Non-contact electronic vehicle speed sensor and vehicle speed detection method

Abstract

The invention discloses a non-contact electronic vehicle speed sensor and a vehicle speed detection method, wherein the vehicle speed sensor comprises a shell, an electronic circuit, a socket connector, magnetic steel and a Hall element, wherein the electronic circuit is positioned inside the shell, the socket connector is used for signal output, and the magnetic steel is installed in the shell and is permanent magnet steel and can provide a static magnetic field. The vehicle speed sensor collects the signal of a gearbox signal gear; when the gear rotates, the density of magnetic lines penetrating through the Hall element is changed to cause the change of Hall voltages, and the Hall element outputs a quasi-sine-wave voltage in a millivolt grade. The quasi-sine-wave voltage is converted into a standard pulse voltage through the magnification of the electronic circuit and is then output through the socket connector. The non-contact electronic vehicle speed sensor has the advantages of noinfluence on output signal voltage amplitudes by rotary speeds, high frequency response, high precision, durability and the like.

Description

technical field [0001] The invention belongs to the field of automotive electronics, in particular to a non-contact electronic vehicle speed sensor. Background technique [0002] At present, the commonly used vehicle speed sensor is composed of driven gear, driven shaft, housing, connector, sealing ring, internal circuit and multi-stage magnetic steel. The principle is: when the car is running, the driven shaft of the mileage sensor rotates through the meshing of the driving gear of the gearbox (also called the mileage gear) with the driven gear of the mileage sensor, and the rotation of the multi-pole magnetic steel in the mileage sensor produces alternating changes. The Hall element circuit inside the mileage sensor generates a square wave signal with constant amplitude and duty cycle through the Hall effect, and only the frequency changes, and the frequency of the square wave signal is proportional to the speed of the driven shaft of the mileage sensor relation. By dete...

AI Technical Summary

Problems solved by technology

[0003] However, in practical applications, it is found that although it can successfully detect the vehicle speed, the effect is not good. In the process of use, the error between the vehicle speed and the actual vehicle speed is large. After the vehicle travels to a certain mileage, it is often found whether there is a vehicle speed signal or a signal instability

These phenomena indicate that the accuracy of the currently used vehicle speed sensors still needs to be improved during their service life.

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