A Design Of Trajectory Measurement System Based On MEMS Sensor

With the general demand for location-based services increasing gradually,measurement of trajectory becomes a hot topic of research.Researchers have proposed various methods,and with characteristics like little external equipment,independent,good performance,high integration,simple structure,and low power consumption,the trajectory measurement system based on MEMS sensor has been widely applied in the military,civil,scientific research and other fields.Firstly,this paper introduces the background and significance of the research,and describes the current situation of domestic and foreign researches and the existing methods of measurement.Study the law of pedestrian movement and summarize gait features such as the stride length,stride frequency and so on.Build acceleration model of pace,expound existing methods of trajectory estimation and propose a measurement scheme that is based on the principle of pedometer.Secondly design a hardware system according to the overall framework of the measurement system,select MPU9255 and barometer BMP180 as the measurement sensor while STM32F103 as the microcontroller and complete the design of peripheral circuit.The data acquisition task is described in detail,the sensor measurement data is observed.Then,analyze the characteristics of the data and set the error model as well.Process the data with a proper filter.Thirdly,according to the functional characteristics,divide the whole system into three units:step counting unit,the heading measurement unit and height measurement unit.Design corresponding algorithm for each measurement unit.Finally,the data is sent to the host computer and the host computer software is written in Matlab,which is used for software debugging and off-line simulation.Observe the measurement results of each unit,draw the curve of the pedestrian movement,and analyze the error of the experiment.In this study,hardware and software design of the trajectory measurement is finished,and the experiment results are analyzed through the data acquisition and simulation.The experimental result shows that the measurement system can track the trajectory of pedestrians,and the position error is relatively low,which proves that the measurement system is feasible.