Microprocessor Implementation of PID Controllers and Lead-Lag Compensators

This paper discusses the microprocessor implementation of two widely used industrial controllers: the PID controller and the Lead-Lag compensator. The main characteristics of this implementation are the general form of the equations used, the high precision maintained, and the capability of handling a wide range of numbers by means of floating point representation in the microprocessor. An 8-bit general purpose microprocessor is employed, and the entire hardware and software required for the floating point arithmetic simulation and the controller´s realization are presented. The flexibility of the proposed design is also discussed. The material presented in this paper may be useful to control engineers interested in microprocessor-based control, as well as to microprocessor/computer specialists interested in applications to the control field.