Data acquisition system plays a very important role in traffic monitoring system. Geomagnetic sensor is a key part of data acquisition system, and its performance plays a decisive role in the accuracy of data acquisition system.
Anisotropic magnetoresistive sensor is made of thin film alloy (permeable alloy), and the magnetic field change is measured by using the basic principle that the resistance characteristics of current-carrying magnetic materials will change in the presence of external magnetic field.
When the sensor is turned on, assuming that there is no external magnetic field, the thin film alloy will have an internal magnetization vector parallel to the current direction.
The working principle of "geomagnetic sensor" is that when the driver parks the vehicle in the parking space, the "geomagnetic sensor" will automatically sense the parking time of the vehicle, and transmit the time to the relay station for billing, so citizens can pay directly on the POS machine with their bank cards.
At the same time, the camera function of the equipment is used to take pictures of vehicles that do not pay fees, and the information of these vehicles is entered into relevant websites, and certain measures are taken for vehicles that evade fees.
Extended data:
First, the advantages of geomagnetic sensor
1, easy to install and maintain, no need to close the lane, little damage to the road surface, no need to damage the road surface when installed on the hanger or on the side of the inspection point, only need to check the geomagnetic sensor when maintaining; The detection point is not easy to be damaged and is not affected by road movement;
2. Geomagnetic sensors are used to detect the changes of the earth's magnetic field when ferromagnetic objects pass by, so they are not affected by climate;
3. By setting the sensitivity, the size of ferromagnetic objects can be identified and the vehicle type can be roughly judged;
4, there is no response to non-ferromagnetic objects, so it can effectively reduce false detection.
Second, the role of geomagnetic sensors
The function of geomagnetic sensor is quite powerful: when the driver parks the vehicle in the parking space, the geomagnetic sensor can automatically sense the arrival of the vehicle and start timing; When the vehicle is about to leave, the sensor will automatically transmit the parking time to the relay station for billing.
Therefore, solving the inefficiency of parking charge was once one of the advantages of geomagnetic sensors.
Three antenna-like devices are erected on the roadside of the parking lot to receive and send information from sensors. According to reports, these three sensing devices can cover the entire parking area. American PNI magnetic sensor is a kind of magnetic sensor used in parking lot.
Now, with the development of magnetic sensors, more and more fields use magnetic sensors.
This kind of magnetic sensor is used in many aspects, from national defense, aerospace to national economy, from medical care to daily life.
Baidu encyclopedia-geomagnetic sensor