介绍了一种用于运动模拟的冗余电机驱动的正交并联机构,并对机构可能的几何误差源进行了全面分析。为了避免误差建模时大量的偏导计算,根据机构支链的正交布置特征并结合运动学影响系数的原理建立了较为完备的误差模型。模型包含了结构参数误差、驱动误差及铰链制造误差在内的144个误差参数。另外,提出了一种确定被动关节转角唯一解的方法。最后,考察了模拟台样机所有误差参数对末端精度的影响,确定了84个对末端精度影响大的误差参数。
A novel parallel robot with orthogonal chains and redundant actuators designed for simulator was presented. Based on the orthogonal feature of the mechanism and the principle of the influence coefficients, the error model was established without the complex partial differentiation, which accommodate all possible geometrical errors, the joint manufacturing errors, the installation errors, the actuation errors etc. A method to confirm the unique striking angle of the passive joint was proposed. Based on the real parallel simulator, the simulation result shows the effect of all the errors on the accuracy and indicates the major errors contributing to the inaccuracies of the end-effector.