Real-time position estimation of mobile platform in indoor and GPS-denied environments

Abstract

Indoor mobile platform localization plays an important role in autonomous navigation. This paper describes the development of a mobile platform localization approach based on wheel odometry and inertial measurement unit (IMU) sensors throughout the travel path. The correctness of the estimated position determines the accuracy with which the trajectory can be predicted. A number of experiments were carried out to understand the variation in IMU data with the sensor placed at different distances along the axis of the robot and its effect on heading angle of the mobile platform and the resulting trajectory. In the east and west directions, as distance between IMU and midpoint of axis joining left and right dc motors becomes greater than 8 cm, effect of positioning of dc motor starts reducing on heading angle θ and goes down to zero at distance greater than 12 cm. In north and south directions, as distance between IMU and midpoint of axis joining left and right dc motors becomes greater than 2 cm, effect of positioning of dc motor completely vanishes. The paper details the experiments carried out, results obtained, and discusses measures to improve the localization accuracy.