LAS signal control unit based on arm Cortex-M3

Abstract

The invention relates to an ARM (advanced RISC machine) Cortex-M3-based LAS (link acknowledgment signal) control unit. A control unit circuit comprises an ARM Cortext-M3 single-chip microcomputer, a balance-unbalance conversion circuit, a 14-core host interface for transmitting a balance signal, an unbalance-balance conversion circuit, a 14-core MMI (man-machine interface) for transmitting a balance signal, a first switch selection circuit, a second switch selection circuit and a power circuit, wherein an AD (analogue-to-digital) function and a PWM (pulse width modulation) function of the ARM Cortext-M3 single-chip microcomputer are used for performing AD acquisition and PWM restoration on an audio signal, detecting whether the audio signal comprises LAS sounds of 820Hz (+ / -10Hz) or not, suppressing or maximally attenuating the LAS sounds when the audio signal is detected to comprise the LAS sounds, and transmitting a message to the MMI to give a prompt to a driver through the MMI if the audio signal is detected not to comprise the LAS sounds. The control unit has the beneficial effects that the LAS sounds are automatically detected in a shunting process, the good condition of a call link is prompted to a shunting driver, and the driver is not required to perform other operation; only the LAS sounds with Fo of 820Hz and Df of 20Hz are processed, so that influence on call quality is avoided.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to an ARM Cortex-M3-based LAS signal control unit, which is used for sampling and restoring audio signals, and detecting signals of a specific frequency (820Hz±20Hz) under the premise of ensuring that the audio signals are as complete as possible. Background technique [0002] At present, in the railway shunting system, in order to ensure the safety of the shunting driver, the shunting operator needs to use a handheld device to guide the operation. The shunting operator must keep talking with the shunting driver at all times to ensure that the shunting driver Shunting is safe. The shunting driver judges whether the communication link with the shunting operator is maintained by whether or not he is talking. When the shunting driver cannot hear the shunting operator speaking, the shunting driver cannot judge whether the call is normal. [0003] UIC (Europea...

AI Technical Summary

Problems solved by technology

[0002] At present, in the railway shunting system, in order to ensure the safety of the shunting driver, the shunting operator needs to use a handheld device to guide the operation. The shunting operator must keep talking with the shunting driver at all times to ensure that the shunting driver Shunting is safe. The shunting driver judges whether the communication link with the shunting man is maintained by whether he is talking. When the shunting driver cannot hear the shunting man’s speech, the shunting driver cannot judge whether the call is normal.

[0003] UIC (European Union of Railways) proposed in FRS (Function Requirement Specification) and SRS (System Requirement Specification) that Cab Radio equipment should have Shunting Mode (shunting mode), in which LAS (link confirmation signal) is used to prompt shunting drivers The communication link with the shunting operator is intact. To realize the above requirements, there must be corresponding equipment. At present, there is no manufacturer in the domestic shunting system that produces such a device for detecting this signal, and there is no relevant technical report in the literature.

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