Steady state trim and open loop stability analysis for the REMUS Autonomous Underwater Vehicle

This paper outlines the results of an investigation into the steady state trim and open loop stability characteristics of the REMUS Autonomous Underwater Vehicle (AUV). The study begins with the construction of an optimization-based facility utilized to trim a non-linear dynamic model of the vehicle. The trim problem for the vehicle is formulated as a non-linear programming problem and solved using a sparse quasi-Newton non-linear algorithm. A numerical linearization routine based on finite differencing is applied to the non-linear vehicle model, together with the development of an analytical approach. Inspection of the vehicle's mode shapes reveals that modal decomposition can be applied, allowing the vehicle's open loop dynamics to be separated into weakly interacting longitudinal, depth-plane and lateral/directional subsystems.