Research On Pedestrian Dead Reckoning By Motion Sensor

Pedestrian dead reckoning by motion sensors, one of basic positioning sc hemes for wearable devices, plays a key role in pedestrian navigation. With si gnal processing of three parts---pace probing, step length estimation, direction estimation--- accumulative error of navigation could be reduced to a low level and high-accuracy could be reached. The main contents were as follows:1) Regarded walk as a coordinate combination of periodic movement from each body parts, it could be indicated that spine wave, the signal from spine, with the same period of stride, had a more stable vertical axis of forward direction than confirmed axis and error rate below 5% could be grasped by spine wave extracted by blind source separate.2) Vibrate signal of unknown point would be indicated by known one and structural property on one vibrator in analysis of reaction system. Restore operators of waist-shoulder system and waist-leg system were fitted by the steady-state response of single degree of freedom and the steady-state response of multi-degree of freedom. Distant entertainment shows that restored signal had a similar accuracy in step length with signal from waist, which ranged from 1 to 4 meters.3) 12-attitude calibration was applied to calibrate electronic compass. Direction experiment showed that angle of calibrated signal was more uniformed and error of direction was reduced. The absolute error between the end points from PDR and AGPS was 5 meters, which was accumulated by 256 meter-long path.