Full redundancy speed measurement method and system for rail

A full redundancy speed measurement method for a rail train, applicable to a full redundancy speed measurement system for a rail train, wherein the full redundancy speed measurement system for a rail train includes a multi-channel speed sensor, an active speed measurement system, a standby speed measurement system, and an active/standby switching device, the multi-channel speed sensor has a plurality of dual-channel groups, the active speed measurement system and the standby speed measurement system both include a speed sensor detection and switching device, a logic processing device, an accelerometer device, and a speed measurement processing device, and the method comprising:

• operating the active speed measurement system and the standby speed measurement system,
• performing, by the active/standby switching device, switching between the active speed measurement system and the standby speed measurement system;
• inputting, by the multi-channel speed sensor, a pulse signal and a phase difference to the active speed measurement system and the standby speed measurement system, wherein a phase difference exists between channels in the dual-channel groups;
• receiving, by the speed sensor detection and switching device, the pulse signal inputted by the multi-channel speed sensor, the speed sensor detection and switching device detecting, by the speed sensor detection and switching device, whether power supply of the multi-channel speed sensor and the pulse signal are normal, and outputting the detected normal pulse signal to the accelerometer device and the speed measurement processing device, and performing, by the speed sensor detection and switching device, switching between different multi-channel speed sensors and between different channel groups;
• receiving, by the accelerometer device, the detected normal pulse signal and the phase difference, calculating, by the accelerometer device, a speed value and an acceleration value of each channel based on the detected normal pulse signal and outputting the speed value and the acceleration value of each channel to the speed measurement processing device, and determining a train running direction based on phase difference;
• receiving and processing, by the speed measurement processing device, the detected normal pulse signal and determining whether the speed value of each channel is in a reasonable interval based on the speed value and the acceleration value of each channel, and determining whether the speed value of each channel in the reasonable interval conforms to the control logic and outputting the speed value of each channel to the logic processing device;
• receiving, by the logic processing device, the speed value of each channel outputted by the speed measurement processing device, and performing, by the logic processing device, a consistency voting on the outputted the speed value of each channel;
• and
• outputting a train running direction and the speed value to a train control system after the consistency voting is approved.