【作者】 何莹；

【导师】 彭芳瑜；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2005， 硕士

【摘要】 高速高精加工的发展对插补技术提出了新的要求。仅基于加工零件几何形状的插补算法已不能满足高速切削加工的需要,因为其没有考虑机床在高速加工条件下的静、动态性给插补造成的影响。本文深入分析了高速加工插补算法的动力学行为,对影响插补结果的动力学因素进行了评价,在此基础上提出了适用于高速加工条件的曲线直接插补算法,主要研究内容如下: 分析了要插补加工对象的几何特性与插补之间的关系,主要是插补曲线曲率与插补精度、插补加速度之间的关系。从分析中发现,在插补算法中加入对曲线曲率的考虑,可以减小插补的弓高误差。建立了机床进给系统的动力学模型,并分析了其中各动力学参数与插补之间的关系。找出对插补结果影响较大的几项参数,确定了用于进行插补速度及加速度规划的机床动力学校验不等式。经实例证明,加入机床动力学校验后的曲线插补算法,速度变化规律可以更符合机床的动力学性能。深入研究了前瞻控制技术在插补算法中的作用,在传统直线插补前瞻控制技术的基础上,作了较大改进,提出了适用于曲线插补的前瞻控制技术。基于对以上各种插补算法中各动力学因素的分析评价,提出了基于曲线与机床动力学特性的前瞻控制曲线插补算法。开发了插补算法性能评估软件。使用者可通过人机交互方式,选择插补控制方式和设定相关的控制参数,并确定加工机床的相关动力学参数。该评价体系软件具有模拟插补器,可进行插补仿真,并对在不同机床及不同加工条件情况下,采用不同插补算法所得的插补结果进行分析比较。更多还原

【Abstract】 The rapid development of high speed machining has brought out new commands to interpolation technology. The interpolation algorithm based on geometry characteristics can no longer match the need of high speed machining, because it does not consider the static and the dynamic characteristics of the machine tool in high speed condition. In this dissertation, the dynamics behaviors in interpolation algorithm of high speed machining are deeply analyzed, and those influence the interpolation are evaluated. A novel interpolation algorithm suitable for high speed machining is proposed based on the work. The main contents of this dissertation are: This research work focuses on the relationship between the geometry characteristics of the machined part and the interpolation process. The connections between the curvature of the curve, the interpolation precision, and the acceleration in interpolation are deeply studied. It is discovered that the interpolation error can be greatly decreased by considering the curvature of the curve in interpolation algorithm. The dynamic models of the feed systems in CNC system are built. The relationships between the dynamic parameters and the interpolation results are concerned. The parameters which have great influences in the interpolation are determined and the dynamic verification inequalities for planning federate and acceleration/deceleration are defined. The example demonstrates that the federate change rule in the new curve interpolation algorithm matches the performance of the machine tool better after considering the dynamic characteristics of the machine tool. The function of look-ahead technique in interpolation is discussed. Compared with the linear interpolation, the look-ahead technology is modified to adapt the curve interpolation. Integrating all the analyses in this dissertation, the look-ahead curve interpolation algorithm based on the geometry characteristics and the dynamic characteristics of the machine tool is finally proposed. Moreover, the evaluating software for the interpolation algorithms is developed. Through the human-machine interface, user can choose the interpolation algorithm, set the interpolation control parameters, and set the dynamic parameters of the machine tool. The evaluating software is able to simulate the working of the interpolator in CNC system. The software can also analyze the performances of different interpolation algorithms in diverse machine tools and under diverse machining conditions.更多还原