• CN:11-2187/TH
  • ISSN:0577-6686

›› 2011, Vol. 47 ›› Issue (7): 8-15.

• 论文 • 上一篇    下一篇

机器人砂带磨削的曲面路径优化算法

王伟;贠超;张令   

  1. 北京航空航天大学机器人研究所
  • 发布日期:2011-04-05

Optimization Algorithm for Robotic Belt Surface Grinding Process

WANG Wei;YUN Chao;ZHANG Ling   

  1. Robotics Institute, Beihang University
  • Published:2011-04-05

摘要: 机器人砂带磨削系统的两个显著优点是弹性接触和宽行加工,能够提高工件的表面质量和加工效率,主要用来完成复杂曲面特征工件的终加工。工件和接触轮之间存在曲面接触,机器人的磨削路径可由接触运动学理论和砂带磨削工艺相结合来生成,有关此方面的研究成果较少。在切削过程中,最重要的是要保证接触轮与工件曲面局部贴合,因此曲面曲率是磨削路径生成的主要因素之一。当曲面局部法曲率较小时,加工路径上的相邻刀位点之间弧长较长,保证加工效率;反之,加工路径上的刀位点致密,避免弓高误差超差。按照接触轮的宽度,生成一系列一定间隔的截面,提取截面与待加工曲面的割线。对于每一条割线,当曲率大于接触轮直径的四分之一时,增加一个中间刀位点,缩短了相邻刀位点之间的割线弧长。离线虚拟仿真验证了该方法的可行性。设计新算法与经典刀具路径规划方法的对比磨削试验,证明了该算法能够提高磨削质量。

关键词: 弧长优化, 机器人, 路径规划, 曲率, 砂带磨削

Abstract: There are two prominent advantages for the robotic belt grinding system, flexible contact and machining with wide bandwidth. It is widely used to improve the surface quality and machining efficiency while finishing the works pieces with complex features. With complex contacts between the contact wheel and the work piece, the grinding paths for robot can be obtain by the theory of contact kinematics and the belt grinding technologies, but there lacks research on robotic grinding path planning. During the grinding process, it is the most important to conform the contact wheel to the local geometrical features on the contact area, so the curvature turns to be the most crucial factors to plan the grinding tool paths. For the local surfaces with small curvature, the arc length between the neighboring cutting locations becomes longer to ensure processing efficiency. Otherwise, for the local areas with large curvature, the arc length becomes shorter to decrease the chord error. A serial of planes are created to intersect with the target surface to be ground, and the corresponding intersecting lines are obtained. For each intersecting line, if the curvature at the cutter locations becomes larger than a quarter of the diameter of the contact wheel, a middle cutter location will be inserted to the tool path. The arc length between the neighboring cutting points is shortened under the constraint of the local curvature. The feasibility of this algorithm is completely approved by the off-line virtual simulation. The comparative belt grinding experiments between the algorithm and the classic tool path planning method, are designed, and the machining quality of the workpiece is increased by the algorithm.

Key words: Abrasive grinding, Arc length optimization, Curvature, Path planning, Robot

中图分类号: