Design and calibration of an inertial sensor system for precise vehicle navigation

This paper presents a developed inertial navigation multi sensor node, along with an efficient calibration technique to improve the accuracy of the measurement acquired from a set of inertial sensors and magnetic encoder. The implemented node consists of a high resolution magnetic compass sensor, a distance sensor works as magnetic encoder, an accelerometer and a gyroscope to detect the linear and angular acceleration. The node is installed on an autonomous mobile vehicle as part of an inertial system to find the real-time position and direction of the vehicle. RF wireless transceivers and a microcontroller are installed to process and to send the measured data wireless to a central processing unit for more processing and evaluation. The whole hardware and software design of the system is presented. Accuracy and calibrations issues are also discussed. Errors caused by bias, scale factors and nonlinearities in the sensor readings which cause accumulations in navigation errors with time are considered.