中文摘要：

并联机构的本质作用之一是在机构的输入端和输出端之间传递运动和力。对并联机构的性能分析需要从该本质功能出发，考虑机构运动和力的传递特性。在螺旋理论中，当运动旋量和力旋量进行互易积运算时，其结果表示该力在运动方向上的瞬时传递功率。结合能效系数法，可将瞬时传递功率和可能的最大传递功率之比定义相关的评价指标，用以分析并联机构的运动／力传递特性。该指标能否实用的关键问题之一是如何理解和求解可能的传递功率的最大值。根据并联机构中可能存在的不同形式的运动旋量和力旋量的组合，将功率最大值的求解问题分为五种情况，对每种情况的计算模型进行详细的推导与解释，尤其是当刚体的力和运动均为浮动的旋量（力旋量／运动旋量）时，提出改进后的特征点法，建立有效的求解模型。此外，以三个常见的并联机构为例，对机构中运动／力传递功率的最大值进行求解，以进一步说明所提计算模型的合理性和实用性。

英文摘要：

One of the essential roles, a parallel manipulator plays, is to transmit the motions and forces between the inputs and outputs. When evaluating the performance of a parallel manipulator, the motion and force transmissibility based on the essential property should be considered. In screw theory, the reciprocal product of a twist and wrench screw is indeed the instantaneous power of the force acted on the rigid body in the direction of movement. Via the ratio coefficient method, the ratio between the actual instantaneous power and the potential maximum power is commonly defined as the evaluation index. One of the vital issues for the functional index is how to calculate the maximum transmission power effectively. According to the different combinations of the wrenches and twists, the calculation of maximum power is divided into five aspects, and the detailed derivation and proof to every aspect is given. In particularly, the improved characteristic point method is introduced to build the effective calculation model for the case that the wrench and twist of the rigid body are both floating. Three typical parallel manipulators are taken as examples to determine the maximum power and to demonstrate the reasonability and effectiveness of the proposed calculation methods.