Enhancing the accuracy of strapdown inertial navigation systems consisting of MEMS sensors

Nowadays, aided Inertial Navigation System (INS) is implemented to increase accuracy of navigation. However, in some cases, it is not possible to use integrated methods, or if the link to the navigational aiding system is lost, INS should be able to operate standalone with the required accuracy, until the link is accessible again. Therefore, the accuracy of INS should be enhanced to the highest extent. Some of the most significant factors in reducing the accuracy of INS are: measurement noise, inertial sensors error, misalignment, and sensor installation error on the body of vehicle. In this article, methods of compensating these factors are presented to increase the accuracy of strapdown inertial navigation systems consisting of MEMS sensors. First, the effect of noise cancelation on accuracy of INS has been studied in practice. Then, a method is presented for calibration of MEMS accelerometers and gyroscopes. In addition, compensation of installation error and sensor misalignment with body-frame coordinate is studied. Efficiency of the compensating methods has been evaluated and reported in practical implementations.