STABILITY ANALYSIS AND CONTROL OF FRACTIONAL ORDER DEPTH MODEL OF AUV

Abstract

The integer order system is normally used for modelling and simulation of dynamic system. Recently fractional order modelling and control trend is introduced. Which is advantageous in dynamic systems with limited memory. In this article Fractional order modelling is considered for Autonomous Underwater Vehicle (AUV). Non integer differentiator is used for fractional order system. The model is considered in state space system. The frequency response and the stability considerations are discussed for fractional order model of Depth system of AUV. The stability considerations are useful in control system point of view or for deciding proper control strategy for AUV depth system. The stability for fractional order AUV model is explained using Riemann Surface with its multi values. The conventional integer Proportional Integral Derivative (PID) Controller is designed for fractional order depth system of AUV and dynamic properties are compared for integer and fractional order models for depth systems.