Improving odometry accuracy for car-like vehicles by using tire radii measurements

Odometry is the most widely used method for determining the momentary position of a mobile robot. In most practical applications, odometry provides easily accessible real time positioning information in-between periodic absolute position measurements. Odometry errors are caused by two dominant error sources in vehicles: systematic errors and nonsystematic errors. Systematic errors stay almost constant over prolonged periods of time and can be calibrated. In most case of mobile robot, unequal wheel diameters are systematic errors. But, they are not systematic errors in case of flexible tires like passenger car case. Radii of flexible tires are always varied by road conditions, rolling of vehicle and etc. So, it is important to measure the variations of tire radii for accurate positioning in odometry navigation of car-like vehicles. The method for measurement of tire radii is described and experimental results are presented in this paper.