Research On Redundant Technology Of MEMS Inertial Navigation System

MEMS(Micro-Electro-Mechanical System)inertial devices are widely applied in the field of inertial navigation for its small size,low weight and cost,low power consumption,high reliability,wide dynamic range,fast response and convenient installation and so on.And how to make full use of the advantages of MEMS inertial navigation system,at the same time,improve the measurement precision and reliability of system,and make the system have good tolerance to achieve reliability and precision of navigation highly,becoming a hot issue of research scholars,however,taking redundancy technology is a effective method to meet these requirements.We built redundant inertial navigation system based on 3 MEMS-IMUs,and carried out a series of research on the key technologies,the main work is as follows:1.Scheme design and performance analysis of MEMS redundant inertial navigation system.We designed a redundant configuration scheme of inertial navigation system considering of reliability,the number of IMU,redundancy configuration mode,measuring method,the system size,weight,cost and power consumption.2.Constructional process of MEMS inertial navigation system hardware platform.Through the analysis of system demand,constructing the system hardware platform including power supply circuit,clock circuit,program storing circuit,signal acquisition circuit and interface level conversion circuit from the selection of FPGA chip and inertial device.3.The characteristic analysis and calibration of MEMS inertial navigation system.We established reasonable static error mathematics model mainly from the MEMS-IMU characters,and then six-position calibration method was proposed to make system calibration test,and detailed derivation of the formula was presented.At the same time,the method is not general in different redundant configuration schemes,the state and measurement equation of Kalman filter established was to be applied to the identification of error parameter.4.Research of fault diagnosis technology.The fault detection and isolation of redundant inertial navigation system is an important content of the thesis,and three kinds of common fault diagnosis methods were introduced: method of generalized likelihood ratio,singular value decomposition,the combination of parity vectormethod and adaptive filtering,and made simulation experiment separately in conditions of different fault.