Multi-path driver passenger full duplex emergency call and stop announcement broadcast coexistence method
By simultaneously transmitting station announcement broadcasts and multi-channel intercom audio signals on a single MVB bus and merging them according to weights, the problem of station announcement broadcasts and emergency intercoms between drivers and passengers being unable to proceed simultaneously is solved, and the coexistence of multi-channel emergency calls and station announcement broadcasts is achieved, reducing system complexity and costs and improving voice quality.
Patent Information
- Application Number
- CN202510920721.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-03
- Publication Date
- 2025-10-03
AI Technical Summary
In the existing technology, the station announcement broadcast and emergency intercom functions between the driver and passengers cannot be carried out simultaneously, which leads to increased hardware complexity and cost, and is prone to signal conflicts or bandwidth competition problems.
The station announcement audio signal and multi-channel intercom audio signals are transmitted simultaneously through a single MVB communication bus, and the weight is calculated according to the real-time power of each intercom audio signal, and the signals are merged to generate the target audio signal.
The coexistence of multiple emergency calls between drivers and passengers and station announcements is achieved, which reduces system complexity and cost, improves voice quality, and avoids signal conflicts.
Smart Images
Figure CN120750472A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of audio processing technology, and in particular to a method for coexistence of multi-channel driver-passenger full-duplex emergency calls and station announcement broadcasts. Background Art
[0002] In modern public transportation systems, real-time communication between drivers and passengers and automatic station announcements are core functions to ensure operational safety and efficiency.
[0003] Conventional communication systems typically use separate hardware channels to handle station announcements and intercom functions. For example, station announcements are transmitted via dedicated audio lines, while intercom systems rely on separate buses or wireless modules. Due to the fixed allocation of channel resources, it is difficult to support both station announcements and emergency intercom simultaneously, which increases hardware complexity and cost. Using a single communication medium can easily lead to signal conflicts and bandwidth competition in multi-device collaboration scenarios. Summary of the Invention
[0004] The embodiments of this specification provide a method for coexistence of multi-channel driver-passenger full-duplex emergency calls and station announcement broadcasts to solve the problem in the prior art that station announcement broadcasts and intercom functions cannot be performed simultaneously.
[0005] To solve the above technical problems, the embodiments of this specification are implemented as follows:
[0006] In a first aspect, embodiments of this specification provide a method for coexistence of multi-channel driver-passenger full-duplex emergency calls and station announcement broadcasts, comprising:
[0007] Acquiring multiple audio signals, wherein the multiple audio signals include a station announcement broadcast audio signal and a multiple intercom audio signal;
[0008] Simultaneously transmit the station announcement audio signal and multiple-channel intercom audio signals via a single MVB communication bus;
[0009] Obtaining a weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal;
[0010] The multi-channel intercom audio signals are combined and processed according to all the weights to obtain a target audio signal.
[0011] In a second aspect, the embodiments of this specification provide a multi-channel driver-passenger full-duplex emergency call and station announcement coexistence system, including:
[0012] An acquisition module is used to acquire multiple audio signals, wherein the multiple audio signals include station announcement broadcast audio signals and multiple intercom audio signals;
[0013] A transmission module, configured to simultaneously transmit the station announcement audio signal and multiple intercom audio signals via a single MVB communication bus;
[0014] A determination module, configured to obtain a weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal;
[0015] The merging processing module is used to merge the multiple intercom audio signals according to all the weights to obtain a target audio signal.
[0016] An embodiment of the present specification can achieve the following beneficial effects: station announcement broadcasts and multi-channel intercom signals are transmitted simultaneously through a single MVB bus, enabling the coexistence of multi-channel driver-passenger emergency calls and station announcement broadcasts, allowing the driver to talk to multiple passengers at the same time, eliminating the hardware redundancy of traditional discrete communication channels, reducing system complexity and cost, merging and processing multi-channel intercom audio data according to weights, improving the voice quality of multi-channel audio signals, and avoiding signal conflicts. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0018] Figure 1 A flowchart of a method for coexistence of multi-channel driver-passenger full-duplex emergency calls and station announcement broadcasts provided in an embodiment of this specification;
[0019] Figure 2 This is a schematic diagram of the structure of a multi-channel driver-passenger full-duplex emergency call and station announcement coexistence system provided in the embodiments of the specification. DETAILED DESCRIPTION
[0020] To make the purpose, technical solutions, and advantages of one or more embodiments of this specification more clear, the technical solutions of one or more embodiments of this specification will be clearly and completely described below in conjunction with the specific embodiments of this specification and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of one or more embodiments of this specification.
[0021] The technical solutions provided by the embodiments of this specification are described in detail below with reference to the accompanying drawings.
[0022] A method for coexistence of multi-channel driver-passenger full-duplex emergency calls and station announcement broadcasts provided in an embodiment of the specification is specifically described with reference to the accompanying drawings.
[0023] Figure 1 The present invention provides a flowchart of a method for coexistence of multi-channel driver-passenger full-duplex emergency calls and station announcement broadcasts provided in an embodiment of the present specification.
[0024] like Figure 1 As shown, the process may include the following steps:
[0025] Step 110: Acquire multiple channels of audio signals, where the multiple channels of audio signals include station announcement audio signals and multiple channels of intercom audio signals.
[0026] In the embodiment of this specification, the station announcement audio signal is generated by the vehicle broadcast controller, transmitted in one direction, and sent by the control system (ACSUCtrl) to the power amplifier module (AMP) for playing pre-recorded station information or emergency notifications.
[0027] The intercom audio signal is a two-way full-duplex communication. The driver and passengers interact in real time through the driver control unit (DACU) and the passenger terminal unit (PECU), and can support 6 simultaneous calls.
[0028] Step 120: Simultaneously transmit the station announcement audio signal and the multiple-channel intercom audio signals via a single MVB communication bus.
[0029] In the embodiments of this specification, all audio signals are transmitted simultaneously via a single MVB communication bus. The MVB bus communication rate is 1.5 Mbps, with control data occupying 256 Kbps and the remaining bandwidth being used for audio signal transmission.
[0030] Step 130: Obtain a weight corresponding to each channel of the intercom audio signal according to the real-time power of each channel of the intercom audio signal.
[0031] Step 140: merging the multiple channels of intercom audio signals according to all the weights to obtain a target audio signal.
[0032] In the embodiments of this specification, real-time power calculation is performed on each intercom audio signal. Based on the real-time power of each intercom audio signal, a weight is calculated for each signal. A weighted mixing method is used to assign a weight to each intercom audio signal to avoid signal overload. Audio signals from multiple devices are weighted and combined into a single output signal.
[0033] It should be understood that the order of some steps in the methods described in one or more embodiments of this specification can be interchanged according to actual needs, or some steps can be omitted or deleted.
[0034] In the embodiments of this specification, station announcement broadcasts and multi-channel intercom signals are transmitted simultaneously through a single MVB bus, enabling the coexistence of multi-channel driver-passenger emergency calls and station announcement broadcasts. The driver can talk to multiple passengers at the same time, eliminating the hardware redundancy of traditional discrete communication channels, reducing system complexity and cost, and merging multi-channel intercom audio data according to weights to improve the voice quality of multi-channel audio signals and avoid signal conflicts.
[0035] based on Figure 1 The method in this specification also provides some specific implementation plans of the method, which are described below.
[0036] To improve voice quality, optionally, before obtaining the weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal in the embodiment of this specification, the method may further include:
[0037] Acquire the far-end audio signal played by the sound playback device and the near-end audio signal collected by the sound collection device;
[0038] An adaptive filter is used to eliminate the echo generated on the echo path between the sound collection device and the sound playback device based on the far-end audio signal and the near-end audio signal, thereby obtaining an echo-cancelled intercom audio signal.
[0039] In the embodiments of this specification, a sound collection device, such as a microphone, collects near-end audio signals and echoes. A sound playback device, such as a speaker, retrieves the played far-end audio signal. In full-duplex intercom scenarios, after the far-end audio signal is played through the speaker, it may be re-collected by the microphone, resulting in an echo. If the echo is not eliminated, the echo will be mixed with the near-end voice signal, resulting in degraded call quality.
[0040] An adaptive filter is used to estimate the echo path based on the far-end audio signal, and the estimated echo signal is subtracted from the near-end audio signal to obtain the intercom audio signal after echo cancellation.
[0041] Optionally, in the embodiment of this specification, obtaining the weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal may specifically include:
[0042] Performing frame processing on each channel of the intercom audio signal;
[0043] Calculate the RMS energy of each frame;
[0044] Based on the root mean square energy and the preset priority, a weight corresponding to each channel of the intercom audio signal is calculated.
[0045] In the embodiment of this specification, the frame processing divides the continuous intercom audio signal into short time frames of fixed length, for example, 1024 sampling points per frame, so as to analyze the signal characteristics frame by frame.
[0046] The root mean square (RMS) energy E is calculated for each frame, and then low-pass filtered to avoid sudden changes. The low-pass filtering formula is: E1(i) = α·E1(i-1) + (1-α)·E(i). α is a smoothing coefficient that controls the response speed; E1(i) is the filter output value of the i-th frame, E1(i-1) is the filter output value of the i-1st frame, and E(i) is the audio energy of the i-th frame.
[0047] Set priorities so that high-priority audio signals receive greater weight, ensuring clear transmission and enhancing safety. For example, if an intercom audio channel is an emergency call, its priority parameter is set to the highest. Even if the real-time power is lower, it can still be output first through weighted amplification.
[0048] Combine the RMS energy and the preset priority to calculate the dynamic gain weight so that the audio signal with high priority and strong current energy has a greater weight. The weight formula is: Among them, w i is the weight of the i-th audio signal, P i Preset weight for audio channel i, E i is the audio energy of channel i, P j Preset weight for audio channel j, E j is the audio energy of the jth channel, ε is the minimum value to prevent the denominator from being zero,
[0049] In practice, if a certain route has high priority but very low energy (such as a whispered emergency command), its weight may still be small, and a minimum gain threshold G can be set. min , ensuring that high priority tracks receive at least the minimum amplification ratio. Allocate target gain G according to weight i , and limit it to a reasonable range while avoiding gain mutation. The target gain formula is G i =G min +(G max -G min )·w i , where G max is the maximum gain threshold.
[0050] Optionally, the merging of multiple intercom audio signals according to all the weights in the embodiment of this specification may specifically include:
[0051] Performing weighted mixing on each intercom audio signal according to all the weights to generate an initial mixed signal;
[0052] Determining whether the total energy of the initial mixed signal exceeds a preset threshold;
[0053] If so, global compression is performed on the initial mixed signal.
[0054] In the embodiment of this specification, multiple intercom audio signals are linearly combined after weight distribution to generate a single mixed signal, ensuring that key audio tracks (such as emergency calls) are dominant in the output.
[0055] Assign a weight to each intercom audio signal to avoid signal overload. The weighted mixing formula is: Among them, y(n) is the initial mixed signal; x i (n) is the nth sampling point of the i-th signal. The weight can be dynamically adjusted based on the real-time power and preset priority.
[0056] If the total energy after mixing exceeds a preset threshold, which may be 131072, global compression is used to reduce the overall amplitude of the signal, and the compressed signal is clipped to limit its amplitude within a quantization range to prevent signal overload and distortion.
[0057] If the total energy after mixing does not exceed the preset threshold, there is no need to use global compression.
[0058] In practical applications, the gain is dynamically adjusted according to the audio power to avoid signal distortion after mixing. The RMS energy of each frame is calculated, and the error is calculated by comparing it with the preset target. The proportional integral algorithm is used to convert the error into a gain adjustment. The formula is: G new =G current +K p error+K i ∑error
[0059] Among them, K p and K i is the proportional and integral coefficient. G new is the updated gain value, G current is the current gain value, and error is the calculation error.
[0060] Set the maximum and minimum gain to prevent overload or noise amplification, limit the gain change rate, avoid instantaneous mutations, and maintain a natural listening experience.
[0061] To improve speech clarity, optionally, before merging the multiple intercom audio signals according to all the weights in the embodiment of this specification, the method may include:
[0062] Set the noise threshold;
[0063] When the real-time power of the intercom audio signal is lower than the noise threshold, the gain of the intercom audio signal is set to zero.
[0064] In the embodiments of this specification, noise suppression is performed on each audio signal, and a noise threshold is set. The threshold can be 166200345. Spectral analysis is performed on each intercom audio signal to identify and suppress noise components in the non-speech frequency band. When the real-time power of the intercom audio is lower than the noise threshold and the spectrum analysis confirms that there is no valid speech component, the gain is set to zero to avoid background noise accumulation.
[0065] In practice, valid speech signals are detected to avoid mixing with invalid signals.
[0066] Optionally, before simultaneously transmitting the station announcement audio signal and the multiple-channel intercom audio signals via a single MVB communication bus in the embodiment of this specification, the method further includes:
[0067] The station announcement audio signal adopts the first compression algorithm, and the transmission rate after compression is 128kbps; each channel of the intercom audio signal adopts the second compression algorithm, and the transmission rate after single-channel compression is 64kbps.
[0068] In the embodiment of this specification, the first compression algorithm can be MP3 compression, and the second compression algorithm can be ADPCM compression. Through differentiated compression strategies, multiple audio signals can be efficiently transmitted on a single MVB bus while meeting the requirements of sound quality, real-time performance and bandwidth utilization.
[0069] Optionally, the embodiments of this specification are applied to FPGA chips.
[0070] In the embodiments of this specification, FPGA chip logic is used for audio acquisition, playback and algorithm processing, with an operating frequency of 96MHz. Data calculation and processing can be completed during the sampling interval. Apart from the analog circuit delay, there is only buffer delay.
[0071] Properly set the buffer size to balance latency and stability. Specifically, an overly large buffer can cause audio delays and lags, reducing call quality. An overly small buffer can cause queue overflow (data loss) or underflow (data shortage) due to clock differences between the transmitting and receiving parties and network transmission jitter, affecting call quality. For example, set the buffer size to 16ms for audio data.
[0072] Through hardware acceleration and parallel computing, the real-time performance, stability and anti-interference capabilities of multi-channel intercom and station announcement broadcasting have been significantly improved.
[0073] Figure 2 This is a schematic diagram of the structure of a multi-channel driver-passenger full-duplex emergency call and station announcement coexistence system provided in the embodiments of the specification.
[0074] like Figure 2 As shown in the embodiment of this specification, a multi-channel driver and passenger full-duplex emergency call and station announcement coexistence system may include:
[0075] An acquisition module 202 is configured to acquire multiple audio signals, wherein the multiple audio signals include a station announcement audio signal and multiple intercom audio signals;
[0076] The transmission module 204 is used to simultaneously transmit the station announcement audio signal and the multiple-channel intercom audio signals through a single MVB communication bus;
[0077] A determination module 206 is configured to obtain a weight corresponding to each of the intercom audio signals according to the real-time power of each of the intercom audio signals;
[0078] The merging processing module 208 is configured to merge the multiple channels of the intercom audio signals according to all the weights to obtain a target audio signal.
[0079] Optionally, before obtaining the weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal in the embodiment of this specification, the system may further include:
[0080] The echo cancellation module is used to obtain the far-end audio signal played by the sound playback device and the near-end audio signal collected by the sound collection device;
[0081] An adaptive filter is used to eliminate the echo generated on the echo path between the sound collection device and the sound playback device based on the far-end audio signal and the near-end audio signal, thereby obtaining an echo-cancelled intercom audio signal.
[0082] Optionally, in the embodiment of this specification, obtaining the weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal may specifically include:
[0083] Performing frame processing on each channel of the intercom audio signal;
[0084] Calculate the RMS energy of each frame;
[0085] Based on the root mean square energy and the preset priority, a weight corresponding to each channel of the intercom audio signal is calculated.
[0086] In the embodiments of this specification, station announcement broadcasts and multi-channel intercom signals are transmitted simultaneously through a single MVB bus, and the multi-channel intercom audio data are merged and processed according to the weights, which can efficiently coordinate multi-channel full-duplex calls and station announcement broadcasts on a single bus while taking into account real-time performance, sound quality and anti-interference capabilities.
[0087] The above description is of specific embodiments of this specification, and other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily have to be performed in the specific order or continuous order shown to achieve the desired results. The various embodiments in this specification are described in a progressive manner, and the same and similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.
[0088] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.
[0089] The foregoing is merely an embodiment of the present invention and is not intended to limit the present application. For those skilled in the art, various modifications and variations may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.
Claims
1. A method for coexistence of full-duplex emergency calls and station announcement broadcasts for multiple drivers and passengers, characterized in that: include: Acquiring multiple audio signals, wherein the multiple audio signals include a station announcement broadcast audio signal and a multiple intercom audio signal; Simultaneously transmit the station announcement audio signal and multiple-channel intercom audio signals via a single MVB communication bus; Obtaining a weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal; The multi-channel intercom audio signals are combined and processed according to all the weights to obtain a target audio signal.
2. The method according to claim 1, characterized in that Before obtaining the weight corresponding to each of the intercom audio signals according to the real-time power of each of the intercom audio signals, the method further includes: Acquire the far-end audio signal played by the sound playback device and the near-end audio signal collected by the sound collection device; An adaptive filter is used to eliminate the echo generated on the echo path between the sound collection device and the sound playback device based on the far-end audio signal and the near-end audio signal, thereby obtaining an echo-cancelled intercom audio signal.
3. The method according to claim 1, characterized in that Obtaining a weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal specifically includes: Performing frame processing on each channel of the intercom audio signal; Calculate the RMS energy of each frame; Based on the root mean square energy and the preset priority, a weight corresponding to each channel of the intercom audio signal is calculated.
4. The method according to claim 1, wherein The merging of the multiple intercom audio signals according to all the weights specifically includes: Performing weighted mixing on each intercom audio signal according to all the weights to generate an initial mixed signal; Determining whether the total energy of the initial mixed signal exceeds a preset threshold; If so, global compression is performed on the initial mixed signal.
5. The method according to claim 1, wherein Before merging the multiple intercom audio signals according to all the weights, the method includes: Set the noise threshold; When the real-time power of the intercom audio signal is lower than the noise threshold, the gain of the intercom audio signal is set to zero.
6. The method according to claim 1, characterized in that Before simultaneously transmitting the station announcement broadcast audio signal and the multiple-channel intercom audio signals via a single MVB communication bus, the method further includes: The station announcement audio signal adopts the first compression algorithm, and the transmission rate after compression is 128kbps; each channel of the intercom audio signal adopts the second compression algorithm, and the transmission rate after single-channel compression is 64kbps.
7. The method according to any one of claims 1 to 6, characterized in that: Applied to FPGA chips.
8. A multi-channel driver-passenger full-duplex emergency call and station announcement coexistence system, characterized by: include: An acquisition module is used to acquire multiple audio signals, wherein the multiple audio signals include station announcement broadcast audio signals and multiple intercom audio signals; A transmission module, configured to simultaneously transmit the station announcement audio signal and multiple intercom audio signals via a single MVB communication bus; A determination module, configured to obtain a weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal; The merging processing module is used to merge the multiple intercom audio signals according to all the weights to obtain a target audio signal.
9. The system according to claim 8, characterized in that Before obtaining the weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal, the system further includes: The echo cancellation module is used to obtain the far-end audio signal played by the sound playback device and the near-end audio signal collected by the sound collection device; An adaptive filter is used to eliminate the echo generated on the echo path between the sound collection device and the sound playback device based on the far-end audio signal and the near-end audio signal, thereby obtaining an echo-cancelled intercom audio signal.
10. The system according to claim 8, wherein: Obtaining a weight corresponding to each intercom audio signal according to the real-time power of each intercom audio signal specifically includes: Performing frame processing on each channel of the intercom audio signal; Calculate the RMS energy of each frame; Based on the root mean square energy and the preset priority, a weight corresponding to each channel of the intercom audio signal is calculated.