A system and method for automatic charging and fault detection of low-voltage batteries

Abstract

This invention relates to an automatic low-voltage battery charging and fault detection system and method. The method includes: Step 1, an intelligent vehicle terminal collects the power supply voltage signal of the low-voltage battery in real time; Step 2, a wake-up signal is sent to the front domain controller via the CAN bus; Step 3, the front domain controller switches from sleep state to working state and sends a wake-up signal to wake up the back domain controller in sleep state; Step 4, the back domain controller outputs power supply voltage to power the vehicle controller and the power battery respectively, the power battery outputs high-voltage power to the DC-DC converter, and the DC-DC converter enters standby state; Step 5, the vehicle controller starts a delay timer to monitor the power supply voltage of the low-voltage battery; Step 6, a control command is sent to the DC-DC converter, and then a sleep command is sent; Step 7, the vehicle intelligent terminal and the vehicle controller monitor the working status of each component and the high-voltage circuit, and the intelligent vehicle terminal uploads and feeds back fault information.

Description

Technical Field

[0001] This invention relates to the field of battery charging technology for new energy vehicles, and in particular to a system and method for automatic charging and fault detection of low-voltage batteries. Background Technology

[0002] Existing battery charging systems consist primarily of a low-voltage battery, an on-board charger, constant-power components, and a manual control switch. They lack intelligent control components such as a battery box (TBOX), domain controller, and VCU, and therefore do not form a closed-loop automatic control logic. Their operation is as follows: when the vehicle is parked and in standby mode, the constant-power components continuously consume energy from the low-voltage battery. When the driver discovers that the vehicle cannot start (indicating a low battery charge), they manually close the control switch to start the on-board charger, which then charges the low-voltage battery. After charging is complete, the driver manually disconnects the control switch to stop charging. Some improved solutions eliminate the manual switch and use fixed time intervals to start the charger, but they lack voltage monitoring. The timing of charging relies entirely on preset times, without considering the actual battery voltage state. Furthermore, they lack specific protection for low battery charge states (below 70%) and do not include fault monitoring and feedback mechanisms. Summary of the Invention

[0003] In view of the above problems, the present invention provides a system and method for automatic replenishment and fault detection of low-voltage batteries, so as to solve the technical problems of inaccurate replenishment timing, high energy consumption, shortened battery life, poor replenishment reliability and low degree of automation in the prior art.

[0004] This invention provides an automatic low-voltage battery charging and fault detection system for use in new energy vehicles. The system includes: an intelligent vehicle terminal for real-time acquisition of the low-voltage battery's supply voltage signal, comparison with a preset voltage threshold, and sending a wake-up signal via a CAN bus if the supply voltage is lower than the threshold; and for real-time monitoring of the operating status of various components and high-voltage circuits during the charging process, uploading and feeding back detected fault information to improve the reliability of the charging process; a CAN bus connected to the intelligent vehicle terminal for transmitting wake-up signals, control commands, and fault information; a front domain controller connected to the intelligent vehicle terminal via the CAN bus for receiving the wake-up signal from the intelligent vehicle terminal and sending a wake-up signal via the CAN bus to wake up the rear domain controller; and a rear domain controller connected to the front domain controller via the CAN bus for receiving... After receiving the wake-up signal from the front domain controller, it provides operating power to the vehicle controller and the power battery. The power battery, electrically connected to the rear domain controller, provides high-voltage power to the DC-DC converter after receiving power from the rear domain controller. The DC-DC converter, connected to the power battery, converts the high-voltage power to low-voltage power according to the vehicle's specifications to replenish the low-voltage battery. The vehicle controller, connected to the rear domain controller and the intelligent vehicle terminal via the CAN bus, detects the low-voltage battery's supply voltage after a delay after receiving power from the rear domain controller. Based on the detection result, it sends control commands to control the start and stop of the DC-DC converter and sends a sleep command via the CAN bus to put all vehicle controllers and components into sleep mode. During the replenishment process, it monitors the working status of each component and high-voltage circuit in real time and sends detected fault information to the intelligent vehicle terminal via the CAN bus.

[0005] This invention provides a method for automatic low-voltage battery recharging and fault detection. The method includes: Step 1, when the vehicle is parked and the low-voltage power main switch is on, the intelligent vehicle terminal collects the supply voltage signal of the low-voltage battery in real time; Step 2, comparing the supply voltage of the low-voltage battery with a preset voltage threshold, if it is less than the voltage threshold, sending a wake-up signal to the front domain controller via the CAN bus; Step 3, when the wake-up signal is received from the intelligent vehicle terminal, the front domain controller switches from a sleep state to a working state and sends a wake-up signal to the rear domain controller via the CAN bus to wake up the sleep rear domain controller, realizing the step-by-step wake-up of the controller, avoiding the simultaneous start-up of all components, and reducing energy consumption; Step 4, after the rear domain controller is woken up, it outputs a supply voltage to power the vehicle controller and the power battery respectively. After receiving the power supply, the power battery starts and outputs a high-voltage power supply to the DC-DC converter. After the power supply is turned on, it enters standby mode, waiting for control commands from the vehicle controller; Step 5, the vehicle controller starts after receiving power from the rear domain controller and begins a delay timer. After a delay of T, the vehicle controller re-detects the power supply voltage of the low-voltage battery to avoid misjudgment due to voltage fluctuations; Step 6, the vehicle controller compares the detected voltage with a preset voltage threshold, and sends control commands to the DC-DC converter based on the comparison result to control the start and stop of the DC-DC converter, realizing automatic power replenishment. Then, it sends a sleep command through the CAN bus, so that all controllers and components of the vehicle enter a sleep state; Step 7, during the power replenishment process, the on-board intelligent terminal and the vehicle controller monitor the working status of each component and the high-voltage circuit in real time. When component damage or high-voltage faults are detected, causing the low-voltage battery to be unable to be replenished, the intelligent on-board terminal uploads and feeds back the fault information detected by itself and the vehicle controller to improve the reliability of the power replenishment process.

[0006] Furthermore, the method also includes: Step 0, selecting a low-voltage battery based on static current statistics and technology, and setting parameters through the vehicle controller based on the selection results and usage requirements.

[0007] Further, step 0 includes: Step 01, calculating the static current of the intelligent vehicle terminal, battery management system, front / rear domain controller, and other components in the cab to obtain the total static current I; Step 02, setting the charging interval to N days and the remaining usable battery capacity coefficient to a according to usage requirements; Step 03, obtaining the minimum battery capacity according to the selection formula battery capacity ≥ I×N×24 / a, and then combining it with usage requirements to obtain the selection result of the low-voltage battery; Step 04, based on the selection result and usage requirements, preset the voltage threshold, delay time T, and DC-DC converter charging duration L through the vehicle controller.

[0008] Furthermore, step 2 also includes: if the supply voltage is not less than the voltage threshold, the vehicle remains in a dormant state, and the intelligent vehicle terminal continuously collects the supply voltage signal of the low-voltage battery.

[0009] Furthermore, T is 30 seconds.

[0010] Furthermore, step 6 includes: Step 61, the vehicle controller compares the detected voltage with a preset voltage threshold. If the voltage is less than the voltage threshold, proceed to step 62; if the voltage is not less than the voltage threshold, proceed to step 63. Step 62, the vehicle controller sends a control command to start the DC-DC converter, converting the high-voltage power supply of the power battery to a low-voltage power supply to replenish the low-voltage battery. After continuously replenishing the battery for a period of L, the vehicle controller sends another control command to stop the DC-DC converter and proceed to step 63. Step 63, the vehicle controller sends a sleep command through the CAN bus, causing all controllers and components of the vehicle to enter a sleep state.

[0011] Furthermore, L is 20 minutes.

[0012] Furthermore, step 7 includes: Step 71, during the power replenishment process, the vehicle controller monitors the operating status of the DC-DC converter, power battery, front / rear domain controller, and high-voltage circuit in real time. If component damage or high-voltage failure is detected, causing the low-voltage battery to be unable to be replenished, the fault information is sent to the intelligent vehicle terminal via the CAN bus, and then proceeds to step 73; Step 72, during the power replenishment process, the intelligent vehicle terminal monitors the operating status of the DC-DC converter, power battery, front / rear domain controller, and high-voltage circuit in real time. If component damage or high-voltage failure is detected, causing the low-voltage battery to be unable to be replenished, then proceeds to step 73; Step 73, the intelligent vehicle terminal uploads the fault information to the background and simultaneously sends the fault information to the vehicle instrument panel via the CAN bus, providing feedback to the user.

[0013] Furthermore, the voltage threshold is set to 24V.

[0014] This invention provides a system and method for automatic replenishment and fault detection of low-voltage batteries, mainly to solve some technical problems existing in the prior art: inaccurate replenishment timing, which easily leads to battery depletion or overcharging; lack of intelligent wake-up and hibernation control, resulting in high energy consumption; lack of protection for low battery depletion state, shortening battery life; lack of fault monitoring and feedback mechanism, resulting in poor replenishment reliability; and cumbersome replenishment control logic with low automation. Attached Figure Description

[0015] Figure 1 A flowchart of a method for automatic recharging and fault detection of low-voltage batteries provided by the present invention; Figure 2Flowchart of another method for automatic charging and fault detection of low-voltage batteries provided by the present invention; Figure 3 This is a flowchart of a method for selecting and setting parameters for a storage battery provided by the present invention; Figure 4 This is a flowchart of an automatic power replenishment method provided by the present invention; Figure 5 This is a flowchart of a fault detection method provided by the present invention. Detailed Implementation

[0016] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0017] Example 1: This invention provides a system and method for automatic low-voltage battery charging and fault detection. The system includes an intelligent vehicle terminal, a CAN bus, a front domain controller, a rear domain controller, a power battery, a DC-DC converter, and a vehicle controller. Figure 1 As shown, the method includes: Step 1: When the vehicle is parked and the low-voltage power main switch is on, the intelligent vehicle terminal collects the power supply voltage signal of the low-voltage battery in real time. Step 2: Compare the supply voltage of the low-voltage battery with the preset voltage threshold. If it is less than the voltage threshold, send a wake-up signal to the front domain controller via the CAN bus. Step 3: When the wake-up signal from the intelligent vehicle terminal is received, the front domain controller switches from the sleep state to the working state and sends a wake-up signal to the rear domain controller through the CAN bus to wake up the rear domain controller in sleep mode. This realizes the step-by-step wake-up of the controller, avoids the simultaneous start-up of all components, and reduces energy consumption. The front domain controller, connected to the intelligent vehicle terminal via a CAN bus, receives wake-up signals from the intelligent vehicle terminal and sends wake-up signals via the CAN bus to wake up the rear domain controller. The front domain controller only communicates bidirectionally with the CAN bus and has no direct power output (except for its own standby power). Its core function is to receive wake-up signals from the TBOX and wake up the rear domain controller via the CAN bus. This application uses this component to transmit the wake-up signal, avoiding unnecessary simultaneous startup of components and reducing energy consumption.

[0018] Step 4: After the rear domain controller is woken up, it outputs the power supply voltage to power the vehicle controller and the power battery respectively. After receiving the power supply, the power battery starts and outputs high voltage power to the DC converter. After receiving the high voltage power, the DC converter enters the standby state and waits for the control command of the vehicle controller. The rear domain controller, connected to the front domain controller via a CAN bus, provides power to the vehicle controller and the power battery upon receiving a wake-up signal from the front domain controller. The power battery, electrically connected to the rear domain controller, provides high-voltage power to the DC-DC converter upon receiving power from the rear domain controller. The DC-DC converter, connected to the power battery, converts the high-voltage power to low-voltage power according to the vehicle's specifications to replenish the low-voltage battery. The rear domain controller has bidirectional communication with the CAN bus and is also electrically connected to the VCU and the power battery. Its core function is to provide power to the VCU and the power battery upon wake-up. Existing technologies typically lack this component, making it impossible to achieve orderly high-voltage power supply startup. This invention uses this component to control the timing of high-voltage power-on, ensuring orderly preparation for power replenishment. The power battery is electrically connected to the rear domain controller and also to the DC-DC converter. Its core function is to provide high-voltage power to the DC-DC converter. Compared to existing "on-board chargers," the power battery provides high-voltage input, working with the DC-DC converter to achieve high-voltage to low-voltage power replenishment, resulting in higher power replenishment efficiency and compatibility with the vehicle's high-voltage system, solving the problems of low efficiency and poor compatibility of existing chargers. DC-DC converter: It is electrically connected to both the power battery and the low-voltage battery. Its core function is to convert the high-voltage power of the power battery into a 24VDC low-voltage power supply to replenish the low-voltage battery. It replaces the simple charger of the existing technology, has a higher conversion efficiency, and can be precisely controlled by the VCU to start / stop, solving the problems of low replenishment efficiency and inaccurate control of the existing technology.

[0019] Step 5: After receiving power from the rear domain controller, the vehicle controller starts and begins a delay timer. After a delay of T, the vehicle controller re-detects the power supply voltage of the low-voltage battery to avoid misjudgment due to voltage fluctuations. The vehicle controller (VCU) is connected to the rear domain controller and intelligent vehicle terminal via a CAN bus. After receiving power from the rear domain controller, it delays and detects the low-voltage battery supply voltage. Based on the detection result, it sends control commands to control the start and stop of the DC-DC converter. It also sends a sleep command via the CAN bus to put all vehicle controllers and components into sleep mode. During the charging process, it monitors the operating status of each component and high-voltage circuit in real time, and sends detected fault information to the intelligent vehicle terminal via the CAN bus. The VCU communicates bidirectionally with the CAN bus and is powered by the rear domain controller. Its core function is to detect the voltage status during the charging process and control the start and stop of the DC-DC converter. Existing technologies lack this component and cannot achieve automated control of the charging process. This patent uses the VCU to achieve secondary confirmation of the charging timing and control the charging duration, ensuring the charging effect.

[0020] Step 6: The vehicle controller compares the detected voltage with the preset voltage threshold, and sends a control command to the DC converter based on the comparison result to control the start and stop of the DC converter to achieve automatic power replenishment. Then, it sends a sleep command through the CAN bus to put all controllers and components of the vehicle into sleep mode. The CAN bus, connected to the intelligent vehicle terminal, is used to transmit wake-up signals, control commands, and fault information. As a communication carrier between controllers, the CAN bus has bidirectional communication connections with the front domain controller, rear domain controller, and VCU, used to transmit wake-up signals, control signals, and status feedback signals. Existing technologies lack a communication bus, making coordinated control of various components impossible. This application utilizes the CAN bus to achieve step-by-step wake-up and signal interaction, ensuring smooth control logic.

[0021] Step 7: During the power replenishment process, the vehicle-mounted intelligent terminal and the vehicle controller monitor the working status of each component and the high-voltage circuit in real time. When component damage or high-voltage faults are detected, causing the low-voltage battery to be unable to be replenished, the intelligent vehicle-mounted terminal uploads and feeds back the fault information detected by itself and the vehicle controller to improve the reliability of the power replenishment process.

[0022] The intelligent vehicle-mounted terminal (TBOX) is used to collect the supply voltage signal of the low-voltage battery in real time and compare it with a preset voltage threshold. If the supply voltage is lower than the threshold, a wake-up signal is sent via the CAN bus. During the power replenishment process, it also monitors the working status of various components and the high-voltage circuit in real time, uploading and feeding back detected fault information to improve the reliability of the power replenishment process. The TBOX is connected to constant power and is electrically connected to both the low-voltage battery and the CAN bus. Its function is to collect the supply voltage signal of the low-voltage battery in real time and it has CAN message sending / receiving capabilities—a core monitoring and wake-up triggering component not found in existing technologies. Compared with existing technologies, the TBOX replaces manual judgment and fixed-time triggering, achieving real-time voltage monitoring and precise triggering of power replenishment.

[0023] This invention provides a system and method for automatic charging and fault detection of low-voltage batteries. The technical solution forms a closed-loop automatic process of "voltage monitoring → step-by-step wake-up → high-voltage power-on → charging control → automatic sleep → fault monitoring" through TBOX, front domain controller, rear domain controller, VCU, DC-DC converter, power battery and CAN bus. It replaces the existing technology of "manual control switch / fixed time charging + simple charger" and solves the technical problems of inaccurate charging timing, high energy consumption, shortened battery life, poor charging reliability and low degree of automation in the existing technology.

[0024] Example 2: This invention provides a system and method for automatic low-voltage battery charging and fault detection. The system includes an intelligent vehicle terminal, a CAN bus, a front domain controller, a rear domain controller, a power battery, a DC-DC converter, and a vehicle controller. Figure 2 As shown, the method includes: Step 0: Select a low-voltage battery based on static current statistics and technology. Based on the selection results and usage requirements, preset parameters through the vehicle controller.

[0025] Existing technologies do not perform precise calculations of battery capacity, relying solely on experience for selection, which can easily lead to insufficient capacity (discharge) or excessive capacity (waste of cost). This application uses static current statistics and formula calculations for precise battery selection, such as... Figure 3 As shown, step 0 includes: Step 01: Calculate the static current of the intelligent vehicle terminal, battery management system, front / rear domain controller, and other components in the cab to obtain the total static current I. Step 02: Based on usage requirements, set the recharge interval to N days and the remaining usable battery capacity coefficient to a; Step 03: According to the selection formula: battery capacity ≥ I×N×24 / a, the minimum battery capacity is obtained. Then, combined with the usage requirements, the selection result of the low-voltage battery is obtained. Step 04: Based on the selection results and usage requirements, preset the voltage threshold, delay time T, and DC converter charging duration L through the vehicle controller.

[0026] For example, firstly, the static current of the vehicle's constantly powered components is calculated: T-box (140mA), BMS (2mA, battery management system), front / rear domain controller (33mA), and other components in the cab (8mA), totaling 183mA. Secondly, calculation parameters are set: number of days of parking N (recharge interval ≥ 5 days), and a battery remaining usable capacity coefficient of 0.3 (corresponding to a capacity not less than 70%, with 30% remaining usable). Finally, the formula "battery capacity ≥ static current × number of days of parking × 24 / 0.3" is used. When N = 5 days, the required capacity is ≥ 73.2Ah. Based on actual usage requirements, an 80Ah low-voltage battery is selected to ensure that the battery capacity is always not less than 70%, avoiding over-discharge. Compared with existing technologies, this application avoids over-discharge of the battery and protects battery life through precise calculation and selection. Based on the selection results and usage requirements, the voltage threshold is set to 24V, T is set to 30 seconds, and L is set to 20 minutes. Compared with existing technologies, this step enables precise setting of power replenishment parameters, avoiding the blindness of power replenishment at fixed times.

[0027] Step 1: When the vehicle is parked and the low-voltage power main switch is on, the intelligent vehicle terminal collects the power supply voltage signal of the low-voltage battery in real time. When the vehicle is parked and the low-voltage main power switch is on, the TBOX continues to work due to constant power supply, collecting the supply voltage signal of the low-voltage battery in real time and feeding the voltage data back to its built-in judgment module in real time. Compared with existing technologies, this step realizes real-time voltage monitoring, replaces manual judgment, and avoids the failure of the battery to be discharged.

[0028] Step 2: Compare the supply voltage of the low-voltage battery with the preset voltage threshold. If it is less than the voltage threshold, send a wake-up signal to the front domain controller via the CAN bus. The TBOX has a built-in judgment module that compares the real-time collected voltage with a preset 24V threshold. If the voltage is ≥24V, the vehicle remains in standby sleep mode, and the TBOX continues to monitor the voltage. If the voltage is <24V, the vehicle proceeds to the next wake-up process. Compared with existing technologies, this step achieves accurate judgment of the timing of charging, avoiding overcharging or untimely charging.

[0029] Step 3: When the wake-up signal from the intelligent vehicle terminal is received, the front domain controller switches from the sleep state to the working state and sends a wake-up signal to the rear domain controller through the CAN bus to wake up the rear domain controller in sleep mode. This realizes the step-by-step wake-up of the controller, avoids the simultaneous start-up of all components, and reduces energy consumption. Step 4: After the rear domain controller is woken up, it outputs the power supply voltage to power the vehicle controller and the power battery respectively. After receiving the power supply, the power battery starts and outputs high voltage power to the DC converter. After receiving the high voltage power, the DC converter enters the standby state and waits for the control command of the vehicle controller. Step 5: After receiving power from the rear domain controller, the vehicle controller starts and begins a delay timer. After a delay of T, the vehicle controller re-detects the power supply voltage of the low-voltage battery to avoid misjudgment due to voltage fluctuations. After receiving power from the domain controller, the VCU starts up, and its built-in delay module begins timing. After a 30-second delay, the VCU re-detects the low-voltage battery's supply voltage through the voltage acquisition interface. The 30-second delay is designed to ensure stable high-voltage power-on and the operation of all components, avoiding misjudgments caused by voltage fluctuations. This step is not present in existing technology, enabling secondary confirmation of the power replenishment timing and improving the accuracy of power replenishment.

[0030] Step 6: The vehicle controller compares the detected voltage with the preset voltage threshold, and sends a control command to the DC converter based on the comparison result to control the start and stop of the DC converter to achieve automatic power replenishment. Then, it sends a sleep command through the CAN bus to put all controllers and components of the vehicle into sleep mode. Step 7: During the power replenishment process, the vehicle-mounted intelligent terminal and the vehicle controller monitor the working status of each component and the high-voltage circuit in real time. When component damage or high-voltage faults are detected, causing the low-voltage battery to be unable to be replenished, the intelligent vehicle-mounted terminal uploads and feeds back the fault information detected by itself and the vehicle controller to improve the reliability of the power replenishment process.

[0031] This invention provides a system and method for automatic charging and fault detection of low-voltage batteries. The technical solution forms a closed-loop automatic process of "voltage monitoring → step-by-step wake-up → high-voltage power-on → charging control → automatic sleep → fault monitoring" through TBOX, front domain controller, rear domain controller, VCU, DC-DC converter, power battery and CAN bus. It replaces the existing technology of "manual control switch / fixed time charging + simple charger" and solves the technical problems of inaccurate charging timing, high energy consumption, shortened battery life, poor charging reliability and low degree of automation in the existing technology.

[0032] Example 3: This invention provides a system and method for automatic low-voltage battery charging and fault detection. The system includes an intelligent vehicle terminal, a CAN bus, a front domain controller, a rear domain controller, a power battery, a DC-DC converter, and a vehicle controller. Figure 1 As shown, the method includes: Step 1: When the vehicle is parked and the low-voltage power main switch is on, the intelligent vehicle terminal collects the power supply voltage signal of the low-voltage battery in real time. Step 2: Compare the supply voltage of the low-voltage battery with the preset voltage threshold. If it is less than the voltage threshold, send a wake-up signal to the front domain controller via the CAN bus. Step 3: When the wake-up signal from the intelligent vehicle terminal is received, the front domain controller switches from the sleep state to the working state and sends a wake-up signal to the rear domain controller through the CAN bus to wake up the rear domain controller in sleep mode. This realizes the step-by-step wake-up of the controller, avoids the simultaneous start-up of all components, and reduces energy consumption. Step 4: After the rear domain controller is woken up, it outputs the power supply voltage to power the vehicle controller and the power battery respectively. After receiving the power supply, the power battery starts and outputs high voltage power to the DC converter. After receiving the high voltage power, the DC converter enters the standby state and waits for the control command of the vehicle controller. Step 5: After receiving power from the rear domain controller, the vehicle controller starts and begins a delay timer. After a delay of T, the vehicle controller re-detects the power supply voltage of the low-voltage battery to avoid misjudgment due to voltage fluctuations. Step 6: The vehicle controller compares the detected voltage with the preset voltage threshold, and sends a control command to the DC converter based on the comparison result to control the start and stop of the DC converter to achieve automatic power replenishment. Then, it sends a sleep command through the CAN bus to put all controllers and components of the vehicle into sleep mode. Compared with existing technologies, this step achieves automated control of the charging process, requiring no manual intervention, and the charging duration is fixed, avoiding overcharging. Figure 4 As shown, step 6 includes: Step 61: The vehicle controller compares the detected voltage with the preset voltage threshold. If the voltage is less than the voltage threshold, proceed to step 62; if the voltage is not less than the voltage threshold, proceed to step 63. Step 62: The vehicle controller sends a control command to start the DC-DC converter, which converts the high-voltage power supply of the power battery into a low-voltage power supply to replenish the low-voltage battery. After replenishing the battery for a period of time L, the vehicle controller sends another control command to stop the DC-DC converter and proceed to step 63. Step 63: The vehicle controller sends a sleep command via the CAN bus, causing all controllers and components of the vehicle to enter a sleep state.

[0033] Step 7: During the power replenishment process, the vehicle-mounted intelligent terminal and the vehicle controller monitor the working status of each component and the high-voltage circuit in real time. When component damage or high-voltage faults are detected, causing the low-voltage battery to be unable to be replenished, the intelligent vehicle-mounted terminal uploads and feeds back the fault information detected by itself and the vehicle controller to improve the reliability of the power replenishment process.

[0034] Throughout the entire charging process, the TBOX and VCU monitor the working status of each component (DCDC, power battery, domain controller, etc.) and the high-voltage circuit in real time. If component damage or high-voltage faults are detected (such as the power battery failing to output high voltage or the DCDC failing to convert voltage), causing the battery to fail to charge, the TBOX (1) immediately uploads the fault information (component name, fault type) to the backend platform via the wireless communication module, and simultaneously sends a fault signal to the vehicle instrument panel via the CAN bus to provide feedback to the user. Figure 5 As shown, step 7 includes: Step 71: During the power replenishment process, the vehicle controller monitors the working status of the DC-DC converter, power battery, front / rear domain controller and high-voltage circuit in real time. If component damage or high-voltage fault is detected, causing the low-voltage battery to be unable to be replenished, the fault information is sent to the intelligent vehicle terminal via the CAN bus, and then proceeds to step 73. Step 72: During the power replenishment process, the intelligent vehicle terminal monitors the working status of the DC converter, power battery, front / rear domain controller and high-voltage circuit in real time. If component damage or high-voltage failure is detected, resulting in the low-voltage battery being unable to be replenished, proceed to step 73. Step 73: The intelligent vehicle terminal uploads the fault information to the backend and simultaneously sends the fault information to the vehicle instrument panel via the CAN bus to provide feedback to the user.

[0035] Furthermore, by simulating actual usage, functional tests were conducted according to the test outline. The test outline was expanded to include tests on the system's response during power-on and charging, the power-up control logic was analyzed, and solutions were discussed to prevent charging failures during the power-up process. Compared to existing technologies, this step enables real-time fault monitoring and feedback, improving the reliability of the power-up system.

[0036] This invention provides a system and method for automatic charging and fault detection of low-voltage batteries. The technical solution forms a closed-loop automatic process of "voltage monitoring → step-by-step wake-up → high-voltage power-on → charging control → automatic sleep → fault monitoring" through TBOX, front domain controller, rear domain controller, VCU, DC-DC converter, power battery and CAN bus. It replaces the existing technology of "manual control switch / fixed time charging + simple charger" and solves the technical problems of inaccurate charging timing, high energy consumption, shortened battery life, poor charging reliability and low degree of automation in the existing technology.

[0037] In summary, this invention provides a system and method for automatic low-voltage battery charging and fault detection. This invention uses a TBOX to monitor the low-voltage battery voltage in real time, setting 24V as the charging threshold. The charging process is only initiated when the voltage falls below this threshold, avoiding the problems of "manual judgment omissions" or "blind charging at fixed times" in existing technologies. Simultaneously, a 30-second delay in the VCU for secondary voltage detection avoids misjudgments caused by voltage fluctuations, ensuring accurate charging timing and preventing the low-voltage battery from being in a depleted state when the vehicle is parked, thus ensuring normal vehicle starting every time. This application combines static current and charging intervals, using precise calculations to ensure the battery capacity is never lower than 70%, avoiding the plate damage and capacity decay problems caused by "frequent charging in low-charge states" in existing technologies. Furthermore, automatic hibernation after charging prevents overcharging, further extending battery life and reducing battery replacement costs for users. This application employs a tiered wake-up logic of "TBOX wakes up the front domain controller → front domain controller wakes up the rear domain controller," waking up relevant components only when power replenishment is needed. Upon completion of power replenishment, the entire vehicle immediately enters sleep mode, avoiding the energy waste associated with existing technologies where "all components start simultaneously during power replenishment" or "manual operation leads to prolonged component operation," thus significantly improving the vehicle's energy utilization rate. This application forms a closed-loop automatic control process of "voltage monitoring → wake-up → high-voltage power-on → power replenishment → sleep mode." From power replenishment triggering and process control to completion, no manual intervention is required, replacing the manual operation of existing technologies, reducing user difficulty, and improving ease of use. This application incorporates comprehensive fault monitoring and control measures, monitoring the status of each component and high-voltage circuit in real time. In case of a fault, information is promptly uploaded to the backend and fed back to the user for timely repair. Simultaneously, the power replenishment logic is optimized through testing to avoid charging failures during the replenishment process. Compared to the shortcomings of existing technologies with "no fault monitoring," this significantly improves the reliability of the power replenishment system and reduces the impact of faults on vehicle use. The system in this application adopts a rated operating voltage of 24VDC, which is compatible with various vehicles that use 24VDC low-voltage power supply. The system has a simple composition and clear control logic. It does not require major modifications to the original structure of the vehicle, making it easy to promote and apply. Compared with the shortcomings of existing technologies such as "poor adaptability and high difficulty in modification", it has a wider range of applications.

[0038] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A low-voltage battery automatic charging and fault detection system, applied to new energy vehicles, characterized in that, The system includes: The intelligent vehicle terminal is used to collect the power supply voltage signal of the low-voltage battery in real time and compare it with the preset voltage threshold. If the power supply voltage is less than the voltage threshold, a wake-up signal is sent through the CAN bus. During the power replenishment process, the terminal monitors the working status of each component and the high-voltage circuit in real time and uploads and feeds back the detected fault information to improve the reliability of the power replenishment process. The CAN bus connects to the intelligent vehicle terminal and is used to transmit wake-up signals, control commands, and fault information. The front domain controller is connected to the intelligent vehicle terminal via the CAN bus. It is used to receive the wake-up signal from the intelligent vehicle terminal and send the wake-up signal via the CAN bus to wake up the rear domain controller. The rear domain controller is connected to the front domain controller via the CAN bus. After receiving the wake-up signal from the front domain controller, it provides working power to the vehicle controller and the power battery. The power battery, electrically connected to the rear domain controller, is used to provide high-voltage power to the DC-DC converter after receiving power from the rear domain controller. The DC-DC converter is connected to the power battery and converts the high-voltage power to low-voltage power according to the vehicle's specifications in order to replenish the low-voltage battery. The vehicle controller is connected to the rear domain controller and the intelligent vehicle terminal via the CAN bus. After receiving power from the rear domain controller, it delays and detects the power supply voltage of the low-voltage battery. Based on the detection result, it sends control commands to control the start and stop of the DC-DC converter. It also sends a sleep command via the CAN bus to put all controllers and components of the vehicle into sleep mode. During the power replenishment process, it monitors the working status of each component and high-voltage circuit in real time and sends the detected fault information to the intelligent vehicle terminal via the CAN bus.

2. A method using the low-voltage battery automatic replenishment and fault detection system as described in claim 1, characterized in that, The method includes: Step 1: When the vehicle is parked and the low-voltage power main switch is on, the intelligent vehicle terminal collects the power supply voltage signal of the low-voltage battery in real time. Step 2: Compare the supply voltage of the low-voltage battery with the preset voltage threshold. If it is less than the voltage threshold, send a wake-up signal to the front domain controller via the CAN bus. Step 3: When the wake-up signal from the intelligent vehicle terminal is received, the front domain controller switches from the sleep state to the working state and sends a wake-up signal to the rear domain controller through the CAN bus to wake up the rear domain controller in sleep mode. This realizes the step-by-step wake-up of the controller, avoids the simultaneous start-up of all components, and reduces energy consumption. Step 4: After the rear domain controller is woken up, it outputs the power supply voltage to power the vehicle controller and the power battery respectively. After receiving the power supply, the power battery starts and outputs high voltage power to the DC converter. After receiving the high voltage power, the DC converter enters the standby state and waits for the control command of the vehicle controller. Step 5: After receiving power from the rear domain controller, the vehicle controller starts and begins a delay timer. After a delay of T, the vehicle controller re-detects the power supply voltage of the low-voltage battery to avoid misjudgment due to voltage fluctuations. Step 6: The vehicle controller compares the detected voltage with the preset voltage threshold, and sends a control command to the DC converter based on the comparison result to control the start and stop of the DC converter to achieve automatic power replenishment. Then, it sends a sleep command through the CAN bus to put all controllers and components of the vehicle into sleep mode. Step 7: During the power replenishment process, the vehicle-mounted intelligent terminal and the vehicle controller monitor the working status of each component and the high-voltage circuit in real time. When component damage or high-voltage faults are detected, causing the low-voltage battery to be unable to be replenished, the intelligent vehicle-mounted terminal uploads and feeds back the fault information detected by itself and the vehicle controller to improve the reliability of the power replenishment process.

3. The method for automatic recharging and fault detection of a low-voltage battery according to claim 2, characterized in that, The method further includes: Step 0, selecting a low-voltage battery based on static current statistics and technology, and setting parameters through the vehicle controller based on the selection results and usage requirements.

4. The method for automatic recharging and fault detection of a low-voltage battery according to claim 3, characterized in that, Step 0 includes: Step 01: Calculate the static current of the intelligent vehicle terminal, battery management system, front / rear domain controller, and other components in the cab to obtain the total static current I. Step 02: Based on usage requirements, set the recharge interval to N days and the remaining usable battery capacity coefficient to a; Step 03: According to the option formula battery capacity ≥ I×N×24 / a, the minimum battery capacity is obtained. Then, combined with the usage requirements, the selection result of the low-voltage battery is obtained. Step 04: Based on the selection results and usage requirements, preset the voltage threshold, delay time T, and DC converter charging duration L through the vehicle controller.

5. The method for automatic recharging and fault detection of a low-voltage battery according to claim 2, characterized in that, Step 2 further includes: if the supply voltage is not less than the voltage threshold, the vehicle remains in a dormant state, and the intelligent vehicle terminal continuously collects the supply voltage signal of the low-voltage battery.

6. The method for automatic recharging and fault detection of a low-voltage battery according to claim 2 or 4, characterized in that, T is 30 seconds.

7. The method for automatic recharging and fault detection of a low-voltage battery according to claim 4, characterized in that, Step 6 includes: Step 61: The vehicle controller compares the detected voltage with the preset voltage threshold. If the voltage is less than the voltage threshold, proceed to step 62; if the voltage is not less than the voltage threshold, proceed to step 63. Step 62: The vehicle controller sends a control command to start the DC-DC converter, which converts the high-voltage power supply of the power battery into a low-voltage power supply to replenish the low-voltage battery. After replenishing the battery for a period of time L, the vehicle controller sends another control command to stop the DC-DC converter and proceed to step 63. Step 63: The vehicle controller sends a sleep command via the CAN bus, causing all controllers and components of the vehicle to enter a sleep state.

8. The method for automatic recharging and fault detection of a low-voltage battery according to claim 4 or 7, characterized in that, L is 20 minutes.

9. The method for automatic recharging and fault detection of a low-voltage battery according to claim 2, characterized in that, Step 7 includes: Step 71: During the power replenishment process, the vehicle controller monitors the working status of the DC-DC converter, power battery, front / rear domain controller and high-voltage circuit in real time. If component damage or high-voltage fault is detected, causing the low-voltage battery to be unable to be replenished, the fault information is sent to the intelligent vehicle terminal via the CAN bus, and then proceeds to step 73. Step 72: During the power replenishment process, the intelligent vehicle terminal monitors the working status of the DC converter, power battery, front / rear domain controller and high-voltage circuit in real time. If component damage or high-voltage failure is detected, resulting in the low-voltage battery being unable to be replenished, proceed to step 73. Step 73: The intelligent vehicle terminal uploads the fault information to the backend and simultaneously sends the fault information to the vehicle instrument panel via the CAN bus to provide feedback to the user.

10. The method for automatic recharging and fault detection of a low-voltage battery according to claim 2, characterized in that, The voltage threshold is set to 24V.

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