Trajectory-Based Synthesis of Propulsion Systems for Fixed-Thrusters AUVs

Abstract

Abstract. This paper presents a synthesis method for the Autonomous Underwater Vehicle (AUV) propulsion system based on the features of a trajectory to follow. This method is based on solid/fluid dynamics analysis of a AUV performing the trajectory following task and gives actuation requirements to achieve it properly. This actuation is then used to generate a propulsion system under the form of a Thrust Configuration Matrix (TCM) that is compatible with the desired trajectory. From this matrix the number of thrusters, their position and direction can then be extracted to synthesis a fitted propulsion system. Thus, the propulsion capabilities of the robot will match the trajectory characteristics and it will be able to follow it. The objective of this work is to provide an evaluation as well as a design method to produce a controllable AUV for a given task. A second use of such an analysis is to provide an evaluation process allowing to perform AUV task-based design. The method is developed for generic fixed-thrusters AUVs on any trajectory, and is applied to an existing 4-thrusters AUV for a seabed scanning flat trajectory. The method shows why the initial AUV propulsion does not match the task and what is the solution solving the issue.

Advances in Reconfigurable Vectorial Thrusters for Adaptive Underwater Robots

“…This issue is solved with the combination of several FTs acting in different directions and with different thrust vectors F T , placed differently by a position vector r C , as in robot ODIN [42,43] (Figure 4a) , which can be considered the first underwater robot with a full holonomic propulsion [48]. Another newest possibility is to use a few or a single reconfigurable thruster (RT) [26], since they may have their thrust vectors redirected, which involves more than one degree of freedom (DOF) per thruster, and so, an integrated solution for propulsion and guidance [27].…”