基于改进弦高误差约束的机器人曲面磨削轨迹规划

Robot surface grinding trajectory planning based on improved chord height error constraint

针对机器人磨削自由曲面存在的轮廓精度低、粗糙度均匀性难以控制等问题,提出一种基于改进弦高误差约束的机器人曲面磨削轨迹规划方法.首先,在分析刀具与曲面局部接触状态的基础上,建立磨削行距计算模型;然后,对弦高误差约束法进行改进,推导考虑轨迹线曲率影响的进给步长计算模型,规划出曲面轮廓误差约束的磨削轨迹;最后,对一张自由曲面进行轨迹规划.结果表明,该方法可将弦高误差控制在给定范围内,提高磨削轨迹的曲率适应性和磨削后工件表面轮廓质量.

Aiming at the problems of low contour accuracy and difficult control of roughness uniformity in robotic grinding of free-form surfaces,a robot surface grinding trajectory planning method based on improved chord height error constraint is proposed.Firstly,on the basis of analyzing the local contact state between the tool and the surface,a calculation model of the cutting distance is established.Then,the constraint method for chord height error is improved,and the calculation model of the feed step considering the influence of the trajectory curvature is deduced,and the grinding trajectory constrained by surface contour error is planned.Finally,trajectory planning is for a free-form surface.The results show that this method can control the chord height error within a given range,improve the curvature adaptability of the grinding trajectory and the surface contour quality of the workpiece after grinding.