Analysis of three recognition modes of license plate recognition

License plate recognition is to replace the traditional IC card technology with license plate recognition technology to solve the traffic jam at the entrance and exit of the parking lot caused by the need to park and swipe the card. This intelligent parking lot management system scheme based on license plate recognition technology consists of a charging system, a license plate recognition integrated machine, a parking lot charging display screen and an intelligent gate. It is the product of the combination of modern advanced technology, and it is an advanced, applicable, economical and reliable vehicle access management system. At present, license plate recognition modes developed by license plate recognition system manufacturers are generally divided into three types: ground loop recognition mode; Video recognition mode; Video+ground sense recognition mode.

(1) Identification mode of grounding circuit

The ground loop is triggered. When the vehicle passes by, the ground loop is triggered, and the camera captures the license plate. Its advantages are high trigger rate, difficult vehicle leakage, practicality and stable performance, and it can output image records of unlicensed vehicles. The disadvantage is that it needs a sense of construction and installation, and the workload is large.

(2) Video recognition mode

The advantage of video trigger is that it does not need ground loop and the construction amount is small. The camera automatically recognizes the license plate information through the dynamic image of the vehicle, and at the same time provides analog trigger recognition. The disadvantage is that it is impossible to output the image of the unlicensed car and it is easy to miss the car. If the license plate result is not recognized, you can manually click the analog trigger to recognize it.

(3) Video+Ground Sense Recognition Mode

Video plus ground sense recognition mode is recognized by video recognition mode and uploaded by ground sense mode, and license plate images need to be set in the output area at the same time. Compared with ground loop recognition and video recognition, video with ground sense can provide faster recognition speed and higher recognition rate.

At present, the most flexible recognition mode is the flexible switching mode of video plus ground sense. The problem of car-following recognition or premature output can be solved by defining the recognition area and output area by software and setting the output position of license plate freely according to the customer's site environment. It is easy to record the information of unlicensed vehicles when they drive to the output area.

Unlicensed cars are divided into two categories: non-automobile unlicensed cars such as tricycles and bicycles, and unlisted cars (or cars with extremely stained number plates). In the future, in the era of easy parking, the powerful vehicle identification technology will be used to apply the vehicle identification algorithm to the research and development of easy parking sign identification system, and the problem of unlicensed vehicle identification in video identification mode will be easily solved.