AUV Thrust Allocation with Variable Constraints

Abstract

Modern multipurpose Autonomous Underwater Vehicles (AUVs) represent the next
generation of robotic systems with new technological tasks faced by researchers. One method
of extending the functionality of the vehicle is installing tunnel thrusters in addition to the stern
propulsion system. Thereby the vehicle becomes able to undertake both survey-style missions
and low speed interactions with the environment. But the efficiency of the tunnel thruster depends
strongly on the vehicle’s velocity, due to hydrodynamic aspects. The usual solution to this problem
uses different control models and thrust allocation methods for these types of mission. A unified
approach to thrust allocation is presented in this paper. The approach is based on solving the
allocation problem by quadratic programming with variable constraints, depending on the velocity
of the AUV and the thrusters’ angle of attack. The well-known implementation of active set
method was used to model the proposed allocation method.