Research On Multi-gait 3D Indoor Positioning Technology Based On Inertial Sensors

With the rapid economic development and the continuous advancement of urbanization,more and more large-scale construction venues have brought many conveniences to people's lives,but also buried many hidden safety hazards.How to help people get out of dangerous buildings in the event of an accident,or to assist firefighters to obtain their own location information during rescue and disaster relief in indoor buildings has become an urgent problem to be solved.At present,most of the indoor positioning solutions on the market are aimed at 2D positioning,that is,positioning on the same plane is completed,which cannot effectively meet the above indoor positioning requirements.3D positioning solutions often need to be used in conjunction with external signals provided by infrastructure,such as Wi-Fi,Zigbee,and radio frequency signals.They cannot be used in emergencies.Therefore,inertial sensor-based indoor navigation and positioning methods It becomes the first choice.The movement of pedestrians indoors is often random,and changes in gait will cause distortion of acceleration data collected by ordinary inertial navigation and positioning,which will affect positioning accuracy.Not only that,because of the influence of accelerometer accumulative errors,inertial sensors generally differ greatly from the actual position in the calculation of elevation.In response to the above-mentioned problems,this paper conducts the following research:(1)For pedestrians moving indoors with multiple gaits,resulting in acceleration changes,the ordinary zero-speed correction cannot accurately detect the zero-speed time of the asynchronous state.A multi-gait recognition algorithm is proposed: the improved K-means clustering method is used to cluster the gait data to identify different gaits.(2)For different gaits that have been identified,by analyzing the corresponding inertial data characteristics,using different zero-speed detection methods to obtain the zero-speed time of the current motion state,so that the system can correctly complete the zero-speed correction,thereby improving the positioning accuracy.(3)Aiming at the problem that the accuracy of the accelerometer is too low,a small barometer is installed in the positioning system to obtain real-time air pressure data.The altitude error parameters are obtained from the altitude calculated by the air pressure data and the altitude calculated by the acceleration data,and In the positioning system,the height information is corrected by the height error to improve the positioning accuracy of the height.Finally,this paper conducts a series of related experiments through the designed data acquisition and storage system to verify the above algorithm.The system can avoid the problem that researchers have to maintain the connection between the inertial device and the laptop to realize the data transmission and cause the deformation of the action during the experiment,and thus cannot obtain the accurate experimental data.Experimental results show that the improved method proposed in this paper effectively enhances the adaptability of the positioning system and has a higher positioning accuracy.It has a good application prospect for indoor positioning requirements including disaster rescue.