A dynamic short circuit protection method and device for a vehicle door lock collision unlocking driving circuit

Abstract

The application discloses a dynamic short-circuit protection method and device for a vehicle door lock collision unlocking driving circuit, and relates to the technical field of vehicle collision safety. The method collects the temperature of a backup power supply module and the power supply voltage of a collision power supply module through a parameter acquisition module, determines an initial current threshold value and a basic filtering time according to the temperature and a preset corresponding relation table, judges whether the power supply voltage is within a preset range and corrects the power supply voltage to obtain a target current threshold value and a target filtering time, configures the target parameters to a driving controller, and the driving controller detects the current of a door lock motor driving circuit in real time. When the current exceeds the target current threshold value and the duration exceeds the target filtering time, the corresponding power switch is turned off. The method realizes adaptive matching of protection parameters and actual working conditions, can avoid false triggering at low temperature, improves protection sensitivity at high temperature and voltage anomaly, prevents damage of the backup power supply caused by over-discharge, and significantly improves the safety performance of the collision unlocking system.

Description

Technical Field

[0001] This invention relates to the field of vehicle collision safety technology, specifically to a dynamic short-circuit protection method and device for a door lock collision unlocking drive circuit. Background Technology

[0002] After a vehicle collision, the door locks need to unlock quickly to allow occupants to escape or for rescuers to provide assistance. To ensure that the doors can unlock reliably after a collision, modern vehicles are generally equipped with a collision power module (CPM), which uses a backup power source such as a supercapacitor to continuously supply power to the door lock motor drive circuit when the main power source fails.

[0003] The door lock motor drive circuit is susceptible to short circuits during operation. If a short circuit occurs and is not promptly disconnected, it can lead to excessive discharge or even damage of the backup power supply, thus affecting the reliability of the collision unlocking function. Therefore, short-circuit protection must be implemented for the door lock motor drive circuit.

[0004] In existing technologies, short-circuit protection typically uses fixed current thresholds and filtering times as protection parameters. However, the collision unlocking drive circuit is powered by a supercapacitor module, and the equivalent series resistance (ESR) of the supercapacitor is extremely sensitive to ambient temperature: at low temperatures, the ESR increases significantly, resulting in a higher peak inrush current at the moment the door lock motor starts; at high temperatures, the ESR decreases, reducing the circuit impedance during a short circuit and causing a steeper rise in the short-circuit current. If a fixed protection threshold is used, a low threshold at low temperatures can easily trigger the protection during normal motor startup, while a high threshold or a long filtering time at high temperatures can lead to delayed protection response, causing the backup power supply to be over-discharged and damaged in a very short time. Furthermore, when the power supply voltage is abnormal, the operating current and short-circuit current characteristics of the drive circuit will also shift, making it impossible for a fixed threshold to simultaneously meet the dual requirements of preventing false triggering and providing timely protection. Summary of the Invention

[0005] The technical problem this invention aims to solve is that the collision unlocking drive circuit is powered by a supercapacitor module. The ESR of the supercapacitor varies significantly with temperature, resulting in large differences in the normal starting current and short-circuit current characteristics of the drive circuit at different temperatures. Simultaneously, abnormal power supply voltage further affects the circuit current characteristics. Existing short-circuit protection schemes use fixed current thresholds and filtering times, which cannot simultaneously adapt to the dual effects of temperature changes and voltage anomalies. At low temperatures, they are prone to false triggering of protection, causing the door lock to fail to unlock after a collision. At high temperatures or with abnormal voltage, the protection response is not timely, leading to damage to the backup power supply, seriously affecting the safety and reliability of the collision unlocking system.

[0006] To address the aforementioned technical problems, this invention provides a dynamic short-circuit protection method for a vehicle door lock collision unlocking drive circuit. The method is used in a collision power module, which includes a backup power module, an MCU controller, a drive controller, and a parameter acquisition module. The drive controller integrates multiple power switches, each of which is connected to a corresponding collision unlocking actuator to form a door lock motor drive circuit. The parameter acquisition module is connected to the MCU controller. The method includes the following steps:

[0007] The temperature of the backup power module and the power supply voltage of the collision power module are collected by the parameter acquisition module. The initial current threshold and the basic filtering time are determined based on the temperature. Determine whether the power supply voltage is within the preset voltage range. If not, correct the initial current threshold and the basic filtering time to obtain the target current threshold and the target filtering time. If yes, use the initial current threshold and the basic filtering time as the target current threshold and the target filtering time, respectively. Configure the target current threshold and the target filtering time to the drive controller; The drive controller monitors the current in the door lock motor drive circuit in real time. When the current exceeds the target current threshold and the duration exceeds the target filtering time, the corresponding power switch is turned off.

[0008] Further, determining the initial current threshold and the basic filtering time based on the temperature includes, The system queries a preset correspondence table based on the real-time temperature of the backup power module to obtain the initial current threshold and basic filtering time corresponding to the real-time temperature; wherein, the preset correspondence table stores the correspondence between different temperature ranges and the pre-stored initial current threshold and pre-stored basic filtering time.

[0009] Furthermore, the correction of the initial current threshold and the basic filtering time includes, When the supply voltage is less than the preset lower voltage threshold or greater than the preset upper voltage threshold, the target current threshold is set to the product of the initial current threshold and the first preset correction coefficient, and the target filtering time is set to the product of the basic filtering time and the second preset correction coefficient, wherein both the first preset correction coefficient and the second preset correction coefficient are less than 1.

[0010] Further, determining the initial current threshold based on the temperature includes, When the temperature is less than the first temperature threshold, the pre-stored first initial current threshold is determined as the initial current threshold. When the temperature is greater than or equal to the first temperature threshold and less than the second temperature threshold, the pre-stored second initial current threshold is determined as the initial current threshold. When the temperature is greater than or equal to the second temperature threshold, the pre-stored third initial current threshold is determined as the initial current threshold; wherein the pre-stored first initial current threshold is greater than the pre-stored second initial current threshold, and the pre-stored second initial current threshold is greater than the pre-stored third initial current threshold.

[0011] Further, determining the base filtering time based on the temperature includes, When the temperature is less than the first temperature threshold, the pre-stored first basic filtering time is determined as the basic filtering time; When the temperature is greater than or equal to the first temperature threshold and less than the second temperature threshold, the pre-stored second basic filtering time is determined as the basic filtering time. When the temperature is greater than or equal to the second temperature threshold, the pre-stored third basic filtering time is determined as the basic filtering time; wherein, the pre-stored first basic filtering time is the same as the pre-stored second basic filtering time, and the pre-stored third basic filtering time is less than the pre-stored second basic filtering time.

[0012] Furthermore, the drive controller is a bridge drive chip, the power switch is a MOSFET, and configuring the target current threshold and the target filtering time to the drive controller includes: the MCU controller writes the target current threshold and the target filtering time into the protection parameter register of the bridge drive chip through an SPI or I2C communication interface.

[0013] Furthermore, turning off the corresponding power switch includes: The bridge driver chip sends a turn-off signal to the gate of the corresponding MOS transistor; The MCU controller records the corresponding fault diagnostic code and reports the fault information via the CAN bus.

[0014] The present invention also provides a dynamic short-circuit protection device for a door lock collision unlocking drive circuit, the device being used to perform the above method, the device comprising: Backup power module, used to provide backup power for the collision unlocking actuator; The parameter acquisition module is used to acquire the temperature of the backup power module and the power supply voltage of the device. The MCU controller is electrically connected to the parameter acquisition module and is used to determine the target current threshold and the target filtering time based on the temperature and the supply voltage, and to configure the target current threshold and the target filtering time to the drive controller; The drive controller is communicatively connected to the MCU controller and integrates multiple power switches. Each power switch is connected to a corresponding collision unlocking actuator to form a door lock motor drive circuit. The drive controller is used to detect the current of the door lock motor drive circuit in real time, and when the current exceeds the target current threshold and the duration exceeds the target filtering time, the corresponding power switch is turned off.

[0015] Furthermore, the collision unlocking actuator includes door lock motors for four doors and two child lock actuators, and the number of power switches integrated in the drive controller corresponds to the number of collision unlocking actuators.

[0016] Furthermore, the backup power module is a supercapacitor module.

[0017] The beneficial effects of this invention are as follows: (1) In view of the characteristics of ESR of supercapacitor changing with temperature, the initial current threshold and basic filtering time are determined independently through temperature segment lookup table mechanism: when the temperature is low, the ESR increases and the peak value of the starting impact current is high, so the current threshold is appropriately increased to avoid false triggering; when the temperature is high, the ESR decreases and the short circuit current rises faster, so the current threshold and filtering time are reduced simultaneously to speed up the protection response, ensure that the backup power supply is protected in time during short circuit, and maintain the availability of the collision unlocking function.

[0018] (2) Adopting a dual-parameter independent correction mechanism: the current threshold and the filtering time are corrected by independent first preset correction coefficient and second preset correction coefficient respectively. The two can be set to different ratios according to actual calibration requirements. Compared with single parameter correction or fixed ratio linkage correction, it can more finely adapt to the changes in current characteristics of the drive circuit under different voltage abnormality scenarios. While ensuring the timeliness of protection, it effectively avoids false triggering and achieves a dual improvement in protection accuracy and reliability.

[0019] (3) The protection parameters are dynamically configured to the hardware register of the drive controller, and the drive controller directly executes the protection action. The response speed is fast and does not depend on the MCU software cycle.

[0020] (4) Fault diagnostic code recording and CAN bus reporting mechanism facilitate vehicle fault diagnosis and after-sales maintenance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the collision power module (CPM) system architecture.

[0023] Figure 2 This is a schematic diagram of the calculation process for dynamic short-circuit protection parameters.

[0024] Figure 3 This is a schematic diagram of the complete execution process of the dynamic short-circuit protection method. Detailed Implementation

[0025] The preferred embodiments of this disclosure are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict.

[0026] The dynamic short-circuit protection device of this invention is specifically implemented as a crash power module (CPM). For example... Figure 1 As shown, CPM includes the following modules: Supercapacitor module (backup power module): When the vehicle's main power supply KL30 fails, it provides backup power to the collision unlocking actuator, ensuring the continued availability of the door lock unlocking function after a collision.

[0027] Parameter acquisition module: includes a capacitor temperature sensor and a KL30 voltage acquisition module, which are used to acquire the real-time temperature T and CPM supply voltage V of the supercapacitor module, respectively, and transmit the acquired data to the MCU controller.

[0028] MCU controller: Receives temperature and voltage data from the parameter acquisition module, executes dynamic protection parameter calculation logic, and communicates via SPI or I / O. 2 The C communication interface writes the target current threshold and target filtering time into the protection parameter register of the drive controller, and records the fault diagnosis code and reports the fault information via the CAN bus after the protection is triggered.

[0029] The drive controller (bridge driver chip TLE92108) integrates multiple MOSFETs (power switches), each connected to a corresponding collision unlocking actuator to form a door lock motor drive circuit. The drive controller monitors the current in each drive circuit in real time via current acquisition pins (CSO1 / CSO2). When the current exceeds the configured target current threshold and the duration exceeds the target filtering time, it immediately sends a turn-off signal to the gate of the corresponding MOSFET, cutting off that drive circuit.

[0030] Collision unlocking actuator: includes door lock motors for four doors and two child lock actuators, totaling six channels, each corresponding to one of the six MOSFETs in the drive controller.

[0031] like Figure 2 As shown, the MCU controller dynamically calculates the protection parameters according to the following logic: Step 1: Read the real-time temperature T collected by the capacitive temperature sensor, consult the preset correspondence table, and determine the initial current threshold and basic filtering time according to temperature segments: When T < -35℃, the initial current threshold is set to 14A and the basic filtering time is set to 50μs; when -35℃ ≤ T < 70℃, the initial current threshold is set to 12.5A and the basic filtering time is set to 50μs; when T ≥ 70℃, the initial current threshold is set to 11A and the basic filtering time is set to 40μs. These parameters reflect that: at low temperatures, the internal resistance of the supercapacitor is relatively large, resulting in a large starting inrush current; therefore, appropriately increasing the current threshold avoids false triggering; at high temperatures, appropriately decreasing the current threshold and filtering time improves protection sensitivity.

[0032] Step 2: Read the supply voltage V collected by the KL30 voltage acquisition module and determine whether it is within the normal range (10V~15V in this embodiment): If V < 10V or V > 15V, trigger independent dual-parameter correction—set the target current threshold to the product of the initial current threshold and the first preset correction coefficient, and set the target filtering time to the product of the basic filtering time and the second preset correction coefficient; the two correction coefficients are independent of each other and are both less than 1, and can be set to different proportions according to actual calibration requirements. For example, in a specific embodiment, the first preset correction coefficient is 90% (i.e., the target current threshold is reduced to 90% of the initial value), and the second preset correction coefficient is 95% (i.e., the target filtering time is reduced to 95% of the basic value); the current threshold reduction is larger to improve protection sensitivity, and the filtering time reduction is smaller to avoid excessive reduction in anti-interference capability. The independent adjustment of the two achieves fine-tuning of protection parameters. In another specific embodiment, when the protection sensitivity requirements for voltage anomalies are relatively consistent, the first preset correction coefficient and the second preset correction coefficient can be taken to have the same value, for example, both 90%. In this case, the target current threshold and the target filtering time are simultaneously reduced by 10%, which simultaneously improves the protection sensitivity under low-voltage or high-voltage anomaly scenarios, thereby simplifying calibration while ensuring protection effectiveness. If V is within the normal range, the initial current threshold and the basic filtering time are directly used as the target values ​​without correction.

[0033] Step 3: The MCU controller communicates via SPI or I... 2 The C communication interface writes the target current threshold and target filtering time into the protection parameter register of the bridge driver chip TLE92108, completing the hardware configuration update.

[0034] like Figure 3 As shown, the complete dynamic short-circuit protection execution process is as follows: (1) Real-time parameter acquisition: The parameter acquisition module continuously acquires the temperature T of the supercapacitor module and the CPM power supply voltage V. The bridge drive chip TLE92108 detects the current of each door lock motor drive circuit in real time through the current acquisition pin.

[0035] (2) Dynamic calculation of protection parameters: The MCU controller determines the basic parameters by looking up the table based on the temperature T, and then determines whether correction is needed based on the voltage V, and calculates the target current threshold and target filtering time.

[0036] (3) Update hardware configuration: The MCU controller updates the hardware configuration via SPI / I. 2 The C interface writes the target current threshold and target filtering time into the protection parameter register of the bridge driver chip TLE92108.

[0037] (4) Judgment of protection trigger: When the current of the door lock motor drive circuit is detected to be greater than the target current threshold and the duration exceeds the target filtering time, it is determined to be a short circuit fault and the protection action is triggered.

[0038] (5) Perform protection action: The bridge driver chip TLE92108 immediately sends a shutdown signal to the gate of the corresponding MOS transistor to shut down the MOS transistor, cut off the door lock motor drive circuit that has been short-circuited, and prevent the backup power supply from being damaged by continuous discharge.

[0039] (6) Fault recording and reporting: The MCU controller records the corresponding fault diagnosis code and reports the fault information to the vehicle network via the CAN bus, which facilitates fault diagnosis and after-sales maintenance.

[0040] (7) Cyclic execution: If the protection is not triggered, the system continues to perform parameter acquisition and protection judgment in a cyclic manner to maintain real-time monitoring of the drive circuit.

[0041] Through the above-mentioned dynamic short-circuit protection mechanism, the present invention achieves adaptive matching between protection parameters and actual working conditions, and can provide accurate and timely short-circuit protection under various temperature and voltage conditions, which significantly improves the safety and reliability of the collision unlocking system.

[0042] It should be understood that in the various embodiments of this document, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this document.

[0043] It should also be understood that, in the embodiments herein, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.

[0044] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this document.

[0045] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0046] In the embodiments provided herein, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, or they may be electrical, mechanical, or other forms of connection.

[0047] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments described herein, depending on actual needs.

[0048] Furthermore, the functional units in the various embodiments of this document can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0049] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this paper, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods in the various embodiments of this paper. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0050] This document uses specific embodiments to illustrate the principles and implementation methods of this document. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and core ideas of this document. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this document. Therefore, the content of this specification should not be construed as a limitation of this document.

Claims

1. A dynamic short-circuit protection method for a door lock collision unlocking drive circuit, characterized in that, The method is used for a collision power module, which includes a backup power module, an MCU controller, a drive controller, and a parameter acquisition module. The drive controller integrates multiple power switches, each of which is connected to a corresponding collision unlocking actuator to form a door lock motor drive circuit. The parameter acquisition module is connected to the MCU controller. The method includes the following steps: The temperature of the backup power module and the power supply voltage of the collision power module are collected by the parameter acquisition module. The initial current threshold and the basic filtering time are determined based on the temperature. Determine whether the power supply voltage is within the preset voltage range. If not, correct the initial current threshold and the basic filtering time to obtain the target current threshold and the target filtering time. If yes, use the initial current threshold and the basic filtering time as the target current threshold and the target filtering time, respectively. Configure the target current threshold and the target filtering time to the drive controller; The drive controller monitors the current in the door lock motor drive circuit in real time. When the current exceeds the target current threshold and the duration exceeds the target filtering time, the corresponding power switch is turned off.

2. The dynamic short-circuit protection method according to claim 1, characterized in that, The step of determining the initial current threshold and the basic filtering time based on the temperature includes, The system queries a preset correspondence table based on the real-time temperature of the backup power module to obtain the initial current threshold and basic filtering time corresponding to the real-time temperature; wherein, the preset correspondence table stores the correspondence between different temperature ranges and the pre-stored initial current threshold and pre-stored basic filtering time.

3. The dynamic short-circuit protection method according to claim 1, characterized in that, The correction of the initial current threshold and the basic filtering time includes, When the supply voltage is less than the preset lower voltage threshold or greater than the preset upper voltage threshold, the target current threshold is set to the product of the initial current threshold and the first preset correction coefficient, and the target filtering time is set to the product of the basic filtering time and the second preset correction coefficient, wherein both the first preset correction coefficient and the second preset correction coefficient are less than 1.

4. The dynamic short-circuit protection method according to claim 2, characterized in that, The step of determining the initial current threshold based on the temperature includes, When the temperature is less than the first temperature threshold, the pre-stored first initial current threshold is determined as the initial current threshold. When the temperature is greater than or equal to the first temperature threshold and less than the second temperature threshold, the pre-stored second initial current threshold is determined as the initial current threshold. When the temperature is greater than or equal to the second temperature threshold, the pre-stored third initial current threshold is determined as the initial current threshold; wherein the pre-stored first initial current threshold is greater than the pre-stored second initial current threshold, and the pre-stored second initial current threshold is greater than the pre-stored third initial current threshold.

5. The dynamic short-circuit protection method according to claim 2, characterized in that, The step of determining the basic filtering time based on the temperature includes, When the temperature is less than the first temperature threshold, the pre-stored first basic filtering time is determined as the basic filtering time; When the temperature is greater than or equal to the first temperature threshold and less than the second temperature threshold, the pre-stored second basic filtering time is determined as the basic filtering time. When the temperature is greater than or equal to the second temperature threshold, the pre-stored third basic filtering time is determined as the basic filtering time; wherein, the pre-stored first basic filtering time is the same as the pre-stored second basic filtering time, and the pre-stored third basic filtering time is less than the pre-stored second basic filtering time.

6. The dynamic short-circuit protection method according to claim 1, characterized in that, The drive controller is a bridge driver chip, the power switch is a MOSFET, and configuring the target current threshold and the target filtering time to the drive controller includes: the MCU controller via SPI or I... 2 The C communication interface writes the target current threshold and the target filtering time into the protection parameter register of the bridge driver chip.

7. The dynamic short-circuit protection method according to claim 6, characterized in that, The corresponding power switches that are turned off include: The bridge driver chip sends a turn-off signal to the gate of the corresponding MOS transistor; The MCU controller records the corresponding fault diagnostic code and reports the fault information via the CAN bus.

8. A dynamic short-circuit protection device for a door lock collision unlocking drive circuit, characterized in that, The apparatus is used to perform the method according to any one of claims 1 to 7, the apparatus comprising: Backup power module, used to provide backup power for the collision unlocking actuator; The parameter acquisition module is used to acquire the temperature of the backup power module and the power supply voltage of the device. The MCU controller is electrically connected to the parameter acquisition module and is used to determine the target current threshold and the target filtering time based on the temperature and the supply voltage, and to configure the target current threshold and the target filtering time to the drive controller; The drive controller is communicatively connected to the MCU controller and integrates multiple power switches. Each power switch is connected to a corresponding collision unlocking actuator to form a door lock motor drive circuit. The drive controller is used to detect the current of the door lock motor drive circuit in real time, and when the current exceeds the target current threshold and the duration exceeds the target filtering time, the corresponding power switch is turned off.

9. The dynamic short-circuit protection device according to claim 8, characterized in that, The collision unlocking actuator includes four door lock motors and two child lock actuators, and the number of power switches integrated in the drive controller corresponds to the number of collision unlocking actuators.

10. The dynamic short-circuit protection device according to claim 8, characterized in that, The backup power module is a supercapacitor module.

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