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Issue 2 ， 2005
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Orientation error analysis of airborne opto-electric tracking and measuring device WANG Jia-qi, JIN Guang, YAN Chang-xiang
Abstract：Opto-electric tracking and measuring device is used to measure flight trace of aircraft. With the development of modern technology, performance demands of aircraft become higher and higher, so does the technology advance of opto-electric tracking and measuring device, especially its measurement precision. Error analysis,distribution and synthesis are very important in developing higher performance opto-electric tracking and measurement device through all the process such as: feasibility demonstration, scheme demonstration, scheme design, design, manufacture, assembly and adjustment, and experimentation. Aiming at the most complicated orientation error analysis, namely measuring error along three axes, we constructed 9 coordinate from measured target to ground center station, carried out 31 times linear coordinate transformation, formed uniform measuring equation containing 35 variables. And we also carried out error analysis and distribution of all factors affecting measurement, and analysis and calculation of orientation error employing Mont Carlo method.Keywords：error analysis;Mont Carlo method;orientation error analysis;opto-electric tracking and measurement- 133
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Published：2020-08-12 -
Design and modeling of MEMS-based solid propellant propulsion
Abstract：MEMS-based solid propellant propulsion was developed.The structural design and fabrication process of the thruster, as well as the approach of propellant injection are presented. A thermal conduct model of ignition phase was established, with which the effect of various parameters on the ignition delay is analyzed. Meanwhile, the development of the model for performance simulation of micro thruster is described. The result indicates that low density, thermal conductivity and specific heat of substrate material of ignitor resistor can reduce the ignition delay time and power consumption; under certain condition, increasing the exit-to-throat section ratio of nozzle will help to raise the thrust and impulse bit of the propulsion in vacuum. It can be concluded that MEMS-based propulsion can meet the requirement of miniaturization, micro thrust and high accurate impulse bit for the propulsion system of micro satellite.Keywords：micro propulsion;micro-electro-mechanical system;ignition delay;micro thrust- 64
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Published：2020-08-12 -
Dynamic numerical simulation of a electromagnetic microfluidic active mixer
Abstract：The dynamic analysis was applied to a microfluidic polymer membrane active mixer in order to optimize its design and improve its performance. The results of the modal and harmonic response analysis were given,which were coupled into the fluid field, giving the Re of the first substep vibration and the maximum Re in the second substep. From mixing experiments, the best mixing took place also in the second substep. The results from simulation and experiments matched well,which proves that the simulation is feasible, and the degree of vibration depends on both amplitude and frequency.Keywords：microfluidic active mixer;numerical simulation;modal;harmonic response;computational fluid dynamics- 47
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Published：2020-08-12 -
Analysis and optimization of a side pull-down electrodes controlled MEMS varactor
Abstract：The analysis and optimization of a SPEC (Side pull-down electrodes controlled) MEMS(Micro-electro-mechanical system) varactor with energy method is presented. A two-step iterative calculation is used to generate the trial displacement function under different control voltages. The calculated displacement as a function of control voltage is verified by FEA(Finite element analysis) simulation with good accuracy. Based on the established method, the geometric parameters of SPEC varactors with aluminum as structure materials are optimized. For a SPEC varactor with an initial aluminum membrane stress of 5 MPa, with young module 70 GPa, plate thickness 1.5 μm, gap 1 μm and total length of the suspended plate 600 μm, the optimized length of side controlling electrodes should be 70 μm, which can achieve a tuning rate of 2∶1. The calculation shows that SPEC MEMS varactor, compared with the conventional two-plate MEMS varactors, can greatly extend the tuning rate of MEMS varactors by reducing or avoiding the pull-in effect.Keywords：varactor;micro-electro-mechanical system;energy method- 54
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Published：2020-08-12 -
MEMS directly modulating wideband IR thermal source
Abstract：A mid-IR thermal source based on electrical heating of platinum film is studied. The IR source with an effectively emitting area diameter of 1.6 mm is obtained from heated platinum thin film resistors that deposit on a Si3N4/SiO2 membrane. It can emit wideband infrared light with a peak wavelength of λ=2.62 μm at 1 106 K and adapt to direct modulation with variable voltage. Appropriate heat transfer makes it possible to reach a modulation frequency as high as 50 Hz. Such specifications meet the requirements of various IR gas sensors, and it can be regarded as a new thermal IR source to be used in NDIR (non-dispersive infrared) gas analyzer.Keywords：infrared sensor;micro-electro-mechanical system;emissivity- 38
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Published：2020-08-12 -
On-line detection of urinary protein and lactate dehydrogenase isoenzyme by capillary electrophoresis microchip
Abstract：The microfluidic chips were fabricated with standard photolithography, wet etching and low-temperature bonding techniques of MEMS(Micro-electro-mechanical system). Clinical urine samples from gestational hypertension syndrome and multiple myeloma patients were analyzed with the microfluidic chips on home-made UV absorption-based biochem-analysis instrument. The results are in accordance with those from standard urinary proteins assay method. The advantages of microchip-based urinary protein assays such as reduction in analysis time (2 min) and reagent consumption display great superiority over the standard urine assay method. Standard models of lactate dehydrogenase isoenzymes were also selected as the samples for initial study of on-chip LDH assay. The integration of on-chip enzyme separation, enzyme reaction and product detection for mixture of LDH1 and LDH5 was realized.Keywords：microfluidic chip;capillary electrophoresis microchip;urinary proteins;lactate dehydrogenase isoenzymes- 42
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Published：2020-08-12 -
Design and measurement of RF-MEMS CPW on HRS
Abstract：This paper presents the design of RF-MEMS(radio-frequency micro-electro-mechanical system) coplanar-waveguide (CPW) on high resistivity silicon (HRS) and its measurement under different bias-voltage are presented. The dimension of the CPW is designed with partial-capacitance method and conformal mapping method. The designed CPW transmission line is realized on 3 inches HRS wafer with a resistivity of 1 000 Ω·cm. The substrate and metal layer are insulated by 0.8 μm silicon dioxide layer formed by oxygenation. 2.5 μm thick electroplated gold is selected as the material of metal layer. The width of the central signal line is 196 μm and the gap between signal line and ground line is 120 μm. The S-parameters measurement of the designed CPW is performed with 0 V and 38 V bias on the central signal line by HP 8722ES network analyzer. The characteristic impedance of designed CPW is extracted using Winkel’s method, and the necessary specific polynomial is also given. The extracted parameters show that the influence of bias-voltage on characteristic impedance is observable. When the bias-voltage on central signal line is transformed from 0 V to 38 V, the change of the real part of the characteristic impedance is about 1.2 Ω,while the image part change is about 0.8 Ω.Keywords：radio-frequency;micro-electro-mcchanical system;coplanar-waveguide;characteristic impedance- 48
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Published：2020-08-12 -
Simulation and experimental study of non-contact piezoelectric micromotor
Abstract：A new non-contact piezoelectric micromotor was presented,based on four-sector and eight-sector excited by electric signals. The mode analysis of the stator was carried out to compute the natural frequency and the corresponding vibration mode by finite element method. The frequency sweep and the vibration mode test were done with a laser Doppler vibrometer. It is shown that the optimum driving frequencies of the stators divided into four-sector and eight-sector are 34.4 kHz and 46.3 kHz, and the corresponding vibration mode were B21 mode and B22, respectively. It is found that the finite element simulation results were in good agreement with experiment. The output characteristics of micromotor were tested. The conclusion is that the revolution speed of the optimum driving frequency of eight-sector is about double than four-sector for three blades and six blades rotors. These demonstrate that the increase of the sector number of stator can not only change the optimum driving frequency, but also increase the revolution speed of rotors obviously. When the difference between A and B phase is changed between 90°and 270°, the direction of the traveling wave along circumferential direction is shifted, so the rotation direction of rotor is also changed. the experiment shows that the non-contact piezoelectric micromotor offers identical performance to different rotation directions.Keywords：vibration mode;non-contact;Piezoelectric micromotor;finite element simulation- 33
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Published：2020-08-12 -
Modeling and control of a macro-micro dual-drive ultra-precision positioning mechanism
Abstract：A macro-micro dual-drive ultra-precision positioning mechanism is presented. Combining macro with micro actuator, a system with large workspace and high resolution of motion was developed. The direct-drive motor is used in the macro motion, and PZT-driven micro stage with high frequency is mounted on the motor and compensates the position error. A high-resolution linear encoder is integrated into the closed-loop feedback, which is used to measure the position of the end-effector mounted in the micro stage. The feedforward and feedback are combined to control the macro stage, and the fuzzy-adaptive PID control algorithm is employed in the micro stage. The experimental results show that the travel range is 100 mm, the settling time is less than 40 ms and the repeatability error is 10 nm.Keywords：macro-micro dual-drive;ultra-precision positioning;modeling;control algorithm- 48
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Published：2020-08-12 -
On sensing apparatus for bending deformation in trenchless underground pipeline detection
Abstract：A new method of using FBG sensor for detection of pipelines is proposed. First, two Fiber Bragg Gratings(FBGs) are mounted on a slim cylindrical substrate in 90° to make a strain detecting sensor with a diameter of 5 mm. Then the sensor is placed in a novel design centering clamping device to deal with the centering and longitudinal force unload problem. By the demarcate method, two coefficients between the two FBGs Bragg wavelength change and the curvature of sensor can be calculated, and the two coefficients are 524.0 733 and 485.7 432. While the centering clamping device drives the sensor to move along the pipeline step by step, the data of Bragg wavelength of the sensor is picked up by demodulator every 50 mm equidistance points. Space curvature information of each point can be calculated from these data. At last, the location and 3D shape of the pipeline is reconstructed by the use of the space curve fitting method, which is based on curvature information of discrete points.Keywords：pipelines detection;trenchless technology;FBG sensor;curve reconstruction- 51
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Published：2020-08-12 -
Comprehensive estimating and measuring method of line-array fiber-optic image bundles based on the modulation transfer function
Abstract：With the definition of the contrast transfer function (CTF), the modulation transfer function (MTF) mathematics-theory relationship of line-array fiber-optics image bundles was established, the influence of phase match between input signal and line-array fiber-optic image bundles on the modulation transfer function was carried out by digital analysis, and the study of experiment was working. The results show that alignment between pixels of image bundle and input pattern has direct influence on measured result of the MTF. A measuring and evaluating method about the MTF of line-array fiber-optic image bundles is studied according to the simulation results. And the analysis is in correspondence with the results of experiment.Keywords：fiber-optic image bundles;modulation transfer function;phase match;measurement- 46
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Published：2020-08-12 -
Design and test of the active micro-motion mechanism for optical mirror segement
Abstract：Active micro-motion mechanism is fundamental for astronomical telescope using segmented mirror to form and maintain required figure by active tip-tilt and/or piston. Mechanical design and laboratory test of such an active mechanism for a mirror segment prototype are described. Technical requirement specifies that active motion range covers up to 2 mm with resolution down to 50 nm. Three displacement actuators with 6 mm working travel and 50 nm motion resolution are adopted with three sets of lever mechanism introduced to increase the resolution of displacement and to abate error in the system. Also, three sets of lever-weight-balance mechanism together with three pairs of tensional spring are integrated to ensure, despite of variable elevation angles of the telescope in operation, constant load on the displacement actuators, whereby the actuators are safely protected with stabler output displacement accuracy, which is undesirably load-dependent. Based on working philosophy of segmented mirrors, mathematical model and experimental method were established for the active micro-motion system to be tested in laboratory, for which displacement sensors of 5 nm output resolution are used. Measurement results have confirmed the feasible design of the active micro-motion mechanism with output displacement resolution as fine as 12 nm and transmission ratio error no greater than 5.6%, besides its execellent linearity and sensitivity.Keywords：micro displacement;resolution;displacement measurement;lever;displacement sensor- 39
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Published：2020-08-12 -
Computer controlled polishing technology for middle or small aspheric lens
Abstract：Based on aspheric computer controlled manufacturing center (FSGJ-3), as forφ108 mm aspheric lens (R=318 mm,k=－3), the polishing equipment, tools, abrasives and testing method used in polishing are researched. Wheeled polishing technology for the middle or small aspheric lens is introduced. It's showed that the final surface figure of the lens is 0.306λ(PV)、0.028λ(RMS) (λ=0.632 8μm). Discussing and analyzing the key technology of middle or small aspheric lens in detail, supplies a basic technology guarantee for aspheric optical component to reduce the size, weight and complexity of decreasing the number of surfaces required to form unaberrated images.Keywords：aspheric lens;wheeled polishing technology;surface figure- 53
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Published：2020-08-12 -
High power, high flattening C+L band erbium-doped fiber source based on fiber loop mirror
Abstract：A fiber loop mirror that is made from 3 dB coupler is employed in dual-stage double-pass one pumping LD configuration, in order to realized high flattening C+L band ASE with high output power. By using two 980 nm LDS, ratio of two stage is acquired, Through optimization of parameter of fiber of the two stage, output ASE of C+L band with power of 15.28 mW(11.84 dB/m) is achieved, and mean wavelength is 1 559.31 nm, without any external spectral filter, power ripple of 3 dB is 66.72 nm (from 1 533.12 to 1 599.84 nm). Fiber loop mirror was used as reflector in the configuration, to enhance the efficiency of LD and improve flatness of spectrum, From the experiment,the best ultra bandwidth ASE source with high output power of 30.11 mW is acquired by adjusting the bi-directional pump power of LDs, besides low demands for flatness.Keywords：C+L band;erbium-doped fiber;ultra broadband light source;fiber loop mirror;amplified spontaneous emission (ASE)- 70
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Published：2020-08-12 -
Technology for measuring spectrum from nanosecond laser plasma soft X-ray source
Abstract：A method detecting and measuring the intensity of spectrum from laser plasma soft X-ray source is presented. A channel electron multiplier (CEM) and a calibrated silicon photodiode are used as detectors in this method, the former is a nonstandard detector and the latter is a standard one. Charge-sensitive preamplifiers and peak detector are used for measuring total charges generated by detectors, and a monochromator with high resolution is employed as spectrometer, formulae to calculate the intensity of spectrum from laser plasma soft x-ray source is given, based on known the grating efficiency of monochromator, CEM's gain and responsivity of silicon photodiode to photons.Keywords：soft X-ray sourcce;Laser plasma;spectrum intensity;peak detector- 38
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Published：2020-08-12 -
Experimental comparison of the characteristics of Y element and Y loop element
Abstract：With filming technology and lithography, two sorts of FSS i.e. Y-aperture element FSS and Y-loop element FSS on different thickness substrates are presented. And the tests under two different polarized waves at 0° and 45° incidence angle are given. The results show that at wide angle, Y-loop element FSS has more stable center frequency and narrower bandwidth than Y-aperture element FSS; Y-loop element FSS is more adaptive to vertically and horizontally polarized wave than Y-aperture element FSS, and its filtering characteristic is more obvious as well; The center frequency and bandwidth of Y-aperture are much more influenced by the substrate thickness change than those of Y-loop element FSS. So from the changes in center frequency and bandwidth versus dielectric substrate thickness, incident angle, direction of polarization, it can be seen that Y-loop element has more stable characteristics than Y-aperture.Keywords：frequency selective surface;vertical polarization;horizontal polarization- 62
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Published：2020-08-12 -
Experimental study of the resolution of an optoelectronic imaging system at 17.1 nm based on MCP detector
Abstract：An optoelectronic imaging system was designed to image EUV light at 17.1 nm. This imaging system is composed of three parts: light source, monochromator and detection system. A Q-modulated Nd-YAG laser (Continuum 9000) is used to produce laser plasma. The grazing monochromator consists of two spherical mirrors and a spherical grazing grating,by which monochromatic light at 17.1 nm is obtained and the detector is a MCP(Microchannel Plate) and phosphor screen assembly. Kodak 400 film is used to record the image of a 3 mm-width-slit obtained by this imaging system. Its spatial resolution of 130 μm is demonstrated in this paper,which is better than that of reference [6].Keywords：extreme ultraviolet;laser-produced plasma;Monochromator;micro channel plate- 34
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Published：2020-08-12 -
Seeking of tissue image digging point method based on genetic-arithmetic
Abstract：For tissue-micro-array manufacture automatization, the fitness point seeking in the wax where the tissue sample to be picked up was studied. Based on digital image of tissue, the mathematical model of seeking was described as seeking the biggest inscribed circle center in the tissue area. The seeking method based on genetic-arithmetic was researched, including the code principle, parameters selection and the implementing method. The arithmetic improvement consists of fitness calculation and initialization selection, etc. The results of theory analysis and experiment prove that this arithmetic is effective and useful to fulfill the on-line manipulation.Keywords：bio-tissue micro array;digital image;genetic-arithmetic- 41
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Published：2020-08-12 -
Adaptive cross-quasi-diamond search algorithm based on initial search point estimation
Abstract：A predictive adaptive cross-quasi-diamond search algorithm (PACQDSA) is presented. Based on the cross-center-biased motion vector distribution characteristic of the real-world sequences and high space-time correlation of adjacent blocks' motion vectors, a cross-quasi-diamond search pattern was designed, and some effective techniques were used, which are composed of the prediction of initial search point, half-stop criteria and adaptive search modes. Experiments show that the algorithm is able to fit for all types of video sequences adaptively in spite of the degree of the motions. Compared with other algorithms, it is 3.56 times faster than NTSS, 3.26 times faster than FSS and 2.71 times faster than DS in average. And it is better than the traditional fast motion estimation algorithms in terms of PSNR, especially for the sequences with large motion. Therefore, the algorithm improves the performance of existing motion estimation algorithms.Keywords：motion estimation;block matching;video compression;diamond search;cross search- 52
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Published：2020-08-12
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