Research On Key Technology Of Pedestrian Navigation Based On MIMU

Pedestrian navigation is an important branch in the field of navigation,which plays an important role in pedestrian positioning information service,greatly improving people's work and life efficiency,showing a broad application prospect in the military and civil fields.In this paper,the key technologies of pedestrian navigation based on MIMU is studied.The main research contents are as follows:(1)Aiming at the alignment of micro inertial devices,the initial alignment algorithm based on magnetometer is studied.The calibration algorithm of magnetometer based on least square fitting is realized.On this basis,the alignment algorithm of magnetometer assisted is studied,and the feasibility of the algorithm is verified by simulation and experiment.(2)Aiming at the problem of rapid increase of the solution error of the navigation system based on MIMU,zero velocity update algorithm based on gait characteristics is studied.A zerospeed detection algorithm based on K-NN detection was improved and compared with the zerospeed interval detection algorithm based on multiple constraints.At the same time,the correction effect of the zero-speed repair algorithm is verified.The experimental results show that the zero velocity update algorithm has a good inhibition effect on the accumulation of navigation errors.(3)Aiming at the heading drift of the pedestrian navigation system,the heading correction algorithm is studied.A correction algorithm based on the lateral restraint of foot movement is proposed.The experimental result shows that the algorithm has a good correction effect on the heading error in the calculation of pedestrian navigation.(4)Aiming at the problem of altitude error in the navigation algorithm,a height correction algorithm based on motion scene feature assistance is studied.On the basis of simple judgment of the sports scene,the fixed step height is used to constrain the height difference in the adjacent zero-speed interval,thereby correcting the height.The experimental results show that through the altitude correction algorithm,the altitude error in the navigation solution has been effectively corrected.(5)Aiming at the data fusion problem of the navigation system,the data fusion method based on Kalman filtering and factor graph optimization is compared.The simulation results show that the data fusion method based on factor graph optimization is better than that based on Kalman filter.(6)To deal with the problem that pedestrian foot motion is complex and not conducive to modeling and simulation,a simplified simulation scheme of pedestrian foot trajectory is designed based on the analysis of pedestrian gait cycle.This scheme divides a complete gait cycle into five phases: foot lift,steering,swing,fall and stand.By controlling acceleration and angular velocity,the simulation of foot position and posture in the gait cycle is realized.And the pedestrian navigation algorithms assisted by ZUPT is used to verify the motion simulation data that integrated walking on flat ground,going upstairs and going downstairs.The result shows that the scheme can be used to simulate the foot trajectory of pedestrians,which provides a simple and effective method for the research of pedestrian navigation.(7)The pedestrian navigation method based on MIMU is studied by experiments.The experimental results show that the proposed method can meet the needs of pedestrian navigation and positioning.