Design Of Low-power Intelligent Parking Lock System Based On Bluetooth

As car ownership is not proportional to the parking growth rate in recent years,parking space vying has become an intractable social issue. Under such circumstance, the parking lock following provides a good solution to this social problem. Considering inconvenience of the traditional manual operation parking lock, high power consumption and unsafety of the current intelligent parking lock, the thesis aims to design an induction intelligent parking lock by using the BLE technology.The whole set of intelligent parking lock system is mainly composed of two parts:BLE4.0 electronic tag and parking lock control module. According to the specific requirements of this project, the system is designed with the BLE technology as the core,and the study, design and implementation of the complete set of the hardware circuit and the corresponding software are accomplished. Based on the BLE processor nRF51822,the hardware circuit of the whole system integrating drive, geomagnetic parking detection,overcurrent protection, alarm and other peripheral hardware circuit, is characterized by stable performance, high anti-interference ability and so on.With the geomagnetic detection technology introduced into the design of parking space detection module, a series of program designs such as the acquisition and processing of geomagnetic signals, the locomotive position detection and the resetting of the reference magnetic field value are accomplished with the help of the anisotropic magneto resistive sensor HMC5883L, and the vehicle detection algorithms of Knaian and Coleri are improved to meet the needs of this subject. Using Bluetooth in the wireless transmission, this project encrypts the Bluetooth communication link in the way in which paring is triggered while connecting and designs the proprietary data protocol format for information exchange. Comparing with the previous infrared remote control and RFID wireless transmission, Bluetooth communication chain road not only is securer, but also lays the foundation for parking lock network and remote control in the future. In addition,this project, taking advantage of the adjustable transmit power of the nRF51822, designs two work modes: normal work mode and low power consumption work mode which switch with each other to minimize system power consumption. Finally, according to the system function, the small while(1) system of the intelligent parking lock is designed,which coordinates each working module to operate stably.After completing the soldering of the circuit board and the programing, debugging of the software according to the hardware and software schemes, the intelligent parking lock system is tested and analyzed from the aspects of wireless communication distance,correct rate of parking detection, machine function and power consumption. The results show that the remote control distance, parking detection function and power consumption of the intelligent parking lock designed in this project meet the performance index.