Fault-Tolerant Microcomputer Control of a Heat Exchanger Network

Abstract

As the use of digital computers in controlling chemical plants increases, loss of control due to computer failure becomes a major concern. A computer control system which is tolerant to faults of various degrees of severity was developed and experimentally tested using a heat exchanger network. Redundancy and diversity are created both in hardware and software.The computer in the control loop generates new alternatives in handling failures of other devices in the control loop by creating functional redundancy. Consequently, tolerance to sensor failure is achieved by control law reconfiguration. The reassignment of control duties due to hardware, software, or sensor failure creates process upsets similar to temporary process disturbances.