Generalized GUI tools for Analysis & Design for Nonlinear System

Abstract

The task of analysis and design of nonlinear control system is more complex than linear control system. Learning in classroom as well in laboratory is also time consuming and cumbersome. There is no universal method of analysis and design available for nonlinear control system. If control system consists of discrete nonlinearity like- Ideal relay, saturation, dead-zone, backlash etc., then graphical methods like DF (Describing Function), PPT (Phase Plane Trajectory), and zames' circle criteria are useful. Apart from discrete, another class of nonlinear system is continuous. Nonlinear dynamics of such system can be represented by analytical expression and it is continuously di erentiable at its operating region. The proven method to handle such nonlinearities is to approximate the system with linear model at its operating point and then treat the system as linear system. All above stated methods are highly complex, time consuming and speci c to particular class of system. It makes equally di cult for students, teachers and researchers to visualize the facts and concept of the nonlinear control system. An interactive and easy to use, MATLAB based GUI tool -\nonlintool" is proposed to serve easy and e ective learning of general class of nonlinear control system based on proven methods. The tool o ers user friendly computational platform for nonlinear control system with almost all type of nonlinearities. It aims to provide quick and e ective means of learning of nonlinear system. Popular methods for stability investigation of nonlinear system like- DF and PPT are covered in the proposed tool. In case of continuous type of nonlinearity, tool covers the entire linearization process and subsequently design process of continuous type nonlinear system. This will signi ficantly reduce the computational burden on the designer. Major advantage of the proposed tool is that, it version independent tool.