NEW MODEL OF THEODOLITE INDUSTRIAL MEASURING SYSTEM

Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision of the TIMS has been considered so low that the TIMS isnt applied to some precise measurements.The error in self locating TIMS is a main factor which affects the precision of the TIMS.A new model of the TIMS is given out in this paper,and it can eliminate the error in self locating the TIMS.The new model is not only investigated and analyzed theoretically but also verified by the real measured data.

General Consideration of Measuring System for Operational Test of Thyristor Valves of Ultra High Voltage DC Power Transmission

Thyristor valve is one of the key equipments for ultra high voltage direct current(UHVDC) power transmission projects.Before being installed on site,they need to be tested in a laboratory in order to verify their operational performance to satisfy the technical specification of project related.Test facilities for operational tests of thyristor valves are supposed to enable to undertake more severe electrical stresses than those being applied in the thyristor valves under test(test objects).On the other hand,the stresses applied into the test objects are neither higher nor lower than specified by the specification,because inappropriate stresses applied would result in incorrect evaluation of performance on the test objects,more seriously,would cuase the damage of test objects with expensive cost losing.Generally,the process of operational tests is complicated and performed in a complex synthetic test circuit(hereafter as STC),where there are a lot of sensors used for measuring,monitoring and protection on line to ensure that the test circuit functions in good condition.Therefore,the measuring systems embedded play a core role in STC,acting like "eyes".Based on the first project of building up a STC in China,experience of planning measuring systems is summarized so as to be referenced by related engineers.

A time-dependent measuring system for welding deformation

In this paper the establishment and application of a time dependent measuring system for welding deformation are presented which is established with high quality sensors shielded from strong welding interference. By using this system, vertical and horizontal displacements of the high temperature area are surveyed at the same time. And this system is also used for monitoring and controlling the deformation of real welded structures.

AN AUTOMATIC HEAT FLUX-TEMPERATURE MEASURING SYSTEM AND ITS APPLICATION

An automatic heat flux-temperature measuring system can be used to measure local body heat flux, local skin temperature, body core temperature, and ambient temperature, as well as mean body heat flux, mean skin temperature, physiological shell thermal insulation and suit thermal insulation. This paper describes the measuring principle, hardware construction, software program and the application in thermal measurements on divers.

Digital Cross-Correlation Detection of Multi-Laser Beams Measuring System for Wind Field Detection

A cross-correlation detection method to process backscatter signals of multi-laser beams measuring （MLBM） is presented, which can be firstly filtered by the digital filter composed of average median filter and finite impulse response （FIR） digital filter. The processing of backscatter signals using single-pulse and three-pulse cross-correlation detection methods is depicted in detail. From calculation results, the multi-pulse cross-correlation detection could effectively improve signal-to-noise ratio （SNR）. Finally, both wind velocity and direction are determined by the peak-delay method based on the correlation function which shows high measuring precision and high SNR of the MLBM system with the assistance of the digital cross- correlation detection.

Application of wavelet analysis to fault diagnosis of angular measuring system

For fault diagnosis, signal singularity and irregularity discontinuity fraction are very significant characteristics of signal. The discontinuity of output signal represents a system fault . In an angular measuring system, function transformer uses two D/A convertors, output circuit fault of a D/A convertor brings about discontinuity of one phase input voltage amplitude of inductosyn, results in a system error exceeding the allowable error and reduces the system accuracy. This is the reason why discontinuity is detected. Fourier transform has no resolution ability in angular domain, but wavelet can analyse signal in angular and frequency domains. So we decompose the error signal of angular measuring system by wavelet, detect the signal singularity at high frequency layer and find out the accurate position of it.

Dynamic error research and application of an angular measuring system belonging to a high precision excursion test turntable

Angular measuring system is the most important component of a servo turntable in inertial test apparatus. Its function and precision determine the turntable＇ s function and precision. It attaches importance to research on inertial test equipment. This paper introduces the principle of the angular measuring system using amplitude discrimination mode. The dynamic errors axe analyzed from the aspects of inductosyn, amplitude and function error of double-phase voltage and wavefonn distortion. Through detailed calculation, theory is provided for practical application; system errors are allocated and the angular measuring system meets the accuracy requirement. As a result, the schedule of the angular measuring system can be used in practice.

Light pen whole space coordinate measuring system based on a tracking turntable

Light pen coordinate measuring system(LPCMS)is a kind of portable coordinate measuring technique based on vision metrology.In classical LPCMS,the measuring range is limited to the camera’s field of view.To overcome this defect,a new LPCMS is designed in this paper to fulfil whole space coordinate measurement.The camera is installed on a turntable instead of a tripod,so that the camera can rotate to track the movement of the light pen.The new system can be applied to large scale onsite measurement,and therefore it notably extends the application of LPCMS.To guarantee the accuracy of the new system,a method to calibrate the parameters of the tracking turntable is also proposed.Fixing the light pen at a stationary position,and changing the azimuth angles of the turntable’s two shafts,so that the camera can capture the images of the light pen from different view angles.According to the invariant spatial relationship between the camera and the pedestal of the tracking turntable,a system of nonlinear equations can be established to solve the parameters of the turntable.Experimental results show that the whole space coordinate measuring accuracy of the new system can reach 0.25 mm within 10 m.It can be concluded that the newly designed system can significantly expand the measuring range of LPCMS without losing too much accuracy.

Effect of Particle Phase Volume, Shape and Liquid Phase Concentrations on Rheological Properties of Large Particulate-Liquid Model Food Systems by Using Ball Measuring System

Rheological properties of large particulate-liquid model food systems were studied by using the BMS （ball measuring system）. The model food systems were composed of alginate gel particles （-10mm） and a gelatinised starch solution with 1% w/w sodium chloride as a liquid phase. The effects of particle phase volume （Ф, 0-0.60）, particle shapes （cube, sphere, rod and disc） and starch concentrations （3% and 5% w/w starch） were investigated. The power law model was successfully applied to characterize the flow properties of each system and the consistency K and power law index n were obtained. The K increased and n decreased with increasing # for samples at all particle shapes at 3% w/w starch in the liquid phase. The particle effect on the viscosity is further analysed by means of the Krieger-Dougherty model and the maximum packing fraction #,, and the intrinsic viscosity [η] were obtained in each system. The Фm, depended on the particle shape, as expected. The [7] value depended on particle shape and was largely in the order of 4.04 （cube）, 3.28 （disc）, 2.56 （sphere） and 2.32 （rod） at 3% w/w starch. The [η] also depended on starch concentration and was 1.1 at 5%,6 w/w starch in the liquid phase with spherical particles. The present results show successful application of BMS to study the rheological properties of large particulate liquid food systems at relatively small scale experiment （-0.5 L） and also that existing models for suspension rheology are applicable for such food systems to a great extend.

THEORETICAL ANALYSIS OF COORDINATES MEASUREMENT BY FLEXIBLE 3D MEASURING SYSTEM

The system mathematical model of flexible 3D measuring system is built by theoretical analysis, and the theoretical formula for measuring space point coordinate is also derived. Frog-jumping based coordinate transform method is put forward in order to solve measuring problem for large size parts. The frog-jumping method is discussed, and the coordinate transform mathematical model is method of the space point coordinate compared to original value, and an advanced method is provided, Form the space point coordinate transform formula can derive the calculation measuring method for measuring large size parts.

Research on Construction Technology of Optical Radiation Measuring System Based on Virtual Instrument Technolo

Using virtual instrument technology, digital signal processing technology and traditional optical radiation measuring technology to construct optical radiation measuring system breaks the construction methods of traditional instruments. Signal processing, collection, control and process of measuring system are implemented by the software LabVIEW8.2. And they are integrated in a computer. The computer not only is data processing center, but also is instrument control center. While measuring, the user uses the mouse to operate the handles including knobs, switch and buttons of virtual instrument panel to select instrument functions and set various parameters, which realizes measuring optical radiation with different wave bands and different intensity. And the user can change insmament operation panel, modify system software, transform instrument function, and customize instrument parameters, which embodies the idea that the software is the instnnnent.

Multi-Aspect Value of Measuring Systems and Methods Based on the Results of Roundness Measurements

The increase of quality consciousness brings about the growth of significance of metrological systems. Besides the significance, the level of automatization, flexibility, accuracy, et al. have advanced. The modern measuring systems are constructed so that nearly all necessary dimensional characteristics can be measured with them. However, conventional measuring systems are provided for particular mode measurements. This research paper presents and compares several conventional and modem measuring systems and methods. The measured value is roundness, one of the basic shapes of cross section in mechanical engineering. This paper arises in search of answers for the question whether conventional measuring techniques and equipments are made redundant because of the modern ones. In what segments and in which criterion are modem methods preferable？

Design on Improving Efficiency for Measuring System Integrated Test of A Space Vehicle

Measuring system is the core part of a space vehicle, and its integrated test is the important means of conducting system-level verification. For the integrated test items and flow, the solution featuring the automatic test method, the combination of different test items, and the electronic data record is proposed in this paper. Applying the above-mentioned solution, the test efficiency could be improved by more than 30% and the safety of test operation could be also exalted. At the same time, the solution has good universality and could provide reference for other similar integrated tests.

Single Camera 3-D Coordinate Measuring System Based on Optical Probe Imaging

A new vision coordinate measuring system--single camera 3 D coordinate measuring system based on optical probe imaging is presented. A new idea in vision coordinate measurement is proposed. A linear model is deduced which can distinguish six freedom degrees of optical probe to realize coordinate measurement of the object surface. The effects of some factors on the resolution of the system are analyzed. The simulating experiments have shown that the system model is available.

Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor

A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

Development of Measuring System of Plant Electrical Potential and Its Application

Based on the characters of plant potentials, it introduced the construction and technology in developing the measuring system of plant electrical potentials, the input impedance of the amplifier must be enough high(= 1010～ 1012Ω) in order to measuring the plant weak signals and ensuring high common mode rejection ratio (CMRR). And wavelet transform was applied in denoising based on cross-validation (CV)threshold value. the experiment showed that this system could effectively detect the change of plant potentials,four-week old cucumber was stimulated by heat wounding, the variation potential (VP) and action potential(AP) would be evoked, the AP's varying amplitude can reach 40mV; the AP changed very fast, its duration time is about 0.01～0.02s and its amplitude often change from 15μV～5mV.

A Study on Comprehensive Modeling for Errors in on-line Measuring System of Machining Center

Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.

Development of an in-situ measuring system for blisk manufacturing

In order to solve the in-situ measurement problem of workpiece with complex structures,a cantilever coordinate measuring machine(CCMM)is proposed to adapt to the finite space constraints of the 5-axis computer numerical control(CNC)processing site.Structure design of dense ball bearing shafting is analyzed and optimized.Factors affecting measurement accuracy of CCMM are analyzed,and measurement accuracy is validated by experiments.Results show that the structure of CCMM is able to satisfy requirements of technical specification,and the in-situ measurement of blisk manufacturing is realized.The CCMM developed is of important significance for machining quantity improvement of blisk and development of large aircraft production.

RESEARCH ON THE ON-LINE MEASURING SYSTEM FOR THE MIDDLE-CONVEX AND VARYING ELLIPSE PISTON SKIRT

The middle convex and varying ellipse piston is th e key component of an internal combustion engine In general,the piston is mac hined by non circular section CNC lathe,but the measuring of piston profile is manipulated by off line Because the off line measuring reference is differen t from the machining reference,the measurement result is diverse from the act ual dimension A new method to measure the middle convex and varying ellipse p iston profile, which is known as on line measuring, is presented By using thi s kind of method,the high measurement accuracy can be gained,as well as meeting the production requirement.

Orthogonality of inductosyn angle-measuring system error and error-separating technology

Round inductosyn is widely used in inertial navigation test equipment, and its accuracy has significant effect on the general accuracy of the equipment. Four main errors of round inductosyn,i.e. the first-order long-period (360°) harmonic error, the second-order long-period harmonic error, the first-order short-period harmonic error and the second-order short-period harmonic error, are described, and the orthogonality of these four kinds of errors is studied. An error separating technology is proposed to separate these four kinds of errors, and in the process of separating the short-period harmonic errors, the arrangement in the order of decimal part of the angle pitch number can be omitted. The effectiveness of the technology proposed is proved through measuring and adjusting the angular errors.