Research Of Accelerometer's Information Processing Technology In Sins

Accelerometer is an important inertial sensitive component in inertial navigation system (INS). Its output is proportional to vehicle's acceleration. The accuracy of accelerometer's output has a direct impact on INS's accuracy. And the output of high-precision quartz-flex accelerometer is analog current. This dissertation focused on the technology of accelerometer's information processing in strapdown inertial navigation system (SINS). Current signal is first changed into frequency signal so that it can be processed by navigation computer. What's more, the original precision should not be decreased by the precision of converted signal.To achieve the high-precision requirement of a accelerometer's information processing in SINS, a new method of processing accelerometer's output by using I/F conversion technology is proposed. Besides, the principle, constitution and methods of improving the precision of SINS are studied.Firstly, the principle and acquisition circuit of quartz-flex accelerometer are introduced. The requirements of INS on accelerometer are analyzed and then the main performance indexes of acquisition circuit are given. In order to achieve those requirements, the design of acquisition circuit is studied as well as the choice of key components which restricts the performance of acquisition circuit. The framework of acquisition circuit is designed after the principle of accelerometer's acquisition circuit is analyzed. Specific parameters of sample resistances, operation amplifier, V/F converter and other important components are investigated then. Components which meet the performance requirements are selected by comparing the performance of different components. Then, the circuit is designed and debugged. So as to guarantee the accuracy of acquisition circuit, many factors that have impacts on the circuit are deeply studied and appropriate measures are taken. After hardware circuit is manufactured and debugged, information processing software is designed, including FPGA program and DSP program. At last, the system performance is tested and the results show that the system meets the requirements of assumed performance indexes.With the advantages of strong anti-interference ability, being convenient for distant transmission, flexible selection of signal frequency, high performance-price ratio and so on, V/F converter is chosen in the hardware circuit of accelerometer's information processing technology. Besides, it can meet the demands of accelerometer's data acquisition in INS.