Abstract: An effective optimal control strategy is proposed in order to solve the stable control problem produced by the disturbance on unmanned underwater vehicle (UUV) in low-speed state. The system state equations with double input of the level rudder and buoyancy compensation are obtained by establis- hing a UUV longitudinal plane movement mathematical model and linearizing the model, and then a line- ar quadratic optimal control scheme based on buoyancy compensation is designed. The optimal control scheme is compared with the classical control scheme through simulation. The result shows that the opti- mal control scheme can shortens setting time by half, and more quickly and effectively make the disturbed system stable.

Key words: automatic control technology, UUV, buoyancy compensation, linearization, linear quadatic regulator, optimal control