一种四自由度冗余串并混联拟人机械臂的动载协调分配优化

Dynamic Load Distribution Optimization for a 4-DOF Redundant and Series-parallel Hybrid Humanoid Arm

基于串联机构与并联机构的特点,提出了一种新型四自由度冗余串并混联拟人机械臂机构,弥补当前拟人机械臂的不足之处。针对该机构主动关节之间驱动力分配存在多解的特点,提出一种机构按照预定轨迹运动的动载协调分配优化方法。基于牛顿-欧拉法建立冗余混联机械臂机构的动力学模型,其中机械臂肩关节机构动力学方程为超静定方程,利用小变形叠加原理建立机构的变形协调补充方程;建立以平均功率、力矩波动和平均功率偏差为目标的多目标优化模型,利用主成分分析法对该模型进行优化求解;通过数值算例验证了该方法的正确性和可行性。研究结果表明,选取最优的分配输入组合可实现机械臂能耗低且平稳地工作。

According to the characteristics of series mechanism and parallel mechanism,a novel 4-DOF redundant and series-parallel hybrid humanoid mechanical arm is proposed to make up the deficiencies of current humanoid manipulator.For the character that distribution of active joints’drive forces is not unique due to the redundant degree of freedom,a dynamic load coordination distribution optimization method for the mechanism tracking anticipant trajectory is proposed.The dynamic model of the mechanism of redundant and hybrid manipulator is established based on the Newton-Euler approach,to derive the deformation equations of compatibility for the shoulder of manipulator since its dynamic equations is hyperstatic equations by utilizing the micro-deformation and superposition principle.A multi-optimization model is established including the average power,torque fluctuation and average power deviation,and the method of principal component analysis is used to solve the model.The correctness and feasibility of this optimization method is verified by numerical examples.Results show that the input combination of optimal allocation is selected to achieve the mainpulator working placidly with low energy consumption.