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《咸淳毗陵志》人物传订误
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作者 陈立军 《史志学刊》 2017年第1期88-92,共5页
《咸淳毗陵志》是现存宋代二十多种府志之一,在研究宋代常州地方史上具有重要史学价值,但其中存在诸多不实之处,严重影响了其可信度和史料价值。目前虽然已有两部点校本《咸淳毗陵志》出版,但是据《续资治通鉴长编》《建炎以来系年要录... 《咸淳毗陵志》是现存宋代二十多种府志之一,在研究宋代常州地方史上具有重要史学价值,但其中存在诸多不实之处,严重影响了其可信度和史料价值。目前虽然已有两部点校本《咸淳毗陵志》出版,但是据《续资治通鉴长编》《建炎以来系年要录》《宋史》的文献记载,《咸淳毗陵志》人物传仍存在六条失校之处。 展开更多
关键词 《咸淳毗陵志》 人物
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Temperature compensation method of silicon microgyroscope based on BP neural network 被引量:5
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作者 夏敦柱 王寿荣 周百令 《Journal of Southeast University(English Edition)》 EI CAS 2010年第1期58-61,共4页
The temperature characteristics of a silicon microgyroscope are studied, and the temperature compensation method of the silicon microgyroscope is proposed. First, an open-loop circuit is adopted to test the entire mic... The temperature characteristics of a silicon microgyroscope are studied, and the temperature compensation method of the silicon microgyroscope is proposed. First, an open-loop circuit is adopted to test the entire microgyroscope's resonant frequency and quality factor variations over temperature, and the zero bias changing trend over temperature is measured via a closed-loop circuit. Then, in order to alleviate the temperature effects on the performance of the microgyroscope, a kind of temperature compensated method based on the error back propagation(BP)neural network is proposed. By the Matlab simulation, the optimal temperature compensation model based on the BP neural network is well trained after four steps, and the objective error of the microgyroscope's zero bias can achieve 0.001 in full temperature range. By the experiment, the real time operation results of the compensation method demonstrate that the maximum zero bias of the microgyroscope can be decreased from 12.43 to 0.75(°)/s after compensation when the ambient temperature varies from -40 to 80℃, which greatly improves the zero bias stability performance of the microgyroscope. 展开更多
关键词 silicon microgyroscope temperature characteristic error back propagation neural network temperature compensation
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NOVEL APPROACH TO LOCATOR LAYOUT OPTIMIZATION BASED ON GENETIC ALGORITHM 被引量:5
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作者 吴铁军 楼佩煌 秦国华 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第2期176-182,共7页
Proper fixture design is crucial to obtain the better product quality according to the design specification during the workpiece fabrication. Locator layout planning is one of the most important tasks in the fixture ... Proper fixture design is crucial to obtain the better product quality according to the design specification during the workpiece fabrication. Locator layout planning is one of the most important tasks in the fixture design process. However, the design of a fixture relies heavily on the designerts expertise and experience up to now. Therefore, a new approach to loeator layout determination for workpieces with arbitrary complex surfaces is pro- posed for the first time. Firstly, based on the fuzzy judgment method, the proper locating reference and locator - numbers are determined with consideration of surface type, surface area and position tolerance. Secondly, the lo- cator positions are optimized by genetic algorithm(GA). Finally, a typical example shows that the approach is su- perior to the experiential method and can improve positioning accuracy effectively. 展开更多
关键词 locator layout locating error fuzzy judgment genetic algorithm(GA)
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Technique of Error Concealment for Block-Based Image Coding Using Genetic Algorithm
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作者 杨守义 罗伟雄 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期164-168,共5页
Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborh... Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborhood match method using genetic algorithm is used to conceal the error blocks. Experimental results show that the searching space can be greatly reduced by using genetic algorithm compared with exhaustive searching method, and good image quality is achieved. The peak signal noise ratios(PSNRs) of the restored images are increased greatly. 展开更多
关键词 block based image coding genetic algorithm error concealment
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FLIGHT CLASSIFICATION MODEL BASED ON TRANSITIVE CLOSURE ALGORITHM AND APPLICATION TO FLIGHT SEQUENCING PROBLEM 被引量:3
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作者 李雄 徐肖豪 李冬宾 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第1期31-35,共5页
A new arrival and departure flight classification method based on the transitive closure algorithm (TCA) is proposed. Firstly, the fuzzy set theory and the transitive closure algorithm are introduced. Then four diff... A new arrival and departure flight classification method based on the transitive closure algorithm (TCA) is proposed. Firstly, the fuzzy set theory and the transitive closure algorithm are introduced. Then four different factors are selected to establish the flight classification model and a method is given to calculate the delay cost for each class. Finally, the proposed method is implemented in the sequencing problems of flights in a terminal area, and results are compared with that of the traditional classification method(TCM). Results show that the new classification model is effective in reducing the expenses of flight delays, thus optimizing the sequences of arrival and departure flights, and improving the efficiency of air traffic control. 展开更多
关键词 air traffic control transitive closure algorithm cost of flight delay classification model
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Wireless location algorithm using digital broadcasting signals based on neural network 被引量:1
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作者 柯炜 吴乐南 殷奎喜 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期394-398,共5页
In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. ... In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. By the learning ability of the NN and the closely approximate unknown function to any degree of desired accuracy,the input-output mapping relationship between coordinates and the measurement data of time of arrival (TOA) and time difference of arrival (TDOA) is established. A real-time learning algorithm based on the extended Kalman filter (EKF) is used to train the multilayer perceptron (MLP) network by treating the linkweights of a network as the states of the nonlinear dynamic system. Since the EKF-based learning algorithm approximately gives the minimum variance estimate of the linkweights,the convergence is improved in comparison with the backwards error propagation (BP) algorithm. Numerical results illustrate thatthe proposedalgorithmcanachieve enhanced accuracy,and the performance ofthe algorithmis betterthanthat of the BP-based NN algorithm and the least squares (LS) algorithm in the NLOS environments. Moreover,this location method does not depend on a particular distribution of the NLOS error and does not need line-of-sight ( LOS ) or NLOS identification. 展开更多
关键词 digital broadcasting signals neural network extended Kalman filter (EKF) backwards error propagation algorithm multilayer perceptron
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Adaptive Fuzzy Neural Control of Dynamic System
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作者 赵保军 韩月秋 毛二可 《Journal of Beijing Institute of Technology》 EI CAS 1999年第2期85-89,共5页
Aim To build an adaptive fuzzy neural controller and simulate it. Methods\ Fuzzy logic and back propagation(BP) algorithm are combined to utilize their advantages while avoiding the disadvantages. Results and Conclus... Aim To build an adaptive fuzzy neural controller and simulate it. Methods\ Fuzzy logic and back propagation(BP) algorithm are combined to utilize their advantages while avoiding the disadvantages. Results and Conclusion\ Simulation results of the third order plant with disturbances and dead times show the validity of the presented controller. The presented controller can control cases that preceding controllers were unable to control. 展开更多
关键词 error back propagation fuzzy logic learning rate nonlinear time varying parameter
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Remote wireless transmission and error recovery of log data
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作者 赵亦朋 李宁 王才志 《Applied Geophysics》 SCIE CSCD 2007年第4期308-312,共5页
Remote transmission of log data is an urgent problem for service companies. Remote transmission technology of log data here refers to both the transmission solution in combination with the CifNet multi-well data manag... Remote transmission of log data is an urgent problem for service companies. Remote transmission technology of log data here refers to both the transmission solution in combination with the CifNet multi-well data management system to automate the transmission, storage, management, and retrieval of log data to reduce turn-over time. It is an applied digital signature technology to implement breakpoint transmission and error recovery and ensure the effectiveness and reliability of log data transmission. 展开更多
关键词 Data transmission LOG CifNet
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A novel method to predict static transmission error for spur gear pair based on accuracy grade 被引量:3
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作者 LIU Chang SHI Wan-kai +1 位作者 Francesca Maria CURÀ Andrea MURA 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第11期3334-3349,共16页
This paper proposes a novel method to predict the spur gear pair’s static transmission error based on the accuracy grade,in which manufacturing errors(MEs),assembly errors(AEs),tooth deflections(TDs)and profile modif... This paper proposes a novel method to predict the spur gear pair’s static transmission error based on the accuracy grade,in which manufacturing errors(MEs),assembly errors(AEs),tooth deflections(TDs)and profile modifications(PMs)are considered.For the prediction,a discrete gear model for generating the error tooth profile based on the ISO accuracy grade is presented.Then,the gear model and a tooth deflection model for calculating the tooth compliance on gear meshing are coupled with the transmission error model to make the prediction by checking the interference status between gear and pinion.The prediction method is validated by comparison with the experimental results from the literature,and a set of cases are simulated to study the effects of MEs,AEs,TDs and PMs on the static transmission error.In addition,the time-varying backlash caused by both MEs and AEs,and the contact ratio under load conditions are also investigated.The results show that the novel method can effectively predict the range of the static transmission error under different accuracy grades.The prediction results can provide references for the selection of gear design parameters and the optimization of transmission performance in the design stage of gear systems. 展开更多
关键词 gear transmission error time-varying backlash prediction method accuracy grade
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Investigation of a Design Modification for Double Helical Gears Reducing Vibration and Noise 被引量:6
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作者 王成 方宗德 贾海涛 《Journal of Marine Science and Application》 2010年第1期81-86,共6页
To reduce vibration and noise and increase transmission efficiency, a three segment method for modifying the pinion profile was proposed. Cutter surface equations were deduced by changing the shape of the cutter-edge,... To reduce vibration and noise and increase transmission efficiency, a three segment method for modifying the pinion profile was proposed. Cutter surface equations were deduced by changing the shape of the cutter-edge, substituting three segment parabolas for the line. The influence of longitudinal tooth modifications on tooth surface load distributions was discussed. Transmission error minimization and uniformity of tooth surface load distribution were chosen as optimization goals and the modified parameters were obtained by applying the complex method. Finally, an experiment comparing the loaded transmission error, vibration, and noise both before and after modifications was carried out. The results indicate that the modified design is reliable. 展开更多
关键词 tooth profile modification tooth longitudinal modification double helical gears loaded transmission error
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Effect of static transmission error on dynamic responses of spiral bevel gears 被引量:4
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作者 唐进元 胡泽华 +1 位作者 吴丽娟 陈思雨 《Journal of Central South University》 SCIE EI CAS 2013年第3期640-647,共8页
The effect of static transmission error on nonlinear dynamic response of the spiral bevel gear system combining with time-varying stiffness and backlash was investigated.Firstly,two different control equations of the ... The effect of static transmission error on nonlinear dynamic response of the spiral bevel gear system combining with time-varying stiffness and backlash was investigated.Firstly,two different control equations of the spiral bevel gear model were adopted,where the static transmission error was expressed in two patterns as predesigned parabolic function and sine function of transmission errors.The dynamic response,bifurcation map,time domain response,phase curve and Poincare map were obtained by applying the explicit Runge-Kutta integration routine with variable-step.A comparative study was carried out and some profound phenomena were detected.The results show that there are many different kinds of tooth rattling phenomena at low speed.With the increase of speed,the system enters into stable motion without any rattling in the region(0.72,1.64),which indicates that the system with predesigned parabolic function of transmission error has preferable capability at high speed. 展开更多
关键词 spiral bevel gear static transmission error dynamic response BIFURCATION
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An improvement to the simulation of phase-change heat-transfer during soil freezing and thawing 被引量:6
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作者 YANG Tao ZHENG Mao-yu 《Mining Science and Technology》 EI CAS 2009年第2期262-268,共7页
A new variable time step method,which is called the backwards calculating time step method,is presented in this paper.It allows numerical simulation of soil freezing and thawing while avoiding "phase change missi... A new variable time step method,which is called the backwards calculating time step method,is presented in this paper.It allows numerical simulation of soil freezing and thawing while avoiding "phase change missing and overflowing".A sensitive heat capacity model is introduced through which the calculation errors are analyzed.Then the equation using the self-adjusted time step is presented and solved using finite differences.Through this equation,the time needed for a space cell to reach the phase change point temperature is calculated.Using this time allows the time step to be adjusted so that errors caused by "phase change missing and overflowing" are successfully eliminated.Above all,the obvious features of this method are an accelerated rate for adjusting the time step and simplifing the computations.An actual example proves that this method can accurately calculate the temperature fields during soil freezing and thawing.It is an improvement over traditional methods and can be widely used on complicated multi-dimensional phase change problems. 展开更多
关键词 backwards calculating time step method phase change missing phase change overflowing
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Performance Analysis of Optical Transmission Based on Seven Cores Fiber 被引量:1
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作者 Hang Zhou Fu Wang +2 位作者 Borui Li Ming Tang Xiangjun Xin 《China Communications》 SCIE CSCD 2016年第9期113-120,共8页
This essay designed a kind of new seven-core fiber with lower crosstalk and loss, and made space division multiplexing transmission experiment based on this seven-core fiber. It is known that crosstalk has the most se... This essay designed a kind of new seven-core fiber with lower crosstalk and loss, and made space division multiplexing transmission experiment based on this seven-core fiber. It is known that crosstalk has the most serious influence in multicore fiber transmission process. Before the experiment, the affecting factors of fiber crosstalk were analyzed through simulation, such as core space, bending radius, and fiber length. Combined with the simulation analysis, the design scheme of multicore fiber with low crosstalk was obtained. Before the fiber design, various factors of influence crosstalk such as the core- to-core distance, bending radius, fiber length and so on. Based on the simulation analysis, conclusion has made on the design scheme of multi-core optimal fiber with low crosstalk. The space division multiplexing and wavelength division multiplexing technology, was adopted to conduct seven-core optical fiber transmission of 58.7kin.The crosstalk of adjacent core was suppressed to as low as 45dB / km, the attenuation of inner core was 0.24dB/ km, the outer cores' 0.32dB/km. Different bit error rate (BER) performances were also studied under different conditions, through reasonably designing the system to reduce the error rate, improve the performance of the system, and realize long distance and large capacity transmission with fiber. 展开更多
关键词 multicore fiber CROSSTALK space division multiplexing
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A New Multi-sensor Data Fusion Algorithm Based on EMD-MMSE 被引量:2
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作者 张琦 阙沛文 +1 位作者 陈天璐 黄晶 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第2期153-158,共6页
A new multi-sensor data fusion algorithm based on EMD-MMSE was proposed.Empirical mode decomposition(EMD)is used to extract the noise of every time series for estimating the variance of the noise.Then minimum mean squ... A new multi-sensor data fusion algorithm based on EMD-MMSE was proposed.Empirical mode decomposition(EMD)is used to extract the noise of every time series for estimating the variance of the noise.Then minimum mean square error(MMSE)estimator is used to calculate the weights of the corresponding series.Finally,the fused signal is the weighted addition of all these series.The experiments in lab testified the efficiency of this method.In addition,the comparison in fusion time and fusion results with existing fusion method based on wavelet and average technique shows the advantage of this method greatly. 展开更多
关键词 data fusion empirical mode decomposition (EMD) minimum mean square error (MMSE) multisensor system
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ReTweeting Analysis and Prediction in Microblogs: An Epidemic Inspired Approach 被引量:11
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作者 王昊 李义萍 +1 位作者 冯卓楠 冯铃 《China Communications》 SCIE CSCD 2013年第3期13-24,共12页
Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the re... Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the retweeting behavior is desirable for a number of tasks such as topic detection, personalized message recommendation, and fake information monitoring and prevention. Interestingly, the propagation of tweets bears some similarity to the spread of infectious diseases. We present a method to model the tweets' spread behavior in microblogs based on the classic Susceptible-Infectious-Susceptible (SIS) epidemic model that was developed in the medical field for the spread of infectious diseases. On the basis of this model, future retweeting trends can be predicted. Our experiments on data obtained from the Chinese micro-blogging website Sina Weibo show that the proposed model has lower predictive error compared to the four commonly used prediction methods. 展开更多
关键词 tweets retweeting PREDICTION SIS epidemic model
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Improved FEC Code Based on Concatenated Code for Optical Transmission Systems 被引量:1
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作者 YUAN Jian-guo JIANG Ze MAO You-ju 《Semiconductor Photonics and Technology》 CAS 2006年第3期211-216,共6页
The improved three novel schemes of the super forward error correction (super-FEC) concatenated codes are proposed after the development trend of long-haul optical transmission systems and the defects of the existin... The improved three novel schemes of the super forward error correction (super-FEC) concatenated codes are proposed after the development trend of long-haul optical transmission systems and the defects of the existing FEC codes have been analyzed. The performance simulation of the Reed-Solomon(RS)+ Bose-Chaudhuri-Hocguenghem(BCH) inner-outer serial concatenated code is implemented and the conceptions of encoding/decoding the parallel-concatenated code are presented. Furthermore, the simulation results for the RS(255,239) +RS(255,239) code and the RS(255,239) +RS(255,223) code show that the two consecutive concatenated codes are a superior coding scheme with such advantages as the better error correction, moderate redundancy and easy realization compared to the classic RS(255,239) code and other codes, and their signal to noise ratio gains are respectively 2-3 dB more than that of the RS(255,239)code at the bit error rate of 1 × 10^-13. Finally, the frame structure of the novel consecutive concatenated code is arranged to lay a firm foundation in designing its hardware. 展开更多
关键词 Optical transmission systems Super forward error correction Concatenated code Frame structure
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Excitation Prediction by Dynamic Transmission Error under Sliding Friction in Helical Gear System 被引量:1
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作者 李文良 王黎钦 常山 《Transactions of Tianjin University》 EI CAS 2013年第6期448-453,共6页
Monte Carlo method was adopted to calculate the meshing error considering the manufacture error and assembly error of the meshing point along the time-varying contact line for helical gear pair. The flexural-torsion-a... Monte Carlo method was adopted to calculate the meshing error considering the manufacture error and assembly error of the meshing point along the time-varying contact line for helical gear pair. The flexural-torsion-axis dynamic model coupled was established under the tooth friction force and solved by the perturbation method to compute real dynamic tooth load. The change laws of the friction force and friction torque were obtained in a meshing period. The transmission error formulation was analyzed to introduce meshing excitations. The maximum dynamic transmission error, the maximum meshing force and the maximum dynamic factor were calculated under different speeds, external loads and damping factors. The conclusions can provide theoretical basis for the gear design especially in tooth profile correction. 展开更多
关键词 helical gear time-varying contact line transmission error dynamic factor
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ENDOPHTHALMITIS INDUCED BY MYCOBACTERIUM TUBERCULOSIS BEING MISDIAGNOSED AS NON-INFECTIOUS UVEITIS 被引量:1
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作者 Han-yi Min Quan-cai Cui 《Chinese Medical Sciences Journal》 CAS CSCD 2005年第4期279-280, ,共2页
ENDOPHTHALMITIS induced by mycobacterium tuberculosis (TB) was rarely reported. Here we present and characterize this typical case to establish the diagnosis.
关键词 ENDOPHTHALMITIS mycobacterium tuberculosis polymerase chain reaction
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Chaotic pulse position modulation ultra-wideband system based on particle filtering 被引量:1
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作者 李辉 Zhang Li 《High Technology Letters》 EI CAS 2013年第1期48-52,共5页
Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error p... Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error propagation.Mismatch of parameters and synchronization error between the receiver and transmitter will arouse high bit error rate.To solve these problems,a demodulation algorithm of CPPM based on particle filtering is proposed.According to the mathematical model of the system,it tracks the real signal by online separation in demodulation.Simulation results show that the proposed method can track the true signal better than the traditional CPPM scheme.What's more,it has good synchronization robustness,reduced error propagation by wrong decision and low bit error rate. 展开更多
关键词 chaotic communications chaotic pulse position modulation (CPPM) particle filtering ULTRA-WIDEBAND
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Attitude Optimization Algorithm of GFIMU with Installation Errors 被引量:2
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作者 曹咏弘 张慧 范锦彪 《Journal of Measurement Science and Instrumentation》 CAS 2011年第2期103-107,共5页
Taking the accelerometer installation errors into consideration, the attitude optimization algorithm of Gyro Free Inertial Meastement Unit (GFIMU) is studied in the high spinning condition in this paper. A ten-accel... Taking the accelerometer installation errors into consideration, the attitude optimization algorithm of Gyro Free Inertial Meastement Unit (GFIMU) is studied in the high spinning condition in this paper. A ten-accelerometer configuration is designed so as to establish a mathematical model to acquire the angular speeds in the case of installation errors. Precision of the algorithm is evaluated by using damping GaussNewton method. A large amotmt of sinmlation results show that ff the accelertlmter's angleinstallation errors main-tain small (〈5°), the errors of attitude angles can be limited within ±1°. Hence, the algorithm has a great applicable value in engineering. 展开更多
关键词 attitude optimization algorithm high spinning ten-ac-elerometer oonfiguration installation error dampingauss-newton method
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