Stewart平台式并联机床的一种运动及受力分析方法

并联机床被誉为21世纪的新型加工中心, 但它所能发挥的性能仍受到现有机构计算理论、测量及标定方法的限制.目前已有的正向求解方法,由于非线性的影响,有求解过程复杂和多解的问题,难以用于并联机床的运动控制,为此,建立了6-3 Stewart平台式并联机床结构的运动学和力学模型,其中采用对称分布的3个位移传感器用于机构的位置分析,并将降阶的运算操作与传感器方式相结合,实现了机构分析的正向算法,并开发了数值模拟程序.这种方法明显降低运算消耗,并提高了精度.

Analysis and Calculation on Kinematics and Statics of Stewart Platform Machine Tools

Parallel structured machine tools are known as a new generation multi-axis machining centre in manufacturing for the 21st century,but because of the complex mechanisms their performance development is limited by the existing mathematical algorithms,measurement technique and calibration method.In current researches, the methods for forward kinematics of parallel mechanisms still have difficult procedures and multi-solutions due to the nonlinear mathematical properties and are unlikely used in kinematics control for parallel structured machine tools. Therefore,in terms of the mechanism features,an analysis model for 6-3 Stewart platform machine tools is established to obtain the kinematics and statics solutions.In particular,3 extra symmetrically located displacement sensors are used for direct kinematics resolution combining some special geometrical operations,hence closed form solution for forward kinematics is implemented and corresponding numerical simulations are developed.