August 20, 2023
Composition of interface subsystem One.1
Composition of interface subsystem One.1.1
The HD Smart Bayonet front subsystem mainly consists of following functional blocks:
Target detection, imaging and recognition unit: including bayonet lock unit, strobe and fill light; virtual coil is installed in bayonet gripper unit to perform functions of detecting vehicles, non-motor vehicles and detecting pedestrians;
External data processing and loading unit: including terminal server;
Network transmission unit: including cross switch and fiber optic transceiver;
Ø CCTV unit (optional): including a high-definition panoramic camera and auxiliary lighting equipment.
Figure 1. Structural diagram of input part of a standard system of intelligent monitoring and registration of road transport with a bayonet mount
Figure 2. Structural diagram of interface of an intelligent system for monitoring and registering vehicles at a video checkpoint for environmental protection
1.1.2 Target detection, image acquisition and processing block
Target detection, acquisition and image processing are performed using a bayonet lock and an additional light source.
The Hikvision camera selected for bayonet capture has a built-in integrated high definition architecture, integrating core functions such as HD video capture and HD video processing. The 300-pixel high-definition capture camera has an effective pixel of 2048 × 1536. In pictures taken, model, car color and facial features of people can be clearly distinguished. Whether license plate recognition speed can be guaranteed depends on number of pixels. license plate takes up space in photo. The license plate recognition algorithm adopted in system can guarantee license plate recognition accuracy of more than 95% when horizontal number of license plate pixels is at least 120.
The bayonet capture unit includes a video detection function, uses a video detection algorithm to fully detect targets and capture vehicles, non-vehicles and pedestrians, and output high-definition photos and license plate recognition data at same time, with a strong light suppression function (back , forward), reduce effect of sunlight on bayonet unit during day and effect of car headlights on bayonet unit at night, and clearly present complete front view of car and characteristics of license plate from pictures taken.
The bayonet assembly and fill light are mounted on same mast, reducing number of masts and investment costs, and making it easier to clean equipment at a later stage.
1.1.3 External data processing and loading unit
The external data processing and loading module consists of a terminal server and related software. The terminal server has a built-in low-power fanless design that can work normally in harsh environments. It uses a large-capacity industrial-grade hard disk drive as a storage medium that can store large-capacity vehicle information records. memory capacity is exceeded, it will automatically update vehicle information and images to cover loop.
The external data of intelligent road vehicle monitoring and recording system can be copied and stored locally in terminal server, and uploaded to central management platform. When network transmission link fails, terminal server can temporarily save vehicle traffic data. When connection is restored, temporarily saved data can be automatically resumed and recordedus to central management platform for centralized storage. There are two options for resuming load strategies: historical data is loaded first and latest data is loaded first.
1.1.4 Network Transmission Block
The network transmission node is mainly composed of cross industrial switches, fiber optic transceivers, optical fibers and other resources to realize interconnection between bayonet interface subsystem and central platform.
1.1.5 Video surveillance unit (optional)
The video surveillance unit consists of a high-resolution panoramic camera and additional lighting equipment (including a lighting control switch, additional light, etc.). For all traffic lanes in each direction, panoramic camera has features such as strong light suppression and automatic day/night switching to collect high-quality video and video information 24/7. The data output interface of high-definition panoramic camera is RJ45 (electrical port 100m), which connects to industrial switch at intersection through a network cable.
1.2 System sitemap
This system uses a 3-megapixel bayonet capture unit that covers 2 traffic lanes (national standard width 3.75m) to provide full field of view coverage. In addition to being able to grab vehicles and pedestrians normally moving in lane, it also has ability to grab vehicles crossing lane.
The bayonet assembly and fill light are installed on same pole, pole is usually 6 meters high. The distance between projection position of bayonet block and position of trigger is about 18 meters.
1.2.1 Site layout, top view
Let's take one-sided 2 lanes as an example, the layout of monitoring points on site is as follows:
Fig. 3. Top view of site plan of a one-way two-lane checkpoint
1.2.2 Site layout, side view
Fig. 4. Standard bayonet layout, side view
Figure 5. Side view of ecological bayonet platform layout
1.3 Equipment setup principles
1) Every 2 lanes are equipped with a 300/3200,000 bayonet capture unit, which is used to collect complete appearance images and real-time data processing of motor vehicles, non-vehicle vehicles and pedestrian targets; among them, ISP image control, auxiliary light Key technologies such as communication signal output and license plate recognition are integrated into bayonet grip unit;
2) Each track of standard mount is equipped with an additional LED light source as an auxiliary light source, and each track of environmental protection mount is equipped with an additional strobe light and a built-in infrared white strobe light as an auxiliary source. image capturing light source Ability to clearly recognize license plate and front elements of the vehicle;
3) Set up a terminal server for each map point (≤12 lanes) to back up external interface information;Chapter 2 System Survey Effect
2.1 Video card capture effect
2.1.1 Three-lane scene capture day effect
Fig. 6. Daytime capture effect 1 scene with three stripes
Fig. 7. Daytime capture effect 2 for three stripe scene
II.1.2 Three-lane night scene capture effect
Fig. 8. Night scene capture effect with three stripes 1