基于数字化技术的多点成形与逆向工程的集成

分析了多点成形技术和逆向工程集成时需要解决的关键技术，包括表面数字化、曲面重构和控制回弹量的方法。用自行研制的激光测量仪实现工件表面数字化，为实例样件的曲面重建和多点成形工件的成形误差检测提供数据源；用基于曲率抽样的拓扑矩形阵列进行NURBS曲面拟合并用多点成形方法成形工件；为了控制工件回弹，用两步配准方法计算成形误差并利用闭环成形修整曲面，最终实现在没有CAD模型而只有实物样件情况下的板类件快速精确成形。与此同时开发了实现相关功能的软件。

Integration of Multi-point Forming and Reverse Engineering Based on Digitalized Techniques

The crucial technologies in integration of multi-point forming(MPF) and reverse engineering, including surface digitization of sheet metal part, surface reconstruction and the method of spring-back controlling, were analyzed. Surface digitization of a sheet metal part was realized through an own developed laser measuring equipment, from which the available data for surface reconstruction of sample part and for forming error inspection of multi-point forming part were provided. Non-uniform rational b-spline (NURBS) surface fitting based on an extracted topology array was made and the method of multi-point forming was used to form parts. In order to control the spring-back of sheet metal part, the forming error was calculated by the method of two-step registration and the surface was modified by closed loop forming. Finally, a rapid precision forming for sheet metal part was fulfilled in the case of no model of CAD and only sample part available. Authors developed a software for the relevant functions.