Papers by Author: Yin Biao Guo

Abstract: According to the demand of precision machining for optical aspheric lens, especially large scale optical aspheric lens, this paper presents an error compensation technique for precision grindging. Based on precision surface grinding machine (MGK7160), grating-type parallel grinding method is put forward to realize grinding paths planning for optical aspheric lens. In order to obtain surface metrology and evaluation after grinding, an on-machine measurement system is built. On the basis of compensation principle, machining error is separated to achieve error compensation. Grinding experiments are carried out and show that it can meet the demand of precision grinding, and the accuacy after error compensation attains 6.5μm.

Abstract: In this paper, a thermal error analysis and compensation method for a high precision aspheric measuring platform driven by a linear motor system is presented. After analyzing the heat source of thermal deformation, the thermal deformation of guide is selected to be object, and the thermal analysis method of guide in heat balance state is proposed. According to the motor temperature at different positions, the thermal error curve of guide is obtained through simulation. Modeling the global positioning error of measuring platform and the compensation model of thermal error using polynomial fitting, the thermal error compensation experiments is implemented by applying compensation system of measuring platform's controller. The experimental results show that the maximum positioning error in heat balance state is reduced from 1.5μm to 0.7μm, which verify the validity of thermal error compensation model.

Abstract: A remote real-time intelligent monitoring system based on ARM and DSP for precision grinding machine was reported in this paper. The monitoring system has many functions, such as video and audio monitoring, image comparison, vibration and temperature signal collection, pretreatment and storage, and real-time intelligent monitoring. A signal synchronous processing method based on interpolation theory was reported, because the frequency difference between the DSP acquisition and the ARM transmission will cause lose and vacancy problem in the process of signal transmission. As shown in the computer simulation results, the monitoring system improves the safety and reliability in the precision grinding machine process.

Abstract: The splicing measuring method applied in large-aperture aspheric surface optical elements, can extend the range of precision measuring instrument and expand measurement capability of the system. In this paper, two methods are proposed: the fitting evaluation method and the curvature comparison method in the light of how to reject the redundant data of the splicing coincidence part, and the theoretical analysis are investigated to calculate the theoretical error. The Talysurf PGI 1240 profilometer of Taylor Hobson Company is used as application object to do experimental research. The results show that the curvature comparison method is feasible and has characteristic such as fast speed, high precision, and good operability.

Abstract: Reported in this paper is an investigation of the process parameter effects on surface roughness and subsurface damage (SSD) in CMP of single crystalline Silicon. For the given experiments, the appropriate method to examine the SSD can be obtained. The surface roughness and figure accuracy were measured with an atomic force microscope (AFM) and Taylor-Hobson profilometer. The experiments results indicate proper process parameter for the best surface roughness, which can be divided into two stages. It should use longer time in the finish polishing stage, while shorter time and reduce the ratio of polishing pads and head in the ultra-finish polishing stage. Generally speaking, the isotropic etching of single crystalline Silicon, anisotropic etching of single crystalline Silicon and hand burnishing are mostly used to find the SSD and it is found that the last method is the best one to see the SSD by SEM.

Abstract: In order to ensure the machining precision of wedge nonaxisymmetric aspheric lens, a parallel grinding method is designed using a clamp with adjustable gradient. Based on the machining method, three path plans of machining are put forward. Simulation results show that the three methods have their particular advantages according to the different requirement of machining.

Abstract: In this paper, according to the bonnet polishing technology, in order to get the change regularity of the bonnet’s deformation, the inflated deformation model of the bonnet, which is made all of rubber or made of rubber but with a nylon enhancement layer, is established and analyzed by using the FEA simulation. And then, by simulating the process of the bonnet polishing the plane wafer, it achieves the contact pressure curve which varies with the bonnet decrement. According to the Preston equation, k can be acquired through the experiment, v can be achieved through mathematical modeling, and p has been achieved in this paper. Thus, the removal function based on FEA will be acquired.

Abstract: In order to turning the skirt of middle-convex and varying ellipse piston, this paper proposes a Variable Cross-section Helix Turning Trajectory (VCHTT) algorithm. it divide the turning trajectory of the piston skirt into transversal and helix, then obtain the coordinates of ellipse transversal cutter-contact points on the basis of centric polar radius arc interpolation (CPRAI) algorithm, and uses line surface intersection method to obtain the coordinates of helix cutter-contact points on the middle-convex and varying ellipse piston skirt. At last，merge two coordinates matrices to obtain the final coordinate surface of cutter-contact points of turning tool. With comparison, it finds that the VCHTT algorithm improves the interpolation accuracy by 0.04um than other methods.

Abstract: Large scale wedge/aspheric lens element is a combination of wedge prism and aspheric lens as a single piece component forming a decentred lens, which is primarily manufactured by Computerized Numerical Control (CNC) machining, especially 3-axis CNC grinding. This paper presents an efficient tool path generation approach based on isophote interpolation. The interpolation guarantees that interpolated points always stay on the iso-inclination curve of the parametric surface. This symmetry ensures that the method can improve and automate large scale wedge/aspheric lens element machining for 3-axis CAD/CAM systems. As part of the validation process, the tool paths generated are analyzed and compare with the desired part.

Abstract: Grinding is a processing method that involves duplicating shape accuracy, so the shape accuracy of the grinding wheel plays a crucial role in machining accuracy. However, this accuracy is difficult to obtain. This paper describes an on-machine wheel profile measuring method that uses a non-contact displacement sensor to obtain the shape accuracy of an arc grinding wheel in a 3-axis aspheric surface grinding machine. This method involves data processing with object radius confined filtering, as well as evaluation using the methods of fitting residual error, measurement uncertainty, and machining result simulation. To verify the feasibility of this measuring method, experiments were performed using two diamond grinding wheels (FEPA D91 with grit size 75-90 μm, and FEPA D15 with grit size 10-25 μm). The experimental results indicate that the method is accurate enough to give the arc grinding wheel profile measurement, while the measuring uncertainty is of the same order of magnitude as the grit size (that is, tens of μm). Moreover, the simulation of the grinding effect with wheel profile measurement data can derive the relationship between the wheel profile error and the machining form error, and can be used to instruct the truing time determination for precision grinding.