Research On Smart Chip Positioning Technology Based On Ultra-wideband

Recent years,with the improvement of information technology,people's demand for location-based services is rising,which promotes the continuous development of location technology.Ultra Wide Band(UWB)technology is a sub-nanosecond ultra-narrow pulse wireless communication technology.Compared with other positioning technologies,UWB has the advantages of high time resolution,good anti-multipath effect,high security,strong penetration and simple hardware structure.Thus UWB is very suitable for indoor high-precision ranging and positioning,and has broad application prospects.For complex indoor environment,this paper introduces several indoor positioning technologies such as geomagnetic,Wi-Fi,infrared,Bluetooth,ultrasound,RFID,UWB.After that,the advantages and disadvantages are analyzed and compared among these technologies.Numerous positioning technologies have produced many positioning principles,such as RSSI positioning,AOA positioning,TOA positioning,TDOA positioning.For TOA localization,the commonly used localization algorithms,such as Taylor algorithm,Chan algorithm,least square method and trilateral localization algorithm,are introduced.This paper mainly studies the location algorithm of UWB technology.A trilateral algorithm based on intersection weighting is proposed.The advantages of the algorithm are illustrated by simulation with MATLAB.At the same time,the positioning system is designed and built,and the ranging and positioning experiments are carried out respectively.The main purpose of ranging experiment is to get the error compensation curve and make the ranging value more accurate.In the range of 0-9 m,ranging is carried out every 20 cm.The average value and standard deviation of ranging results are counted,the error curve is made and fitted,and the fitting error curve is used as compensation to correct the error.The average error after compensation is 0.8cm and the standard deviation is 1.3 cm.In the mean time,the influence of different material occlusion Tag on ranging accuracy is also studied in NLOS case,which is to select the appropriate material as the chip shell.The results show that the influence of cartons and plastic boxes on ranging accuracy is negligible,while the influence of metals on ranging accuracy is obvious.Location experiment site and ranging experiment are located in the same place.Three anchors are arranged on the same horizontal plane,and the card table is in the triangle area formed by three anchors.Random selection of the points on the card table is used for positioning experiment.The positioning results are recorded,and the errors with the actual position are calculated to verify the positioning effect of the positioning system.The positioning results show that the average positioning error is 4.2 cm and the standard deviation of the error is 2.0 cm.In conclusion,the hardware designed in this paper is stable and reliable,and the ranging error is small and stable.The positioning effect of the positioning system is ideal.