The difference between Hall rate wheel speed sensor and electromagnetic induction wheel speed sensor

The specific differences are as follows:

Hall-style wheel speed sensor.

1) Structure. Hall-style wheel speed sensors consist of a sensing head and ring gears. The sensing head consists of permanent magnets, Hall elements, and electronic circuits.

2) Principle. Hall wheel speed sensor uses the Hall effect principle, that is, the current is controlled at both ends of the semiconductor sheet, and a magnetic field with a magnetic field strength of b is applied in the vertical direction of the sheet, then an electric potential proportional to the product of the control current and magnetic induction intensity b will be generated at the other two ends of the sheet, which is the Hall potential.

Magnetoelectric wheel speed sensor.

1) Structure. The magnetoelectric wheel speed sensor is generally composed of a magnetic induction sensing head and a gear ring, and the sensing head is composed of a permanent magnet, a polar shaft, an induction coil, etc. The ring gear is a moving part that is generally mounted on the hub or axle and rotates with the wheel.

The wheel speed sensing head is a stationary component, and there is a certain gap between the magnetic pole of the sensing head and the end face of the ring gear.

Automotive wheel speed sensors are usually installed at the wheels, but in some models they are installed in the final drive or transmission.

The polar axis is divided into three types according to the different shapes: chisel, column, and diamond, as shown in the figure below. Different shapes of sensing heads are mounted differently with respect to ring gears. The rhombic polar axis speed sensor head is generally installed radially perpendicular to the ring gear; The chisel polar axis speed sensor head is axially tangent to the ring gear mounting; The column polar axis speed sensor head is installed axially perpendicular to the ring gear.

In order to avoid the influence of water and dust on the operation of the sensor, the sensor must be greased before installation.

2) Principle. The magnetoelectric wheel speed sensor is composed of a permanent magnetic core and a coil. The magnetic field lines come out of one pole of the core, pass through the ring gear and air, and return to the other pole of the core.

Since the coil of the sensor is wound around the magnetic core, these magnetic field lines also pass through the coil. When the wheel rotates, the gear ring synchronized with the wheel rotates, and the teeth and gaps on the gear ring pass through the magnetic field of the sensor quickly in turn, and the result is that the magnetic resistance of the magnetic circuit is changed, resulting in a change in the induced electric potential in the coil, resulting in an electric potential pulse of a certain amplitude and frequency. The frequency of the pulses, i.e. the number of pulses produced per second, reflects how fast or slow the wheel rotates.

A wheel speed sensor is a sensor used to measure the rotational speed of a car's wheels.

The simplest difference is that the electromagnetic wheel speed sensor is a 2-wire system, and the Hall is a 3-wire system; The electromagnetic type does not need to be powered by electricity, and Hall's must have a power supply.

Hall's frequency is much higher than that of electromagnetism, (i.e., it works more times per second than electromagnetism).

It provides fast and slow voltage signals for vehicle speed, and the ECU has logic analysis capabilities according to SP signals, TPS signals, and VSS signals.

Generally speaking, all speed sensors can be used as wheel speed sensors, but considering the actual factors such as the working environment of the wheel and the size of the space, the commonly used wheel speed sensors mainly include: magnetoelectric wheel speed sensor, Hall wheel speed sensor. The magnetoelectric wheel speed sensor is designed using the principle of electromagnetic induction, and its main components are shown in the figure below.

It has the characteristics of simple structure, low cost, and not afraid of mud and dirt, and has been widely used in the ABS anti-lock braking system of modern cars.

But magnetoelectric wheel speed sensors also have some drawbacks:

1) The frequency response is not high. When the speed of the vehicle is too high, the frequency response of the sensor cannot keep up, and it is easy to produce false signals;

2) The ability to resist electromagnetic interference is poor, especially when the amplitude of the output signal is small. Hall-style wheel speed sensors are made using the Hall effect principle, as shown in the figure below. Hall speed sensors are also widely used in automobiles.

Hall speed sensors have the following features:

1) The voltage amplitude value of the output signal is not affected by the speed;

2) High frequency response;

3) Strong ability to resist electromagnetic interference.

When it comes to wheel speed sensors, most people may not be familiar with it or have even heard of it. I'm going to cover some basic information about wheel speed sensors. The wheel speed sensor is a sensor that measures the speed of the wheels of a car, so anyone who has a car at home should know that it exists.

When we drive, we know the speed of the vehicle through this sensor.

There are also many types of wheel speed sensors, so let's take a closer look at its classification and various characteristics. Wheel speed sensor types and characteristics, concept introduction: Wheel speed sensor is a sensor used to measure the speed of car wheels. Hyundai Motors.

Wheel speed information is required, such as vehicle dynamic control (VDC), automotive electronic stability program (ESP), anti-lock braking system (ABS), automatic transmission control system, etc. Therefore, the wheel speed sensor is one of the most important sensors in modern cars, generally speaking, all speed sensors can be used as speed sensors, but considering practical factors such as the working environment and space size of the wheel, the commonly used speed sensors are. Electromagnetic induction speed sensor, Hall speed sensor, photoelectric speed sensor, magnetoresistive.

Element velocity sensor. Magnetoelectric wheel speed sensor.

The magnetic wheel speed sensor is designed using the principle of electromagnetic induction, and its main components are shown in the figure below. It has the characteristics of simple structure, low cost, and not afraid of mud, and is widely used in the ABS anti-lock braking system of modern automobiles. However, magnetoelectric wheel speed sensors also have some drawbacks.

The frequency response is not high. When the speed is too high, the frequency response of the sensor cannot keep up, and it is easy to generate false signals. on electromagnetic waves.

The resistance to interference is reduced, especially when the amplitude of the output signal is relatively small. Bore wheel speed sensor, Hall speed sensor is made using the Hall effect principle, Hall wheel speed sensor has also been used in automobiles. Bore wheel speed sensors have the following features:

The voltage amplitude value of the output signal is not affected by the speed. high frequency response; Strong anti-interference ability of electromagnetic waves.

The types of wheel speed sensors should be careful, I will only give examples of the two big categories above: Hall wheel speed sensors and magnetoelectric wheel speed sensors. Of course, different types have different characteristics, the application situation is also different, and the efficacy is also different, therefore, when we choose and use, we must analyze which kinds of products are what we really need, in order to give full play to the efficacy of the product, for us.

There are three types. The first is a ring wheel speed sensor, the second is a linear wheel speed sensor, and the third is a Hall wheel speed sensor.

Generally, it is divided into electromagnetic induction, Hall wheel speed, photoelectric speed, magnetoresistive element speed, coil wheel speed sensor, and the use of these types of sensors is different.

Magnetic pulse type, magnetoresistive element type, Hall type, photoelectric type, different types of this type, in fact, are also suitable for different car use.

The wheel speed sensor of the car is divided into two categories, namely active and passive, but the general active wheel speed sensor is used more.

Working principle: 1. To make the Hall integrated circuit play a sensing role, it is necessary to use mechanical methods to change the magnetic induction intensity. When the impeller blades are in the air gap between the magnet and the Hall integrated circuit, the magnetic field deviates from the integrated piece and the Hall voltage disappears.

2. Because of the change of the output voltage of the Hall integrated circuit, a certain position of the impeller drive shaft can be displayed, and the Hall integrated circuit chip is used to ignite the timing sensor. Hall-effect sensors are passive sensors that require an external power supply to operate, and this feature can detect operation at low speeds.

The simplest difference is.

The electromagnetic wheel speed sensor is a 2-wire system, and the Hall system is a 3-wire system; The electromagnetic type does not need to be powered by electricity, and Hall's must have a power supply.

Advantages: Simple structure, low cost, disadvantages.

Output signal. The amplitude changes with the change of speed, if the speed is too slow, its output signal is lower than 1V, the electronic control unit.

It can't be detected.

The response frequency is not high. When the rotational speed is too high, the frequency response of the sensor cannot keep up.

Poor anti-electromagnetic interference ability.

Both photoelectric speed sensors and Hall sensors can be used to detect rotational speed, but their principles and areas of application differ.

The photoelectric speed sensor converts the reflected light or penetrating light signal received by the photoelectric head into the cam and other objects on the rotating object. The sensor is suitable for speed detection at high rotational speeds, small diameters of objects, and no oxidation or scratches on the surface of rotating objects. And since the photohead senses the rotational speed by sensing the light signal, the sensor can also be used to detect the position or angular rent of a rotating object.

Hall sensors detect rotational speed based on the principle of magnetic field sensing. When an object passes with an electric current, a magnetic field is formed around it. The change in the magnetic field sensed by the Hall sensor is converted into an electrical signal output that detects the rotational speed of the object.

The sensor is suitable for speed detection in the case of oxidation or scratches on the surface of rotating objects or large diameters. Hall sensors are also often used to detect the strength or direction of magnetic fields because they are less interfering with the ambient magnetic field.