Abstract: Circular synthetic aperture sonar obtains all-round observation information of underwater targets by performing 360 ° circular motion on the imaging scene, in order to achieve high-precision three-dimensional imaging of underwater targets. Its imaging effect is greatly affected by the circular motion error of unmanned platforms. To address this issue, a centripetal acceleration based nonlinear guidance for circular was designed based on the derivation of the circular path, which has a high degree of fit to the circular trajectory and high control accuracy. In addition, a circular motion control law based on MPC algorithm has been designed, which has fast control response and strong adaptive ability. Integrate the two algorithms well to achieve accurate circular trajectory tracking. The control output of the guidance law is yaw rate, so the control process does not rely on the yaw angle data measured by the USV magnetometer and can be used under conditions with strong magnetic field influence. The superiority of the algorithm was verified through simulation experiments, and the tracking accuracy of the algorithm designed in this paper is 80.1% higher than that of the algorithm described in reference. Further verification of the algorithm's effectiveness through lake experiments shows high control accuracy for circular motion. The research results can provide a control algorithm basis for the circular motion of unmanned ships used for circular synthetic aperture sonar imaging. The research results provide an algorithmic basis for the research of unmanned ship platforms used for circular synthetic aperture sonar imaging.

Key words: Unmanned Surface Vehicle (USV), Circular Synthetic Aperture, Sonar Imaging, Circular motion control, Model Predictive Control (MPC)