With the rapid development of the economy, more and more city vehicles are owned, causing congestion, traffic accidents, and serious traffic pollution. These problems form an electromagnetic field around the coil when the vehicle passes. Above the coil, an eddy current is induced in the metal body. The eddy current is generated in the loop but in the opposite direction, that is, mutual inductance, so that the inductance of the coil is reduced and the resonance frequency of the circuit is increased. Gradually caught people's attention. The Smart-Intelligent Transport System emerged in the late 1980s and early 1990s. Many developed and developing countries have put forward their respective development strategies and tried to promote their own vehicle-based, communications, electronic, and transportation systems (ITS computers and networks) through the development of ITS. Such as high-tech economic development.Vehicle detection technology is an indispensable part of the intelligent transportation system, the level of the level directly affects the overall operation and management level of highway and urban road monitoring system.
The level of vehicle detection technology is mainly reflected in the advanced level of vehicle detectors. The vehicle detector mainly provides various traffic parameters to the information processing and information release unit in the monitoring system through data acquisition and equipment monitoring, and serves as the main basis for the monitoring center to analyze, judge, send out information and propose a control plan. In the past ten years, vehicle detectors have become increasingly systematic and optical-mechanical and electromechanical. With the development of microelectronics and information processing technologies, especially the rapid development of intelligent traffic systems in recent years, traffic monitoring technology has changed to a great extent. The nature. Nowadays, with the application of a wide range of vehicle identification detectors, coupled with fiber-optic communication systems, microprocessor-based signal control equipment, powerful computer systems, and engineering modular artificial intelligence, traffic monitoring systems have become widely available. Comprehensive, intelligent and real-time control development.
1. The vehicle detector free <br> <br> recent years, with the development of sensor technology, microelectronics and information processing technology, the vehicle detector also have a larger development, the emergence of many types, different works However, it can be summarized as two basic functions: one is to detect the presence or presence of a vehicle, and the other is to detect the movement or passage of a vehicle. Any vehicle detector should have at least one of the above two basic functions. For this purpose, the vehicle detector is divided into a present type, a pass type, and a combination of the two. For a presence detector, an output signal can be generated as long as a vehicle to be inspected appears in its monitoring area; The detector (PassageDetector) is based on the arrival or movement of the vehicle, producing a short duration output signal to detect; some detectors can only detect one of the static or dynamic, and some can detect the presence of static, but can also detect The dynamic passage is called a complex detector. If classified according to the working principle of the vehicle detector, it can be divided into electric contact type, photoelectric type, electromagnetic induction type, ultrasonic type, infrared type and other types. At present, the detectors are divided into three categories according to the detector's working mode and the electromagnetic wavelength range during operation: magnetic vehicle detectors, wave-frequency vehicle detectors, and video vehicle detectors.
2. Frequency Magnetic vehicle detector <br> <br> magnetic detector based on the frequency of the vehicle vehicle detector principle of electromagnetic induction, the induction coil which has a detector, a magnetic sensor, a geomagnetic sensor, and a micro magnetic imaging detector coil Detectors and other types.
2.1 Inductive Loop Detector (InductiveLoopDetector) Induction Loop Vehicle Detector is the most widely used vehicle detection device at home and abroad. The detector is a coil sensor, a signal detection processing unit (including a detection signal amplifying unit, a data processing unit, and a communication interface) buried under the road surface, and a feeder. When the current is passing through the vehicle. The induction coil detector has the advantages of low cost, easy installation, high sensitivity, and climate impact, but in actual use, the damage rate of the coil is high due to road construction, road surface deformation and other factors, and it is necessary to enter the highway when replacing the installation and maintenance. The main body, which affects transportation, causes higher costs and the workload of maintenance.
2.2 Magnetic Detector The magnetic detector also works on the basis of detecting changes in the magnetic field. The detector consists of a small coil mounted in the sheath and a bag amplifier located in the control box. When in use, the coil with high magnetic permeability is buried under the road surface and passes through the coil when the vehicle approaches or passes through the coil. The magnetic field is changed so that an induced voltage is generated in the coil and the amplifier sends out the information that the vehicle passes through. This type of detector can only detect the passing of vehicles and has a low limit to the vehicle speed. Its main advantage is that the design is simple and not affected by road surface problems; the main drawback is that static vehicles cannot be detected, so many of the detection methods at today's intersections The application is limited.
2.3 Magnetometer Detector The geomagnetic detector is a high magnetic permeability core and coil mounted in a protective sleeve filled with a non-conductive waterproof material to form a magnetic bar. Open a 0.2-0.6m hole in the direction perpendicular to the traffic flow on the road, and bury the magnetic rod under the road. When the vehicle passes this coil, the magnetic flux passing through the coil changes, generating an electromotive force in the coil. This electromotive force After amplification by the amplifier to push the relay, it sends out a vehicle pass message. A stationary vehicle produces no output and is a pass-through detector. Geomagnetism detectors are more suitable for applications where only the number of passing vehicles is required to be recorded. However, the detection of other traffic flow data is incompetent. It can be seen that the application of geomagnetic detectors is not wide.
2.4 Microloop Detector The Microloop Detector is a patented vehicle sensor that is similar in design to a geomagnetic detector but needs to be connected to a standard induction coil detector processing device. The miniature coil probe converts the increase in magnetic field intensity into a decrease in coil inductance, which drives the toroidal coil amplifier. Like geomagnetic detectors, miniature coil detectors are also designed to detect high-sensitivity locations. One of its advantages is that each channel can install more sensors than geomagnetic detectors. Like geomagnetic detectors, it is also a pass-through detector and cannot detect static vehicles.
2.5 Magnetic Imaging Detector (VMIDetector) The sensor technology developed in the vehicle detector developed by Nu-Metrics is called Vehicle Magnetic Imaging (VMIV) technology. It measures the disturbance or change of the electromagnetic field caused by the appearance of the vehicle. By comparing with the Magnetic Footprint of different recorded vehicles, it can not only separate the truck from the car, but also measure the structure and type of the vehicle. And speed. 3 Frequency-Frequency Vehicle Detector The frequency-conductor vehicle detector is based on microwave, ultrasonic, and infrared detection of vehicle emission frequency. Its disadvantage is that it cannot provide visual surveillance capabilities and record the visual characteristics of a passing vehicle or traffic.
3.Microware Detector) Radar 3.1 Radar (Microwave) Detector (Radar. The detector works according to the principle of Doppler Effect, which consists of a transmitting antenna and a transmitting receiver. Launches on a mast or on a roadside pillar. The antenna transmits a microwave beam to the road surface detection area. When the vehicle passes, the reflected beam returns to the antenna at different frequencies. The detector's transmitting receiver measures the frequency shift caused by the vehicle's movement, which can generate a vehicle sensing output signal. The passing or presence of the vehicle is determined.The microwave detector's operating frequency is usually 24 GHz or 10 GHz.The radar detector has the characteristics of multiple detection areas, which can detect traffic flow, vehicle speed, occupancy rate and other traffic flow information, currently in traffic detection. With great advantages and visual positivity, it is the foundation for future intelligent transportation system development.
basic type. The active infrared detector uses a semiconductor infrared generator as a sensor and has an infrared light source directed to the measurement lane. The vehicle that enters the detection area reflects the infrared light back to the detector and generates a sensing signal. The principle of the passive infrared detector is to detect the change in the infrared radiation intensity of a road surface without a vehicle and the infrared radiation intensity when a vehicle passes through the road. Its typical use is to install signal posts or other columns to detect intersections and pedestrian crossings. This type of detector has the ability to quickly and accurately detect sharply-defined contours. The disadvantage of this detector is that dust and ice mist at the worksite will affect the normal operation of the system.
3.2 Infrared Detector
Infrared detectors are very, there are two types of active and passive detectors (such as radar detectors) connected to detect speeding vehicles. When a speeding vehicle is found, the camera captures the image of the car and uploads it to the video processor for processing. Then, the license plate number of the car can be obtained, and then the license plate number of the car can be obtained on the front variable information logo plate. Speed ​​and give the car a speeding warning. The advanced video vehicle detector can use the all-weather camera in the detection area to record the number of vehicles, queuing scale, and vehicle speed in the area. The above information is fed back to the control center for processing to determine the cycle and control mode of the traffic signal, and can be used. The variant information version provided advice on blockages and accidents to upstream vehicles to complete adaptive control of traffic, vehicle induction and other functions. Video vehicle detectors are very important in current traffic control systems. Currently, they are mainly used in traffic engineering: vehicle detection and classification, congestion classification, prediction of traffic flow, estimation of traffic parameters, identification of characters, and driver behavior. Simulation and other fields. With the development of image processing technology and microelectronics technology, the application range of video vehicle detection technology must be compared with frequency detection. Its disadvantage is that it cannot provide visual surveillance capabilities and record the visual characteristics of the traffic vehicles or traffic conditions.
3.3 Ultrasonic detector (UltrosonicDetector) Ultrasonic vehicle detector is also made using the principle of reflected echo, it is through the ultrasonic echo emitted by the ultrasonic generator and reflected by the vehicle to detect the vehicle, if the probe of the ultrasonic detector The vehicle in the corresponding detection area passes or exists. The probe reflects a bundle of ultrasonic waves and it is reflected back to be received by the same probe. By judging the difference between the signal and the original reflected echo signal in time, the detection area has The passing or existing judgment of the vehicle. It has three types of pulsed, resonant, and continuous wave ultrasonic detectors. The pulse detector hangs above the lane, transmits ultrasonic energy pulses below the lane, and accepts echoes. When there is a vehicle passing from below, echoes are reflected from the roof instead of echoes from the road surface, shortening the distance of the echo and detecting the arrival of the vehicle. The vibration wave type detector installs opposed emitters and receivers on both sides of the lane, and emits resonant ultrasonic waves from the emitter. The ultrasonic waves are received across the lane by the receiver opposite the lane, and the beam is cut off when the vehicle passes through, thereby detecting the ultrasonic waves. Out of the vehicle. Continuous-wave type ultrasonic detectors, which emit a continuous beam of ultrasonic energy to a vehicle approaching the vehicle, can detect the presence of the vehicle due to changes in the reflected frequency of the incoming vehicle due to the Doppler effect.
4. Video Vehicle Detector <br> <br> video vehicle detection system is developed on the basis of traditional television monitoring system, based vehicle detection technology, the camera and computer image processing technology, the implementation of a wide range of vehicles Detection and identification. Video detection, also known as image processing or artificial vision, is a technique that combines video imagery and computerized pattern recognition. The basic principle is that in a very short time interval, two images are successively captured by a semiconductor charge-coupled device (CCD) camera, and this image itself is a digital image, and it is easy to perform the entire or partial region of the two images. In comparison, differences indicate that there are moving objects. The core of the video detection system is a video processor, which is composed of a CPU-based processor, a plurality of circuit modules, and software for analyzing video images, and can receive a plurality of video signals transmitted by a roadside camera.
Simple video vehicle detectors are still images of recorded vehicles that can be expanded with others.
The level of vehicle detection technology is mainly reflected in the advanced level of vehicle detectors. The vehicle detector mainly provides various traffic parameters to the information processing and information release unit in the monitoring system through data acquisition and equipment monitoring, and serves as the main basis for the monitoring center to analyze, judge, send out information and propose a control plan. In the past ten years, vehicle detectors have become increasingly systematic and optical-mechanical and electromechanical. With the development of microelectronics and information processing technologies, especially the rapid development of intelligent traffic systems in recent years, traffic monitoring technology has changed to a great extent. The nature. Nowadays, with the application of a wide range of vehicle identification detectors, coupled with fiber-optic communication systems, microprocessor-based signal control equipment, powerful computer systems, and engineering modular artificial intelligence, traffic monitoring systems have become widely available. Comprehensive, intelligent and real-time control development.
1. The vehicle detector free <br> <br> recent years, with the development of sensor technology, microelectronics and information processing technology, the vehicle detector also have a larger development, the emergence of many types, different works However, it can be summarized as two basic functions: one is to detect the presence or presence of a vehicle, and the other is to detect the movement or passage of a vehicle. Any vehicle detector should have at least one of the above two basic functions. For this purpose, the vehicle detector is divided into a present type, a pass type, and a combination of the two. For a presence detector, an output signal can be generated as long as a vehicle to be inspected appears in its monitoring area; The detector (PassageDetector) is based on the arrival or movement of the vehicle, producing a short duration output signal to detect; some detectors can only detect one of the static or dynamic, and some can detect the presence of static, but can also detect The dynamic passage is called a complex detector. If classified according to the working principle of the vehicle detector, it can be divided into electric contact type, photoelectric type, electromagnetic induction type, ultrasonic type, infrared type and other types. At present, the detectors are divided into three categories according to the detector's working mode and the electromagnetic wavelength range during operation: magnetic vehicle detectors, wave-frequency vehicle detectors, and video vehicle detectors.
2. Frequency Magnetic vehicle detector <br> <br> magnetic detector based on the frequency of the vehicle vehicle detector principle of electromagnetic induction, the induction coil which has a detector, a magnetic sensor, a geomagnetic sensor, and a micro magnetic imaging detector coil Detectors and other types.
2.1 Inductive Loop Detector (InductiveLoopDetector) Induction Loop Vehicle Detector is the most widely used vehicle detection device at home and abroad. The detector is a coil sensor, a signal detection processing unit (including a detection signal amplifying unit, a data processing unit, and a communication interface) buried under the road surface, and a feeder. When the current is passing through the vehicle. The induction coil detector has the advantages of low cost, easy installation, high sensitivity, and climate impact, but in actual use, the damage rate of the coil is high due to road construction, road surface deformation and other factors, and it is necessary to enter the highway when replacing the installation and maintenance. The main body, which affects transportation, causes higher costs and the workload of maintenance.
2.2 Magnetic Detector The magnetic detector also works on the basis of detecting changes in the magnetic field. The detector consists of a small coil mounted in the sheath and a bag amplifier located in the control box. When in use, the coil with high magnetic permeability is buried under the road surface and passes through the coil when the vehicle approaches or passes through the coil. The magnetic field is changed so that an induced voltage is generated in the coil and the amplifier sends out the information that the vehicle passes through. This type of detector can only detect the passing of vehicles and has a low limit to the vehicle speed. Its main advantage is that the design is simple and not affected by road surface problems; the main drawback is that static vehicles cannot be detected, so many of the detection methods at today's intersections The application is limited.
2.3 Magnetometer Detector The geomagnetic detector is a high magnetic permeability core and coil mounted in a protective sleeve filled with a non-conductive waterproof material to form a magnetic bar. Open a 0.2-0.6m hole in the direction perpendicular to the traffic flow on the road, and bury the magnetic rod under the road. When the vehicle passes this coil, the magnetic flux passing through the coil changes, generating an electromotive force in the coil. This electromotive force After amplification by the amplifier to push the relay, it sends out a vehicle pass message. A stationary vehicle produces no output and is a pass-through detector. Geomagnetism detectors are more suitable for applications where only the number of passing vehicles is required to be recorded. However, the detection of other traffic flow data is incompetent. It can be seen that the application of geomagnetic detectors is not wide.
2.4 Microloop Detector The Microloop Detector is a patented vehicle sensor that is similar in design to a geomagnetic detector but needs to be connected to a standard induction coil detector processing device. The miniature coil probe converts the increase in magnetic field intensity into a decrease in coil inductance, which drives the toroidal coil amplifier. Like geomagnetic detectors, miniature coil detectors are also designed to detect high-sensitivity locations. One of its advantages is that each channel can install more sensors than geomagnetic detectors. Like geomagnetic detectors, it is also a pass-through detector and cannot detect static vehicles.
2.5 Magnetic Imaging Detector (VMIDetector) The sensor technology developed in the vehicle detector developed by Nu-Metrics is called Vehicle Magnetic Imaging (VMIV) technology. It measures the disturbance or change of the electromagnetic field caused by the appearance of the vehicle. By comparing with the Magnetic Footprint of different recorded vehicles, it can not only separate the truck from the car, but also measure the structure and type of the vehicle. And speed. 3 Frequency-Frequency Vehicle Detector The frequency-conductor vehicle detector is based on microwave, ultrasonic, and infrared detection of vehicle emission frequency. Its disadvantage is that it cannot provide visual surveillance capabilities and record the visual characteristics of a passing vehicle or traffic.
3.Microware Detector) Radar 3.1 Radar (Microwave) Detector (Radar. The detector works according to the principle of Doppler Effect, which consists of a transmitting antenna and a transmitting receiver. Launches on a mast or on a roadside pillar. The antenna transmits a microwave beam to the road surface detection area. When the vehicle passes, the reflected beam returns to the antenna at different frequencies. The detector's transmitting receiver measures the frequency shift caused by the vehicle's movement, which can generate a vehicle sensing output signal. The passing or presence of the vehicle is determined.The microwave detector's operating frequency is usually 24 GHz or 10 GHz.The radar detector has the characteristics of multiple detection areas, which can detect traffic flow, vehicle speed, occupancy rate and other traffic flow information, currently in traffic detection. With great advantages and visual positivity, it is the foundation for future intelligent transportation system development.
basic type. The active infrared detector uses a semiconductor infrared generator as a sensor and has an infrared light source directed to the measurement lane. The vehicle that enters the detection area reflects the infrared light back to the detector and generates a sensing signal. The principle of the passive infrared detector is to detect the change in the infrared radiation intensity of a road surface without a vehicle and the infrared radiation intensity when a vehicle passes through the road. Its typical use is to install signal posts or other columns to detect intersections and pedestrian crossings. This type of detector has the ability to quickly and accurately detect sharply-defined contours. The disadvantage of this detector is that dust and ice mist at the worksite will affect the normal operation of the system.
3.2 Infrared Detector
Infrared detectors are very, there are two types of active and passive detectors (such as radar detectors) connected to detect speeding vehicles. When a speeding vehicle is found, the camera captures the image of the car and uploads it to the video processor for processing. Then, the license plate number of the car can be obtained, and then the license plate number of the car can be obtained on the front variable information logo plate. Speed ​​and give the car a speeding warning. The advanced video vehicle detector can use the all-weather camera in the detection area to record the number of vehicles, queuing scale, and vehicle speed in the area. The above information is fed back to the control center for processing to determine the cycle and control mode of the traffic signal, and can be used. The variant information version provided advice on blockages and accidents to upstream vehicles to complete adaptive control of traffic, vehicle induction and other functions. Video vehicle detectors are very important in current traffic control systems. Currently, they are mainly used in traffic engineering: vehicle detection and classification, congestion classification, prediction of traffic flow, estimation of traffic parameters, identification of characters, and driver behavior. Simulation and other fields. With the development of image processing technology and microelectronics technology, the application range of video vehicle detection technology must be compared with frequency detection. Its disadvantage is that it cannot provide visual surveillance capabilities and record the visual characteristics of the traffic vehicles or traffic conditions.
3.3 Ultrasonic detector (UltrosonicDetector) Ultrasonic vehicle detector is also made using the principle of reflected echo, it is through the ultrasonic echo emitted by the ultrasonic generator and reflected by the vehicle to detect the vehicle, if the probe of the ultrasonic detector The vehicle in the corresponding detection area passes or exists. The probe reflects a bundle of ultrasonic waves and it is reflected back to be received by the same probe. By judging the difference between the signal and the original reflected echo signal in time, the detection area has The passing or existing judgment of the vehicle. It has three types of pulsed, resonant, and continuous wave ultrasonic detectors. The pulse detector hangs above the lane, transmits ultrasonic energy pulses below the lane, and accepts echoes. When there is a vehicle passing from below, echoes are reflected from the roof instead of echoes from the road surface, shortening the distance of the echo and detecting the arrival of the vehicle. The vibration wave type detector installs opposed emitters and receivers on both sides of the lane, and emits resonant ultrasonic waves from the emitter. The ultrasonic waves are received across the lane by the receiver opposite the lane, and the beam is cut off when the vehicle passes through, thereby detecting the ultrasonic waves. Out of the vehicle. Continuous-wave type ultrasonic detectors, which emit a continuous beam of ultrasonic energy to a vehicle approaching the vehicle, can detect the presence of the vehicle due to changes in the reflected frequency of the incoming vehicle due to the Doppler effect.
4. Video Vehicle Detector <br> <br> video vehicle detection system is developed on the basis of traditional television monitoring system, based vehicle detection technology, the camera and computer image processing technology, the implementation of a wide range of vehicles Detection and identification. Video detection, also known as image processing or artificial vision, is a technique that combines video imagery and computerized pattern recognition. The basic principle is that in a very short time interval, two images are successively captured by a semiconductor charge-coupled device (CCD) camera, and this image itself is a digital image, and it is easy to perform the entire or partial region of the two images. In comparison, differences indicate that there are moving objects. The core of the video detection system is a video processor, which is composed of a CPU-based processor, a plurality of circuit modules, and software for analyzing video images, and can receive a plurality of video signals transmitted by a roadside camera.
Simple video vehicle detectors are still images of recorded vehicles that can be expanded with others.
Photoluminescent Signage,Photoluminescent Super Sign,Photoluminescent Disc,Luminous Powder
JINAN REALGLOW CO.,LTD , https://www.realglowsign.com