含间隙铰的柔性机器人动力学研究

Study on the Dynamics of Flexible Robot with Clearance Joint

论文将多柔体动力学的建模方法引入柔性机器人的动力学分析中,应用Lagrange方程建立空间刚—柔耦合多体系统动力学方程,采用牛顿二状态模型,对含间隙机器人的副间接触和分离过程,建立了铰接间隙动力学方程。仿真分析结果表明,由于间隙铰的存在,间隙运动副反力呈现大幅度连续波动现象,使整个机器人的稳定性大大降低。而当记入大臂的柔性后,间隙副反力的波动减小,所以,机器人可以通过适当添加弹性补偿单元降低部分副间碰撞时的冲击效应,提高机构运转的稳定性。

This paper applies the modeling method of dynamics of flexible multi-body systems into the dynamic analysis of flexible robot and builds the dynamic equations of spatial rigid-flexible coupling multi-body systems by the Lagrange equation. The unified dynamics equation with clearance is built, which considers the influence of joint with clearance and applies the kinematics model of Newton second state. The result of analysis shows that the moving stability of the robot is reduced due to the existing jointing clearance. However, the interior flexibility of the mechanism can reduce the shock effect of collision in the part of motion pair. Therefore, by adding a suitable elastic compensation unit on the parallel mechanism the collision effect can be reduced when part of clearance joint collide and the working stability of mechanism can be enhanced.