An Experimental Study on Trajectory Tracking Control of Torpedo-like AUVs Using Coupled Error Dynamics

Abstract

In this paper, we propose a trajectory tracking controller with experimental verification for torpedo-like autonomous underwater vehicles (AUVs) with underactuation characteristics. The proposed controller overcomes the underactuation problem by designing the desired error dynamics in a coupled form using state variables in body-fixed and world coordinates. Unlike the back-stepping control requiring high-order derivatives of state variables, the proposed controller only requires the first derivatives of the states, which can alleviate noise magnification issues due to differentiation. We adopt time delay estimation to estimate the dynamics indirectly using control inputs and vehicle outputs, making the proposed controller relatively easy to apply without requiring the all of the vehicle dynamics. We also address some practical issues that commonly arise in experimental environments: handling measurement noises and actuation limits. To mitigate the effects of noise on the controller, a filtering technique using a moving window average is employed. Additionally, to account for the actuation limits, we design an anti-windup structure that takes into consideration the nonlinearity between the thrusting force and rotating speed of the thruster. We verify the tracking performance of the proposed controller through experimentation using an AUV. The experimental results show that the 3D motion control of the proposed controller exhibits an RMS error of 0.3216 m and demonstrate that the proposed controller achieves accurate tracking performance, making it suitable for survey missions that require tracking errors of less than one meter.

Wake-Responsive AUV Guidance Assisted by Passive Sonar Measurements

“…Torpedoes have been developed to attack a surface target ship [1][2][3][4][5]. A torpedo can be considered a fast autonomous underwater vehicle (AUV) heading towards the target ship.…”

Underwater Acoustically Guided Docking Method Based on Multi-Stage Planning

“…The advantage of acoustic guidance is that it works over long distances, up to 3 km, and can be omnidirectional [23,24]. The disadvantage is that the positioning accuracy is low, the real-time performance is poor and it is easily exposed [25,26]. The following are typical results of docking using acoustic guidance:…”