Application of Oversampled A/D Converter in Low-cost Strapdown Inertial Navigation System

Abstract

In the strapdown inertial navigation system (SINS) the inertial sensors mounted directly on the vehicle, have large scales inputs. Even in the low-cost SINS the gyroscopes have over 19 bits scales inputs. Conventional A/D converters only have 12~14 bits, can not meet the need. The oversampled A/D converter can reduce the quantization errors and improve the scales to fit for the low-cost SINS. The effect of oversampling was analyzed, not only in reducing quantization errors and signal noise, but also in improving integral filtering precision. The DPS+FPGA structure was used to collect the six signals of gyros and accelerometers in high speed and parallel mode. The experiment results show that, the low-cost SINS using the oversampled A/D converter have good performance in common integrate navigation applications.