Design And Research Of Portable Pedestrian Equipment Based On Micro Sensor Integrated Navigation

Currently,the whole society think highly of the position for individual,and the combination of inertial navigation systems(INS)and Global Positioning System(GPS)is a good way to achieve the personal precise positioning under the complicate environment.The traditional GPS/INS integrated navigation,which is all most used for large carriers,can not be portable for personal navigation.However,the appearance of MEMS sensor makes it possible that the GPS/INS integrated navigation system can be used for personal navigation.GPS and INS have shortcomings respectly.On the one hand,GPS is susceptible to environmental factors,and the positioning information can not be provided when the GPS signal is unlock.On the other hand,the inertia device error will lead to the navigation error accumulated over time.Improving the positioning accuracy and realizing indoor and outdoor seamless positioning become the difficulties of the subject.At last,the key technology as well as the design scheme of hardware and software in the portable personal navigation system are researched intensively.Firstly,according to the market requirements for personal navigation equipment,the design scheme of the portable integrated navigation equipment is formulated.Based on the principle of small size,low power consumption and rich function,the system takes the micro sensors and a GPS receiver as the main data acquisition unit,regards the STM32 as the core processor.The author code the ARM bottom driver program to read and process system data,and the host machine interface is developed to display and storage the real-time data of the portable personal equipment.Secondly,the installation error,the scale factor error and the zero error in MEMS gyro and magnetometer will affect the navigation accuracy,the wavelet is proposed to deal with the noise in MEMS sensors.After that,the eight position method and the quick calibration method are used to verify the parameters in the models respectively,the experiment show that the designed error models can effectively reduce the measurement error of MEMS gyroscope and MEMS magnetometer.An algorithm based on the combination of magnetometer and INS has been designed to reduce the cumulative error in heading calculation by gyroscope alone.Lastly,considering the advantages and disadvantages of INS and GPS,the pedestrian information calculated by EKF and the information of GPS are taken as the observation vector of the Unscented Kalman Filter.The UKF can improve the accuracy of navigation and realize the seamless positioning between indoor and outdoor.The indoor experiments and outdoor individuals carrying experiments show that: in the static condition,the measurement error of the heading angle is less than 2 degrees.In the dynamic condition,the measurement error of the heading angle is less than 3 degrees.And the compliance rate of seamless positioning algorithm achieve 80% based on 15‰ error under the continuous environment of indoor and outdoor.