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Study On The Analysis Of The Data Algorithm By The Precise Maglev Gyro Total Station Under Special Environment And Its Stability

Posted on:2014-09-09Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z Y ZhouFull Text:PDF
GTID:1260330422466208Subject:Geodesy and Survey Engineering
Abstract/Summary:PDF Full Text Request
From the development process of gyro, software and hardware of the gyroscope systemare in constant development and improvement. Domestic and foreign experts and scholars aremainly to make unremitting efforts and exploration in three aspects, namely the improvementof hardware and development, research on the observation method improved and the formulaof the observation data processing and the precision of the observation data, applicationdevelopment of the instrument, to improve the precision, stability and application range of theinstrument through these studies.Over the years, the Chang’an University of Surveying and Spatial Information ResearchInstitute and the Study on the Sixteenth Institute of China Aerospace Science and technologygroup through joint technical research, developed the domestic first based on the magneticbearing system, high precision maglev gyro total station directional accuracy of better than5"in a few minutes, it has applied to several important domestic projects, and achievedsatisfactory precision of orientation. The instrument system using magnetic levitationtechnology makes high-speed rotation of the gyro motor in a suspended state, eliminates theadverse effects of traditional gyro mechanical friction torque, and the interaction between thetorque sensor and gyroscope rotor, measuring two fine for disc position acquisition of40000groups of current value to calculate the North range line. But in some experiments andengineering applications, we find the influence on the value of the rotor current by theinstrument collection for wind, vibration or magnetic field in some environment, data containssignificant noise, dispersion is too large, gyroscope rotor system affected by measurementenvironment, affects the orientation precision and stability of instrument.In order to improve the precision and stability of the instrument, the paper studies themaglev gyro system error problem, the classification research and Analysis on it, it studies thedata of the rotor current through the instrument colledted, using time series analysis, waveletanalysis, adaptive filtering method and the adaptive fading filter for filtering, prediction andmodeling of rotor current data collected, in order to improve the rotor current the precision ofthe data, so as to improve the instrument orientation precision and stability, these are providedan improved basis for future miniaturization, intelligent, automation instrument. The mainconclusions are as follows:1The instrument error mainly includes the system error, random error and the influenceof initial data errors, instrument rotor roundness error and mass unbalance of system error canbe judged by the method of mathematical statistics, observation method, the error is to eliminate or weaken by improving the calculation method and the instrument calibration.These make the rotor speed is not uniform for the voltage instability, the frequency changes,external vibration and temperature gradient changes, it caused moment to point mutation ofactuators by resulting in disturbing torque and accidental error can be analyzed by thestatistical method, using the corresponding data processing method to eliminate.2It is used to analysis the statistical characteristics of the the rotor current data by timeseries analysis which is calculated the directional angle, the orientation error model of themaglev gyro total station about time series of linear and stationary established by computingprogramming. It independently modified rotor current data according to the time sequencemodel built, it can improve orientation precision instrument by using rotor current datacorrection calculation orientation angle.3Due to the influence of the internal structure of the instrument and the externalenvironment, rotor current data of maglev gyro total station will produce unstable fluctuationsduring the directional measurement processes, this instability can be reflected by the residualsequence of conditional heteroscedasticity characteristics. Through the model of conditionalheteroskedasticity (GARCH model) analysis to study the nature and the process of modeling,then it depends on the rotor current data to build a conditional heteroskedasticity model,through the model analysis can not only have basic reason, rotor current data non-stationaryfluctuation is generated from external environmental factors, rather than resulting from theinternal structure of instrument. And can judge the rotor current conditional heteroscedasticdata of the time-varying and clustering of the two characteristics, the best time of instrumentto collect data selection accordingly, and provides a new method for rotor current dataanalysis.4By using wavelet analysis, the error is rejected in the current observation data collected,the effective rotor current data from the strong noise is extracted for calculation of directionalangle data, it effectively improves the directional results of the instrument and the precision oforientation angle.5By the principle and calculation method of using adaptive filtering method, it isestablished the dynamic adaptive filtering method to predict the trend of data model ofmaglev gyro. Prediction of maglev gyro total station observation data of this model is suitablefor periodic variations, this method can be used as the effective means of observation data ofthe automatic monitoring instrument.6The fading factor is introduced into the adaptive filtering algorithm, by using the evanescent adaptive Kalman filtering algorithm to process maglev gyro system acquisitionrotor current value, it has a certain effect on the instrument orientation precision improved,but the effect is not obvious.
Keywords/Search Tags:precise maglev gyro-total-station, error analysis, time series analysis, Generalized conditional heteroskedasticity model, wavelet analysis, adaptive fadingfilter, directional accuracy, stability
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