Process information and maintenance system for distributed control systems

• US 5,796,606 A
• Filed: 02/07/1996
• Issued: 08/18/1998
• Est. Priority Date: 02/07/1996
• Status: Expired due to Fees

• Current Assignee: Nexfor Incorporated (West Fraser Timber Company Limited)
• Original Assignee: Noranda, Inc. (Glencore Plc)
• Inventors: Spring, Robert A.
• Primary Examiner(s): RUGGIERO, JOSEPH F
• Application Number:
  US08/598,021
• Time in Patent Office: 923 Days
• Field of Search: 364/131-136, 364/138, 364/139, 364/146, 364/188, 364/189, 364/550, 364/551.01, 364/184, 364/185, 364/178, 364/179, 364/552, 364/554, 340/517-525
• US Class Current: 700/9
• CPC Class Codes: G05B 19/41855 by local area network [LAN], network structure
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A process information and maintenance system for monitoring, visualizing, triaging and maintaining all control loops of a distributed control system gives the users the number of control loops in the plant, the number of loops that are routinely in manual mode, which loops are frequently in alarm, which loops need tuning, etc.

Claims

1. A process information and maintenance system for continuously monitoring, visualizing, triaging and maintaining all control loops of a distributed control system, comprising:

a distributed control system comprising at least one computer with data acquisition means, storing means and displaying means for acquiring, storing, and displaying data from at least one sensor and at least one actuator connected thereto; and

further comprising automatic control logic means for automatically regulating at least one sensed process value by modifying settings of the at least one actuator, said distributed control system monitoring process functions;

a work station comprising a work station computer connected to the at least one computer in the distributed control system for monitoring control system functions of said distributed control system, the work station computer comprising;

a) means for monitoring and acquiring the data and settings of each control loop of the distributed control system from the at least one computer;

b) means for processing the information acquired in step a);

c) means for storing the processed information of step b);

d) means for triaging the control loops monitored through the stored processed information; and

e) means for displaying the triaged control loops so that a user is informed of a loop'"'"'s unusual behavior;

said work station computer monitoring, visualizing, triaging, and maintaining the distributed control system.

2. A system according to claim 1 wherein the distributed control system comprises a plurality of terminals connected to the at least one computer.

3. A system according to claim 1 wherein the means for acquiring data in the work station computer contains a record for each loop being monitored, the record comprising both static and dynamic information about the loop.

4. A system according to claim 1 wherein the distributed control system contains single-input/single output (SISO) control loops, multiple-input/multiple-output (MIMO) control loops, or both.

5. A system according to claim 1 wherein loops may be defined in the processing and storing means of the work station computer either manually, automatically according to the loop type or automatically according to information in a file.

6. A system according to claim 1 wherein the process information and maintenance system for monitoring, visualizing, triaging and maintaining all control loops of a distributed control system does one or more of the following:

automatically identifies all the standard loops, continuously monitors all loops and recursively calculates standard deviation of the process variable, average error from setpoint, alarm frequency, correlation coefficients and power spectra;

provides short lists of the loops often in manual mode, often in alarm, or loops with a persistent setpoint error;

ranks loops according to their usage in automatic mode, variance; and

automatically prints daily or shift reports identifying the loops most in need of maintenance.

7. A system according to claim 1 wherein the distributed control system is a Bailey Net90, a Rosemount System 3, a Fisher Provox, a Valmet Damatic XD, a Foxboro I/A, a Honeywell TDC 3000, or an ABB Master.