基于磁流变技术的非球面柔顺数控研抛工具研究

Research on the Compliant NC Polishing Tool of Magnetorheological Techniques for Aspheric Parts

针对目前磁流变抛光成本高、抛光力控制复杂的问题,开发了一种新的基于磁流变技术的非球面柔顺数控研抛工具系统,由磁流变阻尼器(MRD)控制研抛过程中的研抛力,由数控车床控制研抛工具位置。介绍了工具系统的组成,阐明了基于MRD的研抛原理,分析了研抛工具与非球面工件之间的接触力及其动态传递过程,建立了研抛力模型和工具系统动态模型,并进行了参数辨识和仿真研究,得到了系统的传递函数的和PID控制器的相关参数,最后进行了系统动态性能和研抛实验验证,实验结果表明,开发的研抛工具系统,具有较好的响应特性,可以实时控制研抛过程中的研抛力,可获得表面粗糙度Ra=0.028μm的非球面镜面表面。

A novel Compliant NC polishing tool for aspheric parts was proposed. The force during polishing process was controlled by Magnetorheological damp （MRD）, and the displacement of the polishing tool was controlled by NC lathe. The composition of the tool system was introduced. Then the polishing principle was explained based on MRD. The force between the tool and aspheric parts and the transfer processing were analyzed, the model of polishing force and the dynamic characteristic were established. The parameters of model were distinguished, and the transfer function was obtained. The parameters of PID controller were obtained by simulation study. On this basis, experiments were carried out. Experimental results indicate that the tool system have a good response characteristic, the polishing force can be controlled simultaneously, and the mirror-like aspheric surface with a roughness value Ra=0.028μm was obtained.