ROV 기반 수중 글라이더 회수 플랫폼의 명령 필터 적응 백스테핑을 이용한 경로 추종 제어에 관한 연구

Abstract

Underwater gliders are attracting attention as robots for collecting ocean data due to their high energy efficientcy and wide exploration range, and research is underway to utilize ROVs to safely retrieve them. However, ROVs are constantly exposed to disturbancs such as waves and currents, making it difficult to maintain stable control. To solve this problem, this paper presents a path that minimizes disturbance and proposes a nonlinear controller that includes an adaptive term for path tracking. First, we calculate the kinematics and dynamics of the developed ROV and proceed with modeling. Next, we present a disturbance model for application to the marine environment. The disturbance consists of sum of wave disturbance and ocean current disturbance. Wave disturbance are generated based on water particl motion and decrease exponentially with depth. The ocean current disturbance is configured to be constant regardless of depth. Design a backstepping controller to control the ROV system. To overcome the influence of disturbance and for convenience of design, Lyapunov-based adaptive term is used. In addition, we add a command filter to solve the complexity of the backstepping method. The command filter can compute the derivate of a virtual control signal without derivatives and includes a filter error compensation mechanism. To compare the performance of the controllers, we further design a sliding mode controller with an adaptive term. The stability of designed controllers are proved based on the Lyapunov theory. Lastly, numerical simulation is performed showing the performance of the proposed controller.