中文摘要：

针对实用约束变胞机构在变胞全过程中的构型转换、构型保持和运动时序问题，引入变胞机构阻力梯度的概念，将约束变胞全过程的调控转化为变胞运动副等效阻力梯度调控的过程，探索实用约束变胞机构设计新方法。通过建立变胞机构的运动循环图，获取约束变胞运动副基于任务的运动规律和对应约束力或约束力矩的联系。通过将约束力与约束力矩等效，定义一种归一化的变胞副的等效阻力系数函数，进而建立变胞机构的等效阻力梯度模型，揭示了变胞运动副的等效阻力、约束特点、约束形式和结构形式的内在联系。以超高压输电线路断股修复机器人的变胞捋线机构的设计为例，演示了基于等效阻力梯度模型的约束变胞机构的设计方法，结果表明提出的设计理论和设计方法是可行和实用的。

英文摘要：

For configuration transforming, configuration keeping and working sequence problems of practical constrained metamorphic process, a concept of equivalent resistance gradient of metamorphic joints is proposed so that the control of constrained metamorphic processes is transformed into the regulating of the corresponding metamorphic joints to investigate a new way for constrained metamorphic metamorphic mechanisms design. By introducing a kinds of metamorphic cyclogram, the relationship bewtten task-based kenimatic rules and constrained forces/torques of the metamorphic joints can be obtained. A non-dimension equivalent resistance of metamorphic joints and the equivalent resistance gradient model of metamorphic mechanism are defined via the equivalent of the constrained force and the torque. The connectionships of equivalent resistances, constraint charecteristics and forms, and the structures of metamorphic joints in the working stages are revealed. The design approach is demonstrated based on the metamorphic cyclogram and the equivalent resistance gradient model for a broken strands reposition metamorphic mechanism of the repair robot for extra-high-voltage power transmission lines. The results show that proposed design theory and method are available and practical.