研究了移动2杆柔体机械手动力学问题。该移动机械手由弹性-阻尼悬架轮式移动载体和2杆柔体机械手组成,并假定移动载体以恒线速度通过不规则路面。综合采用经典有限元法并引入中间单元坐标系和浮动坐标法,以回避由单元刚体运动所导致的弹性构件非零应变,从而精确描述机械手弹性变形与参考运动间的动力学耦合问题。综合利用拉格朗日原理和牛顿-欧拉方程并在笛卡儿坐标系下,以简洁的矩阵、矢量形式构建了该系统的完整动力学模型。采用数值方法给出了该动力学模型正解的仿真结果。通过与刚-柔体模型、刚体模型仿真结果的比较,证实该柔体系统存在动力学耦合现象及构件弹性振动对系统性能有负面影响。
This paper concentrated on the kinematics and dynamics modeling of a mobile 2-link flexible manipulator(M2LFM),which consisted of a mobile base with a 2-DOF linear elastic-damping suspension system and a flexible manipulator and was considered to travel with a constant linear speed over an irregular ground-surface.Based on Lagrange and Newton-Ouler theories,the system dynamics model of the M2LFM in which the reference motion and the elastic deformation were coupled was derived using the finite element method and intermediated element coordinate systems and floating frame of reference formulation which can lead to zero strains,and was compactly described with matrices and vectors measured with respect to a gobal Cartesian frame of reference.At last,the numerical simulations were carried out to the forward dynamics model of a M2LFM and a rigid-flexible one and a rigid one,respectively.These simulation results illustrate these effects of dynamic couplings and elastic vibration on system by comparion.