GARBI was conceived as a Remotely Operated Vehicle (ROV) for exploration in waters up to a depth of 200 meters. GARBI, was designed with the aim of building an underwater vehicle using low cost materials such as fibber-glass and epoxy resins. To solve the problem of resistance to underwater pressure, the vehicle is servo-pressurised to the external pressure by using a compressed air bottle, like those used in scuba diving. Air consumption is required only in the vertical displacements. When the robot dives in the heave direction, a servo system introduces air into the hull in order to increase the internal pressure until it reaches the external pressure. In addition, when the robot goes to the surface, decompression valves release the required amount of air to maintain the internal pressure at the same level as the external one. The vehicle can be fitted with two mechanical arms which would perform some simple tasks of object manipulation through remote-operation.
The vehicle has 4 thrusters (see Figure 4-a) two for horizontal movements (axis x) and two for vertical movements (axis z). It is possible to add another thruster in the transverse direction (axis y). Due to the distribution of weight, the vehicle is passively stable in roll and pitch. The vehicle also has several sensors: 2 compasses, 2 pressure sensors and water speed and water leakage sensors. Dimensions are: length 1.3 m., height 0.9 m and width 0.7 m. Maximum speed is 1 knots and the weight is aprox 150 Kg.
An on board i486 embedded computer is in charge of controlling the vehicle’s sub-systems. The robot is connected to the surface station by means of an umbilical cable for power, video and ethernet communication.