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High Accuracy Michelson Interference Wavemeter

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High Accuracy Michelson Interference Wavemeter

A novel extended Kalman filter for a class of nonlinear systems

ICEMI'2.05第七届国际电子测量与仪器学术会议

作者： Wang Liqiang1 Li Cheng 2.Song Feijun3 (1.Electronic Engineering School, beijing university of Posts and Telecommunications,beijing 100876, china) (2. department of precision instruments and mechanology, tsinghua university, beijing 100084, china) (3 DaHeng Epoch Science and Technology Stock Company Limited,beijing 100086, china)

Structure and operation principle of Michelson wavemeter are formulized in detail. It use stabilized by iodine 633nm He-Ne laser as Optical source. Frequency stabilized by double longitudinal mode is

关键词： Wavement michelson inference frequency-stabilized PLL MCU.

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Progress in Natural Science:Materials International 2006年第9期16卷 912-918页

作者： DONG Zhe and YOU Zheng (department of precision Instrument and {2., tsinghua university, beijing 100084, china) [a]department of precision Instrument and {2. Tsinghua University Beijing China

Estimation of the state variables of nonlinear systems is one of the fundamental and significant problems in control and signal processing. A new extended Kalman filtering approach for a class of nonlinear discrete-time systems in engineering is presented in this paper. In contrast to the celebrated extended Kalman filter (EKF), there is no linearization operation in the design procedure of the filter, and the parameters of the filter are obtained through minimizing a proper upper bound of the mean-square estimation error. Simulation results show that this filter can provide higher estimation precision than that provided by the EKF.

关键词： nonlinear systems state estimation Kalman filtering.

RESEARCH OF MICRO ELECTRO DISCHARGE MACHINING EQUIPMENT AND PROCESS TECHNIQUES

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Chinese Journal of Mechanical Engineering 2002年第2期15卷 177-181页

作者： Li Yong Guo Min Li Fang Zhou Zhaoying department of precision {2. and mechanology, tsinghua university, beijing 100084, china department of precision {2. and mechanology Tsinghua University 北京 100084

Micro electro discharge machining (micro EDM) is a feasible way tomanufacture micro structures and has potential application in advanced industrial fields. For therealization of micro EDM, it is necessary to pay careful attention to its equipment design and thedevelopment of process techniques. The present status of research and development of micro EDMequipment and process techniques is overviewed. A micro electro discharge machine incorporated withan inchworm type of micro feed mechanism is introduced, and a micro electro discharge machine fordrilling micro holes suitable to industrial use is also introduced. Some of the machiningexperiments carried out on the micro EDM prototypes are shown and the feasibility of the micro EDMtechnology to practical use is discussed.

关键词： Micro electro discharge machining Inchworm mechanism Friction drivemechanism Micro electrode Micro hole Micro structure

Step kinematic calibration of a 3-DOF planar parallel kinematic machine tool

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Science china(Technological Sciences) 2008年第12期51卷 2155-2167页

作者： CHANG Peng,WANG JinSong,LI TieMin,LIU XinJun & GUAN LiWen department of precision {2. and mechanology,tsinghua university,beijing 100084,china 1. department of precision {2. and mechanology Tsinghua University Beijing 100084 China

This paper presents a novel step kinematic calibration method for a 3 degree-of-freedom(DOF) planar parallel kinematic machine tool,based on the minimal linear combinations(MLCs) of error *** method using mapping of linear combinations of parameters in error transfer multi-parameters coupling system changes the modeling,identification and error compensation of geometric parameters in the general kinematic calibration into those of linear combinations of *** using the four theorems of the MLCs,the sets of the MLCs that are respectively related to the relative precision and absolute precision are *** simple and feasible measurement methods in practice are given,and identification analysis of the set of the MLCs for each measurement is carried *** to the identification analysis results,a step calibration including step measurement,step identification and step error compensation is determined by taking into account both measurement costs and *** experiment shows that the proposed method has the following merits:(1) the parameter errors that cannot influence precision are completely avoided;(2. it reflects the mapping of linear combinations of parameters more accurately and enhances the precision of identification;and(3) the method is robust,efficient and effective,so that the errors in position and orientation are kept at the same order of the measurement *** to these merits,the present method is attractive for the 3-DOF planar parallel kinematic machine tool and can be also applied to other parallel kinematic machine tools with weakly nonlinear kinematics.

关键词： parallel kinematic machine tools kinematic calibration parameter identification minimal linear combinations

Research on Theoretical Model of Linear Frequency Modulation Interferometry

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Chinese Journal of Lasers 2000年第3期9卷 28-34页

作者： CHEN Yan ZHAO Yang (State Key Laboratory of precision Measurement Technology and instruments, {2. of precision instruments,tsinghua university, beijing 100084,china) 清华大学精密测试技术及仪器国家重点实验室北京 100084

In this paper, the principle of linear frequency-modulation (LFM) with an external microcavity laser is analyzed mathematically and a method to establish the math model of LFM heterodyne interference is presented. The expression of LFM heterodyne interference is deduced by an illustration of a triangular frequency modulation. At present, one application of the LFM technique is non-guide absolute distance measurement. Experimental results of a system for absolute distance measurement based on a microchip solid laser and LFM technique are given. Based on the precisely theoretical model some effective approaches to improve the performance of LFM and decrease the measuring error are discussed.

关键词： linear frequency modulation heterodyne interference absolute distance measurement

Orthogonally linear polarized lasers (I)——principle and devices

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Progress in Natural Science:Materials International 2005年第7期15卷 586-595页

作者： ZHANG Shulian and XU Ting (State Key Laboratory of precision Measurement Technology and instruments, {2. of precision instruments, tsinghua university, beijing 100084, china) State Key Laboratory of precision Measurement Technology and instruments Department of Precision Instruments Tsinghua University Beijing 100084 China

Two kinds of orthogonally polarized lasers, i. e. Zeeman dual-frequency lasers and four-frequency ring lasers (laser gyros) have been developed since the invention of lasers, in which circularly polarized lights oscillate. This paper summarizes recent progress of the study on orthogonally linear polarized lasers with the standing wave cavity. Firstly, the expression of producing orthogonally linear polarized lights in standing wave cavity, i. e. laser frequency splitting, is given. Almost all the birefringence effects made in laser cavity are used to produce orthogonally linear polarized lights. The effect includes quartz crystal birefringence effect, calcite birefringence effect, stress (photo-elastic) birefringence effect and electro-optical birefringence effect. Secondly, several physical phenomena of orthogonally linear polarized lasers are discovered such as aberrance of frequency splitting curves caused by optical activity of quartz crystal, order-passing of longitudinal modes with frequency splitting and strong modes competition. Finally, because the traditional Zeeman dual frequency laser cannot output frequency difference larger than 3 MHz, the approaches of obtaining larger frequency difference are studied. The sequential results, several kinds of orthogonally polarized lasers, are described, such as birefringence dual frequency lasers outputting a frequency difference from 40 MHz to hundreds of megahertz, birefringence-Zeeman dual frequency lasers outputting a frequency difference from 1 MHz to hundreds of megahertz, the LD pumped YAG birefringence dual frequency laser outputting frequency difference of several gigahertz, and the lasers whose longitudinal mode spacing is c/4L instead of c/2. .

关键词： orthogonally polarized laser dual frequency laser intra-cavity birefringence Zeeman effect photo-elastic birefringence electro-optical birefringence frequency splitting.

Study on simulation and experiment of array micro Faraday cup ion detector for FAIMS

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Science china(Technological Sciences) 2010年第12期53卷 3225-3231页

作者： TANG Fei, WANG XiaoHao, ZHANG Liang & YAN ZiLin State Key Laboratory of precision Measurement Technology and instruments, {2. of precision instruments and mechanology, tsinghua university, beijing 100084, china 1. State Key Laboratory of precision Measurement Technology and instruments Department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 China

An array micro Faraday cup ion detector for FAIMS (High-field Asymmetric Waveform Ion Mobility Spectrometry) was introduced, with which the size of the FAIMS system was reduced. With simple structure, good stability, low noise, large measurements range, this detector can work under the condition of atmospheric pressure. The array micro Faraday cup was composed of gate electrode, sensitive electrode and shielding electrode. The sensitive electrode was made of tens of crossing silicon columns with diameter of 2.0 μm. It was fabricated through typical MEMS technology, which was compatible completely with plane FAIMS. It was shown from FLUENT simulation result that the resistance to gas motion was low and the flow field distribution was helpful for full absorption of the ion in this array design. Through electricity simulation, the method to reduce interference on the detection signal of the micro Faraday cup was given out. Connecting with KEITHLEY 2.7 ampere meter, the noise level of the array micro Faraday cup was lower than 0.5 pA. The output signal of the acetone sample measured by experiment was about 2.0 pA. Through contrast experiment, the design parameter of the micro Faraday cup was obtained primarily. This array micro Faraday cup can meet the requirements of the FAIMS system.

关键词： FAIMS MEMS Faraday cup ion detector low current

THEORY OF MUM FOR METAL SPHERICAL ROTOR WITH CONTACTLESS SUSPENSION

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Chinese Journal of Mechanical Engineering 2004年第2期17卷 243-246页

作者： He Xiaoxia Gao Zhongyu Wang Yongliang department of precision {2. and Mechinery,tsinghua university,beijing 100084, china department of precision {2. and Machinery Tsinghua University Beijing 100084 China

Based on the motion equations of an unbalanced spherical rotor withcontactless suspension, three methods of MUM (mass unbalance measurement) are put forward to measurethe total mass unbalance, radical mass unbalance and radical mass unbalance of the rotor. Totalmass unbalance is obtained when the unbalanced rotor plays as a simple pendulum in static *** pendulant period and pendulant midpoint indicate magnitude and direction of total massunbalance of the rotor respectively. Analysis of the motion equations by using the averaging methodyields that the rotor will do a special side oscillation when an auxiliary system makes the rotorspin about its pole axis which is orientating toward the local vertical. The radical mass unbalancecan be obtained by building a proper displacement sensor to sense the amplitude of the sideoscillation. Necessary analysis of the motion equations also shows that when the rotor spins at asmall angular velocity and the rotary axis is perpendicular to the vertical, the pole axis of therotor will precess slowly about the vertical by virtue of the axial mass unbalance. The axial massunbalance can be estimated from the time history of the spin vector of the rotor. Finally,measurement precision of the three methods is compared and how the external torque affects themeasurement precision for the three methods are examined.

关键词： Mass unbalance measurement Radical mass unbalance Axial mass unbalance Static balancing Averaging method

Orthogonal linear polarized lasers (Ⅲ)——Applications in self-sensing

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Progress in Natural Science:Materials International 2005年第11期15卷 961-971页

作者： ZHANG Shulian, DU Wenhua and LIU Gang (The State Key Laboratory of precision Measurement Technology and instruments, {2. of precision instruments, tsinghua university, beijing 100084, china) The State Key Laboratory of precision Measurement Technology and instruments Department of Precision Instruments Tsinghua University Beijing 100084 China

In this paper, the applications of orthogonal linear polarized lasers in self-sensing are reviewed. The properties for such a laser include the production of a new frequency in one longitudinal mode spacing, the tuning of frequency difference, the change of polarization states as cavity tuning, the control of mode competition intensity, the optical feedback, and so on. The orthogonal polarized lasers have been used as a laser nanometer ruler based on competition between two polarized lights in a HeNe laser and as a displacement measurement tool based on the optical feedback in the orthogonal polarized lasers. They are also used in the phase retardation measurement of a waveplate, the angle measurement, the vibration measurement, the pressure/force measurement, the weak magnetic field measurement, and so on. The structures of these new devices are simple and compact with the great advantages of high resolution and high accuracy. Some of these devices can trace to the source of the laser wavelength. The nanometer laser ruler is an example whose measurement range is 12.mm, resolution is 79 nm and linearity is less than 5×10-5. The repeatability of the phase retardation measuring system of waveplate can reach 3’.

关键词： orthogonal polarized laser frequency splitting optical feedback vibration measurement displacement measurement waveplate measurement angle measurement.