POSITION AND ORIENTATION ESTIMATIONS OF A MAGNETICALLY GUIDED-ARTICULATED VEHICLE

초록

For the automated guidance control of a magnetically guided all-wheel steered vehicle, it is necessary to have information about position and orientation of the vehicle, and deviations from the reference path in real time. The magnet reference system considered here consists of three magnetic sensors on the vehicle and magnetic markers which are non-equidistantly buried in the road. This paper presents an observer to estimate such position and orientation at the center of gravity of the vehicle. In this algorithm, based on the simple kinematic model of vehicle, the data of wheel velocity, steering angle, and the discrete measurements of magnets are used. Since this algorithm requires the exact values of initial state, we have also proposed an algorithm of determining the initial position and orientation from the 16 successive magnet pole data, which is given by the magnet measurement system (MMS). The algorithm is capable of continuing to estimate for the case that the magnet sensors fail to measure up to three magnets. It is shown through experimental data that the proposed algorithm works well within permissible error ranges.