DEPTH POSITIONING CONTROL OF A SPHERICAL UNDERWATER ROBOT VEHICLE (URV)

Underwater Robot Vehicles (URVs) are an underwater system that has its own power
and controlled by an onboard computer. URV has been deployed to the numerous
duties without human interventions, such as repairing subsea systems and installing
networks for scientific research and data collection. In most of these applications, a
stable motion is required for the URV. However, the existing URV designs with the
fixed ballast tank which generates an internal dynamic for the water inside the tank,
leading to the unstable motion for the URV. It hypothesized that an alternative tank
mechanism which has variable ballast can perform better and improve the stability of
the URV motion. This work focuses on developing a spherical URV has a variable
ballast tank mechanism. The complete modeling system of the URV was built and the
dimensions and control system components were defined using Simulink!MATLAB
and the characteristic of the system was analyzed using the open loop response.