Model-Free PID Controller Based on Grey Wolf Optimizer for Hovering Autonomous Underwater Vehicle Depth Control

Traditionally, the wearisome effort is required to tune the PID parameters and always resulting in erroneous system behavior. The objective of the present work paper is to develop a tuning method for model-free PID controller parameters by using Grey Wolf Optimizer (GWO) to control the depth of Hovering Autonomous Underwater Vehicle (HAUV). The speed of HAUV thrusters is controlled by a PID controller where the tuning for three PID parameters is done by using GWO algorithms. Sum Square Error (SSE), percentage overshoot and settling time of the depth response are chosen as the fitness functions. The differential equation of the HAUV system in heave direction is considered with the aim to confirm the design of PID controller. The proposed approach is compared with Sine Cosine Algorithm (SCA). The time response specifications of input tracking of HAUV with the presences of external disturbances, model nonlinearities, buoyancy force, hydrodynamic drag force and added mass on the HAUV system are considered as a control scheme performance while the convergence curve of the fitness function indicates the performance of optimization algorithm. Finally, the suggested tuning method promises a fast depth tracking capability as shown in simulation results.