Process Optimization For Precision Compliant Polishing Of Aspherical Parts

With many advantages relative to spherical parts in correction of aberrations,expanding view, improvement of image quality and farther sight distance, theaspheric parts are widely used in modern optical systems, which reduces equipmentweight and column and make the system more compact. High-quality opticalsystem requires improvement not only in precision, efficiency and production costs,but also in the diameter and the relative aperture. Computer-controlled opticalsurfacing (CCOS) technology with high precision and simple process is widely usedto fabricate and design large and medium-sized aspheric parts, and it gets the favourof more and more enterprise and scientific research units.However, there are still many CCOS technology problems that have not beenwell solved, such as low efficiency in surface accuracy convergence, edge effect,larger surface error in small-scale ones and complexity of control systems. Theproblems have a great impact on the development of CCOS technology and theprocessing efficiency and precision of aspherical parts.This paper tries to solve the theoretical model inaccurateness and the lack ofprocess optimization analysis algorithm of the application of CCOS technology tothe precision compliant polishing so as to enhance the processing capacity of theaspherical optical parts.This paper includes the following sections:（1） Simplify the Preston theory to be the theoretical basis of compliantprecision polishing process, and make it suitable for the analysis of the compliantpolishing system. The NC program in the system should be easily modified, andcould take full advantages of the infinitely variable speed function of the CNClathe’s spindle. The control of the compliant device is independent of the CNClathe’s control in the compliant precision polishing of aspheric optical components and the polishing removal is controlled by controlling spindle’s speed which solvesthe difficulties in keeping the control of the compliant device synchronous to theCNC lathe’s control.（2） This paper presents some analytic results in the aspects of the polishingpressure, polishing velocity and dwell time to the polishing removal with themethod of orthogonal design, verifying the feasibility of Preston theory to thecompliant polishing system（3）Geometrical analysis and kinematics analysis are used to accomplish thenumerical simulation analysis algorithm which is implemented in MATLAB, forcompliant precision polishing of aspherical parts.（4） The result of the experiment with simulated parameters verifies theaccuracy of the modeling simulation algorithm.