4-RR_(-)(SS)_(2)高速并联机器人动力尺度综合

Dynamic Dimension Synthesis of 4-RR_(-)(SS)_(2) High Speed Parallel Robot

研究一种新型四自由度高速并联机器人动力尺度综合方法。该机构以4-RR_(-)(SS)_(2)为支链且具有单动平台结构,与采用双动平台结构的此类机构相比,末端动平台质量更轻,从而具有良好的加减速性能。建立机构运动学和动力学模型,并构造出可反映机构运动和力传递特性的链内/链间压力角,以及以单轴最大驱动扭矩全域最大值最小的动力学性能评价指标。在此基础上,综合考虑装配尺寸等几何约束和运动学性能约束,建立了以使机构动力学性能最优的机构尺度综合模型。在探究压力角和动力学性能随尺度变化规律后,给定具体约束条件,通过遗传算法优化得到一组最优尺度,并基于在Lamé抓放轨迹上运动仿真完成伺服电动机参数预估。

A new method of dynamic dimension synthesis for 4-DOF high-speed parallel robot is studied. The mechanism takes RR(SS)2 as the branch chain and has a single acting platform structure. Compared with the mechanism with double acting platform structure, the end moving platform has lighter weight and better acceleration and deceleration performance. The kinematic and dynamic models of the mechanism are established, and the pressure angle between the chain and the chain which can reflect the motion and force transmission characteristics of the mechanism are constructed, and the dynamic performance evaluation index with the minimum maximum single shaft driving torque in the whole area is constructed. On this basis, considering the geometric constraints such as assembly size and kinematic performance constraints, a mechanism dimension synthesis model is established to optimize the dynamic performance of the mechanism. After exploring the variation law of pressure angle and dynamic performance with scale, a set of optimal dimensions is obtained by genetic algorithm optimization with specific constraints, and the servo motor parameters are estimated based on the motion simulation on the Lame grasping and releasing trajectory.