Implementation of PID posture controller for 6 DOF underwater robot

摘要

An underwater robot is widely used in many industries. The posture control of the robot is importance since it makes a robot able to move in hard environment with stability and precision to the desired locations. The designed underwater robot consists of 8 custom made thrusters in order control all robot state variables and make the motion achieve 6 Degrees-Of-Freedom. Newtonian method is used to model the dynamics of the underwater robot. Nonlinearity of the robot dynamics is suppressed by feedback linearization method with proper parameters. Discrete Proportional-Integral-Derivative (PID) controller is used as the thruster controller and also the robot posture controller. The experiments are conducted and all the robot controller gains are tuned. The experimental results show that PID controller can control robot postures with robustness.