Programmable controller including diagnostic and simulation facilities

• US 5,997,167 A
• Filed: 05/01/1997
• Issued: 12/07/1999
• Est. Priority Date: 05/01/1997
• Status: Expired due to Term

• Current Assignee: Power Control Technologies Incorporated
• Original Assignee: Power Control Technologies Incorporated
• Inventors: Crater, Kenneth C., Pierson, Daniel L.
• Primary Examiner(s): Gordon, Paul P.
• Assistant Examiner(s): Robinson, Victoria
• Application Number:
  US08/846,467
• Time in Patent Office: 950 Days
• Field of Search: 364/184, 364/185, 364/140.01, 364/140.04, 364/140.06-140.1, 364/141-147, 364/148.06, 364/578, 364/528.37, 702/179, 702/180, 702/181
• US Class Current: 700/79
• CPC Class Codes: G05B 19/41835 characterised by programme execution
• CPC Class Codes: G05B 19/41885 characterised by modeling, simulation of the manufacturing system
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A controller for one or more pieces of industrial equipment accommodates multiple sensed conditions--that is, different conditions each associated with a different response, which may be an alarm or a branch control procedure. The controller includes a database of diagnostic templates specifying conditions, and actions or states associated therewith. For example, a template may provide multiple, specified, discrete time spans each reflecting a different machine condition, and each specifying a different action associated with that condition. The templates may be associated with a model of machine behavior, e.g., one based on probabilities, which utilizes the templates and programmed control instructions to simulate machine behavior over time. More broadly, the behavior model may be used to perform a simulated execution of control instructions based on various specified values for limit parameters, which may be provided by the user or computed in accordance with the behavior model (e.g., using a Monte Carlo method) as simulation proceeds.

Claims

1. A control system comprising:

a. means for executing a control function comprising a variable sequence of steps;

b. means for receiving data relevant to the control function;

c. a database for storing (i) a plurality of limits each specifying a different condition associated with the control function, and (ii) different actions associated with at least some of the conditions; and

d. means for comparing received data to the stored limits and, upon detection of a match therebetween, causing execution of the steps implementing any associated action;

wherein;

e. the control function is embodied in a sequence of control instructions executable by the execution means; and

f. the database is configured to further store a probability associated with each limit, the control system further comprising means for performing a simulated execution of the control instructions based on the probabilities and the received data.

2. The control system of claim 1 further comprising means for issuing an alert, at least some of the actions comprising actuating the alerting means.

3. The control system of claim 1 wherein at least some of the actions comprise executing a new control function.

4. The control system of claim 1 wherein at least some of the conditions are inefficient behaviors.

5. The control system of claim 1 wherein at least some of the conditions are projected failure states.

6. The control system of claim 1 further comprising means for obtaining input from a user, at least some of the received data being received from the user input means.

7. The control system of claim 6 further comprising means for altering the probabilities based on user input.

8. The control system of claim 1 further comprising a machine interface, at least some of the received data being received from the machine interface, the control function being executed via the machine interface.

9. The control system of claim 1 wherein the probabilities represent a model of machine response.

10. The control system of claim 9 further comprising means for altering the probabilities based on the received data.

11. The control system of claim 1 wherein:

a. the execution means is configured to perform a plurality of control functions each representing a state, at least some of the functions causing a transition to a new state;

b. the database means is configured to store, for each state, (i) a plurality of limits each specifying a different condition, (ii) an action associated with at least some of the conditions, and (iii) a probability associated with each limit; and

c. each control function is embodied in a sequence of control instructions executable by the execution means.

12. The control system of claim 11 wherein at least some of the actions comprise transition to or initiation of new control functions.

13. The control system of claim 11 further comprising simulation means for performing a simulated execution of the control instructions based on the probabilities and the received data, the control function being executed on the simulation means.

14. The control system of claim 13 wherein the simulated execution is a Monte Carlo simulation that dictates, in accordance with the probabilities, transitions among states.

15. The control system of claim 14 wherein at least some of the probabilities are functions of time and represent machine behavior.

16. The control system of claim 15 further comprising means for interfacing to a machine to also execute the control functions thereon, at least some of the received data originating with the machine via the machine interface, the graphic display further depicting actual machine behavior based on the received data.

17. The control system of claim 13 further comprising a graphic display for depicting the simulated execution.

18. A control system comprising:

a. means for executing a plurality of control functions pertaining to at least one machine;

b. means for storing sequences of control instructions, each sequence implementing a control function as a state comprising an action and a predetermined condition for leaving the state, sequences being executable by the execution means; and

c. means for receiving, during execution, data relevant to the state conditions so as to determine transition among states in accordance with the control instructions; and

d. simulation means implementing a model of machine behavior and issuing, to the execution means and in accordance with the model, data relevant to the state conditions.

19. The control system of claim 18 further comprising means for issuing an alert, at least some of the actions comprising actuating the alerting means.

20. The control system of claim 18 further comprising means for obtaining input from a user, at least some of the received data being received from the user input means.

21. The control system of claim 18 further comprising a machine interface, at least some of the received data being received from the machine interface, the control functions being executed via the machine interface.

22. The control system of claim 18 wherein the behavior model comprises a plurality of probability distributions collectively representing a model of machine response.

23. The control system of claim 22 further comprising means for altering the probability distributions based on the received data.

24. The control system of claim 22 further comprising means for altering the probability distributions based on user input.

25. The control system of claim 18 wherein the control function is executed on the simulation means.

26. The control system of claim 25 wherein the simulated execution is a Monte Carlo simulation that dictates, in accordance with a plurality of probability distributions, transitions among control functions.

27. The control system of claim 25 further comprising a graphic display for depicting the simulated execution.

28. The control system of claim 18 further comprising mean for interfacing to a machine to perform thereon the control function, the received data originating with the machine via the machine interface.

29. The control system of claim 28 further comprising a graphic display for depicting machine behavior based on the received data.