Airbag energy storage capacitor monitoring system and method

Abstract

The present application discloses a safety airbag energy storage capacitor monitoring system and method; it relates to the field of automobile safety technology, and monitors the voltage difference across the equivalent series resistor by monitoring the energy storage voltage of the energy storage capacitor of the safety airbag control unit when it is charged twice with a small current and a large current, and determines the equivalent series resistance value of the energy storage capacitor; determines the capacitance value of the energy storage capacitor by monitoring the change of the energy storage voltage when the energy storage capacitor is charged; monitors the connection state of the energy storage capacitor in the circuit by discharging and charging the energy storage capacitor of the safety airbag control unit and monitoring the undervoltage warning of the energy storage voltage. The monitoring function of the energy storage capacitor is realized, and the equivalent series resistance, capacitance value, and connection state of the energy storage capacitor are monitored. While ensuring the charging and discharging efficiency of the system, the reliability of the safety airbag system is improved, problems are discovered in time and repaired or replaced, and personal injury caused by airbag failure at critical moments is avoided.

Description

Technical Field

[0001] The present application relates to the field of automobile safety technology, and in particular to a safety airbag energy storage capacitor monitoring system and method. Background Art

[0002] In the airbag control unit, the energy storage capacitor affects the energy storage voltage and ignition voltage of the control unit, and has a very important impact on the reliability of the airbag.

[0003] At present, the main improvement is to improve the charging and discharging efficiency of the energy storage capacitor. For example, by increasing the discharge current of the energy storage capacitor through the energy storage capacitor discharge circuit composed of a semiconductor switch module and a resistor module, the discharge time can be reduced.

[0004] Because the size and connection of the energy storage capacitor are not monitored, when the equivalent series resistance of the energy storage capacitor is too large, its voltage drop will affect the ignition of the airbag; when the capacitance of the energy storage capacitor is too small, it cannot meet the power supply requirements of the ignition circuit; even in some environments, the energy storage capacitor cannot be effectively connected to the circuit, making the airbag control unit unable to work normally.

[0005] It can be seen that how to solve the problem of the airbag control unit not being able to work properly due to the failure to effectively monitor the energy storage capacitor is a technical problem that needs to be solved urgently by people in this field. Summary of the invention

[0006] The purpose of the present application is to provide a safety airbag energy storage capacitor monitoring system and method, so as to solve the problem that the safety airbag control unit cannot work normally due to the failure to effectively monitor the energy storage capacitor.

[0007] In order to solve the above technical problems, the present application provides an airbag energy storage capacitor monitoring system, including: an equivalent series resistance monitoring unit, a capacitance monitoring unit, a connection status monitoring unit, a charging and discharging circuit, and a controller;

[0008] The charging and discharging circuit is connected to the energy storage capacitor via an equivalent series resistor, and is used to charge and discharge the energy storage capacitor; the equivalent series resistor is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded;

[0009] The equivalent series resistance monitoring unit monitors the voltage difference across the equivalent series resistance when the energy storage capacitor is charged under two currents of different magnitudes; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor;

[0010] The controller controls the charge and discharge circuit to charge the energy storage capacitor with two currents of different sizes and start the equivalent series resistance monitoring unit to determine the resistance value of the equivalent series resistance; controls the charge and discharge circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit to determine the capacitance value of the energy storage capacitor; controls the charge and discharge circuit to discharge the energy storage capacitor and start the connection status monitoring unit to determine the connection status of the energy storage capacitor.

[0011] As an optional solution, the above-mentioned airbag energy storage capacitor monitoring system further includes: a voltage comparison unit; the voltage comparison unit includes: a first comparator, a first resistor, and a second resistor;

[0012] The first input terminal of the first comparator is connected to the reference voltage terminal, the first end of the first resistor is connected to the first end of the equivalent series resistor, and the second end of the first resistor is grounded through the second resistor; the second end of the first resistor is connected to the second input terminal of the first comparator; and the output terminal of the first comparator is connected to the controller;

[0013] The first comparator compares the voltage of the energy storage voltage terminal with the voltage of the reference voltage terminal and outputs a first comparison result. The controller is used to start the equivalent series resistance monitoring unit when the first comparison result is a high level.

[0014] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring system, the equivalent series resistance monitoring unit includes: a second comparator, a first operational amplifier, a third resistor, and a fourth resistor;

[0015] The first input terminal of the second comparator is connected to the reference voltage terminal, the first end of the third resistor is connected to the first end of the equivalent series resistor, and the second end of the third resistor is grounded through the fourth resistor; the second end of the fourth resistor is connected to the second input terminal of the second comparator; and the output terminal of the second comparator is connected to the controller;

[0016] The second end of the third resistor is connected to the non-inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier is connected to the controller; the controller determines the resistance value of the equivalent series resistor based on the voltage change output by the buffer formed by the first operational amplifier within a preset time.

[0017] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring system, the capacitance monitoring unit includes: a second operational amplifier, a fifth resistor, and a sixth resistor;

[0018] The first end of the fifth resistor is connected to the first end of the equivalent series resistor, and the second end of the fifth resistor is grounded through the sixth resistor; the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the output end of the second operational amplifier is connected to the controller, and the controller determines the capacitance of the energy storage capacitor according to the voltage change at the output end of the second operational amplifier within a preset time.

[0019] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring system, the connection status monitoring unit includes: a third comparator, a seventh resistor, and an eighth resistor;

[0020] The first input terminal of the third comparator is connected to the reference voltage terminal, the first end of the seventh resistor is connected to the first end of the equivalent series resistor, and the second end of the seventh resistor is grounded through the eighth resistor; the second end of the seventh resistor is connected to the second input terminal of the third comparator; and the output terminal of the third comparator is connected to the controller;

[0021] The controller controls the charge and discharge circuit to discharge the energy storage capacitor, and determines the connection state of the energy storage capacitor according to the output end of the third comparator.

[0022] In order to solve the above technical problems, the present application also provides a safety airbag energy storage capacitor monitoring method, which is applied to a safety airbag energy storage capacitor monitoring system, including: an equivalent series resistance monitoring unit, a capacitance monitoring unit, a connection state monitoring unit, a charging and discharging circuit, and a controller;

[0023] The charging and discharging circuit is connected to the energy storage capacitor via an equivalent series resistor, and is used to charge and discharge the energy storage capacitor; the equivalent series resistor is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded; the equivalent series resistor monitoring unit monitors the voltage difference between the two ends of the equivalent series resistor when the energy storage capacitor is charged under two currents of different magnitudes; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor; the method comprises:

[0024] Controlling the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit;

[0025] Determining the resistance value of the equivalent series resistor according to the voltage difference across the equivalent series resistor;

[0026] Controlling the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit;

[0027] Determining the capacitance of the energy storage capacitor according to the voltage change of the energy storage capacitor within a preset time;

[0028] Controlling the charging and discharging circuit to discharge the energy storage capacitor and start the connection status monitoring unit;

[0029] The connection state of the energy storage capacitor is determined according to the voltage of the energy storage capacitor.

[0030] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring method, the airbag energy storage capacitor monitoring system further includes: a voltage comparison unit; the voltage comparison unit includes: a first comparator, a first resistor, and a second resistor; the first input terminal of the first comparator is connected to the reference voltage terminal, the first end of the first resistor is connected to the first end of the equivalent series resistor, and the second end of the first resistor is grounded through the second resistor; the second end of the first resistor is connected to the second input terminal of the first comparator; the output terminal of the first comparator is connected to the controller;

[0031] Correspondingly, the controlling the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes and start the equivalent series resistance monitoring unit also includes:

[0032] receiving a first comparison result output by the first comparator;

[0033] When the first comparison result is a high level, the step of controlling the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit is entered.

[0034] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring method, the equivalent series resistance monitoring unit includes: a second comparator, a first operational amplifier, a third resistor, and a fourth resistor;

[0035] The first input terminal of the second comparator is connected to the reference voltage terminal, the first end of the third resistor is connected to the first end of the equivalent series resistor, and the second end of the third resistor is grounded through the fourth resistor; the second end of the fourth resistor is connected to the second input terminal of the second comparator; the output terminal of the second comparator is connected to the controller; the second end of the third resistor is connected to the non-inverting input terminal of the first operational amplifier, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier is connected to the controller;

[0036] Correspondingly, controlling the charge-discharge circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit includes:

[0037] Controlling the charge-discharge circuit to discharge the energy storage capacitor until a first comparison result at the output end of the first comparator is a low level;

[0038] Controlling the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes;

[0039] Receiving two test voltage values ​​output by the first operational amplifier when the energy storage capacitor is charged with two currents of different magnitudes to determine a voltage difference across the equivalent series resistor;

[0040] Correspondingly, determining the resistance value of the equivalent series resistor according to the voltage difference across the equivalent series resistor includes:

[0041] Determining the resistance value of the equivalent series resistance according to the two test voltage values;

[0042] Also includes:

[0043] When a high level signal is output from the second comparator, a warning message that the resistance value of the equivalent series resistor is too high is issued.

[0044] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring method, the capacitance monitoring unit includes: a second operational amplifier, a fifth resistor, and a sixth resistor;

[0045] The first end of the fifth resistor is connected to the first end of the equivalent series resistor, and the second end of the fifth resistor is grounded through the sixth resistor; the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the output end of the second operational amplifier is connected to the controller;

[0046] Correspondingly, controlling the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time and starting the capacitance monitoring unit includes:

[0047] Controlling the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time;

[0048] receiving a voltage at an output terminal of the second operational amplifier and determining a rate of change of the voltage at the output terminal of the second operational amplifier;

[0049] Correspondingly, determining the capacitance of the energy storage capacitor according to the voltage change of the energy storage capacitor within a preset time includes:

[0050] The capacitance of the energy storage capacitor is determined according to the current value of the constant current and the voltage change rate.

[0051] As an optional solution, in the above-mentioned airbag energy storage capacitor monitoring method, the connection status monitoring unit includes: a third comparator, a seventh resistor, and an eighth resistor;

[0052] The first input terminal of the third comparator is connected to the reference voltage terminal, the first end of the seventh resistor is connected to the first end of the equivalent series resistor, and the second end of the seventh resistor is grounded through the eighth resistor; the second end of the seventh resistor is connected to the second input terminal of the third comparator; and the output terminal of the third comparator is connected to the controller;

[0053] Correspondingly, controlling the charging and discharging circuit to discharge the energy storage capacitor and starting the connection status monitoring unit includes:

[0054] Controlling the charge and discharge circuit to discharge the energy storage capacitor;

[0055] Receiving a level signal from an output terminal of the third comparator;

[0056] Correspondingly, determining the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor includes:

[0057] Determining whether the level signal is a low level signal;

[0058] If yes, it is determined that the connection state of the energy storage capacitor is normal;

[0059] If not, it is determined that the connection state of the energy storage capacitor is abnormal.

[0060] The airbag energy storage capacitor monitoring system provided by the present application includes: an equivalent series resistance monitoring unit, a capacitance monitoring unit, a connection state monitoring unit, a charging and discharging circuit, and a controller; the charging and discharging circuit is connected to the energy storage capacitor through an equivalent series resistance, and is used to charge and discharge the energy storage capacitor; the equivalent series resistance is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded; the equivalent series resistance monitoring unit monitors the voltage difference between the two ends of the equivalent series resistance when the energy storage capacitor is charged under two currents of different magnitudes; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor; the controller controls the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes and start the equivalent series resistance monitoring unit to determine the resistance value of the equivalent series resistance; controls the charging and discharging circuit to charge the energy storage capacitor with a constant current and start the capacitance monitoring unit to determine the capacitance value of the energy storage capacitor; controls the charging and discharging circuit to discharge the energy storage capacitor and start the connection state monitoring unit to determine the connection state of the energy storage capacitor. This application monitors the voltage difference across the equivalent series resistor by monitoring the energy storage voltage when the energy storage capacitor of the airbag control unit is charged twice with a small current and a large current, thereby achieving the purpose of monitoring the equivalent series resistance of the energy storage capacitor; by monitoring the change of the energy storage voltage when the energy storage capacitor of the airbag control unit is charged, thereby achieving the purpose of monitoring the capacitance of the energy storage capacitor; by cyclically discharging and charging the energy storage capacitor of the airbag control unit, monitoring the undervoltage warning of the energy storage voltage, and monitoring the connection status of the energy storage capacitor in the circuit. This application realizes the monitoring function of the energy storage capacitor, monitors the equivalent series resistance, capacitance value and connection status of the energy storage capacitor, and improves the reliability of the airbag system while ensuring the charging and discharging efficiency of the system. By monitoring the resistance, capacitance value and connection status, problems can be discovered in time and repaired or replaced, avoiding personal injury caused by airbag failure at critical moments.

[0061] In addition, the present application also provides an airbag energy storage capacitor monitoring method, which corresponds to the above-mentioned airbag energy storage capacitor monitoring system and has the same effect as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0063] Figure 1 A schematic diagram of an airbag energy storage capacitor monitoring system is provided for this application;

[0064] Figure 2A schematic diagram of a voltage comparison unit provided in an embodiment of the present application;

[0065] FIG. 3 (a) and FIG. 3 (b) are partial schematic diagrams of an equivalent series resistance monitoring unit provided in an embodiment of the present application;

[0066] FIG. 4 (a) and FIG. 4 (b) are another partial schematic diagrams of an equivalent series resistance monitoring unit provided in an embodiment of the present application;

[0067] Figure 5 A circuit diagram of a capacitance monitoring unit provided in an embodiment of the present application;

[0068] Figure 6 A circuit diagram of a connection status monitoring unit provided in an embodiment of the present application;

[0069] Figure 7 A flow chart of a method for monitoring an airbag energy storage capacitor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0070] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0071] The core of this application is to provide an airbag energy storage capacitor monitoring system and method.

[0072] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0073] In order to solve the above problems, the present application provides an airbag energy storage capacitor monitoring system. Figure 1 A schematic diagram of an airbag energy storage capacitor monitoring system is provided for this application, such as Figure 1 As shown, it includes: an equivalent series resistance monitoring unit 11, a capacitance monitoring unit 12, a connection state monitoring unit 13, a charge and discharge circuit, and a controller 14;

[0074] The charging and discharging circuit is connected through the equivalent series resistance ESR and the energy storage capacitor C sto The equivalent series resistor is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded;

[0075] The equivalent series resistance monitoring unit monitors the voltage difference across the equivalent series resistance when the energy storage capacitor is charged under two currents of different magnitudes; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection status monitoring unit is used to monitor the connection status of the energy storage capacitor according to the voltage of the energy storage capacitor;

[0076] The controller controls the charge and discharge circuit to charge the energy storage capacitor with two currents of different sizes and start the equivalent series resistance monitoring unit to determine the resistance value of the equivalent series resistance; controls the charge and discharge circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit to determine the capacitance value of the energy storage capacitor; controls the charge and discharge circuit to discharge the energy storage capacitor and start the connection status monitoring unit to determine the connection status of the energy storage capacitor.

[0077] The charge and discharge circuit is designed to be able to charge and discharge the energy storage capacitor. This embodiment does not limit the specific circuit structure. It is connected to the energy storage capacitor through an equivalent series resistor, the equivalent series resistor is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded. It should be noted that the charge and discharge circuit is designed to be able to adjust the current size to meet different monitoring requirements. Figure 2 In FIG. 1 , the charge and discharge circuit is represented by a biased current source Vb.

[0078] The equivalent series resistance monitoring unit is responsible for monitoring the voltage difference across the equivalent series resistance, which is the key to determining the ESR resistance value. The resistance value of the equivalent series resistance is determined by the change in the voltage difference. The equivalent series resistance monitoring unit can use a high-precision voltage sensor to monitor the voltage difference across the equivalent series resistance.

[0079] The capacitance monitoring unit monitors the voltage change of the energy storage capacitor and determines the actual capacitance of the energy storage capacitor by monitoring the voltage change of the energy storage capacitor within a preset time. The capacitance monitoring unit can use an analog-to-digital converter (ADC) to monitor the voltage change of the energy storage capacitor.

[0080] The connection status monitoring unit determines the connection status of the energy storage capacitor by the voltage change of the energy storage capacitor, ensuring that the energy storage capacitor is correctly connected to the circuit. The connection status monitoring unit can determine the connection status by monitoring the voltage drop rate of the energy storage capacitor during the discharge process.

[0081] The controller is responsible for controlling the operation of the charge and discharge circuit, and starts the corresponding monitoring unit for monitoring, and processes the monitoring data. Specifically, the controller uses a microprocessor to realize automatic control and data processing.

[0082] The airbag energy storage capacitor monitoring system provided by the embodiment of the present application includes: an equivalent series resistance monitoring unit, a capacitance monitoring unit, a connection state monitoring unit, a charging and discharging circuit, and a controller; the charging and discharging circuit is connected to the energy storage capacitor through an equivalent series resistance, and is used to charge and discharge the energy storage capacitor; the equivalent series resistance is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded; the equivalent series resistance monitoring unit monitors the voltage difference across the equivalent series resistance; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor; the controller controls the charging and discharging circuit to charge the energy storage capacitor with two currents of different sizes and start the equivalent series resistance monitoring unit to determine the resistance value of the equivalent series resistance; controls the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit to determine the capacitance value of the energy storage capacitor; controls the charging and discharging circuit to discharge the energy storage capacitor and start the connection state monitoring unit to determine the connection state of the energy storage capacitor. This application monitors the voltage difference across the equivalent series resistor by monitoring the energy storage voltage when the energy storage capacitor of the airbag control unit is charged twice with a small current and a large current, thereby achieving the purpose of monitoring the equivalent series resistance of the energy storage capacitor; by monitoring the change of the energy storage voltage when the energy storage capacitor of the airbag control unit is charged, thereby achieving the purpose of monitoring the capacitance of the energy storage capacitor; by cyclically discharging and charging the energy storage capacitor of the airbag control unit, monitoring the undervoltage warning of the energy storage voltage, and monitoring the connection status of the energy storage capacitor in the circuit. This application realizes the monitoring function of the energy storage capacitor, monitors the equivalent series resistance, capacitance value and connection status of the energy storage capacitor, and improves the reliability of the airbag system while ensuring the charging and discharging efficiency of the system. By monitoring the resistance, capacitance value and connection status, problems can be discovered in time and repaired or replaced, avoiding personal injury caused by airbag failure at critical moments.

[0083] According to the above embodiment, in a specific embodiment, the above airbag energy storage capacitor monitoring system further includes: a voltage comparison unit; Figure 2 A schematic diagram of a voltage comparison unit provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the voltage comparison unit includes: a first comparator D1, a first resistor R1, and a second resistor R2;

[0084] The first input terminal of the first comparator is connected to the reference voltage terminal Vref_bist, the first end of the first resistor is connected to the first end (Vsto end) of the equivalent series resistor, and the second end of the first resistor is grounded through the second resistor; the second end of the first resistor is connected to the second input terminal of the first comparator; the output terminal Vsto_bist of the first comparator is connected to the controller;

[0085] The first comparator compares the voltage of the energy storage voltage terminal with the voltage of the reference voltage terminal and outputs a first comparison result. The controller is used to start the equivalent series resistance monitoring unit when the first comparison result is a high level.

[0086] The first comparator is used to compare two voltage values ​​and output a high level or low level signal. The accuracy of voltage comparison is ensured by selecting a high-precision comparator chip.

[0087] The first resistor is connected to the first end of the equivalent series resistor and the second input end of the first comparator, and is used to adjust the threshold of the voltage comparison. The second resistor is connected to the second end of the first resistor and is grounded through it, and can be used for voltage division to further adjust the threshold of the voltage comparison.

[0088] The resistance values ​​of the first resistor and the second resistor are selected according to the actual application environment requirements, and suitable resistance values ​​are selected to adapt to the voltage range of the reference voltage and the equivalent series resistance.

[0089] The voltage across the equivalent series resistor is compared with the reference voltage through the first comparator to determine whether the preset voltage threshold is reached. The output end of the first comparator is connected to the controller to transmit the comparison result to the controller. In this embodiment, the energy storage voltage end (Vsto end) of the airbag control unit is compared with the voltage of the Vref_bist end through the first comparator D1. When the voltage of the Vsto end is not lower than Vref_bist / k bist1 When (k bist1 The output terminal Vsto_bist of the first comparator D1 (representing the voltage division ratio of the voltage comparison unit) will become a high level, and at this time, the next step of monitoring can be started.

[0090] in, .

[0091] Ensure that the system is in a safe and preset state before charging and discharging operations, increasing the safety of the entire monitoring system.

[0092] According to the above embodiment, in a specific embodiment, the above-mentioned airbag energy storage capacitor monitoring system, FIG. 3 (a) and FIG. 3 (b) are partial schematic diagrams of the equivalent series resistance monitoring unit provided in the embodiment of the present application; FIG. 4 (a) and FIG. 4 (b) are another partial schematic diagrams of the equivalent series resistance monitoring unit provided in the embodiment of the present application; as shown in FIG. 3 (a), FIG. 3 (b), FIG. 4 (a), and FIG. 4 (b), the equivalent series resistance monitoring unit includes: a second comparator D2, a first operational amplifier Q1, a third resistor R3, and a fourth resistor R4;

[0093] The first input terminal of the second comparator is connected to the reference voltage terminal, the first end of the third resistor is connected to the first end of the equivalent series resistor, the second end of the third resistor is grounded through the fourth resistor; the second end of the fourth resistor is connected to the second input terminal of the second comparator; the output terminal of the second comparator is connected to the controller;

[0094] The second end of the third resistor is connected to the non-inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier is connected to the controller; the controller determines the resistance value of the equivalent series resistor based on the voltage change output by the buffer formed by the first operational amplifier within a preset time.

[0095] exist Figure 2 Under the premise that the output terminal Vsto_bist of the first comparator D1 is high, the equivalent series resistance (ESR) monitoring of the energy storage capacitor is turned on. After the ESR monitoring is turned on, the energy storage capacitor is discharged until Figure 2 The output terminal Vsto_bist of the first comparator D1 becomes a low level.

[0096] At this point, two charging steps are required:

[0097] 1) First, as shown in Figure 3 (a), a smaller current I0 is used to charge the energy storage capacitor. At this time, the voltages across the ESR can be approximately considered equal. Until the output Vsto_bist of the first comparator D1 just becomes high, the charging with the I0 current is stopped. In the whole process, there are:

[0098] The voltage at the input terminal of the second comparator D2 ; (2)

[0099] Voltage across ESR ; (3)

[0100] in, Indicates the voltage division ratio of the equivalent series resistance monitoring unit;

[0101] 2) Then, as shown in Figure 3 (b), the energy storage capacitor is charged with a current I1 that is much larger than I0. At this time, since the current I1 flowing through the ESR is much larger than the previous I0, a significant voltage drop V will be generated across the equivalent series resistance ESR of the energy storage capacitor. esr1 At this time, due to the short charging time and large capacitance, ESR and C sto The potential between them does not change significantly (for example, for a 4.7mF capacitor, when charged with a 1A current in 50μs, the voltage drop across the capacitor changes by only 11mV, which can be ignored relative to the minimum detection threshold), so:

[0102] Voltage difference across ESR:

[0103] ; (4)

[0104] The voltage at the input of the second comparator D2 is: ; (5)

[0105] Formulas (2), (3), (4), and (5) show that after the above two charging steps, the second comparator can monitor the voltage difference across the ESR, and because the voltage difference across the ESR is proportional to its resistance R ESR By setting the resistor divider ratio of R3 and R4, when the ESR resistance reaches the threshold, the input voltage V bi1 =Vref_bist, so that the output terminal Vesr_bist of the second comparator is high, so as to achieve the purpose of warning that the equivalent series resistance of the energy storage capacitor is too high.

[0106] In addition, when charging with a small current I0 and a large current I1 in sequence, the buffer formed by the operational amplifier transmits the voltage Vadc_esr to the external ADC (as shown in Figures 4 (a) and 4 (b)). At this time,

[0107] ; (7)

[0108] and ; (8)

[0109] in, Indicates the voltage division ratio of the buffer;

[0110] Combined with formula (4), it can be seen that by reading the voltage Vadc_esr through an external ADC and recording the voltage change of the energy storage capacitor when it is charged with small currents I0 and I1, the ESR resistance value can be calculated. This monitoring solution realizes the recording of the ESR resistance value while warning that the equivalent series resistance ESR of the energy storage capacitor is too high. This further accurately collects the state of the energy storage capacitor while ensuring the stability of the airbag control unit.

[0111] The resistance values ​​of the third resistor and the fourth resistor are designed to be precisely matched to ensure accurate measurement of voltage changes. Several different voltage comparison positions can be set so that the equivalent series resistance of energy storage capacitors of different sizes can be monitored.

[0112] In this application, when the voltage received by the second comparator exceeds the reference voltage threshold, that is, when the output is high, the system will issue a warning message that the equivalent series resistance is too high. This warning function is crucial for timely detection of possible failures or performance degradation of the resistor, and helps to take measures in advance to prevent the airbag system from failing.

[0113] According to the above embodiment, in a specific embodiment, the above airbag energy storage capacitor monitoring system, Figure 5 A circuit diagram of a capacitance monitoring unit provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the capacitance monitoring unit includes: a second operational amplifier Q2, a fifth resistor R5, and a sixth resistor R6;

[0114] The first end of the fifth resistor is connected to the first end of the equivalent series resistor, and the second end of the fifth resistor is grounded through the sixth resistor; the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the output end of the second operational amplifier is connected to the controller, and the controller determines the capacitance of the energy storage capacitor according to the voltage change of the output end of the second operational amplifier within a preset time.

[0115] When the capacitance value of the energy storage capacitor is monitored, the voltage value output by the second operational amplifier needs to be read. The voltage value output by the second operational amplifier can be read through an analog-to-digital converter (ADC). The current I2 is used to charge Csto within a certain time (see Figure 5 ). The capacitance of the energy storage capacitor is C sto , so in time The voltage change at the Vsto terminal With the capacitance C sto There are the following relationships:

[0116] ; (9)

[0117] exist The voltage change at the Vsto terminal during the time and the voltage change at the output of the second operational amplifier Vcsto There is also the following relationship:

[0118] ; (10)

[0119] and ; (11)

[0120] in, Indicates the voltage ratio of the capacitance monitoring unit;

[0121] Combining formulas (9), (10), and (11), the expression of the capacitance value can be obtained as follows:

[0122] ; (12)

[0123] That is, at a specific time The Vsto terminal is charged with a specific current I2, which can be detected by monitoring the output voltage of the second operational amplifier. The amount of change within To monitor the capacitance of the energy storage capacitor. By setting the threshold , which can achieve the purpose of warning that the capacitance of the energy storage capacitor is too small.

[0124] The buffer formed by the second operational amplifier provides a stable output voltage, allowing the controller to accurately respond to the state change of the energy storage capacitor. By measuring the rate of change of voltage under constant current, the capacitance of the energy storage capacitor can be accurately calculated to ensure that it meets the requirements of the airbag system.

[0125] According to the above embodiment, in a specific embodiment, the above airbag energy storage capacitor monitoring system, Figure 6 A circuit diagram of a connection status monitoring unit provided in an embodiment of the present application, such as Figure 6 As shown, the connection status monitoring unit includes: a third comparator D3, a seventh resistor R7, and an eighth resistor R8;

[0126] The first input terminal of the third comparator is connected to the reference voltage terminal Vref_bist, the first end of the seventh resistor is connected to the first end Vsto of the equivalent series resistor, and the second end of the seventh resistor is grounded through the eighth resistor; the second end of the seventh resistor is connected to the second input terminal of the third comparator; the output terminal Vsto_uv of the third comparator is connected to the controller;

[0127] The controller controls the charge-discharge circuit to discharge the energy storage capacitor, and determines the connection state of the energy storage capacitor according to the output end of the third comparator.

[0128] When monitoring the connection status of the energy storage capacitor, the charge and discharge circuit is controlled to discharge the energy storage capacitor so that the Vsto terminal discharges for t1 time. If Vsto_uv remains low during the discharge of the Vsto terminal, it indicates that the connection status of the energy storage capacitor is normal; if the energy storage capacitor is not properly connected to the circuit, Vsto will suddenly lose power to below the threshold of the third comparator during discharge, and the output terminal Vsto_uv of the third comparator will become high, at which time an early warning is issued for the abnormal connection of the energy storage capacitor. After the discharge time t1, the energy storage capacitor is charged again.

[0129] The present application also provides a safety airbag energy storage capacitor monitoring method, which is applied to the safety airbag energy storage capacitor monitoring system, including: an equivalent series resistance monitoring unit, a capacitance monitoring unit, a connection state monitoring unit, a charge and discharge circuit, and a controller; the charge and discharge circuit is connected to the energy storage capacitor through an equivalent series resistance, and is used to charge and discharge the energy storage capacitor; the equivalent series resistance is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded; the equivalent series resistance monitoring unit monitors the voltage difference across the equivalent series resistance; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor; the method includes:

[0130] Figure 7 A flow chart of a method for monitoring an airbag energy storage capacitor provided in an embodiment of the present application is shown in FIG. Figure 7 As shown,

[0131] S11: Control the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes and start the equivalent series resistance monitoring unit;

[0132] S12: determining the resistance value of the equivalent series resistor according to the voltage difference across the equivalent series resistor;

[0133] S13: Control the charge and discharge circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit;

[0134] S14: determining the capacitance of the energy storage capacitor according to the voltage change of the energy storage capacitor within a preset time;

[0135] S15: Control the charge and discharge circuit to discharge the energy storage capacitor and start the connection status monitoring unit;

[0136] S16: Determine the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor.

[0137] The controller controls the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes, and starts the equivalent series resistance monitoring unit to determine the resistance value of the equivalent series resistance through the voltage difference under different currents.

[0138] The controller controls the charge and discharge circuit to charge the energy storage capacitor with a constant current and starts the capacitance monitoring unit to determine the capacitance of the energy storage capacitor through the voltage change during the charging process of the constant current within a preset time.

[0139] The controller controls the charge and discharge circuit to discharge the energy storage capacitor and starts the connection status monitoring unit. The voltage is monitored during the discharge process to determine whether the connection status of the energy storage capacitor is normal.

[0140] It ensures that the performance and connection status of the energy storage capacitor are effectively monitored, thereby improving the reliability of the automobile airbag system. By monitoring the equivalent series resistance, capacitance and connection status, problems can be discovered in time and repaired or replaced, avoiding personal injury caused by airbag failure at critical moments.

[0141] According to the above embodiment, in a specific embodiment, the above airbag energy storage capacitor monitoring method and airbag energy storage capacitor monitoring system further include: a voltage comparison unit; the voltage comparison unit includes: a first comparator, a first resistor, and a second resistor; the first input terminal of the first comparator is connected to the reference voltage terminal, the first end of the first resistor is connected to the first end of the equivalent series resistor, and the second end of the first resistor is grounded through the second resistor; the second end of the first resistor is connected to the second input terminal of the first comparator; the output terminal of the first comparator is connected to the controller;

[0142] Correspondingly, the charge and discharge circuit is controlled to charge the energy storage capacitor with two currents of different magnitudes and start the equivalent series resistance monitoring unit, which also includes:

[0143] receiving a first comparison result output by the first comparator;

[0144] When the first comparison result is a high level, the step of controlling the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit is entered.

[0145] In this embodiment, the energy storage voltage terminal (Vsto terminal) voltage of the airbag control unit is compared with the Vref_bist terminal voltage through the first comparator D1. When the Vsto terminal voltage is not lower than Vref_bist / kbist1, the output terminal Vsto_bist of the first comparator D1 will become a high level, and then the next step of monitoring can be started.

[0146] According to the above embodiment, in a specific embodiment, in the above-mentioned airbag energy storage capacitor monitoring method, the equivalent series resistance monitoring unit includes: a second comparator, a first operational amplifier, a third resistor, and a fourth resistor; the first input terminal of the second comparator is connected to the reference voltage terminal, the first end of the third resistor is connected to the first end of the equivalent series resistor, and the second end of the third resistor is grounded through the fourth resistor; the second end of the fourth resistor is connected to the second input terminal of the second comparator; the output terminal of the second comparator is connected to the controller; the second end of the third resistor is connected to the non-inverting input terminal of the first operational amplifier, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier is connected to the controller;

[0147] Correspondingly, the charge and discharge circuit is controlled to charge the energy storage capacitor with two currents of different magnitudes and start the equivalent series resistance monitoring unit, including:

[0148] Controlling the charge-discharge circuit to discharge the energy storage capacitor until a first comparison result at the output end of the first comparator is a low level;

[0149] Controlling the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes;

[0150] receiving two test voltage values ​​output by the first operational amplifier when the energy storage capacitor is charged with two currents of different magnitudes;

[0151] Correspondingly, the resistance value of the equivalent series resistor is determined according to the voltage difference across the equivalent series resistor, including:

[0152] Determine the resistance value of the equivalent series resistance according to the two test voltage values;

[0153] Also includes:

[0154] When a high level signal is received from the second comparator, a warning message that the resistance value of the equivalent series resistor is too high is issued.

[0155] The controller controls the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes. During the charging process, the equivalent series resistance monitoring unit starts to work to monitor the state of the equivalent series resistance.

[0156] In this application, when the voltage received by the second comparator exceeds the reference voltage threshold, that is, when the output is high, the system will issue a warning message that the equivalent series resistance is too high. This warning function is crucial for timely detection of possible failures or performance degradation of the resistor, and helps to take measures in advance to prevent the airbag system from failing.

[0157] According to the above embodiment, in a specific embodiment, the above-mentioned airbag energy storage capacitor monitoring method, the capacitance monitoring unit includes: a second operational amplifier, a fifth resistor, and a sixth resistor; the first end of the fifth resistor is connected to the first end of the equivalent series resistor, and the second end of the fifth resistor is grounded through the sixth resistor; the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the output end of the second operational amplifier is connected to the controller;

[0158] Correspondingly, the charge and discharge circuit is controlled to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit, including:

[0159] Controlling the charge and discharge circuit to charge the energy storage capacitor with a constant current within a preset time;

[0160] receiving a voltage at an output terminal of a second operational amplifier and determining a rate of change of the voltage at the output terminal of the second operational amplifier;

[0161] Correspondingly, the capacitance of the energy storage capacitor is determined according to the voltage change of the energy storage capacitor within a preset time, including:

[0162] The capacitance of the energy storage capacitor is determined according to the current value of the constant current and the voltage change rate within a preset time.

[0163] The buffer composed of an operational amplifier outputs a stable voltage, which can more accurately monitor the charging rate of the energy storage capacitor. The second operational amplifier provides an accurate voltage change rate, allowing the controller to respond to the state change of the energy storage capacitor in a timely manner. By measuring the voltage change rate under constant current, the capacitance of the energy storage capacitor can be accurately calculated to ensure that it meets the requirements of the airbag system.

[0164] According to the above embodiment, in a specific embodiment, the above-mentioned airbag energy storage capacitor monitoring method, the connection state monitoring unit includes: a third comparator, a seventh resistor, and an eighth resistor; the first input terminal of the third comparator is connected to the reference voltage terminal, the first end of the seventh resistor is connected to the first end of the equivalent series resistor, and the second end of the seventh resistor is grounded through the eighth resistor; the second end of the seventh resistor is connected to the second input terminal of the third comparator; the output terminal of the third comparator is connected to the controller;

[0165] Correspondingly, controlling the charge and discharge circuit to discharge the energy storage capacitor and starting the connection status monitoring unit includes:

[0166] Controlling the charge and discharge circuit to discharge the energy storage capacitor;

[0167] Receiving a level signal from an output terminal of the third comparator;

[0168] Correspondingly, the connection state of the energy storage capacitor is determined according to the voltage of the energy storage capacitor, including:

[0169] Determine whether the level signal is a low level signal;

[0170] If so, it is determined that the connection status of the energy storage capacitor is normal;

[0171] If not, it is determined that the connection state of the energy storage capacitor is abnormal.

[0172] If Vsto_uv remains low during Vsto discharge, it indicates that the energy storage capacitor is connected normally; if the energy storage capacitor is not connected normally in the circuit, Vsto will suddenly drop below the threshold of the third comparator D3 during discharge, and the output terminal Vsto_uv of the third comparator D3 will become high, which will issue an early warning of abnormal connection of the energy storage capacitor. After the discharge time t1, the energy storage capacitor is charged again.

[0173] During the discharge process, if the energy storage capacitor is connected normally, its voltage will gradually decrease. Since the voltage drops slowly and does not trigger the output flip of the third comparator, the output of the third comparator will maintain a low-level signal, indicating that the connection status is normal. If the energy storage capacitor is connected abnormally, such as a circuit break or poor contact, its voltage will suddenly drop below the reference voltage of the third comparator, and the comparator output will be a high-level signal. The controller will judge that the connection status is abnormal and issue a corresponding warning or perform fault processing.

[0174] The airbag energy storage capacitor monitoring system and method provided by the present application are introduced in detail above. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0175] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. An airbag energy storage capacitor monitoring system, characterized in that: include: Equivalent series resistance monitoring unit, capacitance monitoring unit, connection status monitoring unit, charge and discharge circuit, controller; The charging and discharging circuit is connected to the energy storage capacitor via an equivalent series resistor, and is used to charge and discharge the energy storage capacitor; the equivalent series resistor is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded; The equivalent series resistance monitoring unit monitors the voltage difference across the equivalent series resistance when the energy storage capacitor is charged under two currents of different magnitudes; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor; The controller controls the charge and discharge circuit to charge the energy storage capacitor with two currents of different sizes and start the equivalent series resistance monitoring unit to determine the resistance value of the equivalent series resistance; controls the charge and discharge circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit to determine the capacitance value of the energy storage capacitor; controls the charge and discharge circuit to discharge the energy storage capacitor and start the connection status monitoring unit to determine the connection status of the energy storage capacitor.

2. The airbag energy storage capacitor monitoring system according to claim 1, characterized in that: Also includes: Voltage comparison unit; The voltage comparison unit includes: a first comparator, a first resistor, and a second resistor; The first input terminal of the first comparator is connected to the reference voltage terminal, the first end of the first resistor is connected to the first end of the equivalent series resistor, and the second end of the first resistor is grounded through the second resistor; the second end of the first resistor is connected to the second input terminal of the first comparator; and the output terminal of the first comparator is connected to the controller; The first comparator compares the voltage of the energy storage voltage terminal with the voltage of the reference voltage terminal and outputs a first comparison result. The controller is used to start the equivalent series resistance monitoring unit when the first comparison result is a high level.

3. The airbag energy storage capacitor monitoring system according to claim 2, characterized in that: The equivalent series resistance monitoring unit includes: a second comparator, a first operational amplifier, a third resistor, and a fourth resistor; The first input terminal of the second comparator is connected to the reference voltage terminal, the first end of the third resistor is connected to the first end of the equivalent series resistor, and the second end of the third resistor is grounded through the fourth resistor; the second end of the fourth resistor is connected to the second input terminal of the second comparator; and the output terminal of the second comparator is connected to the controller; The second end of the third resistor is connected to the non-inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier is connected to the controller; the controller determines the resistance value of the equivalent series resistor based on the voltage change output by the buffer formed by the first operational amplifier within a preset time.

4. The airbag energy storage capacitor monitoring system according to claim 3, characterized in that: The capacitance monitoring unit includes: a second operational amplifier, a fifth resistor, and a sixth resistor; The first end of the fifth resistor is connected to the first end of the equivalent series resistor, and the second end of the fifth resistor is grounded through the sixth resistor; the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the output end of the second operational amplifier is connected to the controller, and the controller determines the capacitance of the energy storage capacitor according to the voltage change at the output end of the second operational amplifier within a preset time.

5. The airbag energy storage capacitor monitoring system according to claim 3, characterized in that: The connection status monitoring unit includes: a third comparator, a seventh resistor, and an eighth resistor; The first input terminal of the third comparator is connected to the reference voltage terminal, the first end of the seventh resistor is connected to the first end of the equivalent series resistor, and the second end of the seventh resistor is grounded through the eighth resistor; the second end of the seventh resistor is connected to the second input terminal of the third comparator; and the output terminal of the third comparator is connected to the controller; The controller controls the charge and discharge circuit to discharge the energy storage capacitor, and determines the connection state of the energy storage capacitor according to the output end of the third comparator.

6. A method for monitoring airbag energy storage capacitor, characterized in that: The invention is applied to a safety airbag energy storage capacitor monitoring system, comprising: an equivalent series resistance monitoring unit, a capacitance monitoring unit, a connection state monitoring unit, a charge and discharge circuit, and a controller; the charge and discharge circuit is connected to the energy storage capacitor via an equivalent series resistance, and is used to charge and discharge the energy storage capacitor; the equivalent series resistance is connected in series with the energy storage capacitor, and the second end of the energy storage capacitor is grounded; the equivalent series resistance monitoring unit monitors the voltage difference between the two ends of the equivalent series resistance when the energy storage capacitor is charged under two currents of different magnitudes; the capacitance monitoring unit monitors the voltage change of the energy storage capacitor; the connection state monitoring unit is used to monitor the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor; the method comprises: Controlling the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit; Determining the resistance value of the equivalent series resistor according to the voltage difference across the equivalent series resistor; Controlling the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time and start the capacitance monitoring unit; Determining the capacitance of the energy storage capacitor according to the voltage change of the energy storage capacitor within a preset time; Controlling the charging and discharging circuit to discharge the energy storage capacitor and start the connection status monitoring unit; The connection state of the energy storage capacitor is determined according to the voltage of the energy storage capacitor.

7. The airbag energy storage capacitor monitoring method according to claim 6, characterized in that: The airbag energy storage capacitor monitoring system further includes: a voltage comparison unit; the voltage comparison unit includes: a first comparator, a first resistor, and a second resistor; the first input terminal of the first comparator is connected to the reference voltage terminal, the first end of the first resistor is connected to the first end of the equivalent series resistor, and the second end of the first resistor is grounded through the second resistor; the second end of the first resistor is connected to the second input terminal of the first comparator; the output terminal of the first comparator is connected to the controller; Correspondingly, the controlling the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes and start the equivalent series resistance monitoring unit also includes: receiving a first comparison result output by the first comparator; When the first comparison result is a high level, the step of controlling the charge and discharge circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit is entered.

8. The airbag energy storage capacitor monitoring method according to claim 7, characterized in that: The equivalent series resistance monitoring unit includes: a second comparator, a first operational amplifier, a third resistor, and a fourth resistor; the first input terminal of the second comparator is connected to the reference voltage terminal, the first end of the third resistor is connected to the first end of the equivalent series resistor, and the second end of the third resistor is grounded through the fourth resistor; the second end of the fourth resistor is connected to the second input terminal of the second comparator; the output terminal of the second comparator is connected to the controller; the second end of the third resistor is connected to the non-inverting input terminal of the first operational amplifier, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier is connected to the controller; Correspondingly, controlling the charge-discharge circuit to charge the energy storage capacitor with two currents of different magnitudes and starting the equivalent series resistance monitoring unit includes: Controlling the charge-discharge circuit to discharge the energy storage capacitor until a first comparison result at the output end of the first comparator is a low level; Controlling the charging and discharging circuit to charge the energy storage capacitor with two currents of different magnitudes; Receiving two test voltage values ​​output by the first operational amplifier when the energy storage capacitor is charged with two currents of different magnitudes to determine a voltage difference across the equivalent series resistor; Correspondingly, determining the resistance value of the equivalent series resistor according to the voltage difference across the equivalent series resistor includes: Determining the resistance value of the equivalent series resistance according to the two test voltage values; Also includes: When a high level signal is output from the second comparator, a warning message that the resistance value of the equivalent series resistor is too high is issued.

9. The airbag energy storage capacitor monitoring method according to claim 8, characterized in that: The capacitance monitoring unit includes: a second operational amplifier, a fifth resistor, and a sixth resistor; the first end of the fifth resistor is connected to the first end of the equivalent series resistor, and the second end of the fifth resistor is grounded through the sixth resistor; the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the output end of the second operational amplifier is connected to the controller; Correspondingly, controlling the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time and starting the capacitance monitoring unit includes: Controlling the charging and discharging circuit to charge the energy storage capacitor with a constant current within a preset time; receiving a voltage at an output terminal of the second operational amplifier and determining a rate of change of the voltage at the output terminal of the second operational amplifier; Correspondingly, determining the capacitance of the energy storage capacitor according to the voltage change of the energy storage capacitor within a preset time includes: The capacitance of the energy storage capacitor is determined according to the current value of the constant current and the voltage change rate.

10. The airbag energy storage capacitor monitoring method according to claim 9, characterized in that: The connection status monitoring unit comprises: a third comparator, a seventh resistor, and an eighth resistor; the first input terminal of the third comparator is connected to the reference voltage terminal, the first end of the seventh resistor is connected to the first end of the equivalent series resistor, and the second end of the seventh resistor is grounded through the eighth resistor; the second end of the seventh resistor is connected to the second input terminal of the third comparator; and the output terminal of the third comparator is connected to the controller; Correspondingly, controlling the charging and discharging circuit to discharge the energy storage capacitor and starting the connection status monitoring unit includes: Controlling the charge and discharge circuit to discharge the energy storage capacitor; Receiving a level signal from an output terminal of the third comparator; Correspondingly, determining the connection state of the energy storage capacitor according to the voltage of the energy storage capacitor includes: Determining whether the level signal is a low level signal; If yes, it is determined that the connection state of the energy storage capacitor is normal; If not, it is determined that the connection state of the energy storage capacitor is abnormal.

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