The wheel speed sensor, also called the wheel speed sensor, is usually used to detect the rotation speed of the car's wheels, and can transmit the speed signal to the ECU, so that the car can respond to the corresponding action. In the operation of a car, it is extremely important to control the speed of the car. The emergence of wheel speed sensors makes the monitoring of the speed of the car more accurate. So how much do you know about the working principle of wheel speed sensors?
What is the working principle of the wheel speed sensor?
Under normal circumstances, the wheel speed sensor must be installed on each wheel of the vehicle. It is completely sealed in a shell made of stainless steel. Compared with the sensor and the connecting wire, the key requirement is high Temperature resistance, corrosion resistance, shock and vibration resistance, usually do not need to take out the sensor after maintenance. The key of this sensor is composed of a rotor with convex teeth and a permanent magnet. The key is divided into two parts, namely, the sensor head and the ring gear. The sensor head is a stationary part, and the key is composed of a permanent magnet, an electromagnetic coil and a magnetic pole. The sensor head generally has two types of shape: the poles are rectangular and the poles are cylindrical. These two types of magnetic heads have obvious advantages of high temperature resistance, shock vibration resistance, and high safety. During installation, a gap of about 1mm is usually left between the magnetic pole of the sensor head and the ring gear. The ring gear is usually mounted on the wheel hub or rear axle, and it can rotate with the rotation of the wheel or transmission.
When the wheel speed sensor is working, it can detect and feedback the motion state of the vehicle at any time. When the wheel rotates, a sudden change voltage signal will be formed in the wheel speed sensor, and the frequency is proportional to the wheel speed. The higher the wheel speed, the higher the frequency of the sensor to form a sudden change signal. After the ECU receives this sudden change signal and After sensing its frequency, it can calculate the wheel speed, acceleration and deceleration, wheel slip rate and other information over time; when the vehicle is braking, when the deceleration or slip rate of the wheel exceeds or is lower than the limit value, the ECU will output a control signal to adjust the brake pressure at any time to make it better improved, so as to prevent the vehicle wheels from locking up., So that the braking system of the vehicle is in the best operating condition at all times.
