Novel automobile low-voltage power distribution controller integrated with storage battery health management

Abstract

The invention relates to a novel automobile low-voltage power distribution controller integrated with storage battery health management, which realizes real-time monitoring and early warning of the health state of a storage battery by integrating an internal resistance detection circuit and an internal resistance detection algorithm in the low-voltage power distribution controller. The controller comprises a voltage sampling circuit, a current sampling circuit, a signal conditioning circuit, an MCU (Microprogrammed Control Unit) and a CAN (Controller Area Network) bus communication module, and can be used for acquiring voltage and current data of the storage battery in real time, calculating the internal resistance and judging the health state of the storage battery. When it is detected that the state of the storage battery is abnormal, early warning information is sent to the central controller through the CAN bus, and a driver is reminded to take corresponding measures. The problems that traditional storage battery health state detection depends on manpower, precision is low, user experience is poor and the like are solved, the reliability of a vehicle power utilization system is improved, the service life of the storage battery is prolonged, risks caused by storage battery faults of the vehicle are reduced, and the method has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile electronic and electrical appliance manufacturing, and in particular to a novel automobile low-voltage power distribution controller integrating battery health management. Background Art

[0002] Although high-voltage lithium-ion batteries are widely used in the power system of electric vehicles, lead-acid batteries still dominate the 12V low-voltage power supply system. Lead-acid batteries have the advantages of mature technology, low cost, and high reliability, and are suitable for powering low-voltage systems in vehicles, such as lighting, instruments, entertainment systems, controllers, etc.

[0003] However, traditional battery health management has many problems: (1) The battery life is limited, usually 3-5 years, and may be shorter in actual use; (2) Battery health status detection mainly relies on manual experience and judgment, which may lead to misjudgment; (3) Ordinary car owners lack professional tools and knowledge and find it difficult to accurately judge the battery status; (4) Car owners do not pay enough attention to 12V battery maintenance; (5) Existing low-voltage distribution controllers have a single function and only have power distribution function, and cannot monitor the battery health status. Summary of the invention

[0004] The present invention provides a novel automotive low-voltage power distribution controller with integrated battery health management. The controller integrates an internal resistance detection circuit and an internal resistance detection algorithm in the low-voltage power distribution controller to achieve real-time monitoring and early warning of the battery health status, thereby improving the reliability of the vehicle's power system, extending the battery life, and reducing the risk of vehicle failure due to battery failure.

[0005] An automotive low-voltage power distribution controller with integrated battery health management, comprising:

[0006] A low-voltage power distribution control unit, used to manage the low-voltage power distribution of the vehicle;

[0007] The internal resistance detection circuit is integrated with the low-voltage power distribution control unit in the same controller to collect the voltage and current data of the battery;

[0008] A micro control unit is connected to the internal resistance detection circuit and embedded with an internal resistance detection algorithm for processing voltage and current data and calculating the internal resistance of the battery;

[0009] CAN bus communication module, used to transmit battery health status information to the vehicle central controller.

[0010] Furthermore, the internal resistance detection circuit includes:

[0011] The voltage sampling circuit uses a high-precision ADC to collect the battery terminal voltage;

[0012] Current sampling circuit, measuring battery charge and discharge current through shunt resistor or Hall sensor;

[0013] The signal conditioning circuit filters and amplifies the collected voltage and current signals.

[0014] Furthermore, the voltage sampling circuit includes a voltage divider network and an input protection circuit, and the current sampling circuit uses a Hall sensor installed on the positive lead of the battery.

[0015] Furthermore, the internal resistance detection algorithm is based on Ohm's law and a transient response model, and calculates the internal resistance of the battery by calculating the transient response of voltage and current, wherein the internal resistance calculation formula is R_internal=ΔV / ΔI, ΔV is the voltage change, and ΔI is the current change.

[0016] Furthermore, the controller also includes a threshold judgment module, which is used to compare the calculated internal resistance with a preset threshold, and comprehensively judge the health of the battery in combination with the voltage data. The threshold judgment module dynamically adjusts the internal resistance threshold according to the battery model and temperature.

[0017] Furthermore, the CAN bus communication module encapsulates the detection results and warning information into CAN messages and sends them to the vehicle central controller. The warning information includes the battery internal resistance value, health status, and recommended maintenance or replacement prompts.

[0018] Furthermore, the controller also includes a data recording module and a low power management module. The data recording module is used to save the historical data of the health status of the battery, and the low power management module is used to adjust the system working mode under different working conditions of the vehicle to reduce power consumption.

[0019] Furthermore, the low power management module puts the system into sleep mode after the vehicle is turned off, and wakes up periodically to monitor the battery status to prevent over-discharge.

[0020] Furthermore, the controller also includes a temperature monitoring module, which measures the battery surface temperature through a temperature sensor and incorporates the temperature data into the health status assessment.

[0021] Furthermore, the method for low voltage power distribution controller to perform battery health management includes the following steps:

[0022] The system regularly collects the voltage and current data of the battery;

[0023] When the internal resistance calculation conditions are met, the system enters the high-frequency sampling mode to collect transient change data of voltage and current;

[0024] Calculate the battery internal resistance based on the collected data, compare the calculated result with the preset threshold, and judge the battery health status in combination with the voltage data;

[0025] Send the battery health status information to the central controller via the CAN bus;

[0026] When an abnormal battery health status is detected, an early warning message is generated and a high-priority early warning message is sent.

[0027] Beneficial effects of the present invention:

[0028] Real-time monitoring and early warning of battery health status can be achieved to avoid problems such as vehicle failure to start due to battery failure; detection accuracy can be improved, and high-precision circuits and algorithms can be used to more accurately evaluate battery health status than traditional manual detection methods; user experience can be improved, and car owners do not need to go to 4S stores to check batteries regularly, as the system will automatically monitor and provide timely reminders; battery life can be extended, and early warnings can be used to enable car owners to take timely maintenance measures; the risk of failure can be reduced to prevent vehicle system failures and safety hazards caused by sudden battery failure; the system has a high degree of integration, and no additional detection equipment is required, reducing costs and complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a schematic diagram of the system architecture of the present invention;

[0031] Figure 2 It is a schematic diagram of the data collection and processing flow of the internal resistance detection circuit of the present invention;

[0032] Figure 3 It is a schematic diagram of the system working process of the present invention;

[0033] Figure 4 It is a schematic diagram of the early warning information display interface of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0035] It should be noted that the references to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0036] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0037] System architecture:

[0038] like Figure 1 as well as Figure 2 As shown, the system architecture of the present invention includes the following modules:

[0039] Low voltage power distribution controller: responsible for power distribution and battery health detection.

[0040] Internal resistance detection circuit: used to collect battery voltage and current data.

[0041] MCU: Embeds an internal resistance detection algorithm to process the collected data and calculate the internal resistance of the battery, and then combines the voltage data to make a comprehensive health assessment.

[0042] CAN bus communication module: transmits detection results and warning information to the vehicle central controller.

[0043] Central controller: receives warning information and reminds the driver through the instrument panel or vehicle display.

[0044] Hardware design:

[0045] Voltage sampling circuit

[0046] The voltage sampling circuit uses a high-precision ADC to directly collect the battery terminal voltage. In this implementation, a 24-bit Σ-Δ ADC is used with an accuracy of ±0.05%, meeting automotive grade requirements. The voltage sampling circuit includes a voltage divider network, an input protection circuit, and a signal conditioning circuit. The voltage divider network is composed of a high-precision resistor divider, which converts the battery terminal voltage (usually around 12V) into an input voltage range acceptable to the ADC (such as 0-5V). The input protection circuit includes a transient voltage suppression diode and a current limiting resistor to prevent overvoltage from damaging the ADC.

[0047] Current sampling circuit:

[0048] The current sampling circuit measures the battery charge and discharge current through a shunt resistor or a Hall sensor. In this embodiment, the Hall sensor is preferably used, which has the characteristics of high precision, high isolation and wide measurement range. The Hall sensor is installed on the positive lead of the battery and can measure the current in the range of -100A to +100A with an accuracy of ±1%. The voltage signal output by the Hall sensor is sent to the ADC channel of the MCU after passing through the signal conditioning circuit.

[0049] Signal conditioning circuit:

[0050] The signal conditioning circuit filters and amplifies the collected voltage and current signals to ensure data accuracy. The voltage signal conditioning circuit includes an RC low-pass filter with a cutoff frequency set to 100Hz to effectively filter out high-frequency noise. The current signal conditioning circuit includes a signal amplification and filtering circuit composed of an operational amplifier. The gain can be configured through software according to actual needs, and the cutoff frequency of the filter circuit is also set to 100Hz.

[0051] Microcontroller:

[0052] Select automotive-grade MCU to support CAN bus communication and real-time data processing. In this implementation, Infineon TC297 series or NXPS32K144 series MCUs are selected. These MCUs have rich peripheral resources, high-performance processing capabilities, and features that meet automotive functional safety standards (ISO26262). The MCU has an operating frequency of more than 100MHz, a built-in high-precision ADC, a CAN controller, and a multi-channel timer, which can meet the needs of real-time data acquisition and processing.

[0053] CAN bus interface circuit:

[0054] The CAN bus interface circuit includes a CAN transceiver and an isolation circuit. The CAN transceiver uses a chip that complies with the ISO11898 standard, supports high-speed CAN (500kbps) and fault-tolerant functions. The isolation circuit uses optocoupler isolation to prevent potential common-mode interference and ground loop interference, and improve the system's anti-interference ability and reliability.

[0055] Software Design

[0056] Data acquisition module:

[0057] The data acquisition module collects the voltage and current data of the battery at regular intervals. The acquisition frequency is divided into two modes: the sampling frequency in the standard mode is 1Hz, which is suitable for normal driving conditions; the sampling frequency in the high-frequency mode is 100Hz, which is suitable for transient conditions such as starting, acceleration, and braking. The data acquisition module is also responsible for the preliminary processing of the collected raw data, including filtering, calibration, and outlier detection.

[0058] Internal resistance calculation algorithm:

[0059] The internal resistance calculation algorithm is based on Ohm's law and transient response model to calculate the internal resistance of the battery. This implementation adopts a combination of the following two methods:

[0060] DC pulse method: When the battery is charged and discharged, the transient changes of voltage and current are measured, and the internal resistance is calculated using the formula R_internal = ΔV / ΔI. ΔV is the voltage change, and ΔI is the current change. To improve the calculation accuracy, the algorithm uses the least squares method to fit multiple sets of measurement data.

[0061] AC injection method: Under certain conditions, such as when the vehicle is stationary, the on-board equipment is controlled to generate a small AC current fluctuation, the corresponding voltage response is measured, and the AC impedance is calculated. The AC injection method can be measured under more working conditions, improving the comprehensiveness of the detection.

[0062] In specific implementation, the algorithm first detects whether the current change meets the calculation conditions (such as the change amplitude is greater than 1A), and then collects high-frequency voltage and current data in a short time window before and after the current change (such as 100ms), and uses the above formula to calculate the internal resistance. In order to improve the calculation accuracy, the algorithm also considers temperature compensation and SOC compensation.

[0063] Threshold judgment module:

[0064] The threshold judgment module compares the calculated internal resistance with the preset threshold value and comprehensively judges the health of the battery in combination with the voltage data. In this embodiment, the internal resistance threshold is dynamically adjusted according to the battery model and temperature. For example, for a standard 12V, 60Ah lead-acid battery, at an ambient temperature of 25°C, the normal value range of the internal resistance is 3-8mΩ, and when the internal resistance exceeds 12mΩ, it is judged to be abnormal.

[0065] In addition, the threshold judgment module also makes a comprehensive judgment based on the voltage data. For example, when the measured open circuit voltage is lower than 12.0V and the internal resistance exceeds 10mΩ, it is judged that the battery is seriously depleted or aged; when the open circuit voltage is normal but the internal resistance is abnormally high, it is judged that the battery has internal failure.

[0066] CAN communication module:

[0067] The CAN communication module encapsulates the test results and warning information into CAN messages and sends them to the central controller. The CAN messages contain the following information: battery voltage, current, internal resistance, temperature, health status (expressed as a percentage), warning level (normal, attention, warning, severe) and recommended measures (such as "recommended charging", "recommended inspection", "recommended replacement", etc.).

[0068] The ID and format of the CAN message follow the communication protocol specifications of the automobile manufacturer. In standard working mode, CAN messages are sent every 10 seconds; when an abnormality is detected, the sending frequency is increased to once per second until the abnormality is eliminated or confirmed.

[0069] For details, see Workflow Figure 3 as well as Figure 4 Shown

[0070] The system's workflow is as follows:

[0071] After the system starts, the low-voltage power distribution controller initializes all modules, including ADC, timer, CAN controller, etc.

[0072] Under normal working conditions, the system collects the voltage and current data of the battery regularly (such as every second) and detects whether the conditions for calculating the internal resistance are met.

[0073] When the internal resistance calculation conditions are met (such as the current change is greater than the threshold), the system enters the high-frequency sampling mode to quickly collect transient change data of voltage and current.

[0074] The MCU calculates the internal resistance of the battery based on the collected data, compares the calculation result with the preset threshold, and makes a comprehensive judgment on the health status of the battery in combination with the voltage data.

[0075] The system periodically (e.g. every 10 seconds) sends the battery health status information to the central controller via the CAN bus.

[0076] If an abnormal battery health status is detected, the system immediately generates a warning message and sends a high-priority warning message to the central controller via the CAN bus.

[0077] The central controller receives the warning information and reminds the driver through the instrument panel or on-board display screen, displaying specific warning information and recommended measures.

[0078] The system also has a data logging function, which regularly saves historical data on the battery's health status to support later analysis and diagnosis.

[0079] After the vehicle is turned off, the system enters low-power mode and wakes up periodically to monitor the battery status to prevent excessive discharge.

[0080] Example 1: Optimized implementation scheme for lead-acid battery internal resistance detection

[0081] In view of the characteristics of lead-acid batteries, this preferred embodiment further optimizes the internal resistance detection algorithm. Considering the relationship between the internal resistance of lead-acid batteries and temperature and SOC, the algorithm introduces temperature compensation and SOC compensation coefficients:

[0082] R_compensated=R_measured*K_temp*K_SOC

[0083] Among them, K_temp is the temperature compensation coefficient, which increases as the temperature decreases; K_SOC is the SOC compensation coefficient, which increases as the SOC decreases. These two coefficients are determined by table lookup method, and the table data is based on a large number of experimental test results.

[0084] In addition, in order to adapt to different types of batteries, the system is designed with an adaptive threshold adjustment mechanism. When the vehicle is used for the first time or the battery is replaced, the system will learn for a period of time to establish the internal resistance baseline value of the battery, and then set a personalized threshold based on this baseline value.

[0085] Example 2: Preferred implementation scheme for low power consumption design

[0086] In order to reduce the burden of the system on the vehicle battery, especially when the vehicle is parked for a long time, this preferred embodiment adopts the following low power consumption design:

[0087] Multi-level working mode: According to the vehicle status, such as driving, idling, and engine off, different working modes are automatically switched to adjust the sampling frequency and processing frequency.

[0088] Select low-power devices for key components: such as low-power MCU, low-power ADC, etc.

[0089] Software optimization: Use interrupt-driven and event-driven programming to reduce unnecessary polling and processing.

[0090] Sleep mechanism: After the vehicle is turned off, the system enters deep sleep mode, retaining only the timed wake-up function and regularly checking the battery status.

[0091] Through the above optimization, the average power consumption of the system when the vehicle is turned off is reduced to below 5mA, greatly reducing the consumption of the battery.

[0092] Example 3: Preferred Implementation Method for Temperature Monitoring

[0093] Considering the important influence of temperature on battery performance and life, the preferred embodiment adds a temperature monitoring function. The system measures the battery surface temperature through an NTC temperature sensor or an infrared temperature sensor, and incorporates the temperature data into the health status assessment.

[0094] When abnormal battery temperature is detected, such as too high, the system generates specific temperature warning information. In addition, temperature data is also used for temperature compensation of internal resistance calculation to improve calculation accuracy.

[0095] The new automotive low-voltage power distribution controller with integrated battery health management of the present invention realizes real-time monitoring and early warning of the battery health status by integrating the internal resistance detection function in the power distribution controller. This technical solution has the advantages of high detection accuracy, good user experience, and low cost. It can be widely used in various automotive electrical systems to improve the reliability and safety of vehicle power systems.

[0096] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0097] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A new type of automotive low-voltage power distribution controller with integrated battery health management, characterized in that: include: A low voltage power distribution control unit, used to manage the low voltage power distribution in the vehicle; An internal resistance detection circuit, integrated with the low-voltage power distribution control unit in the same controller, for collecting voltage and current data of the battery; A micro control unit, connected to the internal resistance detection circuit, embedded with an internal resistance detection algorithm, for processing the voltage and current data and calculating the internal resistance of the battery; CAN bus communication module, used to transmit battery health status information to the vehicle central controller.

2. The low voltage power distribution controller according to claim 1, characterized in that: The internal resistance detection circuit comprises: The voltage sampling circuit uses a high-precision ADC to collect the battery terminal voltage; Current sampling circuit, measuring battery charge and discharge current through shunt resistor or Hall sensor; The signal conditioning circuit filters and amplifies the collected voltage and current signals.

3. The low voltage power distribution controller according to claim 2, characterized in that: The voltage sampling circuit includes a voltage dividing network and an input protection circuit, and the current sampling circuit uses a Hall sensor installed on the positive lead of the battery.

4. The low voltage power distribution controller according to claim 1, characterized in that: The internal resistance detection algorithm is based on Ohm's law and a transient response model, and calculates the internal resistance of the battery by calculating the transient response of voltage and current, wherein the internal resistance calculation formula is R_internal=ΔV / ΔI, ΔV is the voltage change, and ΔI is the current change.

5. The low voltage power distribution controller according to claim 1, characterized in that: It also includes a threshold judgment module, which is used to compare the calculated internal resistance with a preset threshold and make a comprehensive judgment on the health status of the battery in combination with the voltage data. The threshold judgment module dynamically adjusts the internal resistance threshold according to the battery model and temperature.

6. The low voltage power distribution controller according to claim 1, characterized in that: The CAN bus communication module encapsulates the detection results and warning information into CAN messages and sends them to the automobile central controller. The warning information includes the battery internal resistance value, health status, and maintenance or replacement suggestions.

7. The low voltage power distribution controller according to claim 1, characterized in that: It also includes a data recording module and a low power consumption management module. The data recording module is used to save the historical data of the health status of the battery. The low power consumption management module is used to adjust the system working mode under different working conditions of the vehicle to reduce power consumption.

8. The low voltage power distribution controller according to claim 7, characterized in that: The low power management module puts the system into sleep mode after the vehicle is turned off, and wakes up periodically to monitor the battery status to prevent over-discharge.

9. The low voltage power distribution controller according to claim 1, characterized in that: It also includes a temperature monitoring module that measures the battery surface temperature through a temperature sensor and incorporates the temperature data into the health status assessment.

10. A method for battery health management using the low voltage distribution controller according to any one of claims 1 to 9, characterized in that: The following steps are involved: The system regularly collects the voltage and current data of the battery; When the internal resistance calculation conditions are met, the system enters the high-frequency sampling mode to collect transient change data of voltage and current; Calculate the battery internal resistance based on the collected data, compare the calculated result with the preset threshold, and judge the battery health status in combination with the voltage data; Send the battery health status information to the central controller via the CAN bus; When an abnormal battery health status is detected, an early warning message is generated and a high-priority early warning message is sent.

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