Broadcast intercom system for rail transit

Abstract

The invention provides a broadcast intercom system for rail transit, which can realize a double-line broadcast intercom system of an analog line and an Ethernet digital line, can overcome the defect that an early analog bus system is incompatible with a novel digital Ethernet system, can eliminate intercom echoes and audio howling during intercom, and has the advantages of simple structure, low cost and high practicability. Which comprises a plurality of driver control terminals, each driver control terminal comprises a passenger control unit, and the passenger control unit is connected with a loudspeaker and a microphone, and is characterized in that the driver control terminals are connected with other driver control terminals through a digital Ethernet bus and an analog bus respectively; the passenger control unit is connected with a passenger room broadcasting unit through a digital Ethernet bus and an analog bus and used for intercommunication between the driver control terminals, and the passenger room broadcasting unit is further connected with the passenger room broadcasting unit through a digital Ethernet bus and an analog bus and used for broadcasting of the driver control terminals; the passenger control unit is also connected with a passenger alarm terminal through a digital Ethernet bus and an analog bus, and is used for passenger emergency alarm talkback between the driver control terminal and the passenger alarm terminal.

Description

Technical Field

[0001] The present invention relates to the technical field of urban rail transit train communication, and particularly to a broadcast intercom system for rail transit. Background Art

[0002] Most of the previously designed subway train PIS broadcast intercom systems used analog bus intercom. Later, with the development of technology, digital intercom based on Ethernet communication emerged. The two are independent of each other and are respectively applied to different projects. However, in actual applications, different projects need to use different types of broadcast intercom systems, or need to upgrade and transform old systems. Therefore, a broadcast intercom system that can be compatible with analog buses and Ethernet digital lines is required.

[0003] In addition, whether it is an analog line or an Ethernet digital line, problems such as intercom echo and howling will occur during intercom. The reason for the intercom echo is that the local SPK speaker will output the sound input by the local MIC; the local MIC audio input is uploaded to the analog intercom bus. After the audio signal on the intercom bus is collected at the opposite end and output to the SPK speaker, the output audio is collected by the MIC at the opposite end and then transmitted back to the local SPK speaker for output. Howling is a feedback sound. In a broadcast intercom system, a harsh screeching sound will be generated when the feedback loop causes the audio signal to increase excessively. Summary of the Invention

[0004] In view of the above problems, the present invention provides a broadcast intercom system for rail transit, which can implement a dual-line broadcast intercom system for analog lines and Ethernet digital lines, can overcome the defect that the early analog bus system and the new digital Ethernet system are incompatible with each other, and can also eliminate intercom echo and audio howling during intercom.

[0005] Its technical solution is as follows: A broadcast intercom system for rail transit, comprising: a driver control terminal, a plurality of the driver control terminals are provided, the driver control terminal includes a passenger control unit, the passenger control unit is connected with a speaker and a microphone, and is characterized in that: the driver control terminal is respectively connected to other driver control terminals through a digital Ethernet bus and an analog bus for intercom between the driver control terminals; the passenger control unit is also connected to a passenger compartment broadcast unit through a digital Ethernet bus and an analog bus for the driver control terminal to broadcast; the passenger control unit is also connected to a passenger alarm terminal through a digital Ethernet bus and an analog bus for the driver control terminal to conduct passenger emergency alarm intercom with the passenger alarm terminal.

[0006] Further, the passenger control unit includes an IMX6Q core board. The microphone of the driver control terminal is connected to the first operational amplifier chip of the passenger control unit. The first operational amplifier chip is connected to an analog line echo cancellation and noise reduction chip, which is used to eliminate echoes during the intercom. The analog line echo cancellation and noise reduction chip is connected to the first power amplifier chip and a transformer and then connected to a broadcast control relay. The IMX6Q core board is connected to the broadcast control relay, and the broadcast control relay is connected to the broadcast bus in the analog bus for the driver control terminal to broadcast through the analog bus.

[0007] Further, the intercom control relay is connected to the intercom bus in the analog bus. The intercom bus in the analog bus is also connected to the analog line echo cancellation and noise reduction chip after connecting to the second operational amplifier chip. The analog line echo cancellation and noise reduction chip is also connected to an intercom volume adjustment chip. The intercom volume adjustment chip is connected to the second power amplifier chip through an analog switch. The second power amplifier chip is connected to the intercom control relay, and the intercom control relay is connected to the intercom speaker. The IMX6Q core board is respectively connected to the intercom volume adjustment chip, the analog switch, and the intercom control relay for the driver control terminals to intercom through the analog bus.

[0008] Further, the passenger control unit includes an IMX6Q core board. The microphone of the driver control terminal is connected to the third operational amplifier chip of the passenger control unit. The third operational amplifier chip is connected to a digital Ethernet line echo cancellation and noise reduction chip, which is used to eliminate echoes during the intercom. The digital Ethernet line echo cancellation and noise reduction chip is connected to the audio signal acquisition port of the IMX6Q core board. The audio power amplifier of the IMX6Q core board encodes the audio data. The IMX6Q core board is connected to the passenger compartment broadcast unit through the digital Ethernet bus for the driver control terminal to broadcast through the digital Ethernet bus.

[0009] Further, the IMX6Q core board of the driver control terminal is connected to the IMX6Q core board of other driver control terminals through the digital Ethernet bus. The audio power amplifier of the IMX6Q core board decodes the received audio data. The IMX6Q core board is connected to the intercom volume adjustment chip through the audio output port. The audio output port of the IMX6Q core board is also connected to the digital Ethernet line echo cancellation and noise reduction chip to send the feedback signal to the digital Ethernet line echo cancellation and noise reduction chip. The intercom volume adjustment chip is connected to the second power amplifier chip through an analog switch. The second power amplifier chip is connected to the intercom control relay, and the intercom control relay is connected to the intercom speaker. The IMX6Q core board is respectively connected to the intercom volume adjustment chip, the analog switch, and the intercom control relay for the driver control terminals to intercom through the digital Ethernet bus.

[0010] Furthermore, it further includes a monitoring module. The monitoring module includes a fourth operational amplifier chip connected to the broadcast bus in the analog bus. The fourth operational amplifier chip is connected to a third power amplifier chip, and the third power amplifier chip is connected to a monitoring speaker after connecting a monitoring relay, for monitoring the broadcast on the analog bus.

[0011] Furthermore, the IMX6Q core board of the passenger control unit is connected to a TFT-LCD display screen with an LVDS interface through the LVDS interface; the IMX6Q core board is connected to a resistive touch screen through the TSC interface, the IMX6Q core board is connected with a 4-way button keyboard, and the IMX6Q core board is provided with an isolated RS485 interface and an isolated RS232 interface.

[0012] Furthermore, the passenger compartment broadcast unit includes a passenger compartment AMP power amplifier board and a passenger compartment speaker, and the passenger alarm terminal includes an alarm microphone and an alarm speaker.

[0013] In the prior art, analog bus intercom and digital intercom are independently applied. The present invention realizes a dual-line broadcast intercom system for analog lines and Ethernet digital lines, which can overcome the defect that the early analog bus system and the new digital Ethernet system are incompatible with each other, and can solve the adaptation problems caused by different technical solutions adopted in rail transit projects constructed in different periods. At the same time, the dual-line broadcast intercom of the analog line and the Ethernet digital line of the present invention can meet the higher requirements for safety redundancy. In addition, the present invention adopts an analog echo processing chip and a digital echo cancellation and noise reduction chip to optimize the analog line and the Ethernet digital line respectively, which can significantly reduce or even eliminate the echo during the intercom, and effectively suppress the generation of audio howling, so as to improve the call quality, enabling the driver to communicate with passengers or between drivers more clearly and accurately in case of emergency, and ensuring the safe operation of the train. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a system block diagram of a broadcast intercom system for rail transit in an embodiment;

[0015] Figure 2 It is a circuit schematic block diagram of a broadcast intercom system for rail transit in an embodiment;

[0016] Figure 3 It is a schematic flow chart when the broadcast intercom system for rail transit in an embodiment conducts intercom and broadcast. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] See Figure 1, A broadcast intercom system for rail transit according to the present invention includes: a driver control terminal 1, and a plurality of driver control terminals 1 are provided. The driver control terminal 1 includes a passenger control unit, the passenger control unit is connected to a speaker and a microphone, and the driver control terminal 1 is respectively connected to other driver control terminals 1 through a digital Ethernet bus and an analog bus for intercom between the driver control terminals 1. The passenger control unit is also connected to the passenger compartment broadcast unit 2 through the digital Ethernet bus and the analog bus for the driver control terminal 1 to broadcast; the passenger control unit is also connected to the passenger alarm terminal 3 through the digital Ethernet bus and the analog bus for the driver control terminal 1 to conduct passenger emergency alarm intercom with the passenger alarm terminal 3. In practice, the passenger compartment broadcast unit 2 includes a passenger compartment AMP power amplifier board and a passenger compartment speaker, and the passenger alarm terminal 3 includes an alarm microphone and an alarm speaker.

[0018] The broadcast intercom system for rail transit in the embodiment adopts a dual-line broadcast intercom solution of analog lines and Ethernet digital lines, enabling various communication methods between driver control terminals, between the driver control terminal and the passenger compartment broadcast unit, and between the driver control terminal and the passenger alarm terminal, greatly broadening the application scenarios of the product, meeting the requirements of broadcast intercom systems in different periods and of different types. It is applicable to both early analog systems, modern digital systems, and dual-line systems with special safety requirements, which can enhance the market competitiveness of the product.

[0019] See Figure 2 , Specifically, in an embodiment of the present invention, in order to enable the driver control terminal to broadcast through the analog bus, the following settings are made: The passenger control unit includes an IMX6Q core board. The microphone of the driver control terminal is connected to the first operational amplifier chip SA5532 of the passenger control unit. The first operational amplifier chip SA5532 is connected to the analog line echo cancellation and noise reduction chip ML7037-003TB. The analog line echo cancellation and noise reduction chip ML7037-003TB is used for noise reduction, which can significantly reduce or even eliminate the echo during intercom and effectively suppress the generation of audio howling at the same time. The analog line echo cancellation and noise reduction chip ML7037-003TB is connected to the first power amplifier chip LM4950 and a transformer and then connected to the broadcast control relay. The IMX6Q core board is connected to the broadcast control relay, and the broadcast control relay is connected to the broadcast bus in the analog bus.

[0020] In the embodiment, for the intercom between driver control terminals through the analog bus, the following settings are also made: The intercom control relay is connected to the intercom bus in the analog bus. The intercom bus in the analog bus is also connected to the analog line echo cancellation and noise reduction chip ML7037-003TB after connecting the second operational amplifier chip SA5532. The analog line echo cancellation and noise reduction chip ML7037-003TB is also connected to the intercom volume adjustment chip MAX5410. The intercom volume adjustment chip MAX5410 is connected to the second power amplifier chip LM4950 through an analog switch. The second power amplifier chip LM4950 is connected to the intercom control relay. The intercom control relay is connected to the intercom speaker. The IMX6Q core board is respectively connected to the intercom volume adjustment chip, the analog switch, and the intercom control relay.

[0021] Specifically, in an embodiment of the present invention, in order to implement the broadcast of the driver control terminal through the digital Ethernet bus, the following settings are made:

[0022] The passenger control unit includes an IMX6Q core board. The microphone of the driver control terminal is connected to the third operational amplifier chip SA5532 of the passenger control unit. The third operational amplifier chip SA5532 is connected to the digital Ethernet line echo cancellation and noise reduction chip PNC201. The digital Ethernet line echo cancellation and noise reduction chip PNC201 is used for noise reduction, which can significantly reduce or even eliminate the echo during the intercom, and at the same time effectively suppress the generation of audio howling. The digital Ethernet line echo cancellation and noise reduction chip PNC201 is connected to the audio signal acquisition port of the IMX6Q core board. The audio power amplifier of the IMX6Q core board encodes the audio data. The IMX6Q core board is connected to the passenger compartment broadcast unit through the digital Ethernet bus.

[0023] In the embodiment, for the intercom between driver control terminals through the digital Ethernet bus, the following settings are also made: The IMX6Q core board of the driver control terminal is connected to the IMX6Q core board of other driver control terminals through the digital Ethernet bus. The audio power amplifier WM8960G of the IMX6Q core board decodes the received audio data. The IMX6Q core board is connected to the intercom volume adjustment chip MAX5410 through the audio output port. The audio output port of the IMX6Q core board is also connected to the digital Ethernet line echo cancellation and noise reduction chip PNC201, which is used to send the feedback signal to the digital Ethernet line echo cancellation and noise reduction chip PNC201. The intercom volume adjustment chip is connected to the second power amplifier chip LM4950 through an analog switch. The second power amplifier chip LM4950 is connected to the intercom control relay. The intercom control relay is connected to the intercom speaker. The IMX6Q core board is respectively connected to the intercom volume adjustment chip, the analog switch, and the intercom control relay, which is used for the intercom between driver control terminals through the digital Ethernet bus.

[0024] In the prior art, both analog bus intercom and digital intercom have problems of intercom echo and howling. The present invention adopts different chips to perform targeted processing on analog lines and digital lines respectively. In the analog line, through the noise threshold control of the front-end operational amplifier chip, echo cancellation and noise reduction of the echo cancellation and noise reduction chip, and non-linear distortion compensation of the power amplifier chip, a multi-level echo blocking barrier is formed. Combining the step-up transformer and the power amplifier can maintain signal integrity during long-distance transmission. The built-in adaptive impedance matching function of the ML7037 echo cancellation and noise reduction chip can effectively cope with the impedance changes of different cables and reduce signal reflection; the digital line relies on the PNC201 chip and the Ethernet transmission characteristics. The PNC201 chip can eliminate full-band echo above 50 dB and suppress residual howling through non-linear compensation, and can perform high-precision processing on audio signals;

[0025] On both analog lines and digital lines, during intercom, intercom echo can be effectively eliminated and the generation of audio howling can be suppressed, improving the audio quality of the broadcast intercom system, making the calls between drivers and passengers and between drivers clearer and more stable, reducing the interference caused by echo and howling, and improving the performance of the broadcast intercom system.

[0026] See Figure 3 , in the embodiment, during the broadcast process on the analog bus, the data flow is as follows:

[0027] The microphone (MIC) of the driver control terminal undertakes the sound collection work and converts the sound signal to be broadcast into an electrical signal;

[0028] The electrical signal enters the first operational amplifier chip SA5532. The first operational amplifier chip SA5532 will amplify the input weak audio signal. After being processed by the first operational amplifier chip SA5532, the signal voltage amplitude is greatly increased, meeting the input standard of the subsequent audio processing chip;

[0029] The amplified audio signal then enters the analog line echo cancellation and noise reduction chip ML7037-003TB. The analog line echo cancellation and noise reduction chip can perform gain or attenuation operations on different frequency bands of the audio according to different broadcast scenarios and actual needs, making the sound clearer; at the same time, the analog line echo cancellation and noise reduction chip will also carry out noise reduction processing to remove the noise mixed in the signal, optimize the audio quality, and significantly improve the amplitude and frequency characteristics of the processed audio signal;

[0030] The processed signal then enters the first power amplifier chip LM4950. The first power amplifier chip LM4950 is a chip dedicated to audio power amplification, used to increase the audio signal power to a level sufficient to drive loads such as speakers;

[0031] The audio signal output by the first power amplifier chip LM4950 is then connected to the audio bus step-up transformer. The step-up transformer increases the voltage amplitude of the audio signal according to its own turns ratio to achieve long-distance transmission on the broadcast bus and minimize the attenuation of the signal during transmission.

[0032] The boosted audio signal then arrives at the broadcast control relay. The broadcast control relay can control the on / off of the audio signal according to the control signal issued by the system. When the core board issues an instruction to turn on the broadcast, the broadcast control relay closes, and the audio signal can pass through smoothly and enter the broadcast bus. When it is necessary to stop the broadcast or switch the broadcast area, the relay opens, and the audio signal is cut off.

[0033] Finally, the audio signal transmitted through the broadcast bus reaches the passenger compartment broadcast unit. The passenger compartment broadcast unit has a passenger compartment AMP power amplifier board. The passenger compartment AMP power amplifier board will amplify the audio signal again. After processing, the passenger compartment AMP power amplifier board outputs the audio signal to drive the speakers in the passenger compartment to work, completing the analog broadcast to ensure that passengers can clearly hear the broadcast content.

[0034] In the embodiment, during the intercom process on the analog bus, the data flow is as follows:

[0035] The microphone (MIC) of a driver control terminal is responsible for collecting the voice signal of the intercom. It converts the voice of the intercom into an electrical signal. The electrical signal enters the second operational amplifier chip SA5532. The second operational amplifier chip SA5532 will amplify the weak audio signal to increase the signal voltage amplitude to meet the input requirements.

[0036] The amplified audio signal then enters the analog line echo cancellation and noise reduction chip ML7037-003TB. The analog line echo cancellation and noise reduction chip performs gain or attenuation operations on different frequency bands of the audio signal to make the sound clearer. At the same time, the analog line echo cancellation and noise reduction chip also performs noise reduction processing to remove the noise components in the signal and improve the audio quality.

[0037] The signal processed by the audio processing chip then arrives at the second power amplifier chip LM4950. The second power amplifier chip LM4950 amplifies the power of the audio signal to enable it to drive subsequent devices.

[0038] The audio signal output by the power amplifier is stepped up through the audio bus step-up transformer.

[0039] The boosted audio signal reaches the intercom control relay. The intercom control relay controls the on / off of the audio signal according to the control signal of the IMX6Q core board to realize the functions of opening and closing the intercom. When the relay closes, the audio signal enters the intercom bus and starts to be transmitted on the analog bus.

[0040] After the signal is transmitted to the driver control terminal at the opposite end through the intercom bus, the third operational amplifier chip SA5532 of the passenger control unit at the opposite end first collects the signal. The third operational amplifier chip SA5532 amplifies the signal transmitted on the bus again. The amplified signal enters the analog line echo cancellation and noise reduction chip ML7037-003TB at the opposite end, and also performs processing such as equalization adjustment and noise reduction to eliminate the echo during the intercom;

[0041] The processed signal enters the volume adjustment chip MAX5410 at the opposite end. This chip precisely adjusts the volume of the audio signal according to actual needs to meet the volume requirements in different scenarios. The signal with adjusted volume passes through the analog switch at the opposite end. The analog switch decides whether to continue transmitting the audio signal according to the instruction of the IMX6Q core board;

[0042] When the analog switch allows the signal to pass, the signal enters the second power amplifier chip LM4950 at the opposite end for power amplification. When the intercom control relay at the opposite end is closed, the amplified audio signal drives the intercom speaker at the opposite end to work, converting the electrical signal into a sound signal, thereby realizing the intercom function between the driver control terminals and realizing the voice communication between the driver control terminals.

[0043] In the embodiment, during the broadcast process on the digital Ethernet bus, the data flow is specifically as follows:

[0044] The microphone (MIC) of the driver control terminal undertakes the sound collection work and converts the sound signal to be broadcast into an electrical signal;

[0045] The electrical signal enters the operational amplifier chip SA5532. The operational amplifier chip SA5532 amplifies the input weak audio signal. After being processed by the operational amplifier chip SA5532, the signal voltage amplitude is greatly increased, meeting the input standard of the subsequent audio processing chip;

[0046] The audio signal amplified by the operational amplifier chip SA5532 enters the digital Ethernet line echo cancellation and noise reduction chip PNC201. The digital Ethernet line echo cancellation and noise reduction chip PNC201 processes the possible echo and noise problems in the Ethernet transmission environment, eliminates the echo and reduces the noise component in the signal at the same time, ensures the purity and clarity of the audio signal, and provides a better signal source for the subsequent processing links;

[0047] The processed audio signal arrives at the i.MX6Q core board for audio signal acquisition. The i.MX6Q core board acquires the audio signal after echo cancellation and noise reduction processing, converts the analog signal into a digital signal form, and encodes the acquired audio digital signal; the encoded audio data is transmitted through the Ethernet bus;

[0048] When the passenger compartment broadcast unit receives the encoded audio data through the Ethernet bus,

[0049] the passenger compartment AMP power amplifier board will first perform a data decryption operation to restore the encoded audio data to the original audio digital signal form. The passenger compartment AMP power amplifier board amplifies the decrypted audio signal, drives the speaker to work, converts the audio digital signal into a sound signal, realizes the broadcast function, and enables the sound to be clearly transmitted to every corner of the passenger compartment.

[0050] In the embodiment, during the intercom process on the digital Ethernet bus, the data flow is as follows:

[0051] The microphone (MIC) of a driver control terminal is responsible for collecting the intercom sound, which converts the intercom sound into an electrical signal; the electrical signal enters the third operational amplifier chip SA5532, and the third operational amplifier chip SA5532 amplifies the weak audio signal to increase the signal voltage amplitude to meet the input requirements;

[0052] The audio signal amplified by the third operational amplifier chip SA5532 enters the digital Ethernet line echo cancellation and noise reduction chip PNC201. The digital Ethernet line echo cancellation and noise reduction chip PNC201 processes the possible echo and noise problems in the Ethernet transmission environment, eliminates echo interference, reduces the noise level, and ensures the purity and clarity of the audio signal;

[0053] The processed audio signal is then transmitted to the i.MX6Q core board for audio signal acquisition. The i.MX6Q core board acquires the audio signal after echo cancellation and noise reduction processing, converts the analog signal into a digital signal form, and encodes the acquired audio digital signal; the encoded audio data is transmitted through the Ethernet bus;

[0054] When the i.MX6Q core board of the opposite driver control terminal receives the encoded audio data transmitted through the Ethernet bus, it performs an audio signal decoding operation to restore the encoded audio data to the original audio digital signal form, outputs it, and at the same time also feeds it back as a feedback signal to the audio processing chip PNC20, which helps to further optimize the processing effect of the audio signal and make more precise adjustments in aspects such as echo cancellation;

[0055] The output audio signal then enters the volume adjustment chip MAX5410 of the opposite driver control terminal. MAX5410 can accurately adjust the volume of the audio signal according to actual needs to meet the volume requirements in different usage scenarios;

[0056] The signal after volume adjustment then passes through the analog switch of the opposite driver control terminal. The analog switch decides whether to continue transmitting the audio signal according to the instruction of the core board. When the analog switch allows the signal to pass, the signal enters the second power amplifier chip LM4950 of the opposite end for power amplification. After the amplified audio signal passes through the opposite end intercom control relay, when the opposite end intercom control relay is closed, the audio signal drives the opposite end intercom speaker to work, converting the electrical signal into a sound signal, thereby realizing the intercom function between driver control terminals and realizing the voice communication between driver control terminals.

[0057] See Figure 2 , in an embodiment of the present invention, a monitoring module is further provided. The monitoring module includes a fourth operational amplifier chip SA5532 connected to the broadcast bus in the analog bus. The fourth operational amplifier chip SA5532 is connected to the third power amplifier chip LM4950. The third power amplifier chip LM4950 is connected to the monitoring speaker after connecting the monitoring relay. The monitoring relay is connected to the IMX6Q core board. The monitoring module is used to monitor the broadcast content on the analog bus in real time so that relevant personnel can understand the playback situation of the broadcast. Through the monitoring speaker, the staff can directly hear the sound of the broadcast, judge whether the volume of the broadcast is appropriate, whether the sound quality is clear, whether there are noises or distortions, etc., which is convenient for taking timely measures when it is found that the broadcast quality is not good to ensure that the broadcast content can be clearly and accurately conveyed to the audience.

[0058] In an embodiment of the present invention, the IMX6Q core board can be powered by an external DC + 110V power supply. The on-board isolated DC / DC of the core board changes to output DC + 12V. After the DC + 12V power supply is DC / DC converted, it outputs DC + 5V to supply power to the core board and other peripheral circuits. The core board also has a DC + 3.3V power supply output.

[0059] In one embodiment of the present invention, the IMX6Q core board of the passenger control unit is connected to a TFT-LCD display screen with an LVDS interface through the LVDS interface, and the TFT-LCD display screen can display rich information to the driver; the IMX6Q core board is connected to a resistive touch screen through the TSC interface, and the driver can perform intuitive operations with the resistive touch screen; the IMX6Q core board is connected to a real-time clock RTC circuit, and the RTC circuit provides an accurate time reference for the system, which is very important for the driver to record the driving time, grasp the arrival and departure times of the train, and analyze the time series of operation data; the IMX6Q core board is connected to a UART debug serial port, and engineers can output debug information through this serial port for diagnosing system faults and analyzing the running status of the program, and can also receive specific instructions for software upgrade and function testing; the IMX6Q core board is connected to a USB OTG interface, which can be connected to an external storage device to copy driving data; the IMX6Q core board is connected to a 4-way key keyboard, providing a reliable physical operation method for the driver; the IMX6Q core board is connected to 4-way LED indicators, and the 4-way LED indicators can visually display different states of the system; the IMX6Q core board is connected to a buzzer, and the buzzer can be used to issue a sound alarm to attract the driver's high attention and prompt the driver to take corresponding measures immediately to ensure the safe operation of the train; the IMX6Q core board is connected to a hardware watchdog for monitoring the running status of the system, and the IMX6Q core board is connected to an isolated RS485 interface and an isolated RS232 interface for facilitating the connection of external devices.

[0060] In the embodiment, the model of the analog line echo cancellation and noise reduction chip is ML7037-003TB. In other embodiments, alternative models such as FEDL7202-001 and FEDL7732A can also be used; in the embodiment, the model of the digital Ethernet line echo cancellation and noise reduction chip is PNC201. In other embodiments, alternative models such as FM1288 can also be used. The op-amp chip SA5532 can also be replaced by NE5532, the power amplifier chip LM4950 can also be replaced by TPA3116D2, and MAX5410 can be replaced by AD5241, or other models can also be used.

[0061] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0062] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A broadcast intercom system for rail transit, comprising: A driver control terminal, wherein a plurality of driver control terminals are provided, wherein the driver control terminal comprises a passenger control unit, wherein the passenger control unit is connected to a speaker and a microphone, and wherein the driver control terminal is connected to other driver control terminals via a digital Ethernet bus and an analog bus, respectively, for intercom between the driver control terminals; the passenger control unit is also connected to a passenger compartment broadcasting unit via a digital Ethernet bus and an analog bus, for broadcasting by the driver control terminal; the passenger control unit is also connected to a passenger alarm terminal via a digital Ethernet bus and an analog bus, for intercom between the driver control terminal and the passenger alarm terminal for emergency passenger alarms.

2. A broadcast intercom system for rail transit according to claim 1, characterized in that: The passenger control unit includes an IMX6Q core board, which is connected to an analog line echo cancellation and noise reduction chip for eliminating echoes and howling during intercoms via an analog bus; the IMX6Q core board is connected to a digital Ethernet line echo cancellation and noise reduction chip for eliminating echoes and howling during intercoms via a digital Ethernet bus.

3. A broadcast intercom system for rail transit according to claim 2, characterized in that: The microphone of the driver control terminal is connected to the first operational amplifier chip of the passenger control unit, the first operational amplifier chip is connected to the analog line echo cancellation and noise reduction chip, the analog line echo cancellation and noise reduction chip is connected to the first power amplifier chip and the transformer and then connected to the broadcast control relay, the IMX6Q core board is connected to the broadcast control relay, and the broadcast control relay is connected to the broadcast bus in the analog bus, so as to enable the driver control terminal to broadcast through the analog bus.

4. A broadcast intercom system for rail transit according to claim 3, characterized in that: The intercom control relay is connected to the intercom bus in the analog bus, and the intercom bus in the analog bus is also connected to the analog line echo cancellation and noise reduction chip after connecting to the second operational amplifier chip. The analog line echo cancellation and noise reduction chip is also connected to the intercom volume adjustment chip, and the intercom volume adjustment chip is connected to the second power amplifier chip through an analog switch. The second power amplifier chip is connected to the intercom control relay, and the intercom control relay is connected to the intercom speaker. The IMX6Q core board is respectively connected to the intercom volume adjustment chip, the analog switch, and the intercom control relay, and is used for intercom between driver control terminals through the analog bus.

5. The broadcast intercom system for rail transit according to claim 2, characterized in that: The microphone of the driver control terminal is connected to the third op amp chip of the passenger control unit, the third op amp chip is connected to the digital Ethernet line echo cancellation and noise reduction chip, the digital Ethernet line echo cancellation and noise reduction chip is connected to the audio signal acquisition port of the IMX6Q core board, the audio power amplifier of the IMX6Q core board encodes the audio data, and the IMX6Q core board is connected to the passenger room broadcasting unit through the digital Ethernet bus for the driver control terminal to broadcast through the digital Ethernet bus.

6. A broadcast intercom system for rail transit according to claim 5, characterized in that: The IMX6Q core board of the driver control terminal is connected to the IMX6Q core boards of other driver control terminals through a digital Ethernet bus. The audio power amplifier of the IMX6Q core board decodes the received audio data. The IMX6Q core board is connected to the intercom volume adjustment chip through the audio output port. The audio output port of the IMX6Q core board is also connected to the digital Ethernet line echo cancellation and noise reduction chip, which is used to send the step-back signal to the digital Ethernet line echo cancellation and noise reduction chip. The intercom volume adjustment chip is connected to the second power amplifier chip through an analog switch, and the second power amplifier chip is connected to the intercom control relay. The intercom control relay is connected to the intercom speaker. The IMX6Q core board is respectively connected to the intercom volume adjustment chip, the analog switch, and the intercom control relay, and is used for intercom between driver control terminals through the digital Ethernet bus.

7. The broadcast intercom system for rail transit according to claim 2, characterized in that: It also includes a monitoring module, which includes a fourth operational amplifier chip connected to the broadcast bus in the analog bus, the fourth operational amplifier chip is connected to the third power amplifier chip, the third power amplifier chip is connected to the monitoring speaker after connecting to the monitoring relay, and the monitoring relay is connected to the IMX6Q core board for broadcast monitoring on the analog bus.

8. The broadcast intercom system for rail transit according to claim 2, characterized in that: The IMX6Q core board of the passenger control unit is connected to a TFT-LCD display screen with an LVDS interface via an LVDS interface; the IMX6Q core board is connected to a resistive touch screen via a TSC interface, the IMX6Q core board is connected to a 4-way keypad, and the IMX6Q core board is provided with an isolated RS485 interface and an isolated RS232 interface.

9. The broadcast intercom system for rail transit according to claim 1, characterized in that: The passenger compartment broadcasting unit includes a passenger compartment AMP power amplifier board and a passenger compartment speaker, and the passenger alarm terminal includes an alarm microphone and an alarm speaker.

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