Abstract: An indoor positioning system based on MEMS inertial measurement unit was presented in this paper.In this system,the position and direction of pedestrians on a plane (zero slope) are obtained by using the sensors to the waist and knees of the human body.The proposed algorithm can execute reset calculation to the moving steps of pedestrians with wearing knee gyroscope so as to eliminate the error of angular displacement, and can execute resetcontinuous recko-ning for the angular rate obtained by testing gyroscope on the waist so as to get moving direction.The results show that,in a plane,the average trajectory error of the total distance of 62.32 meters is 0.1935 meters and the standard absolute deviation is 0.0512 meters.

Key words: Inertial sensor,Gyroscope,Pedestrian navigation,Dead reckoning