仿袋鼠跳跃机器人变截面曲线柔性脚着地特性研究

Research on Motion Features of Kangaroo Hopping Robot′s Flexible Curve Foot Based on Beam with Varying Section in the Stance Stage

为了改善足部柔性和形状变化自适应能力,提出了采用变截面梁模拟袋鼠柔性脚,运用Hamilton变分原理和有限元方法,建立仿袋鼠跳跃机器人着地阶段的动力学方程;结合实例,应用Matlab对弹性势能变化和踝关节运动轨迹进行了分析;利用ANSYS和ADAMS软件对机器人进行动力学建模和运动仿真,得到了地面反力变化规律和柔性脚刚度特性;最后搭建了跳跃机器人柔性楔形脚和曲线脚的对比实验台,测得着地过程柔性楔形脚和曲线脚的加速度曲线。研究结果表明:柔性曲线脚在着地阶段,具有储存部分落地冲击能量,进而起到缓解冲击和提高机器人起跳性能。

To improve the flexibility of foot and self-adaptive capacity in shape changes,variable cross section beam was proposed to simulate the compliant foot of hopping kangaroo.To establish the kinetic equation of the stance stage of kangaroo hopping robot,Hamilton′s principle together with finite element method was adopted.The changes of elastic potential energy and trajectory of ankle joint in certain example were analyzed by means of Matlab.Through ANSYS and ADAMS,the dynamic modelling and the motion simulation of kangaroo hopping robot were conducted to gain the variation of ground reaction force and the stiffness characteristic of compliant foot.A experimental platform used to contrast flexible wedge foot and flexible curve foot was set up to measure the acceleration curve in the stance stage.The results indicate that flexible curve foot has the capability to dissipate and store part of the landing impact energy,through which the impact can be eased and the performance of take-off can be improved.