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Step Process Control Hardware Wear Distribution Algorithm

IP.com Disclosure Number: IPCOM000036787D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Lee, J: AUTHOR

Abstract

When controlling a given system with multiple actuators (the number of actuators active is the control parameter) in process control, the amount of time that hardware is kept on and/or the frequency that the hardware cycles on/off may contribute to wear. It is desirable to distribute wear on the multiple sets of hardware evenly due to failure rate considerations. This may be accomplished in several different ways.

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Step Process Control Hardware Wear Distribution Algorithm

When controlling a given system with multiple actuators (the number of actuators active is the control parameter) in process control, the amount of time that hardware is kept on and/or the frequency that the hardware cycles on/off may contribute to wear. It is desirable to distribute wear on the multiple sets of hardware evenly due to failure rate considerations. This may be accomplished in several different ways.

The most straightforward method of distributing wear-to-actuator hardware is through operation history. The amount of time each actuator is active along with the number of on/off cycles the actuator has experienced would be recorded in software. Actuators with the least amount of wear based on this data will then be favored. While this system guarantees true even wear of hardware, the amount of software and the additional storage required for recording logged time may not always make it the best method.

Random selection of actuators is another method to distribute wear. Over the life of the process control system, this will yield the same result as the machine history method. In the case of software, however, "random" control can be just as complex as the machine history method.

Software demands can be eased while providing wear distribution through the first-in, first-out (FIFO) scheme. In this scheme, all hardware networks are numbered sequentially. The last hardware network turned on and the l...