Design Of Wearable Positioning Application Based On MEMS-GNSS

Social and Economy have been developing quickly,people’s living standards have generally improved,and their awareness of health has also been continuously strengthened.In order to prevent entering a sub-health state,more and more people choose to participate in outdoor sports.With the continuous update of smart wearable devices,the diversification of device types brings people different experience.Usually contains step counting function,sleep monitoring,etc.For users who are in sport mode,the wearable device can achieve positioning of the user’s movement trajectory and discrimination of the user’s movement mode.However,based on user’s actual feedback,the wearable device failed to meet the user’s expected requirements.Various disadvantages such as insufficient information collected by the equipment,unstable positioning effect,low accuracy of human body gesture recognition,data analysis failed to reflect in real time,and large power consumption are exposed to people.In view of the existing problems of wearable devices,this paper proposes a new type of wearable device application solution-GNSS-assisted MEMS fusion positioning solution,and does the following for this:(1)Design the software and hardware of the data collection system.The hardware platform selects the low-power n RF52832 Bluetooth chip as the MCU to control the communication of each module;the 9-axis MEMS inertial sensor BMX160 is used to collect raw data such as acceleration,angular velocity and surrounding magnetic field strength at the wrist of the human body.Identify and determine which movement mode the human body is,and deduce and position the human body;using the GNSS module N305 to correct the accumulated deviation in the MEMS derivation and positioning;using the Flash module MT25QL512 to store the raw data collected by the MEMS sensor and the GNSS module in real time.Design a software solution for the data collection process.The mobile’s APP communicates with the hardware platform via Bluetooth,and schedules various tasks within the data collection system by entering custom-set instructions.(2)Perform performance evaluation on the positioning algorithm.The algorithm is mainly to realize the positioning function for different movement modes of the human body in different scenarios,and achieve a certain accuracy under the requirement of low power consumption.The algorithm uses GNSS position observation as the measurement benchmark,combined with the nature of the algorithm itself,and evaluates the performance of the algorithm itself through experiments and simulations.By collecting the raw data of MEMS and GNSS in running mode,exporting to PC,and simulating with Matlab,analyzing the simulation results,it can be obtained that adding GNSS position observation to correct positioning deviation can achieve very good results.(3)Specific implementation of wearable device application solutions.By analyzing the shortcomings of the existing wearable device application solutions in the market,in order to achieve real-time monitoring of human body motion status and achieve better positioning results,a GNSS-assisted MEMS fusion positioning application solution has been designed in detail,combining the most obvious features of daily human movement(walking,running,riding)mode,through practical tests to verify the feasibility of the program and the actual positioning effect.The experimental results show that the GNSS-assisted MEMS fusion positioning application scheme can converge the trajectory error to a certain extent,and achieve a good positioning effect.