無人船非線性控制設計

Nonlinear Control Law Design of Unmanned Surface Vessels

航點追蹤設計一直以來都是無人船設計領域相當吸引人且重要之課題。於過去的研究中，研究人員通常會採取線性設計的概念來進行控制器的開發。然而，由於無人船之系統動態方程式具相當高之非線性度及複雜度故針對此系統，傳統之設計方式將不具良好之控制效果。針對此航點追蹤及無人船系統非線性問題，於此研究中，研究團隊嘗試藉由回授線性化技術的應用來提出一可有效控制非線性無人船系統並進行精確追蹤航點之控制器設計。回授線性化方法所設計之控制器具備之優點為：可有效降低追蹤誤差至期望之設計規格。此無人船控制器設計之控制性能經由模擬驗證結果可看出相當具導航設計上之應用價值。 Waypoint tracking design is an attractive and importantissue for unmanned surface vessels. The traditional control law design based on the assumptions that the kinematics and dynamics is linear or can be linearized will be no longer useful or effective to this waypoint tracking design due to the nonlinearities of kinematics and dynamics of motion of unmanned surface vessels for tracking applications. For solving this tracking problem and taking the nonlinear characteristics of the unmanned surface vessels into consideration, a feedback linearization based control law with considering nonlinear horizontal three degrees of freedom motion dynamics of a class of unmanned surface vessels is proposed and positions and yaw/heading angle are simultaneously tracked. The tracking error between unmanned surface vessels and waypoints can be proven to converge to zero asymptotically for this proposed nonlinear control law, and simulation results show the control performance of this method for the trajectory tracking problem of unmanned surface vessels.