Research On Application Of Active Disturbance Rejection Technology To AUV Heading Control

AUV is a complex system with 6 DOF, non-linear, coupled and ever-changing model exposed to severe external disturbances, so heading control of AUV is a tough issue. To improve the accuracy, robustness, and stability of heading control, this paper made a profound analytical research on the application of active disturbance rejection control (ab. ADRC) technology in heading control.Firstly, the hydrodynamic features of the AUV was decided according to general hydromechanics theory and the AUV's special shell, and a sound 6DOF mathematical model for the AUV was obtained. Further, a 3DOF model of it was achieved for heading motion control.Secondly, basic principles for ADRC technology was presented, as well as structure of ADRC controller and discrete algorithm. As for the parameter adjustment for ADRC controller, numerical Simulink was adopted to find the influence of each parameter on the overall control effect and principles for this adjustment were settled.Finally, an ADRC based heading controller was designed. Simulink in MATLAB was adopted to construct the ADRC heading control system and simulate the heading control course. The algorithm was programmed by C++ into a function with generic interface which was added into the AUV dynamic control computer to fulfill the semi-physical simulation.The simulation result showed that this ADRC controller has good controlling effect. It can reject the disturbances of current, pulse partial moment and invariable partial moment. Compare to PID controller, it has better performances respectively with and without the current disturbance conditions. The findings of this paper sets a base for ADRC technology's future application in AUV control of velocity, pitch, depth and tracking.