基于Kane方法的仿鱼机器人波状游动的动力学建模

Dynamic Modeling of a Fishlike Robot with Undulatory Motion Based on Kane’s Method

提出了基于Kane方法的仿鱼机器人波状游动的动力学模型。通过对鱼体波状游动的运动学描述,将仿鱼机器人离散成刚性头部、柔性身体和摆动尾鳍三个部分并划分为多个运动环节进行分析,考虑鱼体外部环境的作用力:流体附加质量、流体加速作用的弗劳德—克里洛夫力、鱼体游动过程中的阻力特征,建立仿鱼机器人的动力学模型。数值实例表明,利用该动力学模型,能够有效地实现给定鱼体各环节的运动参数求解作用力矩、给定作用力矩求解运动规律,进一步设计仿鱼机器人各环节的运动规律,寻找一种实现鱼体推进力最大和推进效率最高的规划方法。该动力学模型的建立为研究仿鱼机器人的运动控制算法和规划算法,揭示鱼体利用流场能量的动力学机理提供了重要理论支撑。

A dynamic model of a fishlike robot with undulatory motion based on Kane＇s method is presented. Through kinematic description of the fish body with undulatory movement, the fishlike robot is divided into rigid head, flexible body and oscillating caudal fin which include many motion links. The dynamic model for a fishlike robot with multiple motion links is developed with the consideration of external environmental forces, such as the fluid added mass, the Froude-Kriloff force of fluid acceleration and the flow drag during fish swimming. The numerical example shows that acting moment of a motion link can be solved for given value of motion parameters with the exploitation of the dynamic model, and vice versa. Furthermore, the planning technique for the maximum thrust and highest propulsive efficiency can be explored by designing the motion law for each motion link. The dynamic model developed is a key theoretical support to the research on motion control algorithm as well as planning algorithm, and the revelation of dynamic mechanism of fish exploiting flow energy.