曲面抛光的材料去除模型与摆线轨迹控制

Material Removal Modeling and Trochoidal Toolpath Control for Surface Polishing

基于柔性盘抛光的材料去除模型,提出了沿摆线轨迹的曲面抛光参数控制方法.首先确定柔性盘与表面的接触状态,采用支持向量机方法建立下压力预测模型,确定接触区的压力分布规律,并依据Preston方程建立材料去除模型,进而依据摆线半径和步距的相对关系,将摆线分为单周期内存在2个交叠区与3个交叠区两种情况,在去除模型基础上将单道摆线分为两部分单独叠加,再根据交叠区宽度作总叠加,控制摆线轨迹参数实现最优去除率分布效果.去除率仿真实验和工业机器人抛光实验结果表明,精抛后工件表面粗糙度达0.57μm,说明提出的摆线轨迹参数控制方法适用于高精度曲面抛光.

By applying the material removal model of polishing with a flexible pad,a parameter control method of curved surface polishing with trochiod trajectory is proposed. First the contact state of a flexible pad and work-piece surface is determined. Pressure prediction model is then established by using the support vector machine method and the pressure distribution of contact area is founded. Then the material removal model is set up by using Preston equation. According to the relationship between radius and step,the trochoid trajectory can be divided into two cases： single-cycle with two overlapping regions and single-cycle with three overlapping regions. Based on the removal model,one single trochoid path is divided into two parts to overlap respectively and then the total overlapping is established according to the width of the overlapping region,so as to control the trochoid trajectory parameters to achieve the optimal removal overlapping. The results of removal rate simulation and robot polishing experiment show that the work-piece surface roughness reaches 0. 57 μm after polishing,which indicates that the proposed parameter control method of trochiod trajectory is feasible for high precision curved surface polishing.