CN203708237U

CN203708237U - LAS signal control unit based on ARM Cortex-M3 single-chip microcomputer

Info

Publication number: CN203708237U
Application number: CN201320836937.3U
Authority: CN
Inventors: 王立东; 路远; 时勇
Original assignee: Tianjin 712 Communication and Broadcasting Co Ltd
Current assignee: Tianjin 712 Communication and Broadcasting Co Ltd
Priority date: 2013-12-18
Filing date: 2013-12-18
Publication date: 2014-07-09
Anticipated expiration: 2023-12-18

Abstract

The utility model relates to a LAS signal control unit based on an ARM Cortex-M3 single-chip microcomputer. A control unit circuit comprises an ARM Cortex-M3 single-chip microcomputer, a balance-unbalance converting circuit, a 14-core host interface used for transmitting balance signals, an unbalance-balance converting circuit, a 14-core MMI (Man-Machine interface) interface used for transmitting balance signals, a first switch selection circuit, a second switch selection circuit and a power supply circuit. By adopting an AD function and an PWM (Pulse-Width Modulation) function of the ARM Cortex-M3 single-chip microcomputer, AD acquisition and PWM reduction are carried out on the audio signals, and whether the audio signals include LAS sound with 820 Hz (+/-10Hz) is detected. When the LAS sound is detected, the LAS sound is restrained or damped maximally. When the LAS sound is not detected in a voice signal, a message is sent to the MMI and a prompt is sent to a driver through the MMI. The beneficial effects of the LAS signal control unit based on the ARM Cortex-M3 single-chip microcomputer are that: in a shunting process, the LAS sound is detected automatically to prompt a shunting driver that a conversation link maintains well without the need for operation by the driver. Only the sound with Fo=820 Hz and Df=20 Hz is processed, and the conversation quality is not influenced.

Description

A kind of LAS signaling control unit based on ARM Cortex-M3

Technical field

The utility model relates to communication technical field, be particularly related to the LAS signaling control unit based on ARM Cortex-M3, for audio signal is sampled, reduced, guaranteeing that audio signal tries one's best under complete prerequisite, detect characteristic frequency (820Hz ± 20Hz) signal.

Background technology

At present, in railway shunting system, for guaranteeing that the driver that shunts carries out safely shunting service, need shunter, by handheld device, it is carried out to task instruction, shunter will keep call with the driver's moment of shunting, and to guarantee the driver's shunting safety of shunting, whether the driver that shunts is to converse to judge whether the talking link between shunter keeps good, when the driver that shunts can't hear shunter while talking, the driver that shunts cannot judge that whether call is normal.

UIC(Europe alliance) at FRS(Function Requirement Specification) and SRS(System Requirement Specification) in propose Cab Radio equipment and should possess Shunting Mode(shunting mode), wherein LAS(link assurance signal) be exactly intact for shunt driver and shunter's talking link of prompting, realize above-mentioned requirements, must there is corresponding equipment, and not yet there is manufacturer production in current domestic car transferring system, this type of detects the device of this signal, also has no in the literature correlation technique report.

Summary of the invention

The purpose of this utility model is exactly for overcoming the deficiencies in the prior art, for railway shunting system action need, a kind of design of the LAS signaling control unit based on ARM Cortex-M3 is provided, form the minimum system of LAS control unit based on ARM Cortex-M3 series monolithic, in the hope of realize the detection to LAS sound by the utility model, connect with the display terminal of Cab Radio, and by display terminal, LAS sound is pointed out, the driver that makes to shunt can be cancelled and be detected LAS function and shielding LAS prompt tone by operation display terminal.

The utility model is to realize by such technical scheme: a kind of LAS signaling control unit based on ARM Cortex-M3, it is characterized in that, control unit circuit comprises 14 core MMI interfaces, the first switch selection circuit of 14 core host interface of ARM Cortex-M3, balance-non-equilibrium change-over circuit, transmitting balance signal, non-equilibrium-balance change-over circuit, transmitting balance signal, and second switch is selected circuit and power circuit;

ARM Cortex-M3 is connected with balance-non-equilibrium change-over circuit output by AD port, is connected with non-equilibrium-balance change-over circuit by DA port, be connected with the first relay, the second relay end respectively by IO port,

The input of balance-non-equilibrium change-over circuit is connected with 14 core host interface; 14 core host interface are used for connecting Cab Radio;

The output of non-equilibrium-balance change-over circuit is connected with 14 core MMI interfaces; 14 core MMI interfaces are used for connecting display terminal (MMI);

The first switch selects circuit to comprise the first relay, the coil-end of the first relay is controlled by an IO end of ARM Cortex-M3, Chang Kaiduan connects the TXD end of ARM Cortex-M3, and normal-closed end connects 14 core host interface TXD ends, and common port connects the TXD end of 14 core MMI interfaces; Second switch selects circuit to comprise the second relay, the coil-end of the second relay is controlled by an IO end of ARM Cortex-M3, Chang Kaiduan connects the input of balance-non-equilibrium change-over circuit, and normal-closed end connects MMI audio input end, and common port connects the audio output of 14 core host interface;

Balance-non-equilibrium change-over circuit comprises change-over circuit and amplifying circuit;

Non-equilibrium-balance change-over circuit comprises change-over circuit, amplifying circuit and filter circuit;

Power circuit is complete machine power supply.

LAS control unit is arranged between Cab Radio and display terminal (MMI), connected mode adopts 14 core cables, form the minimum system of LAS signaling control unit based on ARM Cortex-M3 single-chip microcomputer, utilize the AD/DA function of single-chip microcomputer to realize the collection/reduction of audio signal, realize and the serial communication of Cab Radio display terminal by RXD/TXD.

The beneficial effects of the utility model are: realized 1, shunt in process by the utility model, automatically detect LAS sound, point out the driver's talking link of shunting to remain intact, carry out other operations without driver; 2, only for Fo=820Hz, the LAS sound of Df=20Hz is processed, and does not affect speech quality.

Accompanying drawing explanation

Fig. 1, LAS signaling control unit circuit block diagram based on ARM Cortex-M3

Fig. 2, the utility model application fundamental block diagram;

Fig. 3, signal processing flow figure;

Fig. 4, power circuit principle figure;

Fig. 5, balance-non-equilibrium change-over circuit figure;

Fig. 6, balance-non-equilibrium change-over circuit figure;

Fig. 7, the first switch are selected circuit diagram;

Fig. 8, second switch are selected circuit diagram.

Embodiment

Understand the utility model for clearer, describe in conjunction with the accompanying drawings and embodiments the utility model in detail:

As shown in accompanying drawing 1 to Fig. 8, LAS signaling control unit based on ARM Cortex-M3, control unit circuit comprises 14 core MMI interfaces, the first switch selection circuit of 14 core host interface of ARM Cortex-M3, balance-non-equilibrium change-over circuit, transmitting balance signal, non-equilibrium-balance change-over circuit, transmitting balance signal, and second switch is selected circuit and power circuit;

ARM Cortex-M3 is connected with balance-non-equilibrium change-over circuit output by AD port, be connected with non-equilibrium-balance change-over circuit by DA port, be connected with the first relay, the second relay end respectively by IO port, the input of balance-non-equilibrium change-over circuit is connected with 14 core host interface; 14 core host interface are used for connecting Cab Radio;

LAS control unit adopts the LPC75176 single-chip microcomputer in ARM Cortex-M3 series to form minimum system, mainly applies AD/DA function and the serial ports transmission-receiving function of LPC75176 single-chip microcomputer.

Power circuit, for LAS control unit provides 5V, 3.3V, 1.8V, control the first Control by ARM Cortex-M3, switch the serial communication passage between Cab Radio, LAS control unit, MMI three, default conditions are: connect the serial ports path between Cab Radio and MMI, in the time that LAS control unit (ARM Cortex-M3) can't detect LAS signal, by controlling the first relay, switching over is arrived to normally open, connect the serial ports path between LAS control unit and MMI.

Control the second relay by ARM Cortex-M3: select whether to detect LAS signal, LAS control unit acquiescence does not detect LAS signal, and the second relay keeps being connected between Cab Radio and MMI, the signal that comes from Cab Radio directly sends to MMI end.

The first switch selects circuit to be made up of transistor, resistance device and relay, and wherein transistor forms switching circuit;

Second switch selects circuit to be made up of transistor, resistance device and relay, and wherein transistor forms switching circuit;

Balance-non-equilibrium change-over circuit comprises change-over circuit and amplifying circuit; Change-over circuit is made up of transformer T1 and Resistor-Capacitor Unit, and amplifying circuit is made up of operational amplifier and Resistor-Capacitor Unit;

Non-equilibrium-balance change-over circuit comprises filter circuit, amplifying circuit and change-over circuit; Filter circuit is made up of Resistor-Capacitor Unit, and amplifying circuit is made up of operational amplifier and Resistor-Capacitor Unit, and change-over circuit is made up of transformer T2 and Resistor-Capacitor Unit.

According to the above description, can realize scheme of the present utility model in conjunction with art technology.

Claims

1. the LAS signaling control unit based on ARM Cortex-M3, it is characterized in that, control unit circuit comprises 14 core MMI interfaces, the first switch selection circuit of 14 core host interface of ARM Cortex-M3, balance-non-equilibrium change-over circuit, transmitting balance signal, non-equilibrium-balance change-over circuit, transmitting balance signal, and second switch is selected circuit and power circuit;

Power circuit is complete machine power supply;

2. a kind of LAS signaling control unit based on ARM Cortex-M3 as claimed in claim 1, is characterized in that, power circuit provides 5V, 3.V, 1.8V power supply for LAS control unit.

3. a kind of LAS signaling control unit based on ARM Cortex-M3 as claimed in claim 1, is characterized in that, the first switch selects circuit to comprise the relay drive circuit being made up of transistor; Second switch selects circuit to comprise the relay drive circuit being made up of transistor.

4. a kind of LAS signaling control unit based on ARM Cortex-M3 as claimed in claim 1, is characterized in that, balance-non-equilibrium change-over circuit comprises change-over circuit and amplifying circuit; Change-over circuit is made up of transformer T1 and Resistor-Capacitor Unit, and amplifying circuit is made up of operational amplifier and Resistor-Capacitor Unit; Non-equilibrium-balance change-over circuit comprises filter circuit and change-over circuit; Filter circuit is made up of Resistor-Capacitor Unit, and change-over circuit is made up of transformer T2 and Resistor-Capacitor Unit.