Signal detection method of speed sensor based on eddy current principle

Abstract

The invention relates to a signal detection method of a speed sensor based on an eddy current principle. The method comprises steps that when CH1 or CH2 changes along each time, a periodic pulse A, aperiodic pulse B and a periodic pulse C are generated; pulse edges of the two channels CH1 and CH2 are alternately changed every time; when no phase exists due to the fact that train wheels stop moving, the waveform is kept in an original output state, when the train is stopped being powered on, three-phase pulse input is defaulted, A and B paths are in high levels and the C path is in low level;when one state of three paths of pulses occurs, that a detection channel breaks down is considered; the three paths of pulses are respectively collected, and that a rising edge of the pulse is valid is determined when the rising edge is received each time and the high levels last for a certain time; when the path A is ahead of the path B and the path B is ahead of the path C, that the direction isforward is determined; when the path A lags behind the path B and the path B lags behind the path C, that the direction is reverse is determined; and if the pulse is not received in the continuous Wseconds, that no phase exists is determined.

Description

technical field [0001] The invention relates to the speed measurement technology of the urban rail transit signal system, in particular to a signal detection method of a speed sensor based on the principle of eddy current. Background technique [0002] In the urban rail transit signal system, some trains use eddy current speed sensors as speed sensors. Although such sensors have higher reliability and stability, the output of eddy current speed sensors is FM modulation signal. Due to the signal characteristics and It is not intuitive, so it will be relatively difficult to perform performance testing on it. In addition, most trains in China now use photoelectric speed sensors as speed sensors, and the on-board ATC system is also mainly designed with three-way pulse channel interfaces. The development trend of the eddy current speed sensor and the adaptation of the vehicle ATC system is also a problem. [0003] At present, the development trend of domestic vehicle ATC systems...

AI Technical Summary

Problems solved by technology

[0002] In the urban rail transit signal system, some trains use eddy current speed sensors as speed sensors. Although such sensors have higher reliability and stability, the output of eddy current speed sensors is FM modulation signal. Due to the signal characteristics and It is not intuitive, so it will be relatively difficult to perform performance testing on it. In addition, most trains in China now use photoelectric speed sensors as speed sensors, and the on-board ATC system is also mainly designed with three-way pulse channel interfaces. The development trend of the eddy current speed sensor and the adaptation of the vehicle ATC system is also a problem

[0003] At present, the development trend of the domestic vehicle ATC system is gradually turning to docking with the photoelectric speed sensor. Therefore, the original eddy current speed sensor cannot be adapted to the interface of some vehicle ATC systems.

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