A fully interactive dynamic simulation of a semi-submersible towing a large towfish

Abstract

ISER and DREA are collaborating on the development of SIMRMS, a fully interactive nonlinear submersible /cable /towfish six degree-of-freedom (DOF) time domain simulation. This capability is not found in standard tow system codes. SIMRMS is a meshing of the DREA Submersible Simulation Program (DSSP) and the DYNTOCABS tow cable/towfish simulator. DSSP is a nonlinear 6 DOF vehicle simulator that models control, propulsion, and ballasting. DYNTOCABS provides a three-dimensional, nonlinear, 3 DOF, finite segment simulation of the cable and includes a nonlinear 6 DOF model of an active towfish. The two programs have been merged so that the equations of motion for all system components are simultaneously integrated in time. New features and capabilities have also been developed.

Modelling variable length tows and altitude-keeping with the Canadian Remote Minehunting and Disposal System

“…The RMV and VDT hull hydrodynamics (through hydrodynamic coefficients); RMV and VDT control planes laws (through control gain matrices) and hydrodynamics(through hydrodynamic coefficents); RMV and VDT statics (weight/balance, buoyancy, etc.) are modelled [5,6].…”

“…Aspects of SIMRMS were previously validated [5,6]. This includes the horizontal plane dynamics which tie together Dorado speed over ground, engine speed, cable tension, and the propulsion model.…”

“…As well, Dorado's ability to achieve its trajectory line-following between waypoints, while under tow, and the resulting Dorado yaw and roll angle, etc. The VDT dynamics and hydrodynamics were also validated in the earlier bodies of work [5,6].…”

Identification state feedback control for the depth control of the studied underwater semi-submersible vehicle

“…USVs are suitable for use in data collection under adverse weather conditions [7] . USVs are subjected to external disturbances attributed to unforeseen complex sea states because of the allowed shallow submerging water area.…”

“…A USV system can be considered as one semi-submersible autonomous underwater vehicle system, the depth control of which is difficult to perform because of strong external disturbances from the sea surface. Moreover, a USV system is a strong coupled system, which causes the design of a USV controller [6][7] to be complex.…”