Effects of Accelerometer Signal Processing Errors on Inertial Navigation Systems

Sung, Chang-Ky; Lee, Tae-Gyoo; Lee, Jung-Shin; Park, Jai-Yong

Journal of the Korea Institute of Military Science and Technology 2006;9(4):71-80.

Chang-Ky Sung, Tae-Gyoo Lee, Jung-Shin Lee, Jai-Yong Park

가속도계 신호 처리 오차의 관성항법장치 영향 분석

성창기, 이태규, 이정신, 박재용

국방과학연구소

Abstract

Strapdown Inertial navigation systems consist of an inertial sensor assembly(ISA), electronic modules to process sensor data, and a navigation computer to calculate attitude, velocity and position. In the ISA, most gryoscopes such as RLGs and FOGs, have digital output, but typical accelerometers use current as an analog output. For a high precision inertial navigation system, sufficient stability and resolution of the accelerometer board converting the analog accelerometer output into digital data needs to be guaranteed. To achieve this precision, the asymmetric error and A/D reset scale error of the accelerometer board must be properly compensated. If the relation between the acceleration error and the errors of boards are exactly known, the compensation and estimation techniques for the errors may be well developed. However, the A/D Reset scale error consists of a pulse-train type term with a period inversely proportional to an input acceleration additional to a proportional term, which makes it difficult to estimate. In this paper, the effects on the acceleration output for auto-pilot situations and the effects of A/D reset scale errors during horizontal alignment are qualitatively analyzed. The result can be applied to the development of the real-time compensation technique for A/D reset scale error and the derivation of the design parameters for accelerometer board.

Key Words: SDINS, Accelerometer Board, AD Reset Scale Error, Error Analysis