基于CPG的仿海蟹机器人浮游步态生成方法

Floating gait generation method of crablike robot based on CPG

结合仿生游动机理,针对游泳桨推进仿海蟹机器人提出一种基于中枢模式发生器浮游步态生成方法.采用可独立控制频率、幅值、相位延迟和时间非对称系数的一类非线性振荡器作为节律信号发生器,通过最近相邻耦合的方式构建了仿生游动的链式中枢模式发生器（CPG）运动控制模型,并分析了振荡单元平衡点的性态,证明了振荡器极限环存在的唯一性和稳定性;在此基础上,引入三个顶层控制信号作为CPG网络的激励,分别用来控制机器人的游动速度、转艏速率和浮潜速率,实现了仿海蟹机器人的三维游动控制.实验结果显示样机具有一定稳定性和机动性,机器人的直线游动速度和转艏速度随着游速控制系数和转艏速率控制系数的增加而增大,最大直线游动速度可达0.41 BL/s,最大原地转艏速率可达1.7 rad/s.仿真及实验结果验证了此中枢模式发生器模型的可行性与所提控制方法的有效性.

A floating gait generation method based on central pattern generator（CPG） was proposed combined with bio-inspired swimming mechanism for paddle-driven crablike robot.A type of nonlinear oscillator was used as rhythm signal generator which could independently control the undulation frequency,amplitude,phase difference and time asymmetry coefficient,and the chain CPG motion controlling model for robot swimming was established by means of adjacent weak coupling method.Then,the state of balance point of oscillation unit was analyzed proving the uniqueness and stability of limit cycle of the oscillator model.On this basis,three top-level control signals were introduced as the stimulus for CPG network to control the swimming velocity,turning velocity and floating and submerging velocity,realizing the three-dimensional swimming of the robot.Experimental results show a certain stability and maneuverability of the prototype,and the straight-line swimming velocity and turning velocity both increase with straight-line swimming velocity control coefficient and turning velocity control coefficient,which can be up to 0.41 BL/s of straight-line swimming velocity and 1.7 rad/s of turning velocity at maximum,respectively.Simulation and experimental results verified the feasibility and validity of the proposed CPG control model.