非圆磨削廓形误差形成机理与约束控制方法研究

Non-circular profiles parts are widely used in the automotive, aviation and other industries, and the higher accuracy is be required. Profile error is the main precision index in non-circular contour machining. The profile accuracy is guaranteed indirectly through the control of axis position error. It is difficult to achieve effective control of profile error. Therefore, the formation mechanism and the control method of profile error are studied in the grinding of non-circular profile in this project. Firstly, the regenerative coupling effect, which is between workpiece dynamic deformation for grinding force and processing location errors, will be researched. Secondly, the map relationship model of grinding force-processing location errors-profile shaped errors will be established. Thirdly, based on the constraint control of contour errors, the grinding parameter optimized control theory will be researched, under the conditions of the fluctuation of grinding force and processing location errors, and the decreasing of the contour erorrs is the optimized target. At last, the mathematics model of contour errors, which are caused by processing location errors within cavity and the outside surface non-circular outlines parts, will be established. The online evaluation methods of contour error and dynamic control strategies will be studied in the complex machining. In order to effective control of profile errors and improve the accuracy of non-circular profiles parts, all those researches above will be the theory and techniques foundation for advanced CNC machine tools digital control of machining processes.

非圆轮廓零件广泛应用于汽车、航空等工业中，加工精度要求日益提高。廓形误差是非圆轮廓零件的主要精度指标，而数控机床普遍通过控制各运动轴的位置误差间接保证廓形精度，难以实现廓形误差的有效控制。因此，项目对非圆轮廓磨削廓形误差形成机理与控制方法进行研究。研究磨削力变化产生的工件动态形变与加工位置误差的再生耦合效应，建立磨削力-加工位置误差-廓形误差映射关系模型；基于廓形误差约束控制的思想，提出以廓形误差为优化目标，磨削力波动、加工位置误差为约束条件的磨削参数优化控制理论体系；建立内腔及外表面非圆轮廓零件加工位置误差引起的廓形误差数学模型；研究廓形误差在线评估方法及适应复杂加工条件的在线动态控制策略。为实现非圆轮廓零件磨削廓形误差的有效控制、提高高档数控机床的加工工艺过程控制水平，奠定理论和技术基础。

非圆曲线轮廓类零件如凸轮轴、曲轴、偏心轴、转子发动机燃烧室、椭圆活塞、修正心型柱塞等作为核心部件，广泛的应用于汽车、航空航天等领域中。其加工精度对于设备的性能起着至关重要的作用，该类零件普遍采用磨削加工以保证其精度。而目前数控系统的控制目标是各运动轴的位置，即普遍通过控制X、C轴的位置误差间接保证廓形精度，难以实现廓形误差直接的有效控制。本项目直接以非圆曲线轮廓类零件廓形误差为控制对象，将廓形误差形成机理与控制方法结合起来。建立了非圆轮廓磨削系统动力学模型，揭示廓形误差的力-位再生耦合形成机理；提出了磨削速度、加工轨迹优化方法，实现了非圆轮廓磨削廓形误差离线约束；提出了非圆轮廓磨削廓形误差在线稳定动态控制的方法，基本实现了廓形误差的有效控制。为实现非圆轮廓零件磨削廓形误差的有效控制、提高高档数控机床的加工工艺过程控制水平，提供了理论和技术基础。