一种新型4自由度高速并联机械手动力尺度综合

Dynamic Dimensional Synthesis of a 4-DOF High-speed Parallel Manipulator

研究一种可实现SCARA运动的新型4自由度高速并联机械手动力尺度综合方法。简要阐述该机构中由可变菱形动平台和齿轮增速机构生成绕z轴转动的传动原理。在建立运动学和刚体动力学模型基础上,利用直接和间接雅可比代数特征构造出两类可用于描述运动/力在链内和链间传递能力的压力角,并提出一种基于单轴最大驱动力矩全域最大值最小的动力学性能评价指标。在满足工作空间与机构尺度比、可装配条件等几何约束和运动学性能约束下,综合出一组可使得系统刚体动力学性能全域最优的尺度参数,并利用Adept拓展轨迹预估出电动机参数。

The dynamic dimensional synthesis of a novel 4-DOF SCARA type high-speed parallel robot is investigated. In the light of the principle of changeable rhombus, the mechanical design of the articulated traveling plate for generating the rotation about z axis is briefly described in the first place. This is followed by defining two pressure angles representing the transmissibilities within and amongst limbs, and developing two dynamic performance indices represented by the maximum driving torque of a single drive. Subject to the prescribed transmission angles in conjunction with various geometrical constraints in terms of workspace/machine volume ratio and assembly conditions, an optimization problem is then formulated by minimizing the dynamic performance indices for achieving good kinematic as well as dynamic performance throughout the entire workspace. The servomotor specifications are estimated using the extended Adept cycle.