Noncontact train photoelectric speed sensing device

Abstract

The invention provides a noncontact train photoelectric speed sensing device comprising a photoelectric pulse generation circuit, a forward charge and discharge circuit, a reverse charge and discharge circuit and a data selector. The working principle is that gating of one path of the forward charge and discharge circuit and the reverse charge and discharge circuit is controlled to act as output pulses by the data selector so that the interference of positive narrow pulses in the negative wide pulse period and negative narrow pulses in the positive wide pulse period can be automatically filtered, and especially continuous button or switch contact jitter narrow pulse interference signals can be filtered; the maximum width of the positive narrow pulses required to be filtered can be adjusted by changing the size of output driving current of a forward current driver or the size of forward anti-interference capacitance; and the maximum width of the negative narrow pulses required to be filtered can be adjusted by changing the size of output driving current of a reverse current driver or the size of reverse anti-interference capacitance. The device can be applied to the occasion of train speed detection.

Description

technical field [0001] The invention relates to a sensing and detecting device for rail transit vehicles, in particular to a non-contact photoelectric speed sensing device for trains. Background technique [0002] In the measurement of train speed, magnetoelectric speed sensors and permanent magnet speed sensors have been seldom used due to their reliability and accuracy. At present, there are four kinds of interchangeable photoelectric speed sensors commonly used, and the latest two types , namely TQG9 and TQG15 photoelectric speed sensors. [0003] Photoelectric speed sensors generally have the problems of serious light source pollution and large output waveform distortion. The photoelectric sensor uses a light source to change into intermittent light through the grating disc rotating with the wheel shaft. Since it is a universal joint, this transmission mechanism is directly connected to the inner cavity of the wheel axle box, and it cannot achieve a fully sealed state i...

AI Technical Summary

Problems solved by technology

[0003] Photoelectric speed sensors generally have the problems of serious light source pollution and large output waveform distortion

The photoelectric sensor uses a light source to change into intermittent light through the grating disc rotating with the wheel shaft. Since it is a universal joint, this transmission mechanism is directly connected to the inner cavity of the wheel axle box, and it cannot achieve a fully sealed state in structure. The grating Disc contamination can distort the optical signal, and mutual contamination produces interference pulses

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