Implementation and evaluation of an INS system using a three degrees of freedom MEMS accelerometer

Abstract

Position determination is one the most important aspects of navigation for an autonomous vehicle and can be accomplished through a variety of methods. Advances in Global Positioning System (GPS) technology, improved accuracy by a Wide Area Augmentation System (WAAS), wider coverage, easy integration and low cost, make GPS the most preferable alternative for the navigation of autonomous vehicles. However, an autonomous vehicle must be able to navigate and determine its position on earth without external navigation aids such as GPS, Loran and Transit. A method of inertial navigation, called dead reckoning, where the robot calculates its position from a known reference position through using laser range finders, gyros, shaft encoders and accelerometers, becomes more important for navigation with no external aids. This thesis examines the navigation ability for robots using a three degree of freedom accelerometer, which can sense the instantaneous accelerations in three dimensions. Tests and results of the accelerometer as an inertial system for a mobile robot are implemented in 1-D and 2-D. The results demonstrated that Crossbow MEMS accelerometer can be used for a distance of 10 meters for mobile robot navigation with different levels of errors according to the path followed in 2-D.