基于动态阈值的模糊自适应控制高硬度球面磨削方法

Fuzzy Adaptive Control Optimization of High Hardness Sphere Grinding Based on Dynamic Threshold

为避免高硬度球面磨削过程中工件表面被拉毛,测量电主轴电流而间接获得磨削力,以电主轴电流作为反馈量来控制高硬度球面磨削过程中的磨削力.针对高硬度球面磨削过程中磨削力的特点,采用基于动态阈值的模糊自适应控制策略(DTFACO),自动获取并实时调整电流阈值,对影响磨削力的磨削深度和摆动角速度在线模糊调整,以适应磨削过程并保持磨削过程稳定.实验结果表明,与定进给磨削方式(FFSG)磨削高硬度球面相比,在不降低磨削效率的情况下,DTFACO可以减小磨削后工件表面粗糙度,避免了高硬度球面磨削过程中工件表面被拉毛的现象.

In order to avoid the scratches on the workpiece in the high hardness sphere grinding,the grinding force was got indirectly by measuring the motorized spindle current which is used as a feedback to control the grinding force of the high hardness sphere grinding.A fuzzy adaptive control optimization strategy based on dynamic threshold（DTFACO） was applied according to the features of the grinding force generated in the high hardness sphere grinding process.The current threshold can be auto obtained and rectified on line.The depth of cut and the swing angular speed which affect the grinding force can also be adjusted on line by fuzzy strategy to maintain the grinding process stable.The experimental results indicate that the fuzzy adaptive control optimization strategy based on dynamic threshold can decrease the roughness of the workpiece without decreasing the grinding efficiency.It can avoid the scratches on the workpiece in the high hardness sphere grinding.