Generating Machine-Optimal Numerical Control Paths

本研究的目的是产生最快的刀具路径扫描三维表面。 这将通过首先开发一个数学公式来实现，该公式捕获了加工的所有实际约束，包括电机速度限制、加速度限制、表面光洁度要求、机器运动学和路径不连续性的影响。 公式化的问题很可能不会产生封闭形式的解。 将测试几种数值方法。 一种“贪婪”的办法已显示出初步的希望。 在这种方法中，使用局部最优性准则代替全局最优性准则来生成刀具路径。 第二种方法是使用参数“基础”曲线生成候选刀具路径族。 第三种方法，将研究是一个全球性的搜索，表面将被打破成越来越小的elemefltts，和刀具路径方向将分别在每个元素。 第三种方法计算量大，但也可能产生最好的结果。如果成功，这项研究将产生更快的刀具路径高速加工。 随着数控机床主轴转速的提高，线性驱动系统越来越成为加工性能的瓶颈。升级到更快的线性电机技术是非常昂贵的。 通过这项研究实现的刀具路径将更好地利用当今机床结构的能力与新的主轴技术，并实现更高的生产率，而无需显着增加成本。

The objective of this research is to generate the fastest tool paths to sweep a three-dimensional surface. This will be accomplished by first developing a mathematical formulation which captures all the practical constraints of machining, including motor speed limits, acceleration limits, surface finish requirements, machine kinematics and the effects of path discontinuities. It is likely that the formulated problem will not yield a closed-form solution. Several numerical approaches will be tested. A "greedy" approach has shown initial promise. In this approach, the tool paths are denerated using a local optimality criterion in place of the global optimality criterion. A second approach is to generate candidate tool path families are using parametric "basis" curves. A third approach which will be studied is a global search; the surface will be broken into smaller and smaller elemefltts, and tool paths directions will be varied individually in each element. The third approach is computationally expensive, but is also likely to yield the best results.If successful, this research will yield faster tools paths for high speed machining. As the spindle speeds available in CNC machine tools have increased, linear actuation systems have increasingly become the bottleneck in machining performance. Upgrading to faster linear motor technologies is very expensive. The tool paths enabled by this research will better utilize the capabilities of todays machine tool structures with new spindle technologies, and enable greater productivity without significantly greater costs.