高频激励下旋转柔性臂逆动力学模态自适应方法研究

Adaptive Mode Method in Inverse Dynamics of a Rotating Flexible Manipulator With High-frequency Excitation

在空间柔性机械臂的动力学与控制问题中,逆动力学求解常要求有较高的计算速度.当柔性多体系统受到高频激励时,必须考虑高阶模态才能保证足够的计算精度,但同时提高了计算自由度数,降低了计算速度.为了提高此类问题的计算效率,本文将模态自适应策略应用于旋转柔性臂逆动力学建模,计算了高频激励下产生期望旋转运动的柔性臂关节驱动力矩,验证了该方法的有效性,并研究了重力对计算结果的影响.

In dynamics and control of space flexible manipulators, high computing speed is always required for solving inverse dynamics. However, when the flexible multibody system suffers from high-frequency excitation such as contact impact, high order modes have to be counted to ensure adequate precisions while the computing speed is lowered down. To increase the computational efficiency of such problems, an adaptive mode method was proposed with an application in inverse dynamic modeling of a rotating flexible manipulator. In the process, the axial displacement caused by transverse deformation of the beam-like model was considered, and high order mode coordinates were reduced gradually as they damped off in the proportion of total energy due to structural damping. The control laws of driving torque for the rotary manipulator articulation were computed to account for its validity. Additionally, the influence of gravity was investigated.