仿海蟹机器人浮游步态动力学建模与运动控制

Dynamic Modeling and Motion Control of a Crablike Robot in Floating Gait

为实现足桨耦合推进仿海蟹机器人在未知海流扰动作用下对目标点的跟踪控制,对仿海蟹机器人浮游步态的动力学和运动控制进行研究.综合考虑重力、浮力、游泳足拍动产生的推力以及水动力的影响,建立了仿海蟹机器人水下复杂环境的动力学模型.在此基础上,设计了一种基于指数趋近律的滑模变结构控制器,将游泳足上下拍翼运动和摇翼运动的相位差作为被控量,对机器人的转艏角速率进行控制.通过李亚普诺夫直接法,证明该系统可实现全局渐近稳定.最后进行了单一目标点和多目标点跟踪运动仿真和实验,结果表明:该方法可以使机器人具有良好的目标点跟踪能力,并对系统动力学参数不确定性及外界扰动具有较高鲁棒性.

Investigations on dynamics and motion control for a crablike robot in floating gait are conducted, in order to achieve the waypoint-tracking control of the leg-paddle coupling crablike robot disturbed by unknown current and flow. Firstly, dynamic model of the robot subject to complex underwater environment is established with consideration of the effects of the gravity, the buoyancy, the thrust produced by the swimming leg and the hydrodynamic force. On this basis, a sliding mode variable structure controller based on exponential approach law is designed. The phase difference between the flapping motion and the feathering motion is taken as the controlled variable to achieve the yaw rate control. And the globally asymptotic stability of the control system is proved by the Lyapunov direct method. Simulations and experiments of single and multiple target tracking are carried out, and the results show that the presented controller has strong waypoint tracking ability and robustness against the variations and disturbances of the system dynamics.