基于3-RRRS机构的新型并联机床构型及运动建模

Configuration and Motion Modeling of a New Parallel Machine Tool Based on 3-RRRS Mechanism

提出了一种基于3-RRRS机构的并联机床构型。RRRS是由3个R副和1个S副组成的支链。3-RRRS机构在上下平台之间连接移动平台,实现移动平台相对于下平台的六维运动;安装在移动平台上的动力头完成机床的加工操作。RRRS运动支链的每个R副配备1个驱动动力,共有3个驱动;整个运动支链系统有9个驱动,具有从属驱动特性,使并联机床具有较大的工作空间和较好的运动动态特性。首先,介绍了新型机床的模块化结构;其次,对基于3-RRRS机构的机床进行建模分析,给出了机床操作中各机构变量的运动和控制模型;最后,给出计算实例,并用运动仿真对计算结果进行了验证。相关工作为后续设备的实际使用提供了理论依据。

A novel parallel machine tool configuration is presented based on 3-RRRS mechanism.RRRS refers to kinematic pairs of a branched chain consisting of three R-pairs and an S-pair.The 3-RRRS mecha⁃nism connects a moving platform between top and bottom platforms,by which the six-dimensional motion of the moving platform relative to the bottom platform can be achieved.A power head installed on the moving plat⁃form completes the machining operation of the machine tool.Each R-pair in RRRS motion branch chain is equipped with a drive power where each motion consists of 3 drive pairs.The whole motion branch chain system has 9 driver variables and possesses sub-driver features,which make the parallel machine tool have a larger workspace and better motion and dynamic characteristics.Firstly,the modular structure of the novel machine tool is introduced.Secondly,the modeling analysis of the machine tool based on 3-RRRS mechanism is carried out and the motion and control models of each mechanism variables are given in machine tool operation.Finally,the calculation example is given and the result is verified by using a motion simulation.The related works pro⁃vide a theoretical basis for the practical use of subsequent equipment.