加减速运动条件下6-UPS型并联机床刚体动力学模型简化研究

SIMPLIFICATION OF THE RIGID BODY DYNAMIC MODEL FOR A 6-UPS PARALLEL KINEMATIC MACHINE UNDER THE ACCELERATED MOTION AND THE DECELERATED MOTION

为解决刚体动力学模型的复杂性与控制系统的实时性之间的矛盾,对加减速运动条件下6-UPS型并联机床刚体动力学模型的简化进行了研究。首先采用Newton-Euler法建立了并联机床的刚体动力学模型,将模型分解为18项,并通过仿真分析了并联机床的刚体动力学特性。在此基础上,提出和检验了刚体动力学模型的简化策略。检验结果表明,提出的简化策略具有计算效率高、简化误差小的特点,为并联机床的精确实时控制奠定了基础。

The rigid body dynamic model of the parallel kinematic machine (PKM) is complicated and difficult to be used in the real-time control system. Under the accelerated motion and the decelerated motion, a study on the simplification of the rigid body dynamic model for a 6-UPS PKM is presented. Firstly, the dynamic model is established through Newton-Euler approach and decomposed into eighteen items. According to the working situation, the rigid body dynamic characteristics of the PKM are investigated by the means of numerical simulation. Finally, the simplifying strategies of the dynamic model are presented and verified. It is proved by the verification results that the strategies improve the computational efficiency greatly and only bring small simplifying errors.