Research On The Control System Of The Vectored Thruster AUV

Autonomous Underwater Vehicle (AUV) is a new kind of Underwater Vehiclewhich has no physical connection with the mother ship, relying on its own powernavigating. It not only does not require a huge surface support system but also has theadvantages of wide cruise range, strong ability of automation, high positioning andgood maneuverability. It has very important application value in the measurement ofmarine environment and military field.In order to ensure the AUV to complete a given task，motion control system isvery important. It will directly affect the operating state of the AUV. AUV can notproperly survey the seabed if the motion control system does not work well.According to the requirements of the vectored thruster AUV, a kind of motion controlsystem is proposed. Several connection debugging experiments show that thevectored thruster control system is running well, which can not only eliminate theeffect of the oscillation in the navigation, but also can control the AUV to avoidobstacles. It can meet the requirements of the marine operation task. The design ofmotion control system includes the following parts:The hardware component of vectored control system is designed. Consideringthe control unit functional requirements and control accuracy，a kind of control systembased on embedded ARM processer is designed. And the peripheral circuit of thecontroller, steering、pitch motor and main propulsion control circuit are designed.Motion control strategy of AUV is innovatively designed. From the aspects ofHeading, Depth and Speeding, the motion control strategies are analyzed. Through alot of AUV running experiments in the past, we know that AUV often exist steeringlarge deviation and long-time shortcomings when turning along the target track in thecontrol method of traditional PID. So according to AUV steering characteristics, thispaper proposes a new method of adaptive double-loop PID. It can greatly reduce thesteering deviation and time when AUV turn the rudder angle. Experiments show thatthis method can effectively improve steering path-tracking result.The software of the vectored control system is designed, such as the UDPcommunication program, PID program, servo control program and the main pushmotor control program and so on. According to these, the overall software of the motion control unit is designed with multi-task programming method.