Design And Research On CAN Bus Based Controller Of An Autonomous Underwater Vehicle

The ocean monitoring technology is the significant guarantee for research of ocean science and explore of ocean resource. Autonomous Underwater Vehicle(AUV) is the platform of ocean monitoring instruments and the key equipment for obtaining ocean monitoring data. Basing on the independently developed AUV that has ability of landing and sitting bottom with variable buoyancy system(AUV-VBS), this paper describes the basic function of the AUV and the design requirement of the system controller. The specific implementation method of the hardware and software are presented. The feasibility is verified by all unit experiments and system experiments.CAN bus based distributed control system is used on AUV in this paper. The detail of CAN bus application on AUV is presented including interface design, protocol design and communication software design. Taking implementation of the execution layer as an example, the controller design and implementation are introduced. From the viewpoint of the hardware, a microcontroller with CAN interface is used. Mature expanding technology is applied to enhance the reliability of controller. Special interfaces are designed to control AUV's propeller, plane and rudder with the drivers of motors. For further improving the reliability of the circuit, the high band width optocouplers are used and the linear power rectifier is designed. From the viewpoint of the software, different modules are designed for different functions as the complex requirements of the controller and a mass of use on on-chip resources. Every module provides service by interface function, including CAN communication, PID control, speed control and I2C communication. The relationship between foreground and background program is reasonably designed. Among them, the attitude control is implemented with PID algorithm.To verify the validity and reliability of the controller, many experiments and improvements have been done both in software and hardware. On this foundation, the unit experiments are carried out to validate the performance of the controller and collect enough data to further improve the controller and whole control system. End, in the experiments under water, the distributed control system including four similar controllers runs well with stable performance, good reliability and fast response to emergent instructions and meets the requirements of the control system of AUV.