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

Abstract

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.

Online Trimming of Flight Dynamic Models Using the 2Simulate Realtime Simulation Framework

“…The stationary state of a dynamic system corresponds to the general idea of rest. 2,11 For a closer study of a stationary operating point (trim state) it is necessary to distinguish whether the system is in total rest or only in an acceleration-free condition. A simple spring-mass-damper system is at total rest when in a stationary state.…”

Navigational Error Reduction of Underwater Vehicles with Selective Bathymetric SLAM

“…For many applications of SLAM in the underwater domain, the vehicle is represented by a constant velocity or constant acceleration kinematic model. An initial version of this work was developed using the same representation, but the behaviour of the model was found to lack the shortperiod response typical of an AUV working at survey speed (Sgarioto, 2008), say 2.5 to 4.5 knots. This work is based on a simplification of the full 6 degree-of-freedom model of the REMUS 100 AUV first published by Prestero (2001) and extended by Sgarioto (2007) incorporating PID controllers for yaw, pitch and thrust.…”

Steady State Analysis and Optimization for AUV Using Washout Filter Root Locus Correction Method

“…The stabilization of a relative equilibrium for an underactuated AUV submerged in an ideal fluid in the 3-dimensional space was showed in [6]. Reference [7] addressed the robust stabilization of a relative equilibrium for an underactuated AUV with disturbances rejection. By matching the closed-loop equation and the open-loop equation, an antidisturbance stabilizing controller was presented, which required the knowledge of the uncertain damping.…”

“…The AUV stability design is carried out by two aspects [18]: AUV's ontological structure steady state analysis and internal control system optimization. The ontological structure is the natural property of AUV, and its stability is directly reflected by the AUV's anti-rollover ability and self-return capability [7]. Stability analysis of the AUV mechanical structure is used as the standard for the design of the ontological structure.…”