叶片复杂曲面的机器人抛磨工艺规划

摘要

In order to realize intelligent grinding and machining of workpieces with complex surfaces, robotic grinding process planning for complex blade surfaces was performed.The position planning algorithm of the grind point and the posture planning algorithm based on the maximum contact principle were studied.First,the grind path was obtained through the secant transverse line cutting method and described by NURBS curve,and then the curve feature parameters were extracted and grinding position planning was performed according to the set threshold.Then,based on the maximum contact principle of the grinding wheel andworkpiece,the posture planning of the grind point was presented.After that,the complete grinding path was obtained.Then,the position and posture data were converted from workpiece coordinate system to TCP coordinate system.Finally, the simulation platform of flexible grinding system was constructed to generate robot control program.Experimental results indicate that the proposed path can be used for robotic grinding of blade complex surface.The blades are grinded by using the path obtained by proposed planning method and the path of CAM software planning,and the corresponding surface roughness is 0.695-0.930 μm and 2.803-3.243 μm respectively.Therefore,the proposed method can be applied to the grinding path planning of complex surface.It ensures that the tool and the workpiece are in maximum contact,and thereby avoids uneven grinding caused by the poor position and pose.%为了实现复杂曲面工件的智能抛磨加工,对叶片复杂曲面进行机器人抛磨工艺规划.对抛磨点位置规划算法和基于最大接触原则的抛磨姿态规划算法进行了研究.首先,通过平行截面法获得抛磨路径割线,以非均匀有理B样条(NURBS)曲线描述.接着,提取曲线特征参数,根据设定的阈值进行抛磨点规划,再基于抛磨轮与工件的最大接触原则进行抛磨点姿态规划,从而得到完整的抛磨路径.然后,将工件位姿从工件坐标系转换到TCP坐标系.最后,搭建了柔性抛磨系统仿真平台生成机器人控制程序.实验结果表明,此方法规划的路径可用于叶片复杂曲面的机器人抛磨加工.分别用本文规划所得路径和CAM 软件规划所得路径对叶片进行抛磨加工,测得表面粗糙度分别为0.695~0.930 μm和2.803~3.243 μm.本文提出的抛磨位姿规划方法可用于复杂曲面工件的抛磨路径规划,使工具和工件保持最大接触,从而避免了位姿不合理所产生的过抛和欠抛.