Research On High-precision Positioning Of Smart Phone Based On Internal Sensor Information

With the rapid development of smart devices,people pay more and more attention to the quality of services provided by mobile phones and smart wearable devices.In order to provide better services,there is a large demand for location requests in mobile phone applications,but the positioning accuracy provided by smartphones is limited,and even services cannot be provided in some cases with severe occlusion.A feasible solution is to combine the mobile phone’s internal motion sensor for combined navigation to improve the stability of the mobile phone’s positioning.Due to the performance limitations of mobile phone internal sensors,less research involves the combined positioning of mobile phone internal sensors and GNSS.With the explosive development of smart devices in recent years,the demand for mobile phones to achieve high-precision,high-stability navigation and positioning in the consumer market has become more and more intense.Therefore,the realization of high-precision navigation and positioning for smartphones has important market value.The main research work of this paper is as follows:(1)Quality analysis of smartphone GNSS observation data.Comparing the differences between traditional survey receivers and smartphones in terms of the number of visible satellites,dual-frequency signal reception,carrier-to-noise ratio distribution and multipath errors.(2)Noise reduction for smartphone acceleration and angular velocity data.The wavelet noise reduction method is used to process the output acceleration and angular velocity information of the mobile phone,and the influence of the data noise reduction on the combined navigation results of the mobile phone is tested.The results show that the position,velocity and attitude are significantly improved after noise reduction.(3)The PPP(Precise Point Positioning)accuracy of the mobile phone in static and dynamic scenes is verified.The results show that:in the static scene,the RMS values of the mobile phone’s position error in the three directions of east,north and up are 0.30 m,0.60 m and 0.61 m respectively;in the dynamic scene,the position error RMS of the mobile phone in the three directions of east,north and up are 2.02 m,1.96 m,3.95 m respectively.(4)Tested the dead reckoning capability of the built-in sensor of the mobile phone.The results show that:when the GNSS data is interrupted for 10 seconds,the horizontal accuracy can still be maintained within 10 meters;when the data is interrupted for 25 seconds,the elevation accuracy can be maintained within 10 meters.(5)The combined positioning performance assisted by the built-in sensor information of the mobile phone is tested.The combined positioning performance is tested using the measured vehicle data in the urban environment.From the results,by adding the acceleration and angular velocity information of the mobile phone,the positioning stability in the PPP solution process is improved,and the ability to output short-term high-precision positioning results is improved in the case of severe environmental occlusion.In summary,this paper is based on the mobile phone PPP positioning technology,adds data noise reduction processing,and realizes the mobile phone integrated navigation function assisted by the internal sensor information.The method can weaken the influence of the external environment on the positioning accuracy of the mobile phone,improve the stability of the positioning accuracy of the mobile phone,and enhance the ability to output results in complex scenes in urban areas.The research results can provide theoretical support and algorithm basis for many fields such as mass-market navigation applications,low-cost integrated navigation,augmented reality,and autonomous driving.