The Research And Implementation Of Indoor Navigation Based On Dead Reckoning

With the development of science and technology,large-scale buildings are emerging in an endless stream,and people's demand for indoor navigation based on dead reckoning are also increasing.However,the structure of buildings cuts off the GPS and other satellite positioning signals,resulting in this technology cannot be used for indoor navigation.So based on various types of wireless signals,inertial navigation,geomagnetic navigation and other technologies have become a hot research issue today.This paper mainly focuses on the dead reckoning module,uses geomagnetic navigation technology to assist the traditional inertial navigation method to realize the calculation of indoor human trajectory,and achieves the system on the basis of STM32 microcontroller.High measurement accuracy sensor is the basis of indoor navigation system,however,the sensor exists measurement error because of the limitation of manufacturing process and environmental factors,largely affecting the performance of the geomagnetic navigation.The ellipsoid model is established in this paper,and ellipsoid fitting method is used to modify magnetic sensors.For the error factors of gyroscope and accelerometer,in this paper the simple static error calibration method was used to compensate the error.The simulation show that the error calibration method could effectively improve the measurement precision of the sensor.Interior structure and electronic equipment is of large disturbance to geomagnetism.In order to make geomagnetic sensors measure more accurate data,in this paper,we discussed the method that all interferences were equivalent to an interference source,and through itera ting magnetic angle to get the exact geomagnetic vector.The simulation show that this method could effectively remove indoor environment's influence on the magnetic.Geomagnetic matching algorithm is a key technology of indoor geomagnetic navigation.Therefore,in this paper we analysis the geomagnetic matching method based on Hausdorff distance.It doesn't emphasize the matching relation point to point,breaking traditional thinking of geomagnetic matching,and had lower complexity compared with the traditio nal algorithm.Simulation show that compared with traditional geomagnetic matching algorithm,the geomagnetic matching algorithm based on Hausdorff distance presented the stronger ability of anti-interference and fault tolerance.In the traditional inertial navigation system based on dead reckoning,the system can't be modified errors which have already been made.So traditional inertial navigation system appears easily going wrong room and going through the wall and other wrong paths indoor.In order to solve the above problems,in this paper we put forward an indoor navigation method based on Viterbi algorithm.Establishing the indoor digital geomagnetic map,by using the Viterbi algorithm characteristics we improve error correction to output path,eliminating the interference of t he wrong path.Simulation show that this method greatly increased the success rate of going into the correct room,improving indoor navigation performance.