冗余并联机床驱动力优化解析

驱动冗余可有效消除并联机构在作业空间中的奇异位形,但其导致驱动力分配不唯一。该文针对一台4自由度的冗余并联机床进行了驱动力解析。在运动学分析基础上,得到各支链的偏速度矩阵及偏角速度矩阵,解算各支链的合力/力矩,利用虚功原理建立了该机构的逆动力学方程,并将其变换为线性格式,然后针对驱动冗余的特点,对驱动力分别进行了力优化及能耗优化,其中,力优化计算简单,而能耗优化可降低最大驱动力。该模型适用于冗余并联机构的动力学参数辨识以及动力学控制。

Drive force optimization for a redundant parallel machine

Redundant actuation can effectively eliminate singularities in the task space of a parallel manipulator, but the drive force distribution is not unique because of the redundant actuation. This paper presents an analysis of the redundant actuation of a 4 degree of freedom parallel machine. An inverse kinematic analysis was used to calculate the partial angular velocity matrix and the partial velocity matrix for each link to calculate the resultant force and torque on each link. The inverse dynamics equation was then developed based on the virtual work principle and then linearized. The drive force was then optimized using force optimization and energy optimization due to the redundant actuation. The force optimization method is more efficient while the energy optimization method gives a lower maximum drive force. This dynamic model can be used to identity the dynamic parameters and for dynamic control.