More and more people are buying cars now. In Beijing alone, the number of private cars is close to 600,000. How do we manage the growing number of cars? A geomagnetic sensor is a device that can be used to collect vehicle information and then transmit it to the management center, which analyzes it and manages traffic by controlling traffic lights. The geomagnetic sensor can also take photos and record information on vehicles that do not pay tolls. It can be seen that geomagnetic sensors play a very important role in traffic management. So, what models does it have? What is its working principle?
1. Geomagnetic sensor
Geomagnetic sensor is a type of sensor that uses the different motion states of the measured object in the geomagnetic field. , a measuring device that indicates information such as the posture and movement angle of the measured object by sensing changes in the distribution of the geomagnetic field.
2. Principles of geomagnetic sensors
Currently, the main technical principles that can be used to detect changes in the geomagnetic field distribution are: ① Magnetoresistance effect: When moving along a long and thin iron If a current is applied in the length direction of the magnetic alloy and a magnetic field is applied in the direction perpendicular to the current, the resistance of the alloy strip itself will change. The magnitude of this resistance change is closely related to the magnitude of the magnetic field and current. ② Hall effect: Under the action of a magnetic field perpendicular to the direction of the current, the semiconductor passing through the current forms an accumulation of charges in the direction perpendicular to the current and the magnetic field, resulting in a potential difference. ?③Electromagnetic induction: When the coil cuts the magnetic field lines of the earth's magnetic field, an induced electromotive force will be generated at both ends of the coil. ?④AMR (Anisotropic Magnetic Impedance Sensing)? ⑤GMR (Giant Magnetic) Effect
3.? Application of geomagnetic sensor
①?Fitness plan (step-counter)?②?Navigation Application? Blind area navigation (passing through tunnels, underground shopping malls)? Donkey travel the world? (electro
nic? compass?)? ③? Game applications? ④? Gesture and posture recognition? ⑤? Others
4. The working principle of geomagnetic sensors used in electronic systems
The Earth’s magnetic field is basically constant within a few kilometers, but large ferromagnetic objects will cause huge disturbances to the Earth’s magnetic field. The geomagnetic sensor can distinguish 1/6000 of the change in the earth's magnetic field, and the impact on the geomagnetism when a vehicle passes by will reach a fraction of the geomagnetic intensity. Therefore, using the geomagnetic sensor to detect vehicles has extremely high sensitivity. The geomagnetic sensor is Detecting vehicles by detecting the disturbance caused by the earth's magnetic field when the vehicle passes by is widely used abroad.
5. Advantages of geomagnetic sensors in vehicle detection
1. Easy installation and maintenance, no need to close lanes, little damage to the road surface, when installed on a hanger or side at the detection point There is no need to destroy the road surface, just check the geomagnetic sensor during maintenance; the detection point is not easy to be damaged and is not affected by the movement of the road surface;
2. The geomagnetic sensor uses the changes in the earth's magnetic field when ferromagnetic objects pass by to detect, so it is not affected by climate;
2. By setting the sensitivity, the size of ferromagnetic objects can be identified, and the type of vehicle can be roughly judged;
4. It does not react to non-ferromagnetic objects, so false detections can be effectively reduced.
6. Models of geomagnetic sensors
1. Four-core sensors are used by traditional instruments. At present, more than 80 regular manufacturers in the mainstream market mainly use four-core sensors, which have stable quality and are Very disruptive. The disadvantage is that it is troublesome to make, has high cost, and is not suitable for large-scale automatic assembly line production.
Two-core and two-core sensors are new products launched in recent years, and the stability of the products has yet to be further verified by the market. The tool is simple to produce, low in cost, and suitable for flow operations.
In the information age, of course we must solve problems in more effective ways. With the development of the economy, there are more and more vehicles, and manpower alone is far from enough. For the collection and processing of vehicle data, the geomagnetic sensor acts as a transmission medium, which allows a large amount of information to be transmitted to the center in real time, allowing the management center to make timely processing plans. As magnetic sensor technology matures, it is used in more and more fields.
From aerospace to all aspects of daily life.