Development of a 4-DOF dynamics model of RIB type unmanned surface vehicle for constructing an autopilot system

Abstract

A RIB(Rigid Inflatable Boat) is widely used for coastal transportation and ISR(Intelligence, Surveillance, Reconnaissance) in the military operation. Owing to its wide practical applications, many countries are developing RIB type USV(Unmanned Surface Vehicle). Since RIBs are around 10 meters in length and over 30 knots in speed, its motion characteristics is quite different from that of a large-scale ship. For example, when it turns, large roll motion occurs and it heels opposite to the large ship's turning case. Since the modeling of such motion characteristics is essential to develop high performance autopilot and way-point controller, 4-DOF dynamics model should be considered to identify a RIB type vehicle's motion characteristics. In this paper, a 7-meter class RIB type USVs sea trials results such as speed, turning, and zig-zag were presented and a dynamics model for the description of a RIB's motion was suggested. The suggested model was partly identified based on sea trials results. The developed dynamics model will be used for constructing an autopilot and way-point controller.