Commercial vehicle adaptive volume control method

Abstract

The invention discloses an adaptive volume control method for a commercial vehicle, and belongs to the technical field of vehicle electronics. According to the method, a hardware system comprising a microcontroller, an audio processing module and an environment noise detection module is constructed, and a multi-task software system is operated on the microcontroller, so that volume self-adaptive adjustment based on real-time environment noise is realized. The environment noise detection combines two modes of microphone direct acquisition and non-microphone indirect analysis (through loudspeaker back electromotive force difference). And the system respectively executes self-adaptive volume control logic of the external horn, the internal integral horn and the internal local horn according to a preset threshold value and a coefficient. The system can automatically adapt to different noise environments, effectively reduces the operation burden of a driver, improves the driving safety, optimizes the audio hearing definition and comfort inside and outside the vehicle, and enhances the use compliance of the loudspeaker outside the vehicle.

Description

Technical Field

[0001] This invention relates to the field of vehicle electronics technology, and more particularly to an adaptive volume control method for commercial vehicles, specifically relating to an in-vehicle audio control system for commercial vehicles, and environmental perception and adaptive control technology. More specifically, this invention relates to a microcontroller (MCU)-based adaptive control method and system that detects the noise levels inside and outside the vehicle and automatically adjusts the output volume of external warning horns and in-vehicle multimedia speakers (including overall and partial adjustments) accordingly, aiming to improve the driving safety of commercial vehicles, passenger riding experience, and the compliance and effectiveness of horn use. Background Technology

[0002] With the rapid development of automotive electronics technology, in-vehicle infotainment systems and advanced driver assistance systems (ADAS) have become key to improving vehicle intelligence and driving experience. In the commercial vehicle sector, due to its complex operating scenarios, large interior space, and numerous noise sources, unique requirements are placed on the control of audio systems.

[0003] Currently, commercial vehicles are typically equipped with two main types of horns: external horns (such as air horns and electric horns), primarily used to issue warning signals to pedestrians or other vehicles; and internal horns, used to play multimedia audio (such as music and navigation prompts) or for internal communication. The volume control of these two types of horns presents the following challenges: 1. Issues with External Car Horn Volume Control: Traditional external car horns typically lack manual volume adjustment or have only limited manual volume control, and are generally designed to be loud enough to be effectively heard in noisy environments. However, this can easily cause noise pollution in low-noise environments (such as residential areas, near hospitals, and roads at night), and may even violate local noise regulations. Especially in congested urban areas, a high-volume horn is not only unnecessary when a gentle reminder to pedestrians or vehicles is needed, but may also cause panic or resentment. Drivers often cannot or find it inconvenient to frequently manually switch horn modes or adjust the volume while driving, leading to inconvenience and potential compliance risks.

[0004] 2. In-vehicle speaker volume control: The volume of the in-vehicle multimedia system is usually manually adjusted by the driver via the center console, knob, or steering wheel buttons. Commercial vehicles often encounter complex and changing road conditions, such as transitioning from quiet intercity roads to noisy highways, or from daytime driving to nighttime conditions requiring quiet. These drastic changes in ambient noise necessitate corresponding volume adjustments to ensure audio content (such as navigation instructions and communication information) can be clearly heard. However, during driving, especially on long journeys or in complex road conditions, the driver's primary focus must be on road safety; frequent distractions to adjust the volume increase safety risks.

[0005] Furthermore, the cab and passenger compartment of commercial vehicles are relatively large, resulting in significant differences in noise levels across different locations. For example, the area near the engine compartment, open windows, air conditioning vents, and the rear of the vehicle near cargo or equipment may experience much higher ambient noise levels than other areas. Using a uniform volume output would mean passengers in high-noise areas would have difficulty hearing, while those in low-noise areas would find the sound too loud. Although some high-end models support zoned volume control, these are mostly static, manual settings and cannot dynamically respond to real-time changes in ambient noise levels at different locations while the vehicle is in operation.

[0006] 3. Limitations of Existing Automatic Volume Control Technology: Automatic volume control technology has been applied in consumer electronics (such as smart headphones and smartphones) and some passenger vehicles. For example, noise-canceling headphones actively collect ambient noise and generate inverse sound waves to cancel it out; some passenger vehicles have a "speed-sensitive volume adjustment" function, meaning the volume increases slightly as the vehicle speed increases; and some vehicles have simple scenario-based logic such as "volume decreases when the door is opened." However, these technologies are mainly geared towards the relatively simple and uniform acoustic environment of personal devices or passenger vehicles.

[0007] For commercial vehicles, the application scenarios are more complex: it requires distinguishing between two completely independent sound fields inside and outside the vehicle; it requires balancing the compliant use of external speakers with effective warnings; and it requires handling dynamic noise fields with non-uniform distribution in large spaces and making precise local responses. Existing automatic volume control solutions have not yet been able to systematically and specifically solve these unique problems of commercial vehicles.

[0008] 4. Application of Ambient Noise Detection Technology: Ambient noise detection is the foundation for implementing adaptive control. A common method is direct acquisition using microphones. However, in vehicle applications, especially for external noise detection, additional microphone placement raises issues related to waterproofing, dustproofing, wiring, cost, and reliability. Another approach is to utilize existing vehicle sensors for indirect detection. This invention proposes an innovative "microphone-free" detection method, which infers ambient noise by analyzing the difference between the audio signal driving the external horn and the actual back electromotive force generated by the horn. This makes it possible to achieve noise detection without increasing additional hardware complexity.

[0009] In summary, the commercial vehicle industry currently lacks a systematic solution that can comprehensively consider different acoustic environments inside and outside the vehicle, intelligently and adaptively adjust the volume of various speakers to simultaneously meet the needs of safety, compliance, comfort, and clear hearing. This invention aims to fill this technological gap. Summary of the Invention

[0010] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an adaptive volume control method for commercial vehicles, which can automatically adapt to different noise environments, effectively reduce the driver's operating burden, improve driving safety, optimize the clarity and comfort of audio inside and outside the vehicle, and enhance the compliance of the use of external speakers.

[0011] The above-mentioned objective of this invention is achieved through the following technical solutions: An adaptive volume control method for commercial vehicles, the method being implemented on a platform consisting of a hardware system and a software system running on it, includes the following steps: Step S1: Construct a basic hardware system, which includes at least: The microcontroller unit (MCU) serves as the core controller. The power management module supplies power to all components of the system and is managed by the MCU; Parameter storage component, used to store system control parameters; The signal recognition module is used to identify the status of external function switches; The audio processing module includes an audio isolation distribution unit and an audio power amplifier; the audio isolation distribution unit is used to receive the raw audio input and isolate and distribute it into an internal reference sound source and an external driving sound source; the audio power amplifier is used to receive the external driving sound source and adjust the gain based on the control instructions of the MCU to drive the corresponding speaker; An environmental noise detection module is used to collect vehicle environmental noise signals. Step S2: System parameter configuration, preset control parameters including upper limit value of ambient noise, lower limit value of ambient noise, high noise volume control coefficient, and low noise volume control coefficient in the parameter storage component; Step S3: Build and run a software system on the MCU, and create and schedule multiple software tasks, including system tasks, IO tasks, environmental noise detection tasks, external horn control tasks, and internal horn control tasks. Step S4: Based on the state of the function switch and the ambient noise detection result, execute adaptive volume control logic, including: When the external adaptive function is activated, the output volume of the external horn is dynamically adjusted based on the real-time detected external ambient noise level when the driver triggers the external horn. When the overall adaptive function of the vehicle is turned on, the overall output volume of all the speakers in the vehicle is dynamically adjusted according to the real-time detected overall ambient noise level in the vehicle. When the in-vehicle local adaptive function is activated, the output volume of the speakers in the designated area of ​​the vehicle is independently and dynamically adjusted based on the real-time detected ambient noise level.

[0012] As a further technical solution of the present invention: the environmental noise detection module acquires environmental noise in at least one of the following forms: A) Microphone type: Sound pressure signals are directly collected by one or more microphones placed in specific locations inside and outside the vehicle; B) Non-microphone method: Using the audio processing module and the external speaker, the signal component caused by environmental noise is extracted by analyzing the difference between the expected electrical signal driving the external speaker and the electrical signal actually collected from the external speaker circuit, and the environmental noise intensity is calculated accordingly.

[0013] As a further technical solution of the present invention: the non-microphone form of environmental noise detection specifically includes: Acquire the internal reference audio source signal generated by the audio isolation distribution unit for driving the external horn; Collect the actual voltage and / or current signal in the external horn circuit; By using a signal processing algorithm, the expected driving component related to the internal reference sound source signal is eliminated from the actual voltage and / or current signal to obtain the residual noise signal; Based on the amplitude or energy of the residual noise signal, the equivalent external environmental noise value is calculated through a pre-calibrated mapping relationship.

[0014] As a further technical solution of the present invention: the adaptive volume control logic for the vehicle exterior speaker specifically includes: Continuously monitor the ambient noise level outside the vehicle (Noise_Out); When the driver triggers the external horn, the relationship between the current external ambient noise level and a preset threshold is determined: If the ambient noise level outside the vehicle is less than or equal to the lower limit of ambient noise, the audio power amplifier is controlled to output with a first gain coefficient, which is related to the low noise volume control coefficient. If the ambient noise level outside the vehicle is greater than or equal to the upper limit of ambient noise, the audio power amplifier is controlled to output with a second gain coefficient, which is related to the high noise volume control coefficient. If the ambient noise level outside the vehicle is between the lower and upper limits of the ambient noise, the audio power amplifier is calculated and controlled to output with the corresponding intermediate gain coefficient based on a mapping function.

[0015] As a further technical solution of the present invention: the adaptive volume control logic for the in-vehicle integrated speaker specifically includes: Continuously monitor the overall ambient noise level inside the vehicle (Noise_In_Global); Based on the relationship between the overall ambient noise level inside the vehicle and a preset threshold, the target total gain is dynamically calculated: If the overall ambient noise level inside the vehicle is less than or equal to the lower limit of ambient noise, the target total gain is determined based on the low noise volume control coefficient. If the overall ambient noise level inside the vehicle is greater than or equal to the upper limit of ambient noise, the target total gain is determined based on the high noise volume control coefficient. The target total gain is applied to the audio power amplifier that drives all in-vehicle speakers or its main volume control terminal.

[0016] As a further technical solution of the present invention: the in-vehicle local speaker adaptive volume control logic specifically includes: Continuously monitor the ambient noise level (Noise_In_Zone) in at least one designated area inside the vehicle. For each region with local adaptation enabled, the target region gain corresponding to that region is calculated independently based on the relationship between its ambient noise value and a preset threshold. The target area gain calculated for each area is applied to the independent audio power amplifier channel that drives the speaker in the corresponding area.

[0017] As a further technical solution of the present invention: the method further includes composite control logic: When the overall in-vehicle adaptive function and at least one in-vehicle local adaptive function are activated simultaneously, the final output gain of the horn in the area controlled by the local adaptive function is determined by the overall gain calculated based on the overall noise and the area gain calculated based on the local noise.

[0018] As a further technical solution of the present invention: the external function switches identified by the signal recognition module include at least: a switch for turning on or off the external horn adaptive function, a switch for turning on or off the overall in-vehicle horn adaptive function, and a switch for turning on or off the in-vehicle horn adaptive function in a specific area.

[0019] As a further technical solution of the present invention: the system control parameters stored in the parameter storage component also include: the basic gain of the external speaker, the overall basic gain of the internal speaker, the basic gain of the speakers in each area, the noise detection filtering parameters, and the volume adjustment response speed parameters.

[0020] The present invention also discloses a system for implementing the above-described adaptive volume control method for commercial vehicles, comprising: The hardware system entity defined in step S1 above; A non-transitory computer-readable storage medium storing an executable program, which, when executed by the MCU, enables the software task construction, scheduling, and adaptive volume control logic described in steps S3 and S4 above.

[0021] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: Significantly improves driving safety: Frees drivers from frequent manual volume adjustment, allowing them to focus more on driving and effectively reducing the risk of traffic accidents caused by distracted operation.

[0022] Achieving intelligent and compliant use of vehicle horns: Automatically adjusting the volume of the vehicle horn according to the external ambient noise, enabling vehicles to use the horn in a civilized and compliant manner in quiet areas, reducing the risk of disturbing the peace and imposing fines; and ensuring that the warning sound is loud and effective enough in noisy environments (such as highways and construction zones), thus improving the intelligence and social friendliness of horn use.

[0023] Greatly optimizes the in-vehicle audio experience: Whether it is the overall volume or the local volume, it can dynamically change with the ambient noise in real time, ensuring that audio content such as navigation prompts, communication calls, and entertainment media remains clearly audible and at a comfortable volume for passengers in any position in the vehicle under any driving conditions, solving the problem of uneven sound distribution in large commercial vehicles.

[0024] The system boasts high flexibility and configurability: it offers three main adaptive control modes—external, overall internal, and partial internal—which can be switched on and off independently or used in combination, adapting to the needs of different types of commercial vehicles, from basic to high-end configurations. Two environmental noise detection methods (microphone and non-microphone) also provide options for different cost and design requirements.

[0025] The technology is innovative and reliable: the proposed "microphone-free" environmental noise detection method creatively utilizes the vehicle's existing horn as a sensor, and infers the environmental noise by analyzing the difference between the drive signal and the back electromotive force. It eliminates the need for an additional dedicated microphone, saving costs, simplifying wiring, and improving the system's reliability in harsh environments. It is a powerful technological supplement to this field.

[0026] It has data value: The environmental noise data continuously collected by the system can form historical records, providing valuable first-hand data for analyzing vehicle noise sources, evaluating sound insulation effects, and optimizing the acoustic design of new vehicles.

[0027] In summary, this invention reduces the safety risks associated with frequent volume adjustments by the driver, ensures that passengers in different positions within the vehicle can clearly identify the audio content, and resolves the issue of switching between urban noise-controlled sections (low-noise environment) and highway / construction sections (high-noise environment) when external speakers are used during commercial vehicle operation. It also addresses the issue of adapting the in-vehicle audio playback volume to changes in overall ambient noise levels, ensuring that passengers can clearly identify the audio content under different overall noise conditions (such as high-speed driving (high overall noise), idling (low overall noise), and driving in the rain (high overall noise)). Furthermore, it addresses scenarios with varying local noise levels within commercial vehicles, such as high noise levels on the driver's side due to open windows, high noise levels in the rear passenger area due to cargo vibrations, and local noise levels at a particular passenger location due to the operation of surrounding equipment. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the system composition of a non-microphone noise detection method for adaptive volume control of commercial vehicles according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the system composition of a microphone-based noise detection method for adaptive volume control in commercial vehicles according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the software system composition for implementing adaptive volume control in commercial vehicles according to one of the published embodiments.

[0031] Figure 4 This is a schematic diagram illustrating the non-microphone noise detection principle of a non-microphone method for implementing adaptive volume control in commercial vehicles according to an embodiment of the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] The primary objective of this invention is to overcome the shortcomings of existing technologies and provide an adaptive volume control method for commercial vehicles, which can: Improve driving safety: Reduce driver distraction caused by manually adjusting volume while driving, thus reducing safety hazards.

[0034] Achieving intelligent compliance: The vehicle's external speakers automatically reduce their output volume in low-noise environments to avoid unnecessary noise pollution and meet environmental and regulatory requirements; and ensure sufficient warning volume in high-noise environments.

[0035] Optimize the listening experience: Automatically adjust the volume of the in-vehicle speakers (either overall or in specific areas) based on changes in overall and local ambient noise levels to ensure that passengers in all positions can listen to audio content clearly and comfortably under different driving conditions.

[0036] Offers flexible configuration: Supports the independent or combined activation of multiple control modes such as adaptive external speaker, adaptive overall in-vehicle volume, and adaptive local in-vehicle volume, adapting to different commercial vehicle models and configuration requirements.

[0037] Achieve economical and reliable detection: Provides a variety of environmental noise detection methods, including direct detection based on microphones and indirect detection based on horn electromotive force analysis, enhancing the system's applicability and reliability.

[0038] To achieve the above objectives, this invention provides an adaptive volume control method for commercial vehicles, the core of which lies in constructing an intelligent control platform in which a hardware system and a software system running on it work collaboratively. The method mainly includes the following steps: S1: Build the basic hardware system.

[0039] Construct a hardware platform for implementing adaptive volume control, the platform comprising at least: Microcontroller Unit (MCU): As the core controller of the system, it is responsible for executing control logic, processing data, and managing task scheduling.

[0040] Power management module: Provides stable and reliable power to the MCU and other hardware components of the system, and accepts start / stop control from the MCU.

[0041] Parameter storage components: such as EEPROM or Flash memory, used to store system parameters and user parameters, such as various noise thresholds, volume control coefficients, etc., supporting power-on reading and power-off saving.

[0042] Signal recognition module: Equipped with IO interface, used to recognize external switch signals (such as external adaptive switch, internal adaptive switch, and local adaptive switch).

[0043] Audio processing module: further includes: Audio isolation and distribution unit: This unit receives the raw audio input signal (such as from the multimedia host or warning signal generator) and isolates and distributes it into at least two outputs: one is an "internal output audio source" used to drive analog loads or as a reference signal; the other is an "external output audio source" used to drive external speakers or internal speaker amplifiers. This unit must ensure good isolation to prevent signal crosstalk.

[0044] Audio power amplifier (amplifier): Receives the "external output audio source" signal from the audio isolation distribution unit and adjusts its gain (i.e. volume) according to the control instructions of the MCU to drive the corresponding speakers (external speakers or speakers in various areas of the vehicle) to produce sound.

[0045] Environmental noise detection module: This module collects environmental noise data, specifically using one or a combination of the following two methods: Type A (microphone type): Includes one or more microphones placed in specific locations on the vehicle (such as the front of the vehicle, the driver's cab, and various locations in the passenger area) to directly collect ambient sound pressure signals and convert them into electrical signals for MCU processing.

[0046] Form B (Non-Microphone Form): This form does not rely on a separate microphone but utilizes the audio processing module and the speaker itself as sensors. The principle is as follows: the "external output sound source" signal driving the external speaker is known; when the external speaker emits sound, its voice coil moves in a magnetic field and is simultaneously excited by external ambient sound waves (noise), generating additional mechanical vibrations. This vibration cuts the magnetic field lines, generating an induced electromotive force (EMF) (back EMF) at the ends of the speaker's voice coil. The voltage signal actually measured at the ends of the speaker is the superposition of the driving voltage and this induced EMF caused by external noise. Through audio isolation and distribution, the system can obtain a pure "internal output sound source" (i.e., the original driving signal reference). By comparing the expected signal from the "external output sound source" with the mixed signal actually acquired from the speaker circuit (or by analyzing the voltage / current characteristics at the ends of the speaker), the signal component caused by ambient noise can be separated, thereby indirectly calculating the intensity of the ambient noise.

[0047] S2: System parameter configuration and initialization.

[0048] Key control parameters can be preset in the MCU or through host computer tools, including: Environmental noise limit parameters: Noise_High_Threshold: A threshold used to determine whether to enter a "high noise environment".

[0049] Noise_Low_Threshold: A threshold used to determine whether to enter a "low noise / no noise environment".

[0050] Volume_High (for high noise): The absolute or baseline volume value that the system aims to adjust to when the ambient noise exceeds the upper limit.

[0051] Low noise level (Volume_Low): The absolute or baseline volume value that the system aims to adjust to when the ambient noise is below the lower limit.

[0052] Volume control factor: High-noise volume control factor (K_High, typically >100%): In high-noise environments, the amplification factor applied to the base volume to achieve high power output.

[0053] Low noise volume control factor (K_Low, typically <50%, can be set as needed): In low noise environments, the attenuation factor applied to the base volume is used to achieve low power output.

[0054] Other parameters include: filter time constant, response delay, and logic definition of each switch.

[0055] S3: Building software systems and task scheduling.

[0056] Running an embedded real-time operating system (RTOS) or a foreground / background loop-based software architecture on an MCU to create and manage multiple tasks that execute in parallel or alternately, mainly including: System tasks: Responsible for system initialization, power status monitoring, and read / write access to parameter storage (reading preset parameters, saving user settings or operation logs).

[0057] IO task: Periodically scan or interrupt the response to the state changes of external switches (external adaptive switch, internal adaptive switch, local adaptive switch) and pass the switch events to the corresponding control logic.

[0058] Environmental noise detection task: Perform environmental noise sampling and calculation periodically according to the configuration.

[0059] If a microphone is used, the microphone ADC value is read, and then filtered (such as A-weighted filtering to simulate the human ear response), and the effective value is calculated to obtain the current noise decibel value.

[0060] If a non-microphone method is used, the reference signal of the "internal output sound source" and the actual signal of the speaker circuit are acquired simultaneously. The noise-induced electromotive force component is extracted by signal processing algorithms (such as adaptive filtering, coherence analysis, and differential calculation) and converted into equivalent noise intensity.

[0061] The task also requires distinguishing the location of noise sources: external noise, overall interior noise, and noise in specific areas (localized areas) inside the vehicle. This can be achieved through microphone analysis at corresponding locations or non-microphone analysis targeting specific speakers (such as a door speaker).

[0062] External horn control task: After the external adaptive function is activated, based on the detected external ambient noise level, when the driver presses the horn button, the gain of the audio amplifier is dynamically controlled so that the external horn outputs an appropriate volume.

[0063] In-car speaker control tasks: further subdivided into: In-vehicle overall volume control subtask: After the in-vehicle overall adaptive function is turned on, the total gain of the audio amplifier driving all in-vehicle speakers is dynamically controlled based on the detected overall ambient noise level in the vehicle.

[0064] In-vehicle local volume control subtask: After the in-vehicle local adaptive function is turned on, the gain of the audio amplifier channel driving the speaker in a specific area of ​​the vehicle (such as the driver's side, passenger side, left rear seat, right rear seat, etc.) is independently and dynamically controlled according to the detected ambient noise level of that area.

[0065] S4: Adaptive volume control logic execution.

[0066] Based on different function switch states, execute the corresponding adaptive control process: 1. Adaptive volume control procedure for vehicle exterior speakers: When the IO task detects that the "External Adaptive Volume Switch" is activated (turned on).

[0067] The environmental noise detection task continuously monitors the ambient noise level outside the vehicle (Noise_Out).

[0068] When the driver activates the horn switch to trigger the horn: a) If Noise_Out ≤ Noise_Low_Threshold, it is considered a low-noise environment. The MCU controls the audio amplifier to adjust its gain to a value calculated based on Volume_Low or by applying a coefficient K_Low, achieving low-power, gentle speaker sound.

[0069] b) If Noise_Out ≥ Noise_High_Threshold, it is determined to be a high-noise environment. The MCU controls the audio amplifier to adjust its gain to a value calculated based on Volume_High or the applied coefficient K_High, achieving high-power, loud speaker sound to ensure the warning effect.

[0070] c) If Noise_Low_Threshold < Noise_Out < Noise_High_Threshold, a moderate gain value between low power and high power can be calculated using linear interpolation or other mapping relationships.

[0071] 2. Overall in-vehicle speaker adaptive volume control process: When the IO task detects that the "in-vehicle adaptive volume switch" is activated (turned on).

[0072] The ambient noise detection task continuously monitors the overall in-vehicle ambient noise value (Noise_In_Global).

[0073] The system adjusts the total volume of all in-vehicle speakers in real time according to Noise_In_Global: a) When Noise_In_Global ≤ Noise_Low_Threshold, adjust the total volume to Volume_Low or apply the coefficient K_Low.

[0074] b) When Noise_In_Global ≥ Noise_High_Threshold, adjust the total volume to Volume_High or apply the coefficient K_High.

[0075] c) When between the high and low thresholds, perform smooth automatic follow-up adjustment.

[0076] 3. Local in-vehicle speaker adaptive volume control process: When the IO task detects that the "local in-vehicle volume adaptive switch" is activated (turned on), and may combine with a region selection signal.

[0077] The ambient noise detection task continuously monitors the ambient noise values (Noise_In_Zone1, Noise_In_Zone2,...) of each preset region in the vehicle.

[0078] The system independently adjusts the volume of the speakers in the corresponding region according to the noise level of each region: a) For a certain region i, when Noise_In_Zoni ≤ Noise_Low_Threshold, only reduce the volume of the speakers in that region (apply K_Low).

[0079] b) When Noise_In_Zoni ≥ Noise_High_Threshold, only increase the volume of the speakers in that region (apply K_High).

[0080] c) The volume of other areas remains unchanged or is adjusted independently according to their own noise levels.

[0081] This mode can precisely compensate for uneven noise distribution inside the vehicle.

[0082] S5: Composite logic and advanced functions.

[0083] The above control processes can be combined. For example, overall and local adaptive noise reduction within the vehicle can be activated simultaneously, requiring the system to prioritize or integrate the adjustments: when an overall increase in noise is detected as the primary cause, the overall volume is increased first; when abnormally prominent local noise is detected, additional volume compensation or independent adjustment is applied to specific areas in addition to the overall adjustment. The system can also record noise data for fault diagnosis or to provide data support for vehicle design.

[0084] Specifically, such as Figure 1 , Figure 2 As shown, the implementation method of adaptive volume control for commercial vehicles according to a preferred embodiment of the present invention includes the following steps: Step 1, Creating the basic hardware system includes the following steps: Building a hardware system containing a microcontroller unit (MCU), power management module, signal recognition function, audio isolation and distribution function, audio amplifier, and ambient noise detection function. The ambient noise detection function implements two local noise acquisition methods: Method 1 is based on a non-microphone method, which identifies and analyzes the electromotive force output by the audio speaker; Method 2 is based on a microphone method, which directly obtains the ambient noise intensity. External connections include an external adaptive volume switch, an internal adaptive volume switch, and an internal local adaptive volume switch. Step 2: Create a software system based on the hardware system, running in the MCU. Create multiple tasks for the logic of adaptive volume control in commercial vehicles; create a system task to implement power management, power distribution and management in the hardware control system, and read and write system parameters and user parameters through parameter read / write functions; create an IO task to read the status of external switches in real time; create an environmental noise detection task to implement environmental noise detection based on non-microphone, environmental noise detection based on microphone, and noise location identification; create an external horn control task to control the increase and decrease of external horn volume; and create an internal horn control task to control the increase and decrease of the overall volume of internal horns and the increase and decrease of the volume of local internal horns.

[0085] Step 3: Microphone-based noise detection, using an external microphone to detect ambient noise.

[0086] Step 4: Non-microphone noise detection. The output distribution logic of the input sound source is configured through the audio isolation distribution function. The sound source is clearly divided into two categories: "external output sound source" (corresponding to the external speaker) and "internal output sound source" (corresponding to the analog speaker load). The external speaker will generate corresponding mechanical vibration due to environmental noise, which will be converted into corresponding noise-induced electromotive force. The electromotive force generated by the external speaker is a mixed electromotive force based on the electromotive force of the internal sound source and the external noise-induced electromotive force. Therefore, by analyzing the differences between the internal output sound source and the external output sound source, environmental noise can be detected based on the speaker electromotive force. Step 5: Select different environmental noise detection methods according to different business scenarios. Non-microphone noise detection can directly analyze noise based on existing vehicle horns, and only the controller is needed to identify the noise. Microphone noise detection requires independent microphone placement, which requires longer wiring harnesses and design complexity. Step 6: Identify the "External Adaptive Volume Switch" signal through the IO interface. The MCU triggers the external volume adaptive control process, which includes the following steps: After detecting that the external noise has entered a noise-free environment, when the driver triggers the external horn switch, the MCU controls the external horn to output low power according to the "noise-free volume control coefficient" through the audio amplifier; After detecting that the external noise has entered a noisy environment, when the driver triggers the external horn switch, the MCU controls the external horn to output high power according to the "noise volume control coefficient" through the audio amplifier.

[0087] Step 7: Identify the "in-vehicle adaptive volume switch" signal through the IO interface. The MCU triggers the in-vehicle volume adaptive control process, which includes the following steps: After detecting that the internal noise has entered a noise-free environment state, the MCU controls all in-vehicle audio speakers to output low power according to the "noise-free volume control coefficient" through the audio amplifier; After detecting that the internal noise has entered a noisy environment state, the MCU controls all in-vehicle audio speakers to output high power according to the "noise volume control coefficient" through the audio amplifier.

[0088] Step 8: Identify the "In-vehicle volume local adaptive control enabled" signal through the IO interface. The MCU triggers the in-vehicle volume local adaptive control process, which includes the following steps: After detecting that the local noise in the vehicle has entered a noise-free environment, the MCU controls the corresponding in-vehicle audio speaker to output low power according to the "noise-free volume control coefficient" through the audio amplifier; After detecting that the local noise in the vehicle has entered a noisy environment, the MCU controls the corresponding in-vehicle audio speaker to output high power according to the "noise volume control coefficient" through the audio amplifier.

[0089] Example 1: Construction of Basic Hardware System refer to Figure 1 and Figure 2The core of the adaptive volume control system of the present invention is an embedded hardware platform centered on an MCU (such as STMicroelectronics' STM32F4 series, NXP's S32K series, etc., which are automotive-grade microcontrollers with rich peripherals and computing capabilities).

[0090] MCU (U1): As the main controller, it internally includes a CPU, RAM, ROM, timers, ADC, DAC, PWM, multiple UART / SPI / I2C interfaces, and abundant GPIO. It is responsible for running the entire control software, processing all input signals, executing control algorithms, and generating output control commands.

[0091] The power management module (PMIC, U2) receives power from the vehicle battery (e.g., 12V or 24V) and provides the core voltage (e.g., 3.3V or 5V) to the MCU through DC-DC step-down, LDO regulation, etc., provides analog voltage to other chips (e.g., op-amps, ADC drivers), and provides power enable control for the audio amplifier module. This module typically features overvoltage, overcurrent, and short-circuit protection, as well as low-power mode management functions.

[0092] Parameter storage component (EEPROM / Flash, U3): Connects to the MCU via I2C or SPI bus. Used to store system parameters (such as factory-preset Noise_High_Threshold, Noise_Low_Threshold, K_High, K_Low, filter parameters, etc.) and user parameters (such as user-defined volume preferences, function switch memory states, etc.). The MCU reads parameters from this memory upon power-up and writes them back to the MCU as needed after modification.

[0093] Signal recognition module: mainly composed of the MCU's GPIO interface and its external pull-up / pull-down resistors and filtering circuit. It connects to three physical switches or receives switch signals from the central control system: SW_Out_Adapt (external adaptive switch). SW_In_Global_Adapt (overall adaptive switch for the vehicle interior) and SW_In_Zonal_Adapt (local adaptive switch for the vehicle interior, which may be one or more).

[0094] These switching signals are sent to the MCU's GPIO after passing through the debouncing circuit, and are then polled or interrupted by the IO task.

[0095] Audio processing module: This is the key signal channel of the system.

[0096] Audio isolation distribution unit (U4): This can be implemented using a dedicated audio codec chip or a circuit composed of high-speed operational amplifiers. Its main functions include: 1. Input Buffering and Isolation: Receives raw analog or digital audio signals from the multimedia host (Audio_In) and / or the alarm signal generator (Horn_Trigger_In). High input impedance buffers are used for isolation to prevent interference with pre-amplifier equipment.

[0097] 2. Signal Distribution: The input signal is copied into two or more identical signals. One signal is marked as the internal reference source (Internal_Ref), which is sent directly or after sampling by the ADC to the MCU as a reference signal for the non-microphone detection algorithm. The other signal is marked as the external drive source (External_Drive).

[0098] 3. Gain Pre-adjustment (optional): A variable gain (Gain_Pre) controlled by the MCU via a digital potentiometer or Codec register can be applied to the External_Drive signal. This is the first stage for volume adjustment.

[0099] Audio power amplifier (U5, possibly multi-channel): Receives the External_Drive signal. The MCU controls the amplifier chip's gain register (Volume_Ctrl) via I2C / SPI or analog voltage (generated by a DAC) to achieve precise control of the final output power. The amplifier output is directly driven. External horn: Usually a high-power channel.

[0100] The in-vehicle speaker system may consist of 2 channels (left and right), 4 channels (front left, front right, rear left, rear right), or more channels, used to achieve overall and zoned control.

[0101] Environmental noise detection module: Microphone format (see) Figure 2 Electret or MEMS microphones are placed inside the front bumper or rearview mirror base (Mic_Out), in the driver's cab A-pillar or roof (Mic_In_Driver), and in the roofs of various locations in the passenger area (Mic_In_Pax1, Mic_In_Pax2...). The output of each microphone is preamplified and bandpass filtered (to remove ultrasonic and extremely low frequency interference) before being sent to the MCU's multi-channel ADC for synchronous or time-division sampling.

[0102] Non-microphone form (see) Figure 1 and Figure 4The key point lies in the signal acquisition of the external speaker circuit. On the output line of the amplifier driving the external speaker, a precision sampling resistor (Rsense) or current sensor, combined with a voltage sampling circuit, can be used to obtain the actual voltage V_horn_actual across the speaker and / or the current I_horn flowing through the speaker. Simultaneously, the MCU possesses an "internal reference source" Internal_Ref (i.e., the ideal signal expected to drive the speaker, reconstructed by the DAC or directly taken from the output of the audio isolation distribution unit). The impedance model Z_horn(s) of the speaker in an ideal empty field is known or calibrable. The theoretical expected speaker voltage V_horn_expected can be derived from Internal_Ref and the amplifier gain model, or the expected current I_horn_expected can be calculated from V_horn_expected / Z_horn(s). The vibration generated by external ambient noise on the speaker diaphragm introduces an additional induced electromotive force V_noise_emf. According to circuit principles: V_horn_actual = V_horn_expected + V_noise_emf, or in terms of current: the difference between the actual current and the expected current includes the effect of noise excitation.

[0103] By using signal processing algorithms (e.g., Least Mean Square Error Adaptive Filter, LMS) to filter V_horn_actual or I_horn with Internal_Ref as the reference signal, the component of V_horn_expected can be estimated and eliminated. Thus, the remaining signal E_noise is related to V_noise_emf, and its energy or amplitude can be mapped to the sound pressure level (decibels) of the ambient noise after calibration. Figure 4 The process of signal separation and reconstruction is clearly demonstrated.

[0104] Example 2: Software System and Task Implementation refer to Figure 3 The software system runs on the MCU and can use a real-time operating system such as FreeRTOS to manage multiple tasks.

[0105] System Tasks (Task_System): Entry point: After power-on, hardware initialization is performed first (clock, GPIO, ADC, DAC, communication interface, etc.).

[0106] Loop / Event: a) Call the parameter management interface to read all preset parameters from EEPROM / Flash (U3) into global variables or structures in RAM.

[0107] b) Manage power status and control the power management module (U2) according to the vehicle wake-up / sleep signal to achieve low power consumption of the system.

[0108] c) Provide a background service that responds to parameter update requests (such as commands from a diagnostic instrument) and writes the modified parameters to non-volatile memory.

[0109] d) The system status and critical noise data can be periodically recorded into the memory.

[0110] IO Task (Task_IO): Configured to high priority or triggered by an external interrupt.

[0111] Periodically (e.g., every 10ms) scan the status of GPIOs such as SW_Out_Adapt, SW_In_Global_Adapt, and SW_In_Zonal_Adapt.

[0112] Software debouncing algorithms (such as confirming a change only after multiple consecutive samplings show consistent states) are used to ensure the reliability of the switching signal.

[0113] When any switch state change is detected (such as from OFF to ON), a corresponding event is generated and placed in the event queue, notifying the corresponding control task (external, overall, or partial control task inside the vehicle).

[0114] Environmental noise detection task (Task_Noise_Detect): This is the core of the system's perception.

[0115] Configuration phase: Based on the system configuration, determine which detection methods to enable (microphone list, non-microphone detection channels).

[0116] Sampling loop: a) Microphone Channel Processing: Trigger the ADC to sample the signals from each microphone to obtain a set of discrete voltage values. Perform digital filtering on the data of each channel (e.g., implement A-weighted frequency response), calculate its RMS (root mean square) value, and then perform calibration and conversion based on the microphone sensitivity to obtain the sound pressure level SPL_mic[i] (unit: dB) at each location.

[0117] b) Non-microphone channel processing (for external speakers): Simultaneously acquire the Internal_Ref signal (or obtain it from the internal buffer) and the V_horn_actual / I_horn signal from the speaker circuit. Perform adaptive filtering or differential operation algorithms to extract the E_noise component. Calculate the energy of E_noise and convert it into an equivalent sound pressure level SPL_horn using a pre-calibrated lookup table or formula. This SPL_horn primarily reflects ambient noise outside the vehicle.

[0118] c) Data fusion and distribution: External ambient noise value Noise_Out: Prioritize SPL_horn (if non-microphone detection is enabled), or use the external microphone SPL_mic[Out], or take the weighted average / reliable value of both.

[0119] The overall ambient noise level inside the vehicle (Noise_In_Global) can be the average of all in-vehicle microphones (SPL_mic[i], where i is the in-vehicle index) or the microphone value from a representative location (such as the driver's seat).

[0120] The in-vehicle ambient noise value Noise_In_Zone[k] is directly taken as the value of the corresponding area's microphone SPL_mic[zone_k]. If there is no corresponding microphone, it can be estimated from the overall noise and the known transfer function, or local adaptation can be disabled in this area.

[0121] Output: Update the calculated Noise_Out, Noise_In_Global, and Noise_In_Zone[] to the global shared variable area for other control tasks to read.

[0122] External horn control task (Task_Horn_Ctrl): The behavior of this task is determined by the SW_Out_Adapt switch and the driver's horn button Horn_Button.

[0123] Waiting for events: The task is in a sleep state, waiting for the Event_Out_Adapt_On event from the IO task.

[0124] Adaptive mode activation: a) After the task starts, continuously listen for the Horn_Button signal (which is usually a GPIO input or a message from the CAN bus).

[0125] b) When Horn_Button is detected to be pressed: 1. Immediately read the latest Noise_Out value from the global variable.

[0126] 2. Make judgments based on preset logic: If Noise_Out <= Noise_Low_Threshold, then set the target gain Target_Gain = Base_Gain_Horn * K_Low. (Base_Gain_Horn is the base gain of the speaker, which is configurable).

[0127] If Noise_Out >= Noise_High_Threshold, then set Target_Gain = Base_Gain_Horn * K_High.

[0128] If it is in the middle interval, then Target_Gain = Base_Gain_Horn * [K_Low + (K_High -K_Low) * (Noise_Out - Noise_Low_Threshold) / (Noise_High_Threshold - Noise_Low_Threshold)] (Example of linear interpolation).

[0129] 3. Apply the calculated Target_Gain value to the audio amplifier channel that drives the vehicle's external speakers via a control interface (such as setting a digital potentiometer or writing to the amplifier chip register).

[0130] 4. Maintain this gain until the current horn sound ends (Horn_Button is released).

[0131] c) When the Horn_Button is released, the amplifier gain can be restored to a default standby value or maintained until the next trigger.

[0132] Mode Off: When the Event_Out_Adapt_Off event is received, the task exits adaptive mode. Afterward, the horn button will operate according to the vehicle's factory logic (usually a fixed high volume).

[0133] The in-vehicle horn control task (Task_In_Vehicle_Ctrl) manages the overall and local adaptations within the vehicle. It can be designed as two parallel sub-state machines within a single task, or split into two independent tasks.

[0134] Overall vehicle control sub-process: a) Wait for the Event_In_Global_Adapt_On event.

[0135] b) After activation, a control loop is entered: 1. Periodically (e.g., every 100ms) read Noise_In_Global.

[0136] 2. Applying similar decision logic to the external vehicle control, calculate the total target gain Target_Gain_Global for all in-vehicle speakers. The parameters Base_Gain_Global, K_Low, and K_High used in the calculation are independent of the external speakers.

[0137] 3. Output Target_Gain_Global to the master volume control interface of the audio amplifier (if the amplifier supports master volume control), or adjust the gain of all channels simultaneously.

[0138] 4. To prevent frequent fluctuations near the noise threshold from causing volume jitter, a hysteresis algorithm and a slow ramp adjustment can be introduced.

[0139] c) Upon receiving the Event_In_Global_Adapt_Off event, stop automatic adjustment and lock the in-vehicle volume at the current value or restore it to a preset value.

[0140] In-vehicle partial control sub-process: a) Wait for the Event_In_Zonal_Adapt_On event, which may include zone identification information.

[0141] b) Activate adaptive control for the corresponding region. For example, enable local adaptive control on the "driver's side".

[0142] c) In the control loop: 1. Periodically read the Noise_In_Zone[Driver] of the corresponding region.

[0143] 2. Calculate the target gain Target_Gain_Zone[Driver] for the speaker channel of the region independently based on the noise level of that region. The gain of other regions remains unchanged.

[0144] 3. Adjust only the gain of the amplifier channel driving the driver's side horn.

[0145] d) Local adaptation can be enabled in multiple regions simultaneously, with each region operating and controlled independently.

[0146] e) Composite Logic Processing: When both global and local adaptive modes are enabled simultaneously, a fusion strategy needs to be defined. A simple strategy is: the final gain of a channel = Target_Gain_Global * Target_Gain_Zone[that channel] / Base_Gain_Zone. A more intelligent strategy can be based on the determination of the noise source: if the increase in local noise is caused by the increase in global noise, then global adjustment is mainly relied upon; if the local noise changes independently, then local adjustment plays a major role.

[0147] Example 3: Parameter Configuration and Calibration Example Parameter configuration is fundamental for the system to function. It can be performed using a dedicated calibration tool (connected to CAN or UART) before the vehicle leaves the factory or during maintenance.

[0148] Environmental noise limit calibration: Noise_Low_Threshold: Selects the external or internal noise level measured in a typical quiet environment (such as a suburban road late at night or an underground parking lot) (e.g., 45 dB(A)) with a margin of safety.

[0149] Noise_High_Threshold: Select the value measured in a typical high-noise environment (such as next to a busy highway or construction site) (e.g., 75 dB(A)).

[0150] Volume control coefficient calibration: K_Low: The desired level of volume reduction for the speaker in low-noise environments. For example, setting it to 30% means reducing the volume to 30% of the base volume. It's important to ensure that the reduced volume remains clear and unobtrusive in quiet environments.

[0151] K_High: The desired increase in speaker volume in high-noise environments. For example, set it to 150%, but be careful not to exceed the maximum permissible power of the speaker and amplifier, and to comply with relevant regulations regarding maximum volume limits. For external vehicle speakers, high power output must still be within the regulatory limits.

[0152] Base gain calibration: Base_Gain_Horn: The standard gain of the exterior horn in non-adaptive mode, which typically corresponds to the normal warning volume allowed by regulations.

[0153] Base_Gain_Global: The amplifier gain corresponding to the in-car speakers when the user manually sets a "standard" volume (such as 50%).

[0154] Non-microphone detection calibration: It is necessary to establish a mapping relationship between the E_noise signal energy (or amplitude) and the actual ambient sound pressure level (dB SPL) in an anechoic chamber or an environment with a known sound pressure level, generating a lookup table or fitting a formula. This calibration process is crucial for detection accuracy.

[0155] Example 4: Application Scenario Scenario 1: City Night Driving (Exterior Adaptive) The vehicle entered a residential area, where the environment was quiet. Task_Noise_Detect measured Noise_Out = 40 dB, which is lower than Noise_Low_Threshold (45 dB).

[0156] When a driver sees a pedestrian slowly crossing the road ahead, they should lightly press the horn button.

[0157] When Task_Horn_Ctrl is triggered, Target_Gain = Base_Gain_Horn * 30% is calculated.

[0158] The car horn emits a low-volume "beep," enough to alert pedestrians without disturbing nearby residents. This complies with nighttime noise control requirements.

[0159] Scenario 2: Highway driving (overall adaptive cabin) When the vehicle is cruising on the highway, wind noise and tire noise are very high. Task_Noise_Detect measured the overall noise level inside the vehicle to be 78 dB, which is higher than Noise_High_Threshold (75 dB).

[0160] The navigation system announces the road conditions ahead: "Exit 3 kilometers ahead."

[0161] The overall control loop of Task_In_Vehicle_Ctrl is running, and the total gain of all speakers in the vehicle has been adjusted to Base_Gain_Global * 150%.

[0162] The navigation prompts are broadcast clearly at a loud volume, so that both the driver and passengers can hear them without having to manually turn up the volume.

[0163] Scenario 3: Driving with windows open (partial adaptive cabin interior) The vehicle was traveling on a national highway with the driver's side window open for ventilation. Task_Noise_Detect measured Noise_In_Zone[Driver] = 70 dB using the driver's side microphone, while the average noise level in other areas of the vehicle was only 60 dB.

[0164] The "In-vehicle Partial Adaptation" function is now enabled for the driver's side.

[0165] Music is played at this time. The local control subflow of Task_In_Vehicle_Ctrl only increases the gain of the driver's side horn (e.g., by applying K_High), while the gain of the passenger side and rear horns remains at a normal value calculated based on the overall noise (60 dB).

[0166] Result: The music volume heard by the driver was similar to that heard by other passengers, offsetting the wind noise from the open window and resulting in a balanced listening experience. Without local adaptive tuning, the driver might feel the music is being masked by wind noise and turn up the overall volume, causing other passengers to perceive the sound as excessive.

[0167] Scenario 4: Composite Scenario The vehicle entered a noisy construction zone from a quiet multi-lane road, while passengers in the rear seats were talking. The system detected increased outside noise, leading to an overall increase in interior noise, but with some areas in the rear seats experiencing even higher noise levels (due to the conversation). The exterior noise adaptive function ensured the next horn blast was loud enough. The overall interior noise adaptive function raised the base volume level across the entire vehicle. The local interior noise adaptive function (if the rear area was activated) further moderately boosted the rear speaker volume to compensate for the conversation. Ultimately, this resulted in clear and audible sound throughout the vehicle.

[0168] The adaptive volume control method for commercial vehicles provided by this invention has a complete and specific technical solution. The MCU, memory, audio codec, power amplifier, microphone, and other components it relies on are all mature and commercially available electronic components. The software algorithms, such as ADC sampling, digital filtering, RMS calculation, and adaptive filtering, are all well-known or achievable mature algorithms in the field. Therefore, this invention can be implemented by those skilled in the art based on the description and in conjunction with existing technology.

[0169] This method can be directly applied to various commercial vehicles, including but not limited to freight trucks, long-distance buses, city buses, and construction machinery vehicles. By integrating or modifying this control system, it can effectively address the safety, compliance, and comfort pain points in volume control of existing commercial vehicles, demonstrating clear market demand and significant practical value. Its hardware costs are controllable, and its software is highly reusable, facilitating its promotion and application throughout the automotive industry chain.

[0170] The implementation principle of this invention is as follows: This invention discloses an adaptive volume control method for commercial vehicles, belonging to the field of vehicle electronics technology. This method constructs a hardware system including a microcontroller, an audio processing module, and an environmental noise detection module, and runs a multi-tasking software system on the microcontroller to achieve adaptive volume adjustment based on real-time environmental noise. Environmental noise detection integrates two methods: direct microphone acquisition and indirect non-microphone analysis (through the difference in back electromotive force of the horn). Based on preset thresholds and coefficients, the system executes adaptive volume control logic for external horns, the overall in-vehicle horn, and local in-vehicle horns, respectively. This invention can automatically adapt to different noise environments, effectively reducing driver workload, improving driving safety, optimizing audio clarity and comfort inside and outside the vehicle, and enhancing the compliance of external horn use.

[0171] In embodiments of the present invention, composite logic can be executed to accurately identify environmental noise. If an overall noise increase is detected, the overall volume of the vehicle's speakers will be increased; if a local noise increase is detected, the volume of the vehicle's speakers in that local area will be increased; if an overall noise decrease is detected, the overall volume of the vehicle's speakers in that area will decrease; if a local noise decrease is detected, the volume of the vehicle's speakers in that local area will decrease. In summary, the commercial vehicle adaptive volume control method of the present invention adopts a hardware system construction and software system operation. By detecting external environmental noise, it can automatically and reasonably control the volume of the vehicle's external speakers. By detecting noise inside and outside the vehicle, it can automatically ensure that the effective sound in different driving scenarios and different positions inside the vehicle can be recognized by all passengers during vehicle operation, reducing the safety hazards caused by driver distraction and improving the passenger riding experience. Furthermore, the identification of vehicle noise and the formation of historical data can provide more accurate and detailed noise data for the design of new models, achieving a better driving and riding experience in new models.

[0172] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0173] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0174] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0175] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0176] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for adaptive volume control in commercial vehicles, characterized in that, The method is implemented on a platform consisting of a hardware system and a software system running on it, and includes the following steps: Step S1: Construct a basic hardware system, which includes at least: The microcontroller unit (MCU) serves as the core controller. The power management module supplies power to all components of the system and is managed by the MCU; Parameter storage component, used to store system control parameters; The signal recognition module is used to identify the status of external function switches; The audio processing module includes an audio isolation distribution unit and an audio power amplifier; the audio isolation distribution unit is used to receive the raw audio input and isolate and distribute it into an internal reference sound source and an external driving sound source; the audio power amplifier is used to receive the external driving sound source and adjust the gain based on the control instructions of the MCU to drive the corresponding speaker; An environmental noise detection module is used to collect vehicle environmental noise signals. Step S2: System parameter configuration, preset control parameters including upper limit value of ambient noise, lower limit value of ambient noise, high noise volume control coefficient, and low noise volume control coefficient in the parameter storage component; Step S3: Build and run a software system on the MCU, and create and schedule multiple software tasks, including system tasks, IO tasks, environmental noise detection tasks, external horn control tasks, and internal horn control tasks. Step S4: Based on the state of the function switch and the ambient noise detection result, execute adaptive volume control logic, including: When the external adaptive function is activated, the output volume of the external horn is dynamically adjusted based on the real-time detected external ambient noise level when the driver triggers the external horn. When the overall adaptive function of the vehicle is turned on, the overall output volume of all the speakers in the vehicle is dynamically adjusted according to the real-time detected overall ambient noise level in the vehicle. When the in-vehicle local adaptive function is activated, the output volume of the speakers in the designated area of ​​the vehicle is independently and dynamically adjusted based on the real-time detected ambient noise level.

2. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The environmental noise detection module acquires environmental noise using at least one of the following methods: A) Microphone type: Sound pressure signals are directly collected by one or more microphones placed in specific locations inside and outside the vehicle; B) Non-microphone method: Using the audio processing module and the external speaker, the signal component caused by environmental noise is extracted by analyzing the difference between the expected electrical signal driving the external speaker and the electrical signal actually collected from the external speaker circuit, and the environmental noise intensity is calculated accordingly.

3. The adaptive volume control method for commercial vehicles according to claim 2, characterized in that, The non-microphone form of environmental noise detection specifically includes: Acquire the internal reference audio source signal generated by the audio isolation distribution unit for driving the external horn; Collect the actual voltage and / or current signal in the external horn circuit; By using a signal processing algorithm, the expected driving component related to the internal reference sound source signal is eliminated from the actual voltage and / or current signal to obtain the residual noise signal; Based on the amplitude or energy of the residual noise signal, the equivalent external environmental noise value is calculated through a pre-calibrated mapping relationship.

4. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The adaptive volume control logic for the vehicle's external speakers specifically includes: Continuously monitor the ambient noise level outside the vehicle; When the driver triggers the external horn, the relationship between the current external ambient noise level and a preset threshold is determined: If the ambient noise level outside the vehicle is less than or equal to the lower limit of ambient noise, the audio power amplifier is controlled to output with a first gain coefficient, which is related to the low noise volume control coefficient. If the ambient noise level outside the vehicle is greater than or equal to the upper limit of ambient noise, the audio power amplifier is controlled to output with a second gain coefficient, which is related to the high noise volume control coefficient. If the ambient noise level outside the vehicle is between the lower and upper limits of the ambient noise, the audio power amplifier is calculated and controlled to output with the corresponding intermediate gain coefficient based on a mapping function.

5. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The adaptive volume control logic for the in-vehicle speaker system specifically includes: Continuously monitor the overall ambient noise level inside the vehicle; Based on the relationship between the overall ambient noise level inside the vehicle and a preset threshold, the target total gain is dynamically calculated: If the overall ambient noise level inside the vehicle is less than or equal to the lower limit of ambient noise, the target total gain is determined based on the low noise volume control coefficient. If the overall ambient noise level inside the vehicle is greater than or equal to the upper limit of ambient noise, the target total gain is determined based on the high noise volume control coefficient. The target total gain is applied to the audio power amplifier that drives all in-vehicle speakers or its main volume control terminal.

6. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The in-vehicle local speaker adaptive volume control logic specifically includes: Continuously monitor the ambient noise level in at least one designated area inside the vehicle; For each region with local adaptation enabled, the target region gain corresponding to that region is calculated independently based on the relationship between its ambient noise value and a preset threshold. The target area gain calculated for each area is applied to the independent audio power amplifier channel that drives the speaker in the corresponding area.

7. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The method also includes composite control logic: When the overall in-vehicle adaptive function and at least one in-vehicle local adaptive function are activated simultaneously, the final output gain of the horn in the area controlled by the local adaptive function is determined by the overall gain calculated based on the overall noise and the area gain calculated based on the local noise.

8. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The external function switches identified by the signal recognition module include at least: a switch for turning the external horn adaptive function on or off, a switch for turning the overall in-vehicle horn adaptive function on or off, and a switch for turning the in-vehicle horn adaptive function in a specific area on or off.

9. The adaptive volume control method for commercial vehicles according to claim 1, characterized in that, The system control parameters stored in the parameter storage component also include: the basic gain of the external horn, the overall basic gain of the internal horn, the basic gain of the horns in each area, noise detection filtering parameters, and volume adjustment response speed parameters.

10. A system for implementing the adaptive volume control method for commercial vehicles according to any one of claims 1-9, characterized in that, include: The hardware system entity as defined in step S1 of claim 1; A non-transitory computer-readable storage medium storing an executable program, which, when executed by the MCU, enables the software task construction, scheduling, and adaptive volume control logic described in steps S3 and S4 of claim 1.

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