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Profile Error compensation in precision grinding of ellipsoid optical surface

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Chinese Journal of Aeronautics 2021年第4期34卷 115-123页

作者： Shimeng YU Jiahao ZHU Peng YAO Chuanzhen HUANG Center for Advanced Jet Engineering Technologies(CaJET) School of Mechanical EngineeringShandong UniversityJinan 250061China Key Laboratory of High Efficiency and Clean Mechanical Manufacture Shandong UniversityMinistry of EducationJinan 250061China

Optical glass elements with the ellipsoidal surface are used in many critical aerospace instruments,such as satellites,telescope and cameras.Their optical performance is mainly affected by profile accuracy and surface quality.In this paper,a rectangular ellipsoid surface is precisely ground on a BK7 optical glass blank by grating scanning grinding path with a three-axis CNC precision surface grinder.A profile Error compensation procedure for ellipsoidal grinding is proposed based on the error analysis about the primary error sources in the XY and YZ projection planes during the grinding process.The mathematical prediction models of the wheel arc profile error,the measurement and wear error of the grinding wheel radiuses are established.By applying the proposed Error compensation procedure,the profile accuracy of the ellipsoidal surface was improved from 4 lm to 2 lm in the XY plane,and improved from 15 lm to 5 lm in the YZ plane.

关键词： Aspheric lens Ellipsoid surface Error compensation Grinding wheel truing Precision grinding

Thermal Error compensation of the Wear-Depth Real-Time Detecting of Self-Lubricating Spherical Plain Bearings

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Chinese Journal of Mechanical Engineering 2018年第5期31卷 35-47页

作者： Zhan-Qi Hu Wei Li Yu-Lin Yang Bing-Li Fan Hai-Li Zhou Aviation Key Laboratory of Science and Technology on Generic Technology of Aviation Self-Lubricating Spherical Plain Bearing Yanshan University

The spherical plain bearing test bench is a necessary detecting equipment in the research process of self?lubricating spherical plain bearings. The varying environmental temperatures cause the thermal deformation of the wear?depth detecting system of bearing test benches and then a ect the accuracy of the wear?depth detecting data. However, few researches about the spherical plain bearing test benches can be found with the implementation of the detect?ing Error compensation. Based on the self?made modular spherical plain bearing test bench, two main causes of ther?mal errors, the friction heat of bearings and the environmental temperature variation, are analysed. The thermal errors caused by the friction heat of bearings are calculated, and the thermal deformation of the wear?depth detecting sys?tem caused by the varying environmental temperatures is detected. In view of the above results, the environmental temperature variation is the main cause of the two error factors. When the environmental temperatures rise is 10.3 °C, the thermal deformation is approximately 0.01 mm. In addition, the comprehensive compensating model of the thermal error of the wear?depth detecting system is built by multiple linear regression(MLR) and time series analysis. Compared with the detecting data of the thermal errors, the comprehensive compensating model has higher fitting precision, and the maximum residual is only 1 μm. A comprehensive compensating model of the thermal error of the wear?depth detecting system is proposed, which provides a theoretical basis for the improvement of the real?time wear?depth detecting precision of the spherical plain bearing test bench.

关键词： Self?lubricating spherical plain bearing Wear depth Bearing test bench Thermal error Error compensation

Research on Error compensation of robot based on multi-hole measurement technology and particle swarm optimization

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The Journal of China Universities of Posts and Telecommunications 2021年第4期28卷 88-96页

作者： Wang Xianlun Sun Yuxuan Wang Dong Hu Xiaowei School of Electrical and Mechanical Engineering Qingdao University of Science and TechnologyQingdao 266000China

Robot Error compensation is a technique for enhancing the positioning accuracy of the system. This paper presented an error measuring technique for serial robots based on the multi-hole measuring method, combined with the intelligent particle swarm optimisation(PSO) to obtain the optimal solution of the robot’s Error compensation values, thereby improving the positioning accuracy of the robot. In the experiment, the robot error was measured using self-made multi-hole measuring plates and probes, and the experimental data were combined with PSO for the error comprehensive analysis. The results showed that on this type of serial robot, the multi-hole measuring method and PSO algorithm had obvious Error compensation effects, which effectively improved the positioning accuracy of the robot, with the error reduced by 35% after compensation.

关键词： error model multi-hole measuring technique particle swarm optimisation Error compensation

Non-Exchangeable Error compensation for Strapdown Inertial Navigation System in High Dynamic Environment

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Computers, Materials & Continua 2020年第8期64卷 973-986页

作者： Qi Wang Changsong Yang Shao’en Wu School of Computer and Software Nanjing University of Information Science and TechnologyNanjing210044China Jiangsu Engineering Center of Network Monitoring Nanjing University of Information Science and TechnologyNanjing210044China School of Automation Nanjing University of Information Science and TechnologyNanjing210044China Department of Computer Science Ball State UniversityMuncie47306USA

Strapdown non-exchangeable Error compensation technology in high dynamic environment is one of the key technologies of strapdown inertial navigation system.Mathematical platform is used in strapdown inertial navigation system instead of physical platform in traditional platform inertial navigation system,which improves reliability and reduces cost and volume of system.The maximum error source of attitude matrix solution is the non-exchangeable error of rotation due to the non-exchangeable of finite rotation of rigid bodies.The rotation non-exchangeable error reaches the maximum in coning motion,although it can be reduced by shortening the correction period and increasing the real-time calculation.The equivalent rotation vector method is used to modify the attitude to reduce the coning error in this paper.Simulation experiments show that the equivalent rotation vector method can effectively suppress the non-exchangeable error and improve the accuracy of attitude calculation.

关键词： Strapdown Error compensation coning motion equivalent rotation vector simulation experiments

Research on Error compensation method for dual-beam measurement of roll angle based on rhombic prism(Invited Paper)

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Chinese Optics Letters 2014年第7期12卷 24-27页

作者：张桐冯其波崔存星张斌 Key Laboratory of Luminance and Optical Information Technology of Ministry of Education Beijing Jiaotong University

The fabrication deviation of prisms and the error crosstalk are two major factors that produce serious systematic errors in dual-beam roll measurement based on a rhombic prism, and an Error compensation method is put forward in this letter to reduce these systematic errors. The rotation matrix, reflection matrix, and refraction matrix are used to calculate and obtain the mathematical relationship model of the roll angle as well as the fabrication deviation of prism and error crosstalk. The fabrication deviation can be obtained through comparison experiments and using the least square method. In this way, the systematic error of the roll measurement caused by fabrication deviation of prism and error crosstalk can be eliminated theoretically. The experimental results show that the maximum error of the roll angle measurement reduces evidently to 3.5″ from the previous 347.2″ after compensation.

关键词： Crosstalk Error compensation Fabrication Least squares approximations Systematic errors

Temperature Characteristics and Error compensation for Quartz Flexible Accelerometer

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International Journal of Automation and computing 2015年第5期12卷 540-550页

作者： Jing-Min Gao Ke-Bei Zhang Fu-Bin Chen Hong-Bo Yang Electronic Information and Control Center Beijing Information Science & Technology University Beijing Institute of Control Engineering School of Automation Beijing Information Science & Technology University

Reduction of error due to the influence of temperature on the quartz flexible accelerometer without any heating device is a difficult task, and is also a tendency for research and application. In this paper, static and dynamic temperature compensation models are established in order to reduce the temperature influence on accelerometer measurement accuracy. Combined with the experiment data, the relationship between the accelerometer output accuracy, temperature and the magnitude of acceleration is analyzed. The data collected from the temperature experiment show that output value of the accelerometer varies with temperature. The method of uniaxial quadrature experiment is adopted and the accelerometer output value is gauged at temperature ranging from-20℃ to 50℃. Having used the static and the dynamic temperature compensation models, the accelerometer temperature Error compensation experiment is conducted and the compensated errors by the two models are analyzed. The result shows that the compensated value meets the technical requirements. Two technical indicators, the zero bias K0 and the scaling factor K1, which are used to measure the degree of accelerometers, are both improved and their fluctuation ranges are reduced.

关键词： Acceleration Error compensation temperature charac

Error compensation of Thin Plate-shape Part with Prebending Method in Face Milling

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Chinese Journal of Mechanical Engineering 2015年第1期28卷 88-95页

作者： YI Wei JIANG Zhaoliang SHAO Weixian HAN Xiangcheng LIU Wenping School of Mechanical Engineering Shandong University Engineering Training Center Shandong University Key Laboratory of High-efficiency and Clean Mechanical Manufacture at Shandong University Ministry of Education

Low weight and good toughness thin plate parts are widely used in modem industry, but its flexibility seriously impacts the machinability. Plenty of studies locus on the influence of machine tool and cutting tool on the machining errors. However, few researches focus on compensating machining errors through the fixture. In order to improve the machining accuracy of thin plate-shape part in face milling, this paper presents a novel method for compensating the surfacc errors by prebending the workpiece during the milling process. First, a machining error prediction model using finite element method is formulated, which simplifies the contacts between the workpiece and fixture with spring constraints. Milling fbrces calculated by the micro-unit cutting force model arc loaded on the error prediction model to predict the machining error. The error prediction results are substituted into the given formulas to obtain the prebending clamping forces and clamping positions. Consequently, the workpiece is prebent in terms of the calculated clamping forces and positions during the face milling operation to reduce the machining error. Finally, simulation and experimental tests are carried out to validate the correctness and efficiency of the proposed Error compensation method. The experimental measured flatness results show that the flatness improves by approximately 30 percent through this Error compensation method. The proposed mcthod not only predicts the machining errors in face milling thin plate-shape parts but also reduces the machining errors by taking full advantage of the workpiece prebending caused by fixture, meanwhile, it provides a novel idea and theoretical basis for reducing milling errors and improving the milling accuracy.

关键词： face milling error prediction prebending Error compensation fixture

Geometric error measuring,modeling,and compensation for CNC machine tools:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： Zhao ZHANG Feng JIANG Ming LUO Baohai WU Dinghua ZHANG Kai TANG Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine tools.Considering that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining accuracy.Researchers have studied how to measure,detect,model,identify,reduce,and compensate the geometric errors.This paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric errors.Recent advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated respectively.Besides,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically introduced.Finally,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation error identification error measurement error modeling Geometric error Machine tools

Systematic centroid Error compensation for the simple Gaussian PSF in an electronic star map simulator

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Chinese Journal of Aeronautics 2014年第4期27卷 884-891页

作者： Wang Haiyong Wang Yonghai Li Zhifeng Song Zhenfei School of Astronautics Beihang University Beijing Institute of Space Long March Vehicle National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics

Simulated star maps serve as convenient inputs for the test of a star sensor, whose standardability mostly depends on the centroid precision of the simulated star image, so it is necessary to accomplish systematic Error compensation for the simple Gaussian PSF（or SPSF, in which PSF denotes point spread function）. Firstly, the error mechanism of the SPSF is described, the reason of centroid deviations of the simulated star images based on SPSF lies in the unreasonable sampling positions（the centers of the covered pixels） of the Gaussian probability density function. Then in reference to the IPSF simulated star image spots regarded as ideal ones, and by means of normalization and numerical fitting, the pixel center offset function expressions are got, so the systematic centroid Error compensation can be executed simply by substituting the pixel central position with the offset position in the SPSF. Finally, the centroid precision tests are conducted for the three big error cases of Gaussian radius r = 0.5, 0.6, 0.671 pixel, and the centroid accuracy with the compensated SPSF（when r = 0.5） is improved to 2.83 times that of the primitive SPSF, reaching a 0.008 pixel error, an equivalent level of the IPSF. Besides its simplicity, the compensated SPSF further increases both the shape similarity and the centroid precision of simulated star images, which helps to improve the image quality and the standardability of the outputs of an electronic star map simulator（ESS）.

关键词： Error compensation Image analysis Point spread function Star map simulation Star sensor