Papers by Author: Gui Lin Wang

Abstract: The adoption of conformal optics system can evidently improve the synthetical performance of infrared missiles. Hot-pressing poly-crystal magnesium fluoride (MgF₂) is an ideal material for conformal optics dome. But many problems about machining and surface test of deep aspheric surface have not been solved at present, and there is not much research about the machining characteristics of MgF₂ material. In this paper, in-situ measurement system is designed, so positional errors that introduced by repeating installation can be avoided. Then, machining process of MgF₂ material by single point diamond turning is studied, and optimized diamond turning process is proposed by experiments in order to obtain low surface roughness. Furthermore, surface accuracy is tested by on-machine measurement system. Based on the result, error compensation process of conformal dome is carried out. Finally, the shape error of the dome is less than 0.8μm PV.

Abstract: Fast tool servo system could achieve precise and efficient processing of fine micro-structure for its fast and accuracy response to input control signal, which will directly affect the processing quality of the workpiece surface. Different structural forms of fast tool servo system have been designed and presented in China and overseas, with which generally low the stiffness and natural frequency, only can be used for the rule and the characteristic scale of the larger surface processing. A fast tool servo system whose thrust was up to 12500N, stiffness was 280N/μm, the natural frequency was more than 3kHz , was developed in this paper, as well as the analytical expression of time domain and frequency domain output，which were presented by the modeling analysis; The unknown parameters of the system model were identified by frequency response test. The theoretical and experimental results indicated that the system has good dynamic performance to meet the fine micro-structure of highly efficient, high-precision processing needs.

Abstract: Optical components with complex surfaces or microstructures are more and more widely used, but it is very difficult to manufacture these components by using traditional mechanical fabrication methods. Fast Tool Servo (FTS) system driven by piezoelectric ceramic (PZT) can manufacture these complex surfaces or microstructures efficiently and accurately, owing to its high response frequency, good dynamic performances and high stiffness. In this paper, the cutting characteristics are studied in the FTS machining process, and the identifying algorithm of tool interference is given. A set of high-powered FTS system is developed, which consists of PZT, fast feeding device, DSP28335 control panel and ultraprecision machine tool. The testing results indicate that the FTS system’s motion resolution is 1nm, the stroke is 90μm, and the response frequency is 220Hz while moving distance is 36μm. On the basis of above work, three kinds of typical workpieces with complex surfaces are manufactured by using FTS system. The measuring results indicate that surface accuracy can reach PV 0.14μm, the roughness is less than Ra 12nm, and the means are presented to improve the machining accuracy.

Abstract: In order to keep the stability of tool’s removal function, it is required that the anastomosis be tight between the tool and workpiece surface in Computer-controlled Optical Surfacing (CCOS). In this paper, the influence of tool’s character on anastomosis status is firstly studied. The relation model on the ratio of radius to thickness, Young's modulus of the tool, normal asphericity and normal arc height of workpiece surface is established, and the macroscopical condition of tight anastomosis is derived in aspheric optics machining. According to the microcosmic distribution of surface error, the mathematical relation between anastomosis error and removal rate is researched. In the end, the influence rule of anastomosis status on the convergence ratio of residual error is analyzed in machining zone. Based on the conclusion of machining instance, it is found that workpiece material would be fast removed in middle contact zone when the peak value of tool’s removal function locates in its center position.