Implementing a real-time knowledge-based controller in a velocity controlled, servo motor control system

The system maintains a constant velocity at the output of a DC servomotor in the presence of unknown parameter variations occurring within the motor. The constant velocity is maintained by use of an expert system which modifies the compensator in real-time. Most expert systems require a relatively long period of time to execute in relation to the process being controlled. An architecture which overcomes this problem has been proposed by J.R. James and L.A. Rapisardia (1988); it uses a digital signal processor (DSP) for real-time control and an IBM AT for the inference engine (CLIPS). The knowledge-based controller uses the hardware setup of James and Rapisardia (1988). The software executing on the DSP board is programmed as a tunable proportional-integral-derivative controller. In addition to real-time control, the real-time processor executes a program module that calculates the standard deviation of the output of the system in real time