Vehicle electronic door lock emergency power supply system and method based on super capacitor

Abstract

The invention relates to the technical field of vehicle electronic door locks, in particular to a vehicle electronic door lock emergency power supply system and method based on a super capacitor, and the method comprises the following steps: when a main power supply is normal, charging a super capacitor module by adopting a self-adaptive multi-stage charging strategy; the charging parameters are dynamically adjusted according to the real-time state parameters of the super capacitor module; when it is monitored that the voltage of the main power supply is lower than a failure threshold value and lasts for a first preset time, it is judged that the main power supply fails, and the power supply of the load is switched to the super capacitor module from the main power supply within a preset switching delay; in the emergency power supply state, responding to an unlocking request signal, and obtaining the current residual energy state of the super capacitor module; and the current residual energy state is compared with a preset unlocking energy threshold value, unlocking operation is executed on the electronic lock corresponding to the current residual energy meeting the unlocking condition, and the stability of power supply of the electronic door lock can be improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle electronic door lock technology, specifically to an emergency power supply system and method for vehicle electronic door locks based on supercapacitors. Background Technology

[0002] With the development of automotive intelligence, traditional mechanical door locks are gradually being replaced by electronic door locks. Electronic door locks, driven by motors, offer advantages such as intelligence, high integration, and a good user experience. However, their complete reliance on the vehicle's electrical system also brings safety hazards: in the event of a serious collision, a loose battery connector, or a complete depletion of the 12V low-voltage battery, the main power supply is interrupted, and the electronic door lock system will cease to function due to power loss, preventing occupants from opening the doors from the inside or outside of the vehicle, potentially leading to serious consequences. Ensuring the continued operation of electronic door locks in the event of a main power failure is crucial. Supercapacitor modules, due to their high power density, rapid charging and discharging, and long cycle life, have become an ideal choice for short-term, highly reliable backup power. In existing technologies, a huge inrush current is generated at the moment of switching from main power to backup power due to the voltage difference between the bus distributed capacitance and the supercapacitor. This current not only threatens the safety of power switching devices but may also cause a voltage drop at the load end, affecting the stability of the power supply to the electronic door lock. Summary of the Invention

[0003] The purpose of this invention is to provide an emergency power supply system and method for vehicle electronic door locks based on supercapacitors, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an emergency power supply system and method for vehicle electronic door locks based on supercapacitors, the method comprising the following steps: When the main power supply is normal, an adaptive multi-stage charging strategy is adopted to charge the supercapacitor module. The adaptive multi-stage charging strategy includes at least a constant current charging stage and a constant voltage charging stage, and the charging parameters are dynamically adjusted according to the real-time status parameters of the supercapacitor module. When the main power supply voltage is detected to be lower than the failure threshold and lasts for a first preset time, the main power supply is determined to be faulty, and within a preset switching delay, a power switching operation is performed to switch the power supply of the load from the main power supply to the supercapacitor module. The power switching operation includes a pre-charging stage and a main switch switching stage. In emergency power supply mode, in response to the unlocking request signal, the current remaining energy status of the supercapacitor module is obtained; the current remaining energy status is compared with the preset unlocking energy threshold, and the electronic lock corresponding to the current remaining energy that meets the unlocking conditions is unlocked.

[0005] Preferably, the step of dynamically adjusting the charging parameters based on the real-time status parameters of the supercapacitor module includes: The total voltage, charging current, and temperature of the supercapacitor module are collected in real time; based on the total voltage and charging current, the current health status of the supercapacitor module is calculated. Based on the current health status and temperature, the current value of the constant current charging stage and the voltage value of the constant voltage charging stage are dynamically adjusted. When the current health status is lower than the first threshold or the temperature is higher than the second threshold, the constant current charging current and the constant voltage charging voltage are reduced.

[0006] Preferably, the step of determining main power supply failure when the main power supply voltage is detected to be lower than the failure threshold and remains so for a first preset time includes: The voltage of the main power supply is continuously sampled to obtain a series of voltage sample values; Each of the voltage samples is compared with a preset failure voltage threshold; When a single voltage sample value is lower than the failure voltage threshold, a first timer is started or reset and begins timing. The sampling and comparison operation is continuously performed. When the cumulative timing time of the first timer reaches a first preset time, a confirmation signal of main power failure is generated. If a voltage sample value is higher than the failure voltage threshold before the first timer reaches the first preset time, the first timer is reset.

[0007] Preferably, the pre-charging phase includes: The system detects the first real-time voltage difference between the main power bus voltage and the supercapacitor module output voltage; determines whether the first real-time voltage difference is greater than a first safety threshold; if it is greater, the pre-charging circuit is activated; the pre-charging circuit includes an adjustable current limiting network connected in parallel with the main solid-state switch, the adjustable current limiting network is composed of n parallel resistor-switch branches, n≥2, and the current limiting resistor values ​​of each branch follow a preset decreasing relationship; Based on the value of the first real-time voltage difference, the number of pre-charge branch stages to be activated is determined, and the corresponding resistor-switch branches are turned on in sequence, so that the pre-charge current increases in a discrete step manner. The second real-time voltage difference between the main power bus voltage and the supercapacitor module output voltage is continuously monitored. When the second real-time voltage difference drops below the second safety threshold, the pre-charging stage is completed; the second safety threshold is lower than the first safety threshold.

[0008] Preferably, the step of sequentially turning on the corresponding resistor-switch branches includes: Before turning on the next branch, calculate the instantaneous rate of change of the main power bus voltage; The time interval between the current branch and the next branch activation is dynamically adjusted based on the magnitude of the instantaneous rate of change; wherein the instantaneous rate of change is positively correlated with the time interval, and the current total pre-charge current is sampled after each branch is activated; The sampled current value is compared with a preset safe current value corresponding to the currently active branch combination; if the sampled current value continues to exceed the preset safe current value, the last active branch is turned off.

[0009] Preferably, the main switch switching stage includes: In response to the second real-time voltage difference being lower than the second safety threshold, a conduction command is sent to the main solid-state switch connected to the supercapacitor module; After confirming that the main solid-state switch is fully turned on, an overlapping conduction period is initiated; During the overlapping conduction period, the pre-charge circuit is kept in the conducting state, so that the main solid-state switch and the pre-charge circuit form two parallel conductive paths. During this period, the load current is shared by the low-resistance path of the main solid-state switch and the current-limiting path of the pre-charge circuit, and the current is automatically distributed according to the ratio of their conduction impedances. After the overlapping conduction period ends, a turn-off command is sent to all the conducted resistor-switch branches; a turn-off command is also sent to the solid-state switch connected to the main power supply.

[0010] Preferably, during the overlapping conduction period, the pre-charge circuit is further subjected to a graded shutdown operation, specifically as follows: At the end of the first sub-period after the start of the overlap conduction period, a turn-off drive signal is applied to the resistor-switch branch with the smallest resistance value in the pre-charge circuit. At the end of the second sub-period following the start of the overlapped conduction period, a turn-off drive signal is applied to all remaining resistor-switch branches in the pre-charge circuit, wherein the end of the second sub-period coincides with the end of the overlapped conduction period.

[0011] Preferably, in the emergency power supply state, in response to the unlocking request signal, the steps of acquiring the current remaining energy state of the supercapacitor module, comparing the current remaining energy state with a preset unlocking energy threshold, and performing an unlocking operation on the electronic lock corresponding to the current remaining energy that meets the unlocking conditions include: Monitor the real-time terminal voltage of the supercapacitor module as the current remaining energy state; The real-time terminal voltage is compared with a preset voltage threshold, which serves as the unlocking energy threshold. If the real-time terminal voltage is higher than or equal to the preset voltage threshold, then the unlocking condition is determined to be met. If the judgment result is that the unlocking conditions are not met, an insufficient energy alarm signal is generated and sent; and the sending of unlocking commands to the electronic lock drive circuit is prohibited.

[0012] An emergency power supply system for vehicle electronic door locks based on supercapacitors, applied to the emergency power supply method for vehicle electronic door locks based on supercapacitors as described in any one of the above, comprising: A capacitor module charging module is used to charge a supercapacitor module using an adaptive multi-stage charging strategy when the main power supply is normal. The adaptive multi-stage charging strategy includes at least a constant current charging stage and a constant voltage charging stage, and dynamically adjusts the charging parameters according to the real-time status parameters of the supercapacitor module. The power switching module is used to determine that the main power supply has failed when the main power supply voltage is detected to be lower than the failure threshold for a first preset time, and to perform a power switching operation within a preset switching delay to switch the power supply of the load from the main power supply to the supercapacitor module. The power switching operation includes a pre-charging stage and a main switch switching stage. The unlocking control module is used to respond to an unlocking request signal in emergency power supply mode, obtain the current remaining energy status of the supercapacitor module, compare the current remaining energy status with a preset unlocking energy threshold, and perform an unlocking operation on the electronic lock corresponding to the current remaining energy that meets the unlocking conditions.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. After the main solid-state switch is turned on, the pre-charge circuit is not immediately turned off. Instead, the two are connected in parallel to supply power, allowing the load current to be automatically and smoothly transferred according to the impedance ratio. This reduces the instability of power supply caused by the switching dead zone. During the overlapping conduction period, the pre-charge circuit is subjected to a "staged shutdown" operation. The branch with the largest current and the smallest resistance is turned off first, and then the other branches are turned off. The exit process of the pre-charge circuit is decomposed from a large current step into two small steps, which effectively suppresses the current surge and voltage disturbance during shutdown. This ensures the smoothness of the switching between the main power supply and the supercapacitor module power supply path and improves the stability of the current during the switching process. 2. Based on the remaining energy state after unlocking, determine whether it is sufficient to perform at least one more unlocking operation, and update the system status indicator accordingly. In emergency power supply mode, when responding to an unlocking request, the system first obtains the current remaining energy state of the supercapacitor and compares it with the energy threshold required for unlocking. Unlocking will only be performed if sufficient energy is confirmed; otherwise, unlocking will be prohibited and an alarm will be issued. This reduces the likelihood of system crashes due to insufficient energy and improves the certainty and success rate of each operation. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a system structure block diagram of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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. Example

[0017] Please see Figures 1 to 2 This invention provides a technical solution for an emergency power supply system and method for vehicle electronic door locks based on supercapacitors: an emergency power supply method for vehicle electronic door locks based on supercapacitors, comprising the following steps: S1: When the main power supply is normal, an adaptive multi-stage charging strategy is adopted to charge the supercapacitor module. The adaptive multi-stage charging strategy includes at least a constant current charging stage and a constant voltage charging stage, and the charging parameters are dynamically adjusted according to the real-time status parameters of the supercapacitor module. The steps for dynamically adjusting charging parameters based on the real-time status parameters of the supercapacitor module include: real-time acquisition of the total voltage, charging current, and temperature of the supercapacitor module; calculation of the current health status of the supercapacitor module based on the total voltage and charging current; and dynamic adjustment of the current value of the constant current charging stage and the voltage value of the constant voltage charging stage based on the current health status and temperature, wherein when the current health status is lower than a first threshold or the temperature is higher than a second threshold, the constant current charging current and constant voltage charging voltage are reduced. Specifically, the supercapacitor module is composed of multiple supercapacitor units connected in series or parallel. Its total capacity is precisely calculated to ensure that, after being fully charged, it can provide the energy required for at least five complete unlocking operations within 24 hours after the external battery is disconnected. The nominal voltage of the supercapacitor module is 2.7V or 5.4V, and it integrates a boost chip with automatic switching function: this chip is the core of the entire system. It connects between the supercapacitor module and the electronic lock drive module. The boost chip integrates an automatic power switching circuit and a boost DC-DC converter. When the main power supply is normal, it supplies power to the electronic lock and simultaneously performs constant current / constant voltage charging on the supercapacitor module to keep it fully charged. Through sensors and measurement circuits, the total voltage, charging current, and module temperature of the supercapacitor module are collected in real time. During the constant current charging phase, the voltage jump at the supercapacitor module terminals is measured (…). ) and known charging current ( According to the formula Calculate its equivalent series internal resistance ( ), calculate the current Compared with the initial internal resistance of the supercapacitor module at the time of manufacture ( Compare according to the formula Calculate current health status Based on the current calculation Based on the collected temperature values, the current value during the constant current charging stage and the voltage value during the constant voltage charging stage are dynamically adjusted, and a health state threshold is preset (e.g., ...). ) and a temperature threshold (e.g., When the current health status is below the health status threshold or the temperature value is above the temperature threshold, the capacitor module is determined to be in a "sub-healthy" or "high-temperature" state. In this case, both the constant current charging current and the constant voltage charging voltage are reduced. For example, the current value in the constant current charging stage is set to 70% of the rated current, and the voltage value in the constant voltage charging stage is set to 95% of the rated voltage. When the current health status is greater than or equal to the health status threshold or the temperature value is less than or equal to the temperature threshold, the capacitor module is determined to be in good condition. At this time, charging can be performed according to the standard rated parameters, i.e., the current value in the constant current charging stage and the voltage value in the constant voltage charging stage are both set to their maximum values. The controller uses an MCU (microcontroller unit) with ADC (analog-to-digital converter) and computing capabilities. The MCU reads the total voltage of the module through a voltage sampling circuit, the charging current through a current sensor (such as a Hall sensor), and the temperature through a thermistor mounted on the module surface. Whenever the charger starts a new constant current charging cycle, the MCU captures the voltage jump at the moment charging begins. And combined with the stable charging current at this moment Calculate the current The MCU's non-volatile memory stores the factory default information. Value, calculated accordingly The MCU internally stores a "charging parameter lookup table", which is based on... With T as input, the MCU outputs the set values ​​of the current during the constant current charging stage and the voltage during the constant voltage charging stage. The MCU sends the retrieved set values ​​of the current during the constant current charging stage and the voltage during the constant voltage charging stage to the digital charging controller (or outputs an analog reference signal via a DAC), thereby adjusting the charger's output in real time by increasing the internal resistance ( The system automatically reduces charging stress (current and voltage) at low temperatures or high temperatures, effectively slowing down the aging rate of the supercapacitor and significantly extending its service life. When the capacitor is in good condition, it uses full charging to ensure that its stored energy and output power can meet the needs of emergency power supply. It can automatically sense, judge, and execute the optimal charging strategy, realizing intelligent charging management. By collecting the total voltage, charging current, and temperature of the supercapacitor module in real time and calculating its health status online, the system can achieve intelligent charging management. It can dynamically adjust the constant current charging current and constant voltage charging voltage according to the capacitor's "health condition". When the capacitor is in poor health or the temperature is too high, it automatically reduces the charging stress, effectively slowing down the aging process and improving the reliability and safety of the system for long-term use; when the capacitor is in good condition, it charges at full capacity to ensure sufficient backup energy. S2: When the main power supply voltage is detected to be lower than the failure threshold and lasts for a first preset time, the main power supply is determined to be faulty, and within the preset switching delay, a power switching operation is performed to switch the power supply of the load from the main power supply to the supercapacitor module. The power switching operation includes a pre-charging stage and a main switch switching stage. When the main power supply voltage is detected to be lower than the failure threshold and remains below it for a first preset time, the steps for determining the main power supply failure include: continuously sampling the voltage of the main power supply to obtain a series of voltage sample values; comparing each of the voltage sample values ​​with a preset failure voltage threshold; when a single voltage sample value is lower than the failure voltage threshold, starting or resetting a first timer and making it start timing; continuously performing sampling and comparison operations; when the cumulative timing time of the first timer reaches a first preset time, generating a confirmation signal of main power supply failure; if a voltage sample value is higher than the failure voltage threshold before the first timer reaches the first preset time, resetting the first timer. Specifically, after generating the confirmation signal of the main power supply failure, the following steps are performed: A second preset time switching delay is initiated; within the switching delay, a switching operation from the main power supply to the backup supercapacitor module is performed; the failure voltage threshold is a dynamic value, set proportionally according to the rated voltage of the main power supply, or dynamically adjusted according to the current load power; the length of the first preset time is dynamically adjustable, based on the depth to which the main power supply voltage is lower than the failure voltage threshold; the greater the voltage drop below the threshold, the shorter the first preset time is used. By determining the "duration time," the accuracy of failure determination is improved, thereby improving the accuracy of subsequent electronic lock unlocking. This is based on a dynamic safety threshold (determined by the capacitor). The pre-charging strategy, determined by factors such as switch tolerance and adjustable current limiting network, improves the speed and safety of the pre-charging process by sequentially turning on the resistive branches and adaptively adjusting the conduction interval with the voltage change rate, supplemented by current closed-loop protection.

[0018] The pre-charging phase includes: detecting a first real-time voltage difference between the main power bus voltage and the supercapacitor module output voltage; determining whether the first real-time voltage difference is greater than a first safety threshold; the first safety threshold is dynamically set based on at least one parameter among the current health status of the supercapacitor module, the maximum allowable surge current of the main solid-state switch, and the system load urgency indicator; if it is greater, the pre-charging circuit is activated; the pre-charging circuit includes an adjustable current limiting network connected in parallel with the main solid-state switch, the adjustable current limiting network consisting of n parallel resistor-switch branches, n≥2, each branch The current-limiting resistor values ​​of the circuits follow a preset decreasing relationship, and the current-limiting resistor values ​​of each branch in the adjustable current-limiting network follow a proportional relationship of R, R / 2, R / 4, ...; based on the value of the first real-time voltage difference, the number of pre-charging branch stages to be activated is determined, and the corresponding resistor-switch branches are turned on sequentially, so that the pre-charging current increases in a discrete stepwise manner; the second real-time voltage difference between the main power bus voltage and the supercapacitor module output voltage is continuously monitored, and when the second real-time voltage difference drops below the second safety threshold, the pre-charging stage is completed; the second safety threshold is lower than the first safety threshold; The steps for sequentially turning on the corresponding resistor-switch branches include: calculating the instantaneous rate of change of the main power bus voltage before turning on the next branch; dynamically adjusting the time interval between the current branch and the next branch turn-on action based on the magnitude of the instantaneous rate of change; wherein the instantaneous rate of change is positively correlated with the time interval; after each branch is turned on, sampling the current total pre-charge current; comparing the sampled current value with a preset current safety value corresponding to the currently turned-on branch combination; if the sampled current value continuously exceeds the preset current safety value, then turning off the last turned-on branch. Specifically, the first safety threshold is calculated and set in real time. This threshold is not a fixed value, but is dynamically determined by the following parameters: the current health status of the supercapacitor module (…). ): The lower the internal resistance, the higher the allowable voltage difference threshold. The maximum allowable surge current of the main solid-state switch can be appropriately increased to speed up the process; Based on the switch specifications, calculate the amount needed to avoid exceeding [the limit]. Maximum permissible voltage difference; System load urgency indicator: In "Emergency Mode", the system load can be appropriately increased. This sacrifices some safety for a faster switching speed; it detects the first real-time voltage difference ( The voltage difference between the main power bus voltage and the supercapacitor voltage is the first real-time voltage difference. When this difference exceeds the first safety threshold, the pre-charge circuit is activated. The core of this pre-charge circuit is an adjustable current-limiting network connected in parallel with the main solid-state switch. This network consists of multiple (n≥2) parallel resistor-switch branches, with branch resistance values ​​following a proportional relationship of R, R / 2, R / 4, ... By combining and activating different branches, the pre-charge current can be precisely controlled to vary from large to small, based on the initial... The magnitude of the voltage difference determines the starting point. A larger voltage difference requires a larger resistance value in the branch that initiates the conduction (e.g., R is conducted first) to ensure the initial current is not excessive. A smaller voltage difference allows for direct conduction of the branch with a smaller resistance (e.g., R / 2) to accelerate the process. Before preparing to conduct the next stage branch, the controller calculates the instantaneous rate of change of the main power bus voltage. Based on the magnitude of this rate of change, it dynamically adjusts the time interval between stage conductions. A large instantaneous rate of change indicates a rapid voltage rise and fast charging. In this case, the waiting time is extended to prevent voltage overshoot or excessive total current due to excessively fast action and current accumulation. A small instantaneous rate of change indicates a slow voltage rise. At this point, shorten the waiting time, increase the current promptly, and accelerate the pre-charging process. After each branch is turned on, immediately sample the total pre-charging current and compare it with the preset safe current value corresponding to the currently turned-on branch combination. If the sampled current continuously exceeds the safe value, it indicates that there is a deviation between the actual operating conditions and the model prediction (such as a sudden reduction in load). The system will immediately shut down the last turned-on branch and return to the safer current level of the previous stage, thus forming a fast negative feedback protection loop. Throughout the pre-charging process, the system continuously monitors the second real-time voltage difference. The completion of pre-charging is marked by the second real-time voltage difference dropping below the second safe threshold. The second safety threshold is a threshold lower than the second real-time voltage difference. Its setting primarily considers that the voltage drop across the tiny on-resistance of the main solid-state switch when fully turned on is insufficient to cause a damaging circulating current. When the second real-time voltage difference is less than the second safety threshold, the pre-charging phase is complete, and the system sends a signal allowing the main solid-state switch to turn on. Dynamic thresholds and current closed-loop protection ensure that inrush currents are strictly limited within safe limits. Adaptive timing control and branch selection strategies based on the initial voltage difference avoid unnecessary waiting, ensuring that the pre-charging process always proceeds at the optimal speed while maintaining safety. Through dynamic safety thresholds, adjustable current limiting networks, and adaptive timing control, the aforementioned problems are solved, achieving a safe, fast, and adaptive pre-charging process.

[0019] The main switch switching phase includes: in response to the second real-time voltage difference being lower than the second safety threshold, sending a turn-on command to the main solid-state switch connected to the supercapacitor module; after confirming that the main solid-state switch is fully turned on, initiating an overlapping conduction period, during which the pre-charging circuit is maintained in a conducting state, such that the main solid-state switch and the pre-charging circuit form two parallel conductive paths, during which the load current is shared by the low-resistance path of the main solid-state switch and the current-limiting path of the pre-charging circuit, and the current is automatically distributed according to the ratio of their conduction impedances; after the overlapping conduction period ends, sending a turn-off command to all the turned-on resistor-switch branches; and sending a turn-off command to the solid-state switch connected to the main power supply. During the overlapping conduction period, a graded shutdown operation is also performed on the pre-charge circuit, specifically as follows: at the end of the first sub-period after the start of the overlapping conduction period, a shutdown drive signal is applied to the resistor-switch branch with the smallest resistance value in the pre-charge circuit; at the end of the second sub-period after the start of the overlapping conduction period, shutdown drive signals are applied to all remaining resistor-switch branches in the pre-charge circuit; wherein the end of the second sub-period coincides with the end of the overlapping conduction period; Specifically, the overlapping conduction period is initiated by triggering a timer with a fixed delay at the same time as applying a conduction drive signal to the main solid-state switch. The preset duration of the overlapping conduction period is greater than the sum of the conduction delay time and rise time specified in the main solid-state switch datasheet. Within a controlled time period (overlapping conduction period), a parallel physical structure consisting of switches and resistors is constructed and maintained, which is achieved through precise timing control and specific circuit structure operation. For example, by limiting the minimum length of the overlap conduction period, sufficient time is ensured for current transfer to complete; by using graded shutdown, a large current step is decomposed into two small steps, enabling a seamless and smooth transition from the pre-charging state to the main circuit power supply state, reducing voltage drops or current oscillations during the switching process, thus achieving smooth switching between the main power supply and the supercapacitor module power supply path and improving the stability of the current during the switching process. The "overlap conduction period" is introduced, where the pre-charging circuit is not immediately turned off after the main solid-state switch is turned on, but the two are connected in parallel to supply power, allowing the load current to automatically and smoothly transfer according to the impedance ratio, reducing the instability of power supply caused by the switching dead zone. During the overlap conduction period, the pre-charging circuit is subjected to a "graded shutdown" operation, first turning off the branch with the largest current and the smallest resistance, and then turning off the remaining branches, decomposing the exit process of the pre-charging circuit from a large current step into two small steps, effectively suppressing the current surge and voltage disturbance during shutdown. Specifically, after confirming the second real-time voltage difference Below the second safety threshold Then, a turn-on command is first sent to the main solid-state switch connected to the supercapacitor module. After confirming that the main solid-state switch connected to the supercapacitor module is fully turned on (for example, by monitoring that its gate drive voltage reaches a standard high level, or after a fixed delay sufficient to ensure its full turn-on), a preset duration of overlapped turn-on period is initiated. ), instead of immediately shutting off the pre-charge circuit; during this overlapping conduction period ( During the overlapping conduction period, all branches of the pre-charge circuit remain in the conducting state. At this time, the circuit forms two parallel paths from the supercapacitor to the load: one is the main solid-state switch path connecting the supercapacitor module, and the other is a high-impedance current-limiting path (pre-charge circuit). According to Ohm's law, the load current will be automatically distributed according to the impedance ratio of these two paths. Since the on-resistance (R_DS(on)) of the low-impedance main path is much smaller than the equivalent resistance of the pre-charge circuit, most of the load current will naturally and smoothly transfer to the low-impedance main path. The current in the pre-charge circuit will decrease accordingly. During the overlapping conduction period, not all pre-charge branches are turned off at once, but a fine-grained step turn-off is performed to minimize the current step. After the start of the overlapping conduction period, after a first sub-period (T1), a turn-off drive signal is sent to the branch with the smallest resistance in the pre-charge circuit (such as the R / 4 branch). Assuming that the total current of the pre-charge circuit is 2A at this time, the R / 4 branch with the smallest resistance carries a current of about 1.5A. Turning off this branch means the total pre-charge current jumps from 2A to 0.5A. This is a controlled, known current step, much smaller than the 2A step produced by turning off the entire pre-charge circuit at once, significantly reducing the impact on the system. After the start of the overlapped conduction period, through a second sub-period (T2), the system sends a turn-off drive signal to all remaining branches in the pre-charge circuit (such as branches R and R / 2). At this time, the end of the second sub-period T2 coincides with the entire overlapped conduction period. The endpoints coincide, and after completion, the remaining branches (R and R / 2) carry only 0.5A of current. Turning them off at this point results in a very small current change (0.5A drops to 0), and the resulting voltage disturbance is negligible. At this point, the load current is 100% supplied through the main solid-state switch connected to the supercapacitor module, and the switching is complete. In the above process, the timing of sending the turn-off command to the solid-state switch connected to the main power supply (hereinafter referred to as S1) can be before, during, or after the start of the overlapping conduction period. A preferred approach is to turn off the solid-state switch connected to the main power supply after confirming that the main solid-state switch connected to the supercapacitor module is fully turned on (i.e., at the start of the overlap conduction period). This is because the load power supply is now jointly guaranteed by the main solid-state switch connected to the supercapacitor module and the pre-charge circuit. Turning off the solid-state switch connected to the main power supply ensures system isolation from a failed main power supply. The existence of the overlap conduction period ensures that at least one path supplies power to the load at any given time, completely eliminating the risk of voltage dips. The tiered shutdown operation decomposes the pre-charge circuit's exit process from a large current step into "a medium step + a small step," maximally suppressing the rate of change of current (di / dt) and the resulting voltage noise and electromagnetic interference. The remaining branch roads For example: The main solid-state switch connected to the supercapacitor module is turned on, and all pre-charge branches are turned on. Current begins to automatically transfer to the main solid-state switch connected to the supercapacitor module; at time T1: branch R / 4 is turned off. The total pre-charge current experiences a "moderate, controlled" decrease, at time T2 ( ): Turn off branches R and R / 2. The total precharge current experiences a “tiny” drop to zero, a “two-step” drop, which is much smoother than a direct “jump” from a certain current value to zero.

[0020] When the main power supply voltage drops below a preset threshold (e.g., 8V), the automatic power switching circuit immediately activates, cutting off the main power supply path and seamlessly switching the power source to the supercapacitor module. Simultaneously, its internal boost DC-DC converter activates, stabilizing the voltage fluctuations during supercapacitor module discharge (e.g., from 5.5V to 2.5V) to 9V, continuously powering the motor of the electronic lock drive module. The main controller (MCU) is connected to the boost chip and the electronic lock drive module, receiving unlocking signals (such as from the door handle microswitch, remote key, or the car's CAN signal) and controlling the motor's rotation direction and timing. The voltage monitoring circuit monitors the terminal voltage of the supercapacitor module in real time.

[0021] S3: In emergency power supply mode, in response to the unlocking request signal, obtain the current remaining energy status of the supercapacitor module; compare the current remaining energy status with the preset unlocking energy threshold, and perform unlocking operation on the electronic lock corresponding to the current remaining energy that meets the unlocking conditions; In emergency power supply mode, in response to an unlocking request signal, the following steps are taken: First, the current remaining energy state of the supercapacitor module is obtained. Then, the current remaining energy state is compared with a preset unlocking energy threshold. For electronic locks with the current remaining energy that meet the unlocking conditions, the unlocking operation is performed: Second, the real-time terminal voltage of the supercapacitor module is monitored as the current remaining energy state. Third, the real-time terminal voltage is compared with a preset voltage threshold, which is the unlocking energy threshold. If the real-time terminal voltage is higher than or equal to the preset voltage threshold, the unlocking conditions are met. If the unlocking conditions are not met, an insufficient energy alarm signal is generated and sent. Finally, the sending of unlocking commands to the electronic lock drive circuit is prohibited. Specifically, generating and sending an insufficient energy alarm signal includes at least one of the following methods: controlling an indicator light to flash in a preset alarm mode; controlling a buzzer to emit an alarm sound; sending alarm information to a designated terminal device via a wireless communication module; after performing the unlocking operation, it also includes: re-acquiring the remaining energy status of the supercapacitor module after unlocking; determining, based on the remaining energy status after unlocking, whether it can still meet at least one subsequent unlocking operation, and updating the system status indication accordingly. In emergency power supply mode, when responding to an unlocking request, the current remaining energy status of the supercapacitor (such as terminal voltage) will be acquired first and compared with the energy threshold required for unlocking. The unlocking operation will only be performed if sufficient energy is confirmed; otherwise, unlocking will be prohibited and an alarm will be issued. This reduces the "half-action" phenomenon (such as lock tongue jamming) caused by insufficient energy and improves the certainty and success rate of each operation.

[0022] An emergency power supply system for vehicle electronic door locks based on supercapacitors, applied to the emergency power supply method for vehicle electronic door locks based on supercapacitors as described in any one of the above, comprising: A capacitor module charging module is used to charge a supercapacitor module using an adaptive multi-stage charging strategy when the main power supply is normal. The adaptive multi-stage charging strategy includes at least a constant current charging stage and a constant voltage charging stage, and dynamically adjusts the charging parameters according to the real-time status parameters of the supercapacitor module. The power switching module is used to determine that the main power supply has failed when the main power supply voltage is detected to be lower than the failure threshold for a first preset time, and to perform a power switching operation within a preset switching delay to switch the power supply of the load from the main power supply to the supercapacitor module. The power switching operation includes a pre-charging stage and a main switch switching stage. The unlocking control module is used to respond to an unlocking request signal in emergency power supply mode, obtain the current remaining energy status of the supercapacitor module, compare the current remaining energy status with a preset unlocking energy threshold, and perform an unlocking operation on the electronic lock corresponding to the current remaining energy that meets the unlocking conditions.

[0023] Charging and Ready Phase: When the vehicle's main power supply is normal, the main power supply charges the supercapacitor module through the boost chip until it reaches full charge; the system is in a low-power monitoring state.

[0024] Power Fault Detection and Automatic Switching Phase: The boost chip continuously monitors the main power supply voltage. When the main power supply voltage is detected to be lower than the preset fault threshold, the boost chip automatically executes the switching logic, disconnects the main power supply, and instantly connects the path from the supercapacitor module to the boost DC-DC converter.

[0025] Emergency Unlocking Control and Energy Management Phase (Software Control Core): The main controller (MCU) receives a valid unlocking request signal. The MCU reads the current voltage value of the supercapacitor through the voltage monitoring circuit and estimates the remaining energy. Energy Decision Logic: The MCU compares the estimated remaining energy with the minimum energy threshold required for a single unlocking operation. If the remaining energy is sufficient, the MCU sends a drive signal to the electronic lock drive module to control the motor to perform an unlocking operation. If the remaining energy is lower than the single unlocking threshold, the MCU sends a "low power, unable to unlock" warning signal to the user through the vehicle network (such as CAN bus) or indicator lights to avoid ineffective motor stalling and save the last bit of energy for other critical functions (such as hazard lights). Unlocking Count and Status Recording: The MCU records the number of unlocking operations in emergency situations in non-volatile memory (EEPROM or Flash).

[0026] Assume a vehicle's electronic door lock includes a 12V vehicle battery (main power supply), a boost chip with integrated automatic switching function, and a two-cell... The system consists of a 5.4V / 50F module composed of supercapacitors connected in series, a main controller, and a 9V-16V DC motor.

[0027] Supercapacitor Capacity Calculation Verification: Single unlocking operation: motor operating current approximately 1A, operating time 0.5 seconds, operating voltage 9V.

[0028] Single energy demand (joule).

[0029] Total energy requirement for 5 unlocking attempts .

[0030] Considering the efficiency of the boost circuit (assuming...) ), and the depth of capacitor discharge (from 5.4V to 2.5V), the energy the capacitor needs to store. .

[0031] Supercapacitor energy storage formula: .

[0032] Substitute: .

[0033] Calculation yields Therefore, a 50F capacitor module is selected to meet the energy requirement of "5 unlocking cycles," and combined with the self-discharge characteristics of the capacitor, the energy reserve can be guaranteed for 24 hours.

[0034] Under normal conditions, the 12V power supply charges the supercapacitor to 5.4V via a boost chip. When a collision causes a power outage on the 12V supply, the boost chip detects the input loss, immediately switches to capacitor power supply mode, and boosts the capacitor voltage to 9V. At this point, if a passenger presses the door unlock button, the MCU detects the signal, checks the capacitor voltage (e.g., 4.8V), calculates sufficient remaining energy, and drives the motor to unlock, recording the unlock count as 1 in the EEPROM. This process can be repeated up to 5 times. The supercapacitor has a long charge-discharge cycle life, far exceeding the vehicle's lifespan, eliminating the need for replacement. It also has a wide temperature range and no risk of combustion or explosion, making it particularly suitable for the harsh automotive environment. A dedicated boost chip stably boosts the wide voltage range of the supercapacitor during discharge to the 9V required by the motor, ensuring consistent unlocking force and speed, and preventing unlocking failures due to voltage drops. Utilizing the boost chip's built-in power path management function, the switching speed is fast (microseconds), requiring no software intervention, ensuring the system's instantaneous response capability during power interruptions. By estimating and making decisions based on remaining energy through software, the system ensures a sufficient number of unlocking attempts while avoiding ineffective operations before energy depletion. It also provides clear status feedback to the user, enhancing system intelligence and user experience. The supercapacitor's self-discharge rate is far lower than that of a battery, allowing it to retain most of its charge even after long-term vehicle parking, ensuring availability in emergencies and meeting the stringent requirement of "a minimum of 5 unlocking attempts within 24 hours."

[0035] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An ultracapacitor-based emergency power supply method for a vehicle electronic door lock, characterized by, The method comprises the following steps: When the main power supply is normal, the super capacitor module is charged by using an adaptive multi-stage charging strategy, the adaptive multi-stage charging strategy at least comprises a constant current charging stage and a constant voltage charging stage, and charging parameters are dynamically adjusted according to real-time state parameters of the super capacitor module; When it is monitored that the main power supply voltage is lower than a failure threshold value and lasts for a first preset time, it is determined that the main power supply fails, and within a preset switching delay, a power supply switching operation is performed to switch the power supply of the load from the main power supply to the super capacitor module, wherein the power supply switching operation comprises a pre-charging stage and a main switch switching stage; In the emergency power supply state, in response to an unlocking request signal, the current residual energy state of the super capacitor module is obtained; The current residual energy state is compared with a preset unlocking energy threshold value, and the electronic lock corresponding to the current residual energy that meets the unlocking condition is unlocked.

2. The supercapacitor-based emergency power supply method for a vehicle electronic door lock according to claim 1, characterized by: The step of dynamically adjusting the charging parameters according to the real-time state parameters of the super capacitor module comprises: The total voltage, charging current and temperature of the super capacitor module are collected in real time; the current health state of the super capacitor module is calculated based on the total voltage and charging current; The current value of the constant current charging stage and the voltage value of the constant voltage charging stage are dynamically adjusted according to the current health state and temperature, wherein when the current health state is lower than a first threshold value or the temperature is higher than a second threshold value, the constant current charging current and the constant voltage charging voltage are reduced.

3. The supercapacitor-based emergency power supply method for a vehicle electronic door lock according to claim 1, characterized by: The step of determining that the main power supply fails when it is monitored that the main power supply voltage is lower than a failure threshold value and lasts for a first preset time comprises: The voltage of the main power supply is continuously sampled to obtain a series of voltage sampling values; Each voltage sampling value is compared with a preset failure voltage threshold value; When a single voltage sampling value is lower than the failure voltage threshold value, a first timer is started or reset and starts timing; The sampling and comparison operations are continuously performed, and when the cumulative timing time of the first timer reaches a first preset time, a confirmation signal of the main power supply failure is generated, and if there is a voltage sampling value higher than the failure voltage threshold value before the first timer reaches the first preset time, the first timer is reset.

4. The supercapacitor-based emergency power supply method for vehicle electronic door lock according to claim 1, characterized in that: The pre-charging stage comprises: A first real-time voltage difference between the main power supply bus voltage and the super capacitor module output voltage is detected; it is judged whether the first real-time voltage difference is greater than a first safety threshold value; if yes, a pre-charging circuit is started; the pre-charging circuit comprises an adjustable current limiting network connected in parallel with the main solid-state switch, the adjustable current limiting network is composed of n parallel resistance-switch branches, n≥2, and the resistance values of the branches follow a preset decreasing relationship; Based on the value of the first real-time voltage difference, the number of pre-charging branch stages to be started is determined, and the corresponding resistance-switch branches are sequentially turned on, so that the pre-charging current increases in a discrete step-by-step manner; A second real-time voltage difference between the main power supply bus voltage and the super capacitor module output voltage is continuously monitored, and when the second real-time voltage difference drops below a second safety threshold value, the pre-charging stage is completed; the second safety threshold value is lower than the first safety threshold value.

5. The supercapacitor-based emergency power supply method for vehicle electronic door lock according to claim 4, characterized in that: The step of sequentially turning on the corresponding resistance-switching branch includes: Before turning on the next branch, calculate the instantaneous rate of change of the main power bus voltage; According to the size of the instantaneous rate of change, dynamically adjust the time interval between the current branch and the next branch turning on operation; wherein the instantaneous rate of change and the time interval are in a positive correlation, and after each branch is turned on, the current total pre-charging current is sampled; Compare the sampled current value with the preset current safety value corresponding to the current combination of the turned-on branches; if the sampled current value continuously exceeds the preset current safety value, turn off the last turned-on branch.

6. The supercapacitor-based emergency power supply method for a vehicle electronic door lock according to claim 1, characterized by: The main switch switching stage includes: In response to the second real-time voltage difference being lower than the second safety threshold, send a turn-on instruction to the main solid-state switch connected to the super capacitor module; After confirming that the main solid-state switch is completely turned on, start an overlapping conduction period; During the overlapping conduction period, the conduction state of the pre-charging circuit is maintained, so that the main solid-state switch and the pre-charging circuit form two parallel conduction paths, during which the load current is shared by the low-resistance path of the main solid-state switch and the current-limiting path of the pre-charging circuit, and the current is automatically distributed according to the conduction impedance ratio of the two; After the overlapping conduction period ends, send a turn-off instruction to all the resistance-switching branches that have been turned on; send a turn-off instruction to the solid-state switch connected to the main power supply.

7. The supercapacitor-based emergency power supply method for a vehicle electronic door lock according to claim 6, characterized by: During the overlapping conduction period, the pre-charging circuit also performs a hierarchical turn-off operation, specifically as follows: At the end of the first sub-period after the start of the overlapping conduction period, a turn-off driving signal is applied to the resistance-switching branch with the smallest resistance in the pre-charging circuit; At the end of the second sub-period after the start of the overlapping conduction period, a turn-off driving signal is applied to all the remaining resistance-switching branches in the pre-charging circuit, wherein the end of the second sub-period coincides with the end of the overlapping conduction period.

8. The supercapacitor-based emergency power supply method for a vehicle electronic door lock according to claim 1, characterized by: In the emergency power supply state, in response to an unlocking request signal, the current residual energy state of the super capacitor module is obtained; The step of comparing the current residual energy state with the preset unlocking energy threshold to perform an unlocking operation on the electronic lock that meets the unlocking condition includes: Monitor the real-time terminal voltage of the super capacitor module as the current residual energy state; Compare the real-time terminal voltage with the preset voltage threshold as the unlocking energy threshold, If the real-time terminal voltage is higher than or equal to the preset voltage threshold, it is determined that the unlocking condition is met; If the judgment result is that the unlocking condition is not met, an energy shortage alarm signal is generated and sent; and an unlocking instruction is prohibited from being sent to the electronic lock driving circuit.

9. An emergency power supply system for a supercapacitor-based vehicle electronic door lock, applied to the supercapacitor-based vehicle electronic door lock emergency power supply method according to any one of claims 1-8, characterized in that, It includes: The capacitor module charging module is used to charge the super capacitor module with an adaptive multi-stage charging strategy when the main power supply is normal, and the adaptive multi-stage charging strategy at least includes a constant current charging stage and a constant voltage charging stage, and dynamically adjusts the charging parameters according to the real-time state parameters of the super capacitor module; The power switching module is used for determining that the main power supply is failed when it is monitored that the main power supply voltage is lower than a failure threshold and lasts for a first preset time, and performing a power switching operation within a preset switching delay to switch the power supply of the load from the main power supply to the super capacitor module, wherein the power switching operation comprises a pre-charging phase and a main switch switching phase. The unlocking control module is used for, in the emergency power supply state, acquiring a current residual energy state of the super capacitor module in response to an unlocking request signal; comparing the current residual energy state with a preset unlocking energy threshold, and performing an unlocking operation on the electronic lock corresponding to the current residual energy satisfying an unlocking condition.

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