Development of Two Control Strategies for Tracking the Trajectory of An Unmanned Underwater Structure Inspection Vehicle

This paper presents the development of two dual-loop control strategies for an underwater Remotely Operated Vehicle, ROV. The first strategy consists of two PID controllers while the second one features a LQG controller in the inner loop, and a PID controller in the outer loop. The transient response of the two strategies is compared when an anti-windup gain is applied and when there is no anti-windup gain, and a way to tune this gain in the case of statespace controllers is proposed. For further comparison, the strategies are simulated for a variable set point, for the three variables to be controlled, x, z, yaw, so that both their tracking and the effect of coupling can be seen. In conclusion, the use of anti-windup gain is recommended for control systems that reach saturation, so that they can react quickly when they are in an operating zone, and the use of a random matrix for the calculation of this gain in state-space controllers is suggested. © Published under licence by IOP Publishing Ltd.