Pose estimation of a vehicle on rough terrain by using the Sun direction

We are interested in the pose measurement of a rover using Sun direction while it moves on a rough terrain. First, we derived a sensor fusion formula to estimate rover pose from a three-dimensional gyro sensor, Sun direction sensor and gravity sensor. We developed a prototype of a Sun direction sensor, which can achieve fast and precise measurement even when rover pose changes dynamically. This sensor consists of a two-DOF mechanically rotational sensor base and an optical position sensing device. This sensor keeps its sensor head directed towards the Sun by controlling the two-DOF sensor base. We constructed a test system which consists of a Sun direction sensor, three gyro sensors, and an accelerometer on our mobile robot platform Yamabico AQURO.