Sliding Mode Control of an Underwater Robotic Vehicle including Adaptive Fuzzy Dead-zone Compensation

Due to the great technological improvement obtained in the last decades, it became possible to use robotic vehicles for underwater exploration. During the execution of a certain task with the robotic vehicle, the operator needs to monitor and control a number of parameters. If some of these parameters, as for instance the position and the orientation of the vehicle, could be controlled automatically, the teleoperation of the vehicle can be enormously facilitated. Based on experimental tests, it was verified that ROV’s thruster system can exhibit dead-zone nonlinearities. This work describes the development of a variable structure control strategy for an underwater robotic vehicle with a thruster system subject to dead-zone input. Numerical results are presented in order to demonstrate the control system performance.