. . . . "[0025] Here, Pn, Vn, Ab, G, and Wb are a 3???1 matrix, respectively, G is a matrix of [0,0, g]T, and dPn, dVn, and d?? denotes differentiations of Pn, Vn, and ?? with respect to time, respectively. [0026] Accordingly, the acceleration information and the angular velocity information for the body frame outputted from the acceleration sensors and the angular velocity sensors respectively are compute" .