摘要：In order to solve the problems of garage expand, video based searching costs high, ultrasonic detector based searching cannot achieve. This paper presents a vehicle trajectory tracking algorithm based on ultrasonic waveform recording. Parking management system can determine the parking position through the ultrasonic detector, so as to achieve vehicle reverse lookup. The system first uses the vehicle license plate recognition system to obtain the vehicle information, and sets the ultrasonic detector at the intersection to perceive the detection time and waveform recording signal. Firstly according to the time series determine the direction of the vehicle at the intersection. Then via the ultrasonic wave curve of two directions at the intersection to Identify the vehicle profile and determine the turning direction. Finally, the car's parking position is tracked through the parking space detector. This paper developed the WeChat public number for vehicle reverse lookup and payment. The user concerned to find car only need to enter the license plate number and can pay online fare. The system has been tested to be stable and reliable, which is a feasible solution to realize vehicle reverse searching at low cost.
