Sound power adjustment system based on adaptive vehicle battery state

Abstract

The application discloses a sound power adjusting system based on vehicle-mounted battery state self-adaption, relates to the technical field of automobile electronic control, and comprises the following modules: a vehicle state sensing and data acquisition module, which is used for analyzing bus messages to obtain power parameters and load states and collecting battery physical parameters; a decision and strategy control module, which is connected to the sensing module and is used for calculating a sound allowed output power threshold value in a current working condition and generating a control instruction according to a power priority mapping table and a battery state power calculation model; an execution and audio processing module, which is used for adjusting an amplifier carrier frequency and gain according to the instruction and performing audio frequency band processing; and a cross-domain isolation power supply protection module, which is used for providing isolation power supply and switching to an emergency energy storage element when voltage drops. Through a load preloading mechanism and dynamic internal resistance evaluation, the application realizes adaptive matching of sound power and vehicle battery state, and effectively prevents system reset due to voltage drop.

Description

Technical Field

[0001] This application relates to the field of automotive electronic control technology, and in particular to an audio power adjustment system based on adaptive on-board battery status. Background Technology

[0002] With the increasing intelligence and comfort of automobiles, high-powered in-vehicle audio systems have become standard equipment. However, the electrical environment inside a vehicle is extremely complex. The vehicle battery not only needs to power the audio system, but also needs to drive the engine starter, air conditioning compressor, and various electronic devices in the vehicle body.

[0003] Existing in-vehicle audio power management solutions typically rely on instantaneous monitoring of the bus voltage. This passive monitoring mechanism suffers from significant lag; the control system only begins power limiting after a substantial voltage drop has occurred. When a high-power load (such as an air conditioning compressor) suddenly starts, or when the battery's internal resistance increases significantly due to aging, the bus voltage often drops below the undervoltage protection threshold within a very short time. At this point, existing audio systems cannot adjust their output power in time, easily triggering undervoltage reset or shutdown, resulting in interrupted audio playback. Furthermore, current technology lacks the ability to assess the battery's dynamic internal resistance in real time, failing to accurately quantify the voltage maintenance capability of older batteries at high power output, and making it difficult to prevent system instability caused by battery performance degradation at its source.

[0004] In terms of power regulation strategies, traditional technologies often employ simple threshold-based logic. When low battery power or excessively high temperature is detected, the system typically resorts to forced mute or a significant reduction in gain. This approach ignores the continuity of the user's listening experience, easily causing abrupt interruptions in the audio signal or drastic volume fluctuations. Furthermore, existing Class D amplifier controls lack sophisticated thermal management and frequency band processing mechanisms. Under high load or high temperature conditions, they cannot maintain operation by adjusting the switching frequency or compressing energy in specific frequency bands, often leading to the device completely shutting down due to overheat protection, thus reducing system availability.

[0005] Furthermore, the switching action of high-power Class D amplifiers in vehicles generates strong electromagnetic interference. In existing circuit designs, the isolation between power circuits and logic control circuits is often inadequate, allowing high-frequency switching noise to couple to the control terminal through ground loops, interfering with the normal operation of the logic circuits. Simultaneously, during cold starts of the vehicle engine (especially in vehicles equipped with automatic start-stop systems), the main power supply voltage experiences a significant transient drop. Conventional power supply circuits struggle to maintain a stable voltage for the control chip under such deep voltage drops, frequently causing the audio control unit to power down and reset, losing the current sound settings and playback status, thus affecting the system's operational reliability. Summary of the Invention

[0006] The purpose of this invention is to provide an audio power adjustment system based on the adaptive state of the vehicle battery, which at least solves the technical problems of existing vehicle audio systems being prone to bus voltage drops and system resets under vehicle battery aging or transient high power conditions, as well as the lack of coordinated control with vehicle power and battery health status.

[0007] This invention provides the following solution:

[0008] According to one aspect of the present invention, an audio power adjustment system based on vehicle battery state adaptive is provided, comprising:

[0009] The system includes a vehicle status perception and data acquisition module, a decision-making and strategy control module, an execution and audio processing module, and a cross-domain isolation power supply protection module.

[0010] The input terminal of the vehicle status perception and data acquisition module is connected to the vehicle's controller area network flexible data rate bus and on-board battery pack. It is used to parse vehicle bus messages in real time and obtain vehicle power operation parameters and on-board load device switch status, as well as collect the physical status parameters of the on-board battery pack.

[0011] The decision and strategy control module is connected to the vehicle state perception and data acquisition module. It is used to receive the vehicle power operation parameters, the on-board load device switch status and physical state parameters. Based on the internally stored power priority mapping table and battery state power calculation model, it calculates the allowable output power threshold of the audio system under the current operating conditions and generates power control commands and frequency band processing commands.

[0012] The execution and audio processing module is connected to the decision and strategy control module through a general-purpose input / output interface. It includes a digital signal processor unit and a Class D power amplifier control unit, which are used to adjust the pulse width modulation carrier frequency and gain of the power amplifier circuit according to the power control command, and to perform frequency band attenuation or dynamic compression processing on the audio signal according to the frequency band processing command.

[0013] The cross-domain isolated power supply protection module is connected to the vehicle's main power line and the power input terminal of the execution and audio processing module, respectively. It is used to supply power to the decision and strategy control module and the execution and audio processing module, and to switch to emergency energy storage element power supply when the voltage drop rate of the vehicle's main power line exceeds a preset threshold.

[0014] Furthermore, the vehicle status perception and data acquisition module is equipped with a load start signal preloading mechanism; the load start signal preloading mechanism is used to monitor the start request message on the controller area network flexible data rate bus, and when the status bit of the start request message with a specific identifier is detected to flip, before the actual current consumption of the physical actuator of the vehicle's high-power load device causes the bus voltage to drop, a load pre-intervention interruption signal is generated and sent to the decision and strategy control module.

[0015] Furthermore, the vehicle state perception and data acquisition module includes a battery state monitoring unit, which is used to execute dynamic internal resistance calculation logic. The dynamic internal resistance calculation logic specifically involves using the current step generated by the fluctuation of the audio system output power or the sudden change in vehicle load as an excitation. Within a preset sampling window, the battery terminal voltage and current values ​​at the start and end times are collected respectively, and the ratio of the absolute value of the voltage change to the absolute value of the current change within the sampling window is calculated. The ratio is then used as the real-time dynamic internal resistance value of the battery.

[0016] Furthermore, the decision and strategy control module executes the following arbitration logic based on the power priority mapping table: when an emergency braking signal is detected or the bus voltage is lower than the minimum voltage protection threshold, the power limiting coefficient is set to zero; when an engine start signal is detected, the power limiting coefficient is set to a first preset value; when an air conditioning compressor start signal is detected simultaneously and the bus voltage drops below the threshold voltage, the power limiting coefficient is set to a second preset value, wherein the second preset value is greater than the first preset value; when the vehicle is detected to be in an external charging state or a stable voltage cruising state, the power limiting is lifted.

[0017] Furthermore, the decision and strategy control module calculates the target power value using the battery state-of-charge (SOC) power calculation model. The calculation model first calculates the limit power value based on voltage drop limitations, using the current battery terminal voltage, the system's minimum safe voltage, the real-time dynamic internal resistance, and the equivalent series resistance of the circuit. The calculation model further maps the battery's current state of charge (SOC) to an energy weighting coefficient. When the SOC is in the intermediate range, the energy weighting coefficient decays as the SOC decreases according to a sinusoidal curve. The decision and strategy control module performs a comprehensive calculation using the limit power value, the energy weighting coefficient, and the power limitation coefficient determined by the power priority mapping table to obtain the target power value.

[0018] Furthermore, the Class D power amplifier control unit is used to execute a carrier frequency dynamic adjustment strategy based on thermal feedback; the Class D power amplifier control unit reads the junction temperature data inside the power amplifier chip in real time, and adjusts the switching frequency of the output stage in stages according to the junction temperature data: when the junction temperature is lower than the first-level temperature control threshold, the high-frequency mode is maintained; when the junction temperature is between the first-level temperature control threshold and the second-level temperature control threshold, the switching frequency is reduced to the medium-frequency mode; when the junction temperature exceeds the second-level temperature control threshold, the low-frequency protection mode is entered.

[0019] Furthermore, the digital signal processor unit is used to execute the following frequency band processing logic: when the battery state of charge is lower than a preset power threshold, the coefficients of a finite-length unit impulse response filter are loaded to apply gain attenuation that conforms to logarithmic attenuation characteristics to the high-frequency audio signal above the preset cutoff frequency; when the battery temperature exceeds a preset temperature threshold or a transient high-current discharge condition is detected, the low-frequency dynamic range compression logic is activated to perform root mean square detection only on the low-frequency components, and the compressor is started to limit the dynamic range when the amplitude exceeds the threshold.

[0020] Furthermore, the cross-domain isolated power supply protection module adopts a physical isolation architecture between the power domain and the logic domain; the cross-domain isolated power supply protection module physically divides the system's grounding network into analog power ground and digital logic ground, which are connected through a high-frequency bypass element; the cross-domain isolated power supply protection module has a digital isolation chip based on magnetic coupling technology between the external data interaction interface and the system's internal controller, which is connected to the data transmission path between the external data interaction interface and the system's internal controller to block high-frequency switching noise and high-voltage surges generated by the power circuit from coupling to the control logic circuit.

[0021] Furthermore, the cross-domain isolated power supply protection module integrates an emergency energy buffer unit. The emergency energy buffer unit uses a series-connected supercapacitor bank as the emergency energy storage element and is configured with a power switching architecture based on an ideal diode controller. The power switching architecture utilizes power metal-oxide-semiconductor field-effect transistors connected in series on the vehicle's main power line and the backup power path. The control circuit monitors the voltage difference between the vehicle's main power line voltage and the supercapacitor terminal voltage. When the vehicle's main power line voltage is detected to drop below the supercapacitor terminal voltage, the control circuit turns off the transistors in the path of the vehicle's main power line and turns on the transistors in the backup power path, allowing the supercapacitor bank to supply power to the system.

[0022] Furthermore, the vehicle status perception and data acquisition module is connected to the vehicle's human-machine interface terminal via a local area network bus; the decision and strategy control module is used to calculate the remaining safe playback time, which is calculated based on the difference between the current state of charge of the battery and the minimum reserve charge threshold to ensure engine start, and estimated in conjunction with the average current consumption of the audio system; the vehicle status perception and data acquisition module sends the power limitation coefficient determined by the decision and strategy control module when generating the power control command and the remaining safe playback time to the human-machine interface terminal, which provides visual feedback on the display interface through the color change of the circular progress bar and the numerical display based on the received data.

[0023] The above solution achieves the following beneficial technical effects:

[0024] This application improves the stability of the vehicle's electrical system by employing a load start signal preloading mechanism and a power calculation model based on the battery's dynamic internal resistance. The system utilizes the time difference between CAN bus message transmission and physical actuator action to trigger power limiting before the actual bus voltage drop. Simultaneously, by combining real-time calculated battery dynamic internal resistance and terminal voltage, it quantifies the limitation of power output caused by battery aging, effectively preventing transient drops in bus voltage and audio system resets due to battery aging or sudden load changes.

[0025] This application optimizes the audio listening experience under limited battery power. The decision module maps the battery state of charge to a non-linear energy weighting coefficient, smoothly attenuating power according to a sine curve as the battery power decreases, avoiding abrupt changes in the listening experience. At the same time, combined with the thermal feedback-based switching frequency adjustment of the Class D amplifier and the frequency band processing strategy of the DSP, it actively reduces high-frequency gain or compresses low-frequency dynamics under low battery or high-temperature conditions, maintaining the continuity of audio output while ensuring battery life and device safety.

[0026] This application enhances the system's anti-interference capability and operational reliability in complex electromagnetic environments. The cross-domain isolated power supply protection module constructs a physical isolation architecture between analog power ground and digital logic ground, utilizing a magnetically coupled digital isolation chip to block the coupling of high-frequency switching noise from the power circuit to the control logic; in conjunction with an emergency energy buffer unit composed of supercapacitors, it ensures that the core control logic can still maintain a stable power supply during cold starts of the vehicle engine or short circuits in the main power circuit, preventing the loss of configuration parameters. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the system architecture provided by one or more embodiments of the present invention.

[0028] Figure 2This is a schematic diagram of the multi-protocol bus signal parsing logic provided in one or more embodiments of the present invention.

[0029] The module includes: 100, Vehicle Status Perception and Data Acquisition Module; 200, Decision and Strategy Control Module; 300, Execution and Audio Processing Module; 400, Cross-Domain Isolation Power Supply Protection Module; and 500, CAN FD Bus. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Figure 1 The present invention provides an audio power adjustment system based on vehicle battery state adaptive, which includes: a vehicle state perception and data acquisition module 100, a decision and strategy control module 200, an execution and audio processing module 300, and a cross-domain isolation power supply protection module 400.

[0032] The input of the vehicle status perception and data acquisition module 100 is physically connected to the vehicle's Controller Area Network Flexible Data Rate Bus (CAN FD bus) 500 and the on-board battery pack. The vehicle status perception and data acquisition module 100 is used to acquire in real time the operating parameters of the vehicle's powertrain, the on / off status of on-board load devices, and the physical status parameters of the on-board battery pack. The output of the vehicle status perception and data acquisition module 100 is connected to the input of the decision and strategy control module 200.

[0033] The decision and strategy control module 200 is the core logic unit of the audio power adjustment system based on the adaptive state of the vehicle battery. In one embodiment, the decision and strategy control module 200 uses a field-programmable gate array (FPGA) chip as the main controller. The decision and strategy control module 200 internally stores a power priority mapping table and a battery state power calculation model. The decision and strategy control module 200 is used to calculate the allowable output power threshold of the audio system under the current operating conditions based on the received state parameters, and to generate corresponding power control commands and frequency band processing commands.

[0034] The execution and audio processing module 300 is connected to the output of the decision and strategy control module 200. The execution and audio processing module 300 and the decision and strategy control module 200 are directly connected via a general purpose input / output (GPIO) hardware line to enable parallel transmission of instructions. The execution and audio processing module 300 includes a digital signal processor (DSP) unit and a Class D power amplifier control unit. The execution and audio processing module 300 is used to adjust the pulse width modulation (PWM) carrier frequency and gain of the power amplifier circuit according to power control instructions, and to perform frequency band attenuation or dynamic compression processing on the audio signal according to frequency band processing instructions.

[0035] The cross-domain isolation power supply protection module 400 is connected to both the vehicle's main power supply line and the power input terminal of the execution and audio processing module 300. The cross-domain isolation power supply protection module 400 is used to maintain the stability of the system power supply when the vehicle's main power supply voltage fluctuates, and to provide electrical isolation between the control circuit and the power circuit.

[0036] During the operation of the audio power adjustment system based on the adaptive state of the vehicle battery, the vehicle state perception and data acquisition module 100 continuously parses vehicle bus messages via the CAN FD bus 500. The parsed message content includes engine speed signals, air conditioning compressor start / stop signals, and navigation remaining range data. Simultaneously, the vehicle state perception and data acquisition module 100 collects real-time temperature, state of charge (SOC), and dynamic internal resistance data of the vehicle battery pack through connected sensor groups.

[0037] The decision and strategy control module 200 receives the parsed message data and sensor-collected data. Based on preset logic, the module determines the vehicle's current operating mode. Operating modes include, but are not limited to, engine start mode, energy recovery mode, parking mode, and high-power load access mode. Combining the vehicle's operating mode and the real-time battery status, the module calculates the target power value using an internal algorithm. .

[0038] When the decision and strategy control module 200 determines that the audio power needs to be adjusted, it sends a control level signal to the execution and audio processing module 300 via GPIO hardware lines. In response to the received signal, the execution and audio processing module 300 adjusts the register configuration of the Class D power amplifier control unit via the I2C bus, changing the switching frequency and gain of the output stage; simultaneously, it controls the DSP unit to call pre-stored filter coefficients to perform digital domain processing on the audio signal of a specific frequency band.

[0039] The cross-domain isolated power supply protection module 400 continuously monitors the power bus voltage during system operation. When the voltage drop rate exceeds a preset threshold, the cross-domain isolated power supply protection module 400 switches the power supply path and uses internal energy storage elements to provide emergency power to the decision and strategy control module 200 and the execution and audio processing module 300 to prevent the system from resetting due to voltage transients.

[0040] In addition, the vehicle status perception and data acquisition module 100 is connected to the vehicle's human-machine interface terminal via a local area network (LIN) bus. The audio power adjustment system based on the vehicle battery status adaptively sends the current available power data and battery health status to the head-up display (HUD) or central control screen for display through this link.

[0041] See attached document Figure 2 The vehicle status perception and data acquisition module 100 integrates a high-speed bus transceiver and a protocol controller to realize the physical layer access and link layer parsing of the vehicle controller area network flexible data rate bus (CAN FD bus) 500.

[0042] The vehicle status perception and data acquisition module 100 performs hardware filtering and software parsing based on identifiers (IDs) through its internal bus protocol controller. The bus protocol controller is configured with a specific acceptance mask and acceptance code to filter out key messages related to power management and audio control from the massive bus data stream. The filtering of key messages does not rely on a polling mechanism; instead, it uses interrupt triggering or direct memory access (DMA) to load valid data into a specific address segment of the buffer to reduce processing latency.

[0043] Specifically, the vehicle status perception and data acquisition module 100 configures corresponding message parsing rules for different vehicle status parameters. For engine operating status, the module locks the message with extended frame ID 0x0CF00400, extracts the engine speed data field, and determines whether the engine is in the starting process based on the characteristic of a non-zero and continuously rising speed. For high-power load device status, the module locks the message with extended frame ID 0x18FEF100, and parses the status of the air conditioning compressor clutch request or the electronic compressor enable position. For navigation and vehicle trip information, the module locks the message with standard frame ID 0x321, extracts the remaining mileage data to help determine whether to enter the energy-saving range strategy.

[0044] To address the voltage transient drop and lag response issue caused by high-power load connection, the vehicle state perception and data acquisition module 100 is equipped with a load start signal preloading mechanism. This mechanism utilizes the characteristic that the transmission time of control commands on the bus is earlier than the action time difference of the physical actuators to achieve feedforward prediction of load connection. The preloading mechanism obtains the preset time advance by monitoring the "compressor start request" signal issued by the air conditioning control unit (HVAC ECU), rather than monitoring the current feedback signal after the compressor actually closes. Lead time The settings satisfy the following timing relationship:

[0045] ;

[0046] in: This indicates the physical moment when the bus voltage begins to drop due to the activation of the air conditioner compressor relay or the conduction of the power transistor. This indicates the moment when the vehicle status perception and data acquisition module 100 captures the start request message with ID 0x18FEF100 on the CANFD bus; In this embodiment, the minimum safe response time window required for the system to perform power adjustment is set to 50 milliseconds (ms).

[0047] Through the aforementioned preloading mechanism, the system can perform audio power limiting operations in advance before the actual voltage drop occurs. The vehicle status perception and data acquisition module 100 has an internal ring buffer for temporarily storing recent bus status snapshots. When a specific status bit with ID 0x18FEF100 is detected to flip, the module immediately generates a high-priority "load pre-intervention" interrupt signal and sends it to the decision and strategy control module 200, without waiting for subsequent periodic status synchronization.

[0048] Furthermore, the design of the physical layer interface circuit of the bus protocol controller, the baud rate configuration (such as a data domain baud rate of 2Mbps or 5Mbps), and the sampling point settings can be implemented by those skilled in the art in accordance with the ISO 11898-1:2015 standard and the specific vehicle electronic and electrical architecture specifications. The specific circuit parameters are well-known technologies in the field and will not be elaborated here.

[0049] The vehicle status perception and data acquisition module 100 also has fault-tolerant processing capabilities for abnormal messages. When the bus load rate exceeds 80% or an increase in the error frame count is detected, the module will automatically reduce the sampling frequency of non-critical data and prioritize the real-time capture of critical control messages such as ID 0x0CF00400 and 0x18FEF100, ensuring accurate acquisition of vehicle power and load status even under network congestion conditions.

[0050] The vehicle status perception and data acquisition module 100 includes an independent battery status monitoring unit. This unit consists of a temperature acquisition circuit subsystem and a power metering circuit subsystem at the physical level, and is used to provide high-frequency and high-precision battery physical parameters to the decision-making level.

[0051] The temperature acquisition circuit subsystem employs a dedicated resistor-to-digital converter (RTD-to-Digital Converter) chip in conjunction with a negative temperature coefficient (NTC) thermistor. In this embodiment, the MAX31865 chip is selected as the analog front-end interface. The NTC thermistor is thermally coupled to the surface of the battery cell or the module bus of the vehicle battery pack to sense the real-time battery temperature. The MAX31865 chip is configured in proportional measurement mode, and an external high-precision reference resistor is connected in series with the NTC thermistor to eliminate the influence of excitation current source fluctuations on measurement accuracy.

[0052] The temperature acquisition circuit converts the read thermistor resistance value into a digital signal and transmits it to the main controller via the Serial Peripheral Interface (SPI). Based on the specific constants of the NTC thermistor material, the main controller uses the Steinhart-Hart equation to establish a polynomial relationship between the natural logarithm of the resistance value and the reciprocal of the absolute temperature, thereby calculating the precise absolute temperature of the battery.

[0053] The power metering circuit subsystem uses the LTC2945 wide-input-range power monitoring chip. The high-side current sensing terminal of this chip is connected across a precision shunt resistor in the main output circuit of the battery pack. The shunt resistor is made of manganese-copper alloy, with a resistance value selected between 0.5 milliohms and 2 milliohms to balance detection sensitivity and low insertion loss. The LTC2945 chip integrates a 12-bit analog-to-digital converter (ADC) to synchronously acquire battery terminal voltage and circuit current at a set sampling rate.

[0054] To achieve real-time assessment of battery state of health (SOH), the battery state monitoring unit executes logic to calculate the dynamic internal resistance change rate. This logic does not rely on static measurements but instead utilizes current steps caused by fluctuations in audio system output power or sudden changes in vehicle load as excitation. Within an extremely short time window of less than 50 milliseconds, the system samples the battery terminal voltage and current values ​​at the start and end times. Subsequently, the system calculates the ratio of the absolute value of the voltage change to the absolute value of the current change within this time window to obtain the dynamic internal resistance value. When the rate of change of this dynamic internal resistance value continuously exceeds a preset aging threshold (e.g., 5 mΩ / s), the system determines that the battery is in a high-impedance state and marks it as requiring the triggering of a power limiting strategy.

[0055] For acquiring the battery's state of charge (SOC), the system employs a strategy combining the ampere-hour integration method and the open-circuit voltage method. During vehicle operation, the system utilizes current sampling data provided by the LTC2945 to perform time-based cumulative integration calculations on the instantaneous current. The controller performs algebraic operations on this integral value and the initial SOC, and then corrects it by incorporating the coulombic efficiency coefficient corresponding to the current temperature, thereby obtaining real-time SOC percentage data.

[0056] For the configuration of external filter capacitors for the MAX31865 and LTC2945 chips, the Kelvin connection method in PCB routing, and the selection of pull-up resistors for the I2C / SPI bus, those skilled in the art can refer to relevant datasheets and mixed-signal circuit design specifications for implementation. The specific circuit layout is well-known in the field and will not be elaborated further here. Through the combination of the above hardware circuits and computational logic, the battery state monitoring unit can provide high-precision voltage, current, and temperature data in a wide temperature range of -20℃ to +65℃, providing a reliable data foundation for subsequent power decisions.

[0057] The decision and strategy control module 200 has a built-in power priority mapping table based on erasable programmable read-only memory (EPROM) or flash memory. This mapping table does not use a single linear logic, but is constructed as a discrete mapping relationship between multi-dimensional state vectors and power limitation coefficients. The decision and strategy control module 200 determines the current power limitation coefficient based on preset arbitration logic by periodically scanning the vehicle state vector. .

[0058] The vehicle state vector is composed of real-time data provided by the vehicle state perception and data acquisition module 100, including the engine start signal. Emergency braking signal Air conditioner compressor status signal and bus voltage values The arithmetic logic unit (ALU) within the decision and strategy control module 200 performs Boolean logic operations on the aforementioned state signals and compares them with thresholds to generate corresponding operating condition flags. To achieve electromagnetic compatibility and energy distribution balance between the audio system and key vehicle loads under different vehicle operating conditions, the decision and strategy control module 200 executes the following defined power limiting coefficients. Calculation logic:

[0059] ;

[0060] in: This represents the dimensionless power limitation factor, with a value ranging from 0 to 1.0. This is the Boolean value for the emergency braking signal; 1 indicates that it has been triggered. This is the real-time monitoring value of the current DC bus voltage; The minimum voltage protection threshold for the system to maintain normal operation is set to 9 volts (V) in this embodiment. This represents the Boolean state value during the engine starting process; 1 indicates that the starter motor is engaged or rotating. The Boolean status value for requesting the air conditioner compressor to start, where 1 indicates that the compressor is engaging. To determine the threshold voltage for a voltage transient drop caused by the load, this embodiment sets it to 11.9 volts (V). and These are Boolean flags for the vehicle's fast charging status and normal cruising status, respectively.

[0061] Regarding the first scenario in the above calculation logic, when an emergency braking signal is detected or the bus voltage is lower than the minimum protection threshold, the system determines it as the highest priority safety condition. At this time, the decision and strategy control module 200 forcibly sets the power limiting coefficient to zero, aiming to immediately cut off the audio load to eliminate potential power interference to the brake assist system or airbag control unit, while preserving the power supply to the chassis domain controller.

[0062] Regarding the second scenario in the aforementioned calculation logic, when an engine start signal is detected, the system identifies it as a short-term high-current surge condition. Following the JASO D003 automotive electronics standard's principle of prioritizing critical loads, the system limits the audio power to 30% of its rated value. This operation prevents the high current demand of the starter motor from causing the audio system to repeatedly restart due to undervoltage, and also avoids exacerbating the voltage drop at startup caused by the large capacitor charging circuit of the audio amplifier.

[0063] Regarding the third scenario in the aforementioned calculation logic, when the air conditioner compressor starts and the bus voltage drops below a threshold, the system determines it to be a transient load disturbance condition. Unlike conventional logic that only detects the compressor start signal, this invention introduces a voltage drop condition as an AND gate input, triggering the limit only when the compressor start-up actually causes power grid fluctuations. In this case, the coefficient is set to 0.7, i.e., reducing power output by 30%, to smooth voltage fluctuations and prevent light flickering or reset of sensitive electronic devices.

[0064] Regarding the fourth scenario in the above calculation logic, when the vehicle is in a state of external charging or stable voltage cruising, the system determines that the energy is sufficient, removes the power limit, and allows the audio system to output at full power.

[0065] Furthermore, to prevent frequent fluctuations in the power limiting coefficient due to signal jitter, the decision and strategy control module 200 introduces a hold timer when executing the aforementioned arbitration logic. This hold timer is used when the system switches from a low-power state to a high-power state (e.g., from...). Switch to When switching from high power to low power, the output command can only be updated if the high-priority signal is withdrawn and the duration exceeds the preset stable window (e.g., 500ms). When switching from high power to low power, the command is executed immediately without delay to ensure the timeliness of the protection action.

[0066] The decision and strategy control module 200 internally operates a multi-dimensional dynamic power calculation model. This model first obtains the real-time dynamic internal resistance value ΔR (i.e., the aforementioned dynamic impedance) and the current battery terminal voltage provided by the battery state monitoring unit. The system defines a limit power value to prevent voltage drop to bottom. The physical meaning of this value is: under the current battery internal resistance and terminal voltage conditions, the audio system output power causes the bus voltage to drop to the system's minimum safe voltage. The critical power at that time.

[0067] Limiting power value The computational model is constructed as follows:

[0068] ;

[0069] in: This represents the theoretical maximum allowable input power based on voltage drop limits, expressed in watts (W). The power conversion efficiency coefficient of the audio system is 0.85 in this embodiment, taking into account both DC-DC conversion loss and Class D amplifier efficiency. This represents the battery terminal voltage collected at the current moment. The preset minimum safe voltage for the system is set to 9.5 volts, which is slightly higher than the aforementioned forced disconnection threshold, leaving a safety margin. This is the real-time value of the battery's current dynamic internal resistance. This is the equivalent series resistance of the wiring harness and connectors between the battery pack and the power input terminal of the audio system. This value is a fixed constant and is pre-stored in the system memory.

[0070] Through the above calculations, the system can quantify the specific limitations of battery aging on power output capability. When battery aging leads to an increase in ΔR, the calculated... This will significantly reduce current surges at the source, preventing voltage collapse in older batteries due to high-current discharge.

[0071] After determining the physical power limit, the system further introduces a State of Charge (SOC)-based energy management strategy. The decision and strategy control module 200 maps the current SOC value to a dimensionless energy weighting coefficient. This mapping relationship is not a simple linear function, but rather employs a piecewise nonlinear adjustment strategy to balance user experience and battery life retention. Energy weighting coefficient. The calculation logic is as follows:

[0072] ;

[0073] This functional relationship design allows the audio system to operate at full power when the battery is sufficient (>80%); when the battery is in the middle range, the power is allowed to decay smoothly according to a sine curve to avoid abrupt changes in sound; when the battery is low to the warning line (≤30%), the power is forcibly clamped to 20% to maximize the usage time of the remaining battery.

[0074] Finally, the decision and strategy control module 200 integrates the aforementioned power priority limiting coefficients. Physical limit power and energy weighting coefficient The target power value finally sent to the execution layer is calculated. .

[0075] Target power value The comprehensive calculation formula is as follows:

[0076]

[0077] in: This refers to the rated maximum design power of the audio system.

[0078] To prevent due to or Sampling noise leads to Due to high-frequency jitter in the numerical value, the system performs a first-order low-pass digital filter on the command before outputting it. The filter's cutoff frequency is set to 5 Hz to ensure that the power adjustment command can respond to second-level changes in operating conditions while filtering out millisecond-level measurement noise.

[0079] The specific code for floating-point arithmetic, trigonometric function lookup table implementation, and digital filter involved in the computational model can be implemented by those skilled in the art according to the embedded development specifications of FPGA or MCU, and these are well-known technologies in the field, so they will not be elaborated here. Through this dynamic model, the system achieves adaptive control.

[0080] The execution and audio processing module 300 integrates a Class D power amplifier control unit, which serves as the system's final power execution mechanism. At the physical layer, it is constructed using a multi-channel digital input Class D audio amplifier chipset. In this embodiment, a TI TAS6424 integrated circuit chip with hardware diagnostics and protection functions is used. The Class D power amplifier control unit is connected to the decision and strategy control module 200 via a two-wire serial bus (I2C) interface. Its device address is configured within the address space of 0x34 to 0x3F, and it receives hardware mute and fault reset signals from the control layer via general purpose input / output (GPIO) pins.

[0081] The Class D amplifier control unit is configured to implement a dynamic carrier frequency adjustment strategy based on thermal feedback pulse width modulation (PWM). This strategy aims to balance the total harmonic distortion (THD) of the audio signal with the heat dissipation of the power devices. The Class D amplifier control unit reads data from the junction temperature sensor integrated within the amplifier chip in real time.

[0082] Based on the read junction temperature data, the system modifies the internal frequency control register of the chip via the I2C bus to dynamically switch the PWM switching frequency of the output stage. Switching frequency The dynamic adjustment logic is defined by the following piecewise functions:

[0083] ;

[0084] in: The first-level temperature control threshold; This is the secondary temperature control threshold.

[0085] When the junction temperature is below the first-level threshold, the system maintains a high switching frequency of 450kHz to ensure the resolution and transient response of the audio signal across the entire frequency band. When the junction temperature rises to between the first-level and second-level thresholds, the system reduces the frequency to 300kHz to reduce the switching losses of the metal-oxide-semiconductor field-effect transistor (MOSFET) and thus suppress the rate of temperature rise. When the junction temperature exceeds the second-level threshold, the system is forced into a low-frequency protection mode of 150kHz to maintain basic audio functions without interruption and prevent the chip from triggering over-temperature shutdown (OTSD).

[0086] Upon receiving a power adjustment command from the decision and strategy control module 200, the Class D amplifier control unit executes sensorless power switching logic. This logic eliminates pop noise or abrupt changes in gain at the speaker level. Instead of directly overwriting the gain register, the system operates the volume control register of the TAS6424 chip. The control unit utilizes the chip's built-in digital state machine to progressively adjust the output gain according to logarithmic curve characteristics, with a minimum resolution of 0.1 dB.

[0087] The sensorless power switching process has a fixed transition time constant. In this embodiment, it is 20 milliseconds (ms). During this period, the output gain... The current value smoothly transitions to the target value, achieving an auditory fade-in or fade-out effect. Furthermore, the Class D amplifier control unit implements transient overload protection at the hardware level. The chip's built-in current sensing circuit continuously monitors the output current of each channel. When an overcurrent event is detected that meets the following conditions:

[0088] ;

[0089] in, The overcurrent threshold is set to 15 amps. The detection time window is set to 10 milliseconds. The Class D amplifier control unit will bypass the I2C communication delay of the software layer and directly trigger the hardware protection logic, forcibly pulling the PWM output duty cycle low and inserting a 5-millisecond mute interval. After the overcurrent condition disappears, the system automatically calls the above fade-in logic to restore the output, thereby achieving a microsecond-level circuit protection response.

[0090] The execution and audio processing module 300 integrates a high-performance audio digital signal processor (DSP), which in this embodiment uses an ADAU1452 or an audio processing chip with equivalent computing power. This DSP unit is connected to a non-volatile memory via a four-wire serial peripheral interface (QSPI) to store multiple sets of preset filter coefficient tables and acoustic calibration parameters. The DSP unit is located before the Class D power amplifier control unit in the signal chain and is responsible for real-time frequency domain processing of the multi-channel audio pulse code modulation (PCM) data stream.

[0091] When the decision and strategy control module 200 determines that the vehicle is in a low-battery state, specifically when the battery state of charge (SOC) is below 30%, the DSP unit executes a high-frequency energy attenuation strategy. Since high-frequency signals contribute little to the listening experience in the audio power spectrum but still consume current, the system reduces high-frequency gain by loading specific finite-length unit impulse response (FIR) filter coefficients. The FIR filter is configured as a 128th order filter with a cutoff frequency of... Set to 2 kHz.

[0092] For frequency bands above the cutoff frequency, the attenuation gain applied by the system It follows the logarithmic decay property:

[0093] ;

[0094] in: For frequency Gain attenuation at a given point, in decibels (dB). The high-frequency segmentation point frequency is 2000Hz, which is taken here. The attenuation slope coefficient is set to 3dB / oct in this embodiment, meaning that the gain decreases by 3dB for every doubling of the frequency.

[0095] When the vehicle status perception and data acquisition module 100 detects the battery temperature When the temperature exceeds 50 degrees Celsius, or a transient high-current discharge condition is detected, the DSP unit activates the low-frequency dynamic range compression (DRC) logic. This logic divides the audio signal in the frequency domain, processing only low-frequency components below 200 Hz. The root mean square (RMS) detector within the DSP unit calculates the energy amplitude of the low-frequency channel in real time. When the amplitude exceeds a preset threshold, the compressor is activated, and the compression ratio is set. The ratio is 2:1. This is intended to limit the instantaneous current spikes caused by the high dynamic range of bass signals, preventing battery voltage drops.

[0096] During vehicle operation, to combat the interference of environmental noise on auditory perception, the DSP unit runs a background noise compensation algorithm. This algorithm dynamically adjusts the gain in the mid-frequency band (300Hz to 3000Hz) based on vehicle bus data (such as vehicle speed signal or air conditioning fan speed level). Instead of full-band boosting, the compensation algorithm uses a parametric equalizer (PEQ) to enhance the signal-to-noise ratio of the speech band, ensuring clarity of navigation voices or human voices while limiting total power output.

[0097] Furthermore, to maintain sound fidelity in low-power mode, the DSP unit constructs a pre-distortion-based total harmonic distortion plus noise (THD+N) compensation loop. The QSPIFlash memory pre-stores 100 sets of linearization correction parameters, corresponding to different power levels and power supply voltage combinations. The DSP unit monitors the distortion of the output signal in real time through a feedback loop and adjusts the compensation based on the current power supply voltage. With target power The corresponding predistortion parameters are indexed and loaded via a lookup table. These parameters affect the amplitude mapping of the digital audio stream, providing inverse compensation for the transmission characteristics of the power amplifier circuit in the low-voltage or nonlinear region, thereby ensuring the output linearity of the system under power-constrained conditions.

[0098] For the specific programming development environment (such as SigmaStudio), I2S audio interface timing configuration, and specific tap coefficient calculation method of the FIR filter for the ADAU1452 chip, those skilled in the art can refer to the relevant chip manual and digital signal processing theory for implementation. These are well-known technologies in the field and will not be elaborated here.

[0099] The cross-domain isolated power supply protection module 400 serves as the system's energy management and electrical safety barrier, physically located between the vehicle's main power harness and the system's internal low-voltage logic circuitry. This module primarily consists of a voltage regulator circuit unit based on a wide-input-voltage synchronous buck converter and a digital signal isolation unit based on magnetic coupling technology. It aims to address high-power ground potential interference and power transient fluctuations in the complex electromagnetic environment of an in-vehicle system.

[0100] The voltage regulation circuit unit uses the LT8610 monolithic synchronous buck switching regulator as the core power conversion device. The input power pin (VIN) of the LT8610 chip is not directly connected to the positive terminal of the vehicle battery, but is connected in series with an electromagnetic interference (EMI) suppression circuit composed of a π-type filter. The π-type filter consists of two ceramic capacitors and a common-mode inductor, used to filter out high-frequency conducted noise on the power supply bus. The enable pin (EN / UVLO) of the LT8610 chip is connected to the input power supply through a precision voltage divider resistor network, setting the system's undervoltage lockout threshold to ensure that the converter automatically stops operating to protect the downstream circuitry when the input voltage falls below a preset value (e.g., 5.5V).

[0101] In the circuit topology design, the LT8610 chip is configured in synchronous rectification mode, integrating high-efficiency power switches at the top and bottom. The switching frequency is set to 2MHz by connecting a resistor of a specific value between the RT pin and ground. This frequency selection is intended to avoid the amplitude modulation (AM) broadcast band, reducing RF interference to the in-vehicle entertainment system. The LT8610's output provides stable 3.3V and 1.2V DC voltages to the decision and strategy control module 200 (FPGA domain) and the digital logic section (DSP domain) in the execution and audio processing module 300 through an LC smoothing circuit consisting of a power inductor and a low equivalent series resistance (ESR) capacitor. This power supply path maintains the output voltage ripple peak-to-peak value of less than 10mV even during load dump transients of up to 42V from the input voltage.

[0102] To prevent high-frequency switching noise generated by high-power Class D amplifiers from coupling to sensitive digital control logic through the ground loop, the cross-domain isolation power supply protection module 400 establishes a strict physical isolation architecture between the "power domain" and the "logic domain". The architecture physically divides the system's grounding network into analog power ground (PGND) and digital logic ground (DGND). There is no direct electrical connection between the two; instead, high-frequency bypassing is achieved through a single-point high-voltage capacitor or ferrite bead.

[0103] On the digital communication link spanning these two isolated ground planes, the system employs a digital isolation chip for signal transmission. In the debugging and data interface circuit of this embodiment, the ADuM4160 Universal Serial Bus (USB) isolator is used. The ADuM4160 chip, based on iCoupler magnetic coupling isolation technology, is positioned between the system's external data interface and the internal DSP / FPGA controller. The primary-side power supply (VBUS1) of the ADuM4160 is taken from the interface power supply of the external diagnostic equipment, and the secondary-side power supply (VBUS2) is taken from the internal isolation power supply generated by the LT8610. Through its on-chip air-core transformer structure, this chip provides a root mean square (RMS) electrical isolation withstand voltage of up to 2500V while achieving bidirectional transparent data transmission at full speed (12Mbps) or low speed (1.5Mbps).

[0104] For GPIO control signals and I2C bus signals between the FPGA and the Class D power amplifier within the system, the system is also equipped with multi-channel digital isolators (such as the ADuM14xx series) to match the isolation barrier standard built by the ADuM4160. The control signals pass through the isolation layer in the form of light or magnetic pulses, ensuring that even if a power stage short circuit occurs in the Class D power amplifier, causing a violent fluctuation in ground potential, the high-voltage surge will not reverse-dam the low-voltage control chip at the front end.

[0105] The cross-domain isolated power supply protection module 400 integrates an emergency energy buffer unit and a transient current protection unit to solve the problem of control system reset caused by bus voltage drop under vehicle start-up or high load conditions, as well as overcurrent protection against sudden short circuits at the load end.

[0106] The emergency energy buffer unit uses a series-connected electric double-layer capacitor (EDLC) array as the energy storage element. In this embodiment, two supercapacitors with a nominal capacity of 10 farads (F) are connected in series to form the energy storage tank. To solve the voltage balance problem of the series capacitors, the system uses the LTC3225 supercapacitor charger chip. This chip is configured in adaptive charging mode, which adjusts the charging current by monitoring the input power supply voltage to ensure that energy storage is completed without pulling down the main power supply voltage. The LTC3225 chip integrates an active voltage balancing circuit, which monitors the midpoint voltage of the two supercapacitors in real time and adjusts the charging rate of each cell through the internal shunt FET to ensure that the voltage across each capacitor is strictly maintained at a preset cutoff voltage (e.g., 2.5V), preventing cell overvoltage aging.

[0107] In power supply path management, this invention does not employ traditional diode "OR" logic, but instead constructs a low-loss power switching architecture based on an ideal diode controller. This architecture utilizes an N-channel power MOSFET instead of a Schottky diode connected in series in the output path between the main power supply and the supercapacitor. The control circuit adjusts the gate voltage by monitoring the voltage difference between the MOSFET's drain and source. When the vehicle's main power supply voltage... Under normal conditions, the main circuit MOSFET is turned on, and the supercapacitor is in standby mode; when the main power supply voltage drops below the supercapacitor terminal voltage, the supercapacitor will be switched on. At that moment, the control circuit turns off the main MOSFET and fully turns on the backup MOSFET within microseconds, achieving seamless power supply switching.

[0108] To quantify emergency power supply capacity to support the system's endurance requirements, the capacitor capacity configuration of the emergency energy buffer unit is based on the system's sustainment time. Calculations are performed. This sustaining time must cover the longest voltage drop window during a cold start of the vehicle's engine (typically 3 to 5 seconds). The minimum total capacitance required by the system. Follow the energy conservation calculation model below:

[0109] ;

[0110] in: This represents the equivalent total capacitance after series connection, in farads (F). The average power consumption of the control logic section in the decision and strategy control module 200 and the execution and audio processing module 300 is expressed in watts (W). This indicates the minimum time the system must remain operational after the main power is disconnected, expressed in seconds (s). This indicates the conversion efficiency of the back-end DC-DC regulator circuit; in this embodiment, the value is 0.9. This indicates the initial voltage of the supercapacitor at the moment of switching; This indicates the minimum input cutoff voltage (UVLO threshold) that the back-end voltage regulator circuit can maintain at the output.

[0111] The transient current protection unit is located at the output of the supercapacitor power supply circuit and employs the ACS730 Hall effect current sensor chip. This chip provides a sensing bandwidth of up to 1MHz and can capture nanosecond-level current transients. The ACS730 chip is connected in series in the power loop, converting the load current flowing through it into an analog voltage signal output to the analog-to-digital converter interface of the FPGA controller. This sensor provides electrical isolation between the primary conductive path and the secondary signal circuit, with an isolation withstand voltage rating of 2100V RMS, preventing high-voltage surges in the power stage from coupling to the low-voltage control side.

[0112] The system is equipped with tiered overcurrent protection logic. When the current detected by the ACS730 exceeds 120% but is below 200% of the rated value, the system determines it as an overload and limits the gain of the Class D power amplifier via a software interrupt. When the detected current instantaneously exceeds 200% of the rated value (i.e., short-circuit condition), the hardware comparator circuit directly triggers a "global shutdown" signal. This signal bypasses the software processing layer and directly pulls low the enable pin of the LTC3225 and the output enable terminal of the back-end regulator, cutting off the power output within 10 microseconds to prevent the fault from escalating and the PCB copper foil from melting.

[0113] For the selection of peripheral resistors and capacitors, PCB thermal design, and differential signal trace impedance matching of the LTC3225 and ACS730 chips, those skilled in the art can refer to relevant integrated circuit datasheets and automotive electronics reliability design specifications for implementation. The specific engineering implementation is well-known in the field and will not be elaborated upon here. Through the aforementioned supercapacitor energy storage and rapid switching mechanism, the system can ensure that the core control logic does not lose power or reset, maintaining the configuration parameters and operating status of the audio system even under the most severe electrical conditions in the vehicle.

[0114] The audio power adjustment system based on the vehicle battery status adaptive design establishes a communication link with the vehicle's infotainment head unit and head-up display (HUD) via a local area network (LIN) bus. The vehicle status perception and data acquisition module 100, acting as the master node of the LIN bus, is responsible for scheduling communication time slots on the bus and packaging the system status data processed by the decision and strategy control module 200 to send to the human-machine interface terminal, which acts as the slave node.

[0115] At the physical layer connection, the vehicle state perception and data acquisition module 100 uses a transceiver chip (such as TJA1021) compliant with the LIN 2.2A standard, connected to the vehicle dashboard wiring harness via a single-wire bidirectional communication interface. The data link layer follows a predefined LIN description file (LDF) and uses an unconditional frame format for periodic data broadcasting. The data field of the unconditional frame includes the current power limitation factor, battery health (SOH) percentage, real-time power supply voltage value, and the system's estimated remaining playback time.

[0116] To eliminate user confusion regarding sudden drops in audio volume, the system implements visual status feedback logic on the human-machine interface terminal. When the decision and strategy control module 200 issues a power limiting command, the vehicle status perception and data acquisition module 100 simultaneously sends a status flag to the central control screen. Based on this flag, the graphical user interface (GUI) rendering engine of the central control screen dynamically generates a power-limited icon in the status bar area and displays the current power output capacity in real time as a circular progress bar. The color mapping logic of the circular progress bar is related to the power limiting coefficient. Direct association: Green when the coefficient is 1.0; Yellow when the coefficient is 0.7; Red with a flashing indicator when the coefficient is 0.3 or 0.

[0117] The system also features a function to estimate remaining playback time based on current energy consumption. This function aims to provide users with an intuitive reference for remaining battery life in parked, engine-off mode, alleviating range anxiety. The decision and strategy control module 200 uses a moving average filtering algorithm to process the average discharge current over the past minute, and combines this with the battery's current state of charge (SOC) and a preset minimum charge threshold for engine start-up to calculate the remaining safe playback time. Remaining safe playback time The calculation model is as follows:

[0118] ;

[0119] in: This indicates the estimated number of minutes the audio playback can continue. This represents the current percentage of the battery's state of charge. To ensure the minimum remaining battery power threshold that allows the engine to restart, this embodiment sets it to 20%; This refers to the nominal capacity of the vehicle battery pack, measured in ampere-hours (Ah). The average current consumption of the audio system over the last 60 seconds is expressed in amperes (A). This is the basic static current of the vehicle in sleep / wake-up mode, measured in amperes (A).

[0120] The system will calculate The data is transmitted to the human-machine interface terminal via the LIN bus. If less than 10 minutes have passed, the GUI interface will automatically pop up a "Low Battery Warning" dialog box, prompting the user to start the engine or lower the volume.

[0121] In addition, the human-machine interface terminal provides a software interface for user intervention. A soft switch for audio priority mode is integrated into the GUI settings menu. When the user activates this switch, a override command is sent to the vehicle status perception and data acquisition module 100 via the LIN bus. Upon receiving this command, the decision and strategy control module 200 temporarily bypasses the power limiting strategy based on air conditioning or slight voltage fluctuations, forcibly releasing full power output. To prevent excessive battery discharge, this audio priority mode only applies when the battery voltage is low. Above 11.5 volts and battery temperature Execution is only permitted when the temperature is below 60 degrees Celsius. Once the voltage is detected to drop below 11.0 volts, the system will disregard the user's software settings, forcibly take over control, and cut off the high-power output path to prioritize the safe power supply to the vehicle chassis and powertrain domains.

[0122] For the checksum calculation, bit timing definition of frame synchronization interval field, and specific rendering code implementation of the graphical interface in the LIN communication protocol, those skilled in the art can design them according to the LIN Alliance specifications and the human-machine interface development guidelines of various car manufacturers. These are well-known technologies in the field and will not be elaborated here. Through the above communication and interaction logic, the system realizes closed-loop management from the underlying electrical control to the upper-level user perception.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An audio power adjustment system based on adaptive vehicle battery status, characterized in that, include: The vehicle status perception and data acquisition module has its input end connected to the vehicle's controller area network flexible data rate bus and on-board battery pack. It is used to parse vehicle bus messages in real time and obtain vehicle power operation parameters and on-board load device switch status, as well as collect the physical status parameters of the on-board battery pack. The decision and strategy control module is connected to the vehicle state perception and data acquisition module. It is used to receive the vehicle power operation parameters, the on-board load equipment switch status and physical state parameters, calculate the allowable output power threshold of the audio system under the current working condition based on the internally stored power priority mapping table and battery state power calculation model, and generate power control commands and frequency band processing commands. The execution and audio processing module is connected to the decision and strategy control module through a general input / output interface. It includes a digital signal processor unit and a Class D power amplifier control unit, which are used to adjust the pulse width modulation carrier frequency and gain of the power amplifier circuit according to the power control command, and to perform frequency band attenuation or dynamic compression processing on the audio signal according to the frequency band processing command. The cross-domain isolated power supply protection module is connected to the vehicle's main power line and the power input terminal of the execution and audio processing module, respectively. It is used to supply power to the decision and strategy control module and the execution and audio processing module, and to switch to emergency energy storage element power supply when the vehicle's main power voltage drop rate exceeds a preset threshold. The vehicle status perception and data acquisition module is equipped with a load start signal preloading mechanism. The load start signal preloading mechanism is used to monitor the start request message on the controller area network flexible data rate bus, and when the status bit of the start request message with the identifier is detected to flip, before the physical actuator of the high-power load device of the vehicle actually consumes current and causes the bus voltage to drop, a load pre-intervention interruption signal is generated and sent to the decision and strategy control module. The vehicle state perception and data acquisition module includes a battery state monitoring unit, which is used to execute dynamic internal resistance calculation logic. The dynamic internal resistance calculation logic is as follows: using the current step generated by the fluctuation of the audio system output power or the sudden change of vehicle load as excitation, within the preset sampling window, the battery terminal voltage and current values ​​at the start and end times are collected respectively, and the ratio of the absolute value of the voltage change to the absolute value of the current change within the sampling window is calculated, and the ratio is used as the real-time dynamic internal resistance value of the battery.

2. The audio power adjustment system based on adaptive vehicle battery status according to claim 1, characterized in that, The decision and strategy control module executes the following arbitration logic based on the power priority mapping table: When an emergency braking signal is detected or the bus voltage is lower than the minimum voltage protection threshold, the power limiting factor is set to zero. When an engine start signal is detected, the power limiting factor is set to the first preset value; When an air conditioner compressor start signal is detected simultaneously and the bus voltage drops below the threshold voltage, the power limiting factor is set to a second preset value, wherein the second preset value is greater than the first preset value. The power limit is lifted when the vehicle is detected to be in an external charging state or in a stable voltage cruise state.

3. The audio power adjustment system based on adaptive vehicle battery status according to claim 2, characterized in that, The decision and strategy control module uses the battery state power calculation model to calculate the target power value; The calculation model first calculates the limit power value based on the voltage drop limit, based on the current battery terminal voltage, the system minimum safe voltage, the real-time dynamic internal resistance value, and the equivalent series resistance of the line. The calculation model further maps the current state of charge of the battery to an energy weighting coefficient. When the state of charge is in the middle range, the energy weighting coefficient decays as the state of charge decreases according to the characteristics of a sine curve. The decision and strategy control module performs a comprehensive calculation on the limit power value, the energy weight coefficient, and the power limitation coefficient determined by the power priority mapping table to obtain the target power value.

4. The audio power adjustment system based on adaptive vehicle battery status according to claim 1, characterized in that, The Class D power amplifier control unit is used to execute a carrier frequency dynamic adjustment strategy based on thermal feedback; The Class D power amplifier control unit reads the junction temperature data inside the power amplifier chip in real time and adjusts the switching frequency of the output stage in stages according to the junction temperature data: When the junction temperature is below the first-level temperature control threshold, maintain high-frequency mode; When the junction temperature is between the primary temperature control threshold and the secondary temperature control threshold, reduce the switching frequency to medium frequency mode. When the junction temperature exceeds the secondary temperature control threshold, it enters low-frequency protection mode.

5. The audio power adjustment system based on adaptive vehicle battery status according to claim 1, characterized in that, The digital signal processor unit is used to execute the following frequency band processing logic: When the battery state of charge is lower than the preset power threshold, the coefficients of the finite-length unit impulse response filter are applied to apply gain attenuation that conforms to the logarithmic attenuation characteristic to the high-frequency audio signal above the preset cutoff frequency. When the battery temperature exceeds the preset temperature threshold or a transient high-current discharge condition is detected, the low-frequency dynamic range compression logic is activated, and only the root mean square detection is performed on the low-frequency components. When the amplitude exceeds the threshold, the compressor is started to limit the dynamic range.

6. The audio power adjustment system based on adaptive vehicle battery status according to claim 1, characterized in that, The cross-domain isolated power supply protection module adopts a physical isolation architecture between the power domain and the logic domain. The cross-domain isolation power supply protection module physically divides the system's grounding network into analog power ground and digital logic ground, which are connected by a high-frequency bypass element. The cross-domain isolated power supply protection module has a digital isolation chip based on magnetic coupling technology between the external data interaction interface and the internal controller. The digital isolation chip is connected to the data transmission path between the external data interaction interface and the internal controller, blocking the high-frequency switching noise and high-voltage surge generated by the power circuit from coupling to the control logic circuit.

7. The audio power adjustment system based on adaptive vehicle battery status according to claim 1, characterized in that, The cross-domain isolated power supply protection module integrates an emergency energy buffer unit, which uses a series-connected supercapacitor group as the emergency energy storage element and is configured with a power switching architecture based on an ideal diode controller. The power switching architecture utilizes power metal-oxide-semiconductor field-effect transistors connected in series on the vehicle's main power line and backup power path, and the control circuit monitors the voltage difference between the vehicle's main power line voltage and the supercapacitor terminal voltage. When the voltage of the vehicle's main power line is detected to drop below the voltage at the supercapacitor terminal, the control circuit turns off the transistors in the path of the vehicle's main power line and turns on the transistors in the backup power path, so that the supercapacitor bank supplies power to the system.

8. The audio power adjustment system based on adaptive vehicle battery status according to claim 1, characterized in that, The vehicle status perception and data acquisition module is also connected to the vehicle's human-machine interaction terminal via a local area network bus. The decision and strategy control module is used to calculate the remaining safe playback time. The calculation of the remaining safe playback time is based on the difference between the current state of charge of the battery and the minimum reserve charge threshold to ensure engine start, and is estimated in combination with the average current consumption of the audio system. The vehicle status perception and data acquisition module sends the power limitation coefficient determined by the decision and strategy control module when generating the power control command and the remaining safe playback time to the human-machine interaction terminal. The human-machine interaction terminal is used to provide visual feedback on the display interface through the color change of the circular progress bar and the numerical display based on the received data.

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