Design And Implementation Of Dual-mode Parking Space Detector Applied To NB-IoT

The difficulty of parking has become a major problem in urban traffic management.In the short period of time,it is difficult to construct a large number of parking spaces.How to effectively use existing parking space resources has become the key.With the development of Internet of Things technology,intelligent parking space detection systems are widely used to detect parking space status and improve parking efficiency.This paper presents a scheme that uses NB-IoT technology to communicate and combines geomagnetic sensors and millimeter wave radar to detect parking spaces.The research content of the paper includes:(1)Detection of parking spaces using geomagnetic sensors.According to the principle of the geomagnetic sensor,the geomagnetic sensor is used to collect geomagnetic data,and a geomagnetic detection algorithm is designed to determine whether there is a car on the parking space according to the change of geomagnetic information on the parking space.Complete the hardware and software design of geomagnetic detection.(2)Millimeter wave radar detects parking spaces.Based on the principle of millimeter wave radar detecting cars,FFT processing is performed on the difference frequency signal data output by the millimeter wave radar to extract useful spectrum features in the difference frequency signals,and judge whether there is a car in the parking space according to the spectrum features.Complete the software and hardware design of millimeter wave radar detection.(3)The combination of geomagnetic sensor and millimeter wave radar.Geomagnetic detection is easily affected and interfered by the surrounding environment.After working for a long time,the surrounding magnetic field may drift,resulting in a decrease in the accuracy of geomagnetic detection.The millimeter wave radar can detect whether there is a car above the parking space.Combining geomagnetism and millimeter wave radar,an algorithm combining geomagnetism and millimeter wave radar is designed and implemented in software.A large number of actual tests are carried out,and the test accuracy meets the design requirements.(4)Application and optimization of NB-IoT technology.Complete the hardware design of the NB communication module.Since the application of NB-IoT is not yet mature and the packet loss rate is high in large-scale concurrency,this paper optimizes the packet sending logic of NB-IoT communication and implements it with software,which effectively reduces the packet loss rate.After actual testing,the packet loss rate is less than 1%.This article combines the latest NB-IoT technology with dual-mode parking space detection technology.It uses NB-IoT technology to transmit parking space status information to the cloud platform.The cloud platform pushes the parking space information to the parking space management platform.It can significantly improve the management efficiency of the parking lot,which is also of great significance to alleviate the difficulty of parking in the city.