Position estimation using GPS and dead reckoning

A method for estimating vehicle position by using GPS, a fiber optic gyro and encoders is proposed. The position estimator in this method is the optimal in the sense of least variance. The production of an experimental autonomous mower and the evaluation of the performance of the method are reported. The relation between the performance and the accuracy of GPS is discussed in terms of the parallelism of the lines, the uniformity of the spaces between the lines, and the straightness of the lines.