基于Kane方程的冗余驱动5UPS/PRPU并联机床动力学分析

Dynamics Analysis of 5UPS/PRPU Parallel Machine Tool with Redundant Actuation Based on Kane Equation

为了解决冗余驱动并联机构的驱动力协调问题,搭建基于动力学的控制系统,实现冗余驱动并联机床的力位混合控制,以原有5UPS/PRPU并联机床为研究对象,改变中间PRPU约束分支为冗余驱动分支,构成冗余驱动并联机床,在其运动学分析的基础上,采用计算效率较高的Kane方法建立了该并联机床的动力学模型;应用ADAMS软件仿真得出驱动力并与Kane动力学模型求解出的驱动力进行比较,验证了Kane动力学模型的正确性,为冗余驱动并联机床力位混合控制研究奠定了理论基础。

In order to further study and solve the problems of the driving force coordination of parallel machine tool with redundant actuation,build a control system based on dynamics and realize the forceposition hybrid control,the original 5UPS/PRPU parallel machine tool was taken as research object,and a drive for middle PRPU constraint branch was increased to make it a redundant actuation branch.Finally,the 5UPS/PRPU parallel machine tool with redundant actuation was built. The Kane equation of higher computation efficiency was taken to establish the dynamics model. The mechanical structure was introduced,the kinematics property of the parallel machine tool was analyzed from the three aspects of speed,partial speed and acceleration. The dynamics model of the system was established,and the redundant driving force was solved. By using ADAMS software,the no-load translation example driving force was simulated and compared with the no-load translation example driving force obtained by Kane dynamic model of the parallel machine tool. The results showed that the simulated and calculated driving forces were very similar,the maximum deviation absolute value was only 0. 068 N. It proved the validity of Kane dynamical model and obtained the mechanism of driving force coordination and distribution.Redundant actuation can effectively reduce the peak value of driving force of the parallel machine tool and make the driving forces change slowly during the motion process. Besides,it has the advantages of high rigidity,high bearing capacity,good stability and so on. The correct establishment of the dynamic model was the prerequisite of realizing real-time control strategy. It was of great significance to the research on redundant actuation of the parallel machine tool.