Smart Parking Lot License Plate Recognition Technology System Solution

The system automatically identifies the number and license plate features of vehicles entering the parking lot, verifies the legal identity of the user, automatically compares the blacklist database, automatically alarms, and can monitor and manage the entire parking lot, including entrance and exit management, internal management, collection, storage of data and system working status, so that administrators can monitor, maintain, count, query and print reports, etc. Vehicles entering and leaving the parking lot are completely under the monitoring of the system, making the parking lot's entry and exit, charging, anti-theft, and parking space management fully intelligent and convenient, fast, safe and reliable.

1 Overview

In modern parking lot management, various aspects of management are involved, among which vehicle management is an important aspect. Especially for special parking lots and large yards, it is required to strictly manage various vehicles in real time, strictly monitor their entry and exit time, and register and identify various vehicles. If they are internal vehicles, they will be released normally. In order to improve this management mode that is not commensurate with modern parking lots and large yards, it is necessary to realize the automation and intelligence of parking lot security work as soon as possible, and manage it in the form of computer network, so as to effectively and accurately monitor and manage all vehicles at the entrance and exit. The system is required to provide corresponding application software to achieve efficient and intelligent camp management.

2 System Features Its main features are as follows:

The recognition system's dependence on the environment is reduced to a minimum, allowing it to operate normally around the clock while maintaining a high recognition rate.

The DSP-based high-speed hardware recognition system improves the speed and accuracy of recognition. DSP (digital signal processor) is a unique microprocessor that uses digital signals to process large amounts of information. Its working principle is to receive analog signals and convert them into digital signals of 0 or 1. The digital signals are then modified, deleted, and enhanced, and the digital data is interpreted back into analog data or actual environment formats in other system chips. It is not only programmable, but its real-time running speed can reach tens of millions of complex instruction programs per second, far exceeding general-purpose microprocessors. It is an increasingly important computer chip in the digital electronic world. Its powerful data processing capabilities and high operating speed are the two most commendable features.

The front-end recognition technology can still realize the function of license plate recognition when the management system crashes, and can automatically display the recognition results on a large outdoor display screen. Radio Frequency Identification (RFID) is an automatic recognition technology that has emerged since the 1990s. RFID is a technology that uses radio frequency signals to achieve contactless information transmission through spatial coupling (alternating magnetic field or electromagnetic field) and achieves recognition through the transmitted information. From the basic principle of information transmission, RFID is based on the transformer coupling model (energy transfer and signal transmission between primary and secondary) in the low frequency band and the spatial coupling model of radar detection targets in the high frequency band (the radar transmits electromagnetic wave signals and returns to the radar receiver with target information after hitting the target).

The minimum recognizable license plate width is 85 pixels, and monitoring and identification cameras can be shared, effectively protecting customer investments.

It can adapt to complex climate and lighting conditions, such as cloudy days, rainy days and nights, and still ensure high recognition rate.

It can adapt to high-speed and heavy traffic, and can still ensure a high recognition rate (>93%) when the vehicle speed is between 120 and 180 km/h and the single-lane traffic volume is 30 vehicles/minute.

It can realize frame-by-frame processing of video images and video triggering without burying ground sensor coils to avoid damaging the road surface.

The project is easy to install, runs stably, and does not interfere with the user's existing system.

It has extremely high processing capabilities and can identify and process all images of the vehicle while it is moving. It does not rely on a single picture, effectively improving the device's ability to adapt to complex environments.

Rich output interfaces and open underlying protocols support rapid secondary development and integration.

3 System Structure and Process An industrial computer (front-end management host) is set up in the control center of each entrance and exit, which receives the license plate recognition results and image information sent by the SWHV-LPR01 license plate reader.

The screen display on the entrance control machine is divided into two parts. The left half can receive the recognition result of the SWHV-LPR01 license plate automatic recognition device and directly display the license plate number. The right half receives the result processed by the front-end machine and directly displays the vehicle "release" or "banned". The more detailed information of this license plate is displayed on the display of the control center. Then the front-end management host sends the relevant information to the management system of the server through the network. The central management system archives the relevant content and data and stores them in the database (using SQL SERVER 2000 database) to establish a query system and for comparison during export.

3.1 Vehicles entering the community When a vehicle approaches the community entrance

The system automatically detects the approach of a vehicle, automatically captures a photo of the vehicle, identifies the vehicle's license plate number, records the time of entry, license plate number, and vehicle photo, and then determines the type of vehicle (local or external) by querying the registered vehicle records in the database. Different control strategies can be adopted according to the type of vehicle, which can be mainly divided into the following two situations:

Vehicles registered in this community - the screen displays the vehicle image, license plate number, date and time of entry, and fee payment status, and the system lifts the gate to let the vehicle pass.

Outside vehicles (no parking spaces in this area) - can be released after confirmation by the gate or released with a temporary card, etc., and the screen will display outside vehicles.

3.2 Vehicles exiting the community When a vehicle approaches the community exit

The system can automatically detect the approach of a vehicle, automatically capture a photo of the vehicle, automatically identify the vehicle's license plate number, record the time of exit, license plate number, and vehicle photo, and then determine the type of vehicle (local vehicle or external vehicle) by querying the registered vehicle records in the database. Different control strategies can be adopted according to the type of vehicle, which can be mainly divided into the following two situations:

External vehicles - according to the different nature of the vehicle (taxi, delivery truck, official car and social vehicle), different charging standards are determined (mainly free, time-based, per-trip, etc.), and the charging amount of the vehicle is determined in combination with the parking time of the vehicle. Then the vehicle can be released after confirmation by the gate or released after the temporary card is taken back, etc. The screen displays the external vehicle and the recorded license plate number, vehicle photo, card number, entry time, exit time, charging amount, etc.

The system is a new barrier-free parking lot management system that uses the SWHV-LPR01 license plate recognition device of Beijing Xinluwei Technology Development Co., Ltd., and vehicles entering the parking lot do not need to stop. Drivers do not need to stop at the entrance or exit. When a vehicle enters the parking lot entrance, the Xinluwei SWHV-LPR01 license plate recognition device automatically captures the vehicle photo and recognizes the license plate number, and transmits the license plate number, color, license plate feature data, entry time information, etc. to the management computer. Vehicles can enter the parking lot without barriers, providing users with a brand-new service model.