Papers by Author: Shi Han Zhang

Abstract: According to needs of aspheric lens grinding and measurement with X/Y/Z 3-axis grinding machines, a CAM system is designed and implemented. The system, based on the parallel grinding geometry model, has realized the function of grinding locus planning, form error compensation, NC program auto-generation, on-machine measurement, grinding wheel on-machine measurement, simulation and technical database. To verify the stability of this CAM system, experiments were performed with three independent machining experiments. The experimental results indicate that the system realized the whole process of aspheric grinding, and it improved the machining efficiency and automation. Especially, this system adopted on-machine form error compensation technology and improved the machining accuracy. By implementing the error compensation integrated in the CAM system, the surface form error of a 430mm×430mm aspheric lens is decreased from PV8.2µm to PV4.1µm. The grinding accuracy was improved 100%.

Abstract: In accordance with the requirements and characteristics of non-axisymmetric aspheric surface measuring, three measuring paths were put forward and estimated. The applicant situations of the three paths were also analyzed. A data processing system was created for the measuring of non-axisymmetric aspheric surface. Levenberg-Marquardt method was adopted as the nonlinear least squares to fit the discrete data. The fitting result was assessed by the fitting residuals. The experimental results show that the fitting residuals was in the 10-3mm magnitude when convergence index parameter set as 1×10-10mm. Compared with the theory equation, it’s shown that the method can not only be used for non-axisymmetric aspheric surface quality evaluation, but also can generate compensation data to improve machining precision.