Design and Installation Requirements of License Plate Recognition System - Tigerwong

In the intelligent car parking system industry, license plate recognition system is an advanced intelligent charging system. It uses license plate recognition technology, which is highly intelligent, easy to use and safe, and is welcomed by the market. However, the license plate recognition system is greatly affected by environmental factors. If the environmental conditions are not suitable, the system will not operate normally. Therefore, when we install the license plate recognition system, some on-site environments need to be tested. The following are the design and installation requirements of license plate recognition system: I. engineering test: 1. Standard lens 5mm; The correlation between the linear distance (m) and the pixel (P) of the license plate is sorted as follows: 3.5m156p; 4m140p 5m112p; 5.5m105p 6m96p 7m82p 2. Standard lens 4mm; The correlation between the linear distance (m) and the pixel (P) of the license plate is sorted as follows: 2.5m156p; 3m140p 4m112p; 4.5m105p 5m96p 6m82p 2 Recognition requirements: small license plate recognition (90-120 pixels), large license plate recognition (120-160 pixels). Full resolution capture of on-site vehicle photos triggered by ground feeling, and the width of license plate (the pixel size of the license plate can be displayed by framing the picture software). III. engineering principle: the best straight-line distance: the straight-line distance from the camera lens to the outside of the ground sense, generally about 5m for 5mm lens and about 4m for 4mm lens.

IV. engineering requirements: 1. The erection height of the all-in-one machine: the general standard is 1.5m-1.8m; 2. The camera column: installed on the inner side of the road gate, about 50 away from the gate rod Cm; prevent the brake rod from blocking the camera capture, thus affecting the recognition effect; wiring: network line, power line, ground sensing switching value signal line (connected to the vehicle inspection output). 3. Ground sensing position at the entrance and exit: the length of the integrated machine occupies 0.5m, according to the Pythagorean law (A & sup2; B & sup2; = C & sup2;) Calculation: 1) the horizontal distance between the camera lens of 5mm lens and the brake rod should be kept at about 4.3m; if the camera height exceeds 0.5m, it should be reduced by about 0.25m; 2) the horizontal distance between the camera lens of 4mm lens and the brake rod should be kept at about 3.2m; if the height exceeds 0.5m, it should be reduced by about 0.25m. 4. Speed bump location: installed at the entrance and exit ground sense At about 1m from the outside, ensure that the front of the following car does not touch the ground feeling; in order to prevent the owner from following the car too close, a warm prompt board should be erected and kept away from 3m. 5. Fill light: the column height is 0.6m and installed at 50cm-80cm from the inner side of the ground feeling (keep the fill light on the front of the license plate) , it can be reflected on the license plate by shooting on the ground induction coil to ensure the license plate recognition effect. 6. Monitoring picture (bottom inclination) : try to keep the width of the license plate parallel to the horizontal and no more than 15 degrees at most. From the system requirements, we can draw the requirements of the system for the on-site environment. In addition, according to the problems encountered in other projects, I summarized the following points: 1. When the vehicle enters the image capture area, the vehicle is facing the camera, and the effect is the best; 2. The place where the license plate recognition is installed should have sufficient straight-line distance, It is convenient for installation and debugging, and the distance can be calculated as follows (vehicle length the best recognition distance of the camera); 3. Avoid 90 & deg; install license plate recognition system equipment after turning; 4. Avoid installing license plate recognition system equipment on the uphill and downhill; 5. Avoid installing this system in the chaotic environment on site (there are many pedestrians, and pedestrians often enter and leave the vehicle channel, which is easy to cover the license plate) 6. Avoid the channel with serious water and sewage on the road when it rains (it is easy to block the license plate);.