Modular Control System Simulator

Abstract

In this paper, we introduce a modular control system simulator for positioning servo applications. The program package was originally written for elevator car positioning simulations, but because of its straightforward modular structure it can easily be tailored for other types of applications as well. The simulator contains all the necessary functions needed to design an appropriate positioning servo when an estimate of the system model is known. The numerical system model is assumed to be a rational z-domain transfer function and it can be identified a priori from measured excitation and response signals by using some prediction error type algorithm. Although all the internal computations are performed using floating-point numbers, the simulator has built-in A/D and D/A converters to quantize the input and output sequences artificially. The simulator also has a programmable noise generator to generate additive measurement error to the simulated feed-back signal. The control and noise- filtering algorithms can be changed by replacing the existing modules with user-written FORTRAN subroutines. All the data transfers between individ ual modules are well defined to ensure easy modifiability of the overall system. The simulation software runs in a desk top personal computer.