【作者】 方益奇；

【导师】 孙怀安；

【作者基本信息】 西安电子科技大学 ， 机械制造及其自动化， 2003， 硕士

【摘要】 本文主要讨论一种界于并联机构和并联机器人范畴的闭链机构。涉及到 2R 开链机构的运动学、动力学分析和机构特性研究，并且进行 2R 机构的运动学和动力学的仿真，针对不同的驱动配置研究输出点的运动性能。由开链机构的拓扑产生并联机构，在此涉及的两自由度机构有：5R、4RP 和 3RPR。并对上述三种机构的类型进行了分析，同时给出 5R、4RP 机构存在曲柄的充要条件。进而研究平面闭链机构的柔性工作空间，并利用隐函数定理快速地推导出平面闭链 5R 和 4RP 机构的工作空间的边界条件。通过机构雅可比矩阵的求解，分析机构的运动奇异性。结合实例提出一种机构构形变异和驱动变异，其可以避免奇异中对机构影响最大的驱动奇异。将适用于研究四杆机构或者单自由度机构的误差分析方法拓展的 4RP机构上面，进行机构的位移误差和速度误差分析，并分析速度误差对位移误差的影响；提出判断机构运动性能指标的数学模型——雅可比矩阵的条件数。最后将用于机器人的控制理论应用到并联机构上面来，涉及控制原理的构成、位置控制、坐标控制以及力的控制。并结合柔性铰链，对 4RP 进行了创新性地设计和研究，使其结构上合理组合，由此产生一种微型机器人泳动机构。更多还原

【Abstract】 This paper is mainly concerned with a closed-loop mechanism that lies betweenparallel mechanism and parallel robotics. The analysis of kinematical and dynamicalmodel and mechanical characteristics are involved, and the emulation of the motion anddynamic is put into reality. The motion performance of the output varies because of thedifferently applied actuations. Two-degree-of-freedom parallel mechanism is dealt withby the definition of topology. Three ordinary types of parallel mechanism 5R、4RP and3RPR are analyzed. And the sufficient condition of full crank is derived. Then withimplicit function theorem the flexible workspace is dealt with. By using the Jacobianmatrix of the hybrid input mechanism, the sensitivity of output is obtained. Then thecondition number of Jacobian matrix is derived. According to the discussion of theJacobian matrix, we find out the dual instantaneous self-motion singularities of themanipulators. The feasibility of its avoidance from the actuating-singularity by means ofstep motors and mutation of mechanism is proven with the help of the condition numberof the Jacobian matrix. Based on the stochastic clearance model, the outputdisplacement error of the plane closed-loop mechanism is analyzed. By means of thedifferentiation of the Jacobian matrix, the velocity error caused by the tolerance of thebar is derived. Considering the influence of the velocity error on the output trajectory’scurvature, we interpolate and fit the curve between two given points of calculation.Finally, the theory of control is applied to the parallel mechanism, which including theprinciple theory of auto control, position control, coordination control and force control.With flexible joints and 4RP mechanism, a vibrating micro-robotic mechanism isinvited.更多还原