Fault Tolerant Control for a Fractional Order AUV System

In the last decade Autonomous Underwater Vehicles are used in large number. The control issue of these vehicles is very challenging due to uncertain underwater environment. Conventional controllers may fail during operations especially when changes in the system occur, since it is impossible to re tune the controller in water. Hence the autonomous underwater system must have controller capability to detect, identify and tolerate fault, abort the ongoing mission and return to water surface. In this paper fault tolerant control algorithm is designed and applied to fractional order model of AUV. While designing fault tolerant controller state observer feedback technique is used. It is observed that the fractional order system is stable for fractional order greater than 1 and less than 2 under normal and under actuator failure conditions. For gain optimization of feedback controller LMI approach is used.