中文摘要：

2自由度并联转台凭借其运动方式的特殊性,提高了传统转台在大负载、高速度、高加速度及大范围转动条件下的运动性能,具有广阔的应用前景。显然,精确的动力学模型是实现其高速、高精度运动控制的前提条件。Omni-Wrist III是一种可实现类球面运动的2自由度并联转台,具有结构对称,工作空间大等特点。基于其几何结构的特殊性,建立该机构的几何约束方程,推导出一种简化的动平台运动学模型,在此基础上得到各支链的运动学模型。从机构运动学模型出发,建立基于Lagrange方法的机构动力学模型,讨论转台有效惯量随机构位形的变化规律及简化条件,最后对其动力学特性进行仿真分析。该模型可用于结构组件设计的改进、控制模型的参数识别及电动机的选型。

英文摘要：

The 2-DOF parallel platform can greatly enhance the traditional platform pointing capability under heavy load, high velocity, high acceleration and large workspace conditions, and expand the application of parallel platforms in a wide field because of the particularity of movement pattern. Obviously, the precise dynamic model is the prerequisite for the achievement of its high velocity, high precision motion control. Omni-wrist III is a quasi-sphere motion 2-DOF parallel platform has symmetric structure and large workspace. The geometric constraint equations of this mechanism are established based on the particularity of the geometric structure, the detailed compact kinematic model of moving platform and four legs are derived. The dynamic model is established based on the Lagrange method and the effective inertia variety with the change of mechanism is discussed. The simulation of mechanism dynamics is implemented by using Adams software. The derived model will be useful to improve the design of the mechanical components, the control algorithm of this manipulator and the selection of motor.