameters from the process model; and

placing the advanced control logic parameters within the advanced control element for use by the advanced control element to control the process.

25. The method of developing the advanced control element of claim 24, wherein the step of providing the advanced control element includes the step of providing the advanced control element as a function block.

26. The method of developing the advanced control element of claim 25, wherein the step of communicatively connecting the advanced control element within the process control routine includes the steps of communicatively connecting one of the control inputs to a first function block and of communicatively connecting one of the control outputs to a second function block.

27. The method of developing the advanced control element of claim 26, wherein the step of communicatively connecting one of the control outputs to the second function block includes the step of communicatively connecting the one of the control outputs to a control function block to provide control of a control loop within the process control routine.

28. The method of developing the advanced control element of claim 26, wherein the step of communicatively connecting the one of the control outputs to the second function block includes the step of communicatively connecting the one of the control outputs to an output function block associated with a device to provide control of the device.

29. The method of developing the advanced control element of claim 24, wherein the step of providing the advanced control element includes the step of providing the advanced control element as a Fieldbus function block.

30. The method of developing the advanced control element of claim 24, wherein the step of developing the advanced control logic parameters includes the step of developing model predictive control coefficients.

31. The method of developing the advanced control element of claim 24, wherein the step of developing the advanced control logic parameters includes the step of developing neural network logic parameters.

32. The method of developing the advanced control element of claim 24, wherein the step of using the advanced control element to provide excitation waveforms to each of the process inputs includes the step of generating a series of pulses of pseudo-random length as the excitation waveforms.

33. The method of developing the advanced control element of claim 24, wherein the step of using the advanced control element to provide excitation waveforms to each of the process inputs includes the step of generating a series of excitation waveforms adapted to develop a process model for the process for use in producing a model predictive controller.

34. The method of developing the advanced control element of claim 24, wherein the step of creating a process model from the collected data includes the step of generating a set of response curves from the collected data as the process model.

35. The method of developing the advanced control element of claim 34, wherein the step of creating a process model from the collected data includes the step of altering one or more of the set of response curves generated from the collected data to produce an altered set of response curves and using the altered set of response curves as the process model.

36. The method of developing the advanced control element of claim 24, further including the step of using the advanced control element in a simulation environment.

37. The method of developing the advanced control element of claim 36, wherein the step of using the advanced control element in a simulation environment includes the step of connecting the advanced control element to a simulated process element.

38. The method of developing the advanced control element of claim 37, wherein the step of using the advanced control element includes the step of developing the simulated process element from the process model.

39. The method of developing the advanced control element of claim 37, wherein the step of using the advanced control element includes the steps of altering the process model and developing the simulated process element from the altered process model.

40. The method of developing the advanced control element of claim 24, wherein the step of providing an advanced control element includes the step of placing control logic in the advanced control element prior to the step of communicatively connecting the advanced control element within the process control routine.

41. The method of developing the advanced control element of claim 24, further including the step of providing the process model to the advanced control block for use in controlling the process.

42. The method of developing the advanced control element of claim 24, wherein the step of creating the process model from the collected data includes the step of screening the collected data and creating the process model from the screened data.

43. An advanced control element development system adapted to develop an advanced control element for use in a process control routine that is executed within a process control system, the advanced control element development system including:

a computer readable medium;

a first routine stored on the computer readable medium and adapted to be executed on a processor that creates an advanced control element having a first plurality of control inputs adapted to receive process outputs and having a second plurality of control outputs adapted to provide control signals to process inputs;

a second routine stored on the computer readable medium and adapted to be executed on a processor that enables a user to communicatively connect the advanced control element within the process control routine;

a third routine stored on the computer readable medium and adapted to be executed on a processor that uses the advanced control element to provide excitation waveforms to each of the process inputs;

a fourth routine stored on the computer readable medium and adapted to be executed on a processor that uses the advanced control element to collect data reflecting the response of each of the process outputs to the excitation waveforms;

a fifth routine stored on the computer readable-medium and adapted to be executed on a processor that creates a process model from the collected data;

a sixth routine stored on the computer readable medium and adapted to be executed on a processor that develops advanced control logic parameters from the process model; and

a seventh routine stored on the computer readable medium and adapted to be executed on a processor that places the advanced control logic parameters within the advanced control element to enable the advanced control logic element to control the process.

44. The advanced control element development system of claim 43, wherein the first routine creates the advanced control element as a function block.

45. The advanced control element development system of claim 44, wherein the second routine enables a user to connect the advanced control element within the process control routine by connecting one of the control inputs to a first function block and by connecting one of the control outputs to a second function block.

46. The advanced control element development system of claim 43, wherein the first routine creates the advanced control element as a Fieldbus function block that uses the Fieldbus protocol.

47. The advanced control element development system of claim 43, wherein the sixth routine develops the advanced control logic parameters as model predictive control coefficients.

48. The advanced control element development system of claim 43, wherein the sixth routine develops the advanced control logic parameters as neural network logic parameters.

49. The advanced control element development system of claim 43, wherein the third routine causes the advanced control element to generate excitation waveforms at each of the control outputs for delivery to each of the process inputs.

50. The advanced control element development system of claim 43, wherein the seventh routine places the process model in the advanced control element.

51. The advanced control element development system of claim 43, further including an eighth routine stored on the computer readable medium and adapted to be executed on a processor that produces a process simulation element from the process model.

52. The advanced control element development system of claim 43, wherein the fifth routine includes another routine that enables screening of the collected data to produce a set of screened data and wherein the fifth routine creates the process model from the screened data.

53. A method of using a multiple-input/multiple output advanced control element capable of controlling a process, wherein the advanced control element was is based on a process model developed for the process, the method comprising the steps of:

generating a process simulation element from the process model;

communicatively connecting the process simulation element to the advanced control element; and

using the advanced control element to control the process simulation element.

54. The method of using the multiple-input/multiple output advanced control element of claim 53, further including the step of testing the advanced control element as connected to the process simulation element before using the advanced control element to control the process.

55. The method of using the multiple-input/multiple output advanced control element of claim 53, further including the step of using the advanced control element and the process simulation element in a training environment.

56. The method of using the multiple-input/multiple output advanced control element of claim 53, wherein the step of generating a process simulation element includes the steps of altering the process model and using the altered process model to generate the process simulation element.

57. The method of using the multiple-input/multiple output advanced control element of claim 56, further including the step of testing the advanced control element as connected to the process simulation element to determine the operation of the advanced control element in the presence of process/process-model mismatch.

58. The method of using the multiple-input/multiple output advanced control element of claim 53, including the steps of connecting the advanced control element to the process and using the advanced control element to control the process while the advanced control element controls the process simulation element.

59. The method of using the multiple-input/multiple output advanced control element of claim 58, further including the step of comparing process outputs of the process to outputs of the process simulation element to measure process/process-model mismatch.

60. The method of using the multiple-input/multiple output advanced control element of claim 58, further including the step of providing an output of the process simulation element to an input of the advanced control element for use in controlling the process.