Airbag firing channel control circuit, airbag controller, and vehicle

Abstract

The application relates to the technical field of vehicles, in particular to an airbag ignition channel control circuit, an airbag controller and a vehicle, wherein the airbag ignition channel control circuit comprises: a first control circuit for sending a first control signal; a second control circuit for sending a second control signal; a constant current source control circuit, the constant current source control circuit comprises a first switch, the first switch is closed when receiving a first closing signal; a second switch, the second switch is closed when receiving a second closing signal; an explosion tube resistance on an ignition loop, one end of the explosion tube resistance is connected with the first switch, the other end of the explosion tube resistance is connected with the second switch, when the first switch is closed and the second switch is closed, ignition current flowing through the explosion tube resistance generates heat dissipation power consumption, which can activate a gas generator and complete airbag detonation. Therefore, the problems that the cost is increased, the volume and weight of the controller are increased and the like caused by the increase of the ignition chip required by the airbag controller for adding the ignition loop are solved, the cost can be reduced, and the chip risk can be avoided.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to an airbag ignition channel control circuit, an airbag controller, and a vehicle. Background Technology

[0002] The airbag control unit (ACU) is the core control component of a car's airbag system. When a collision occurs, it accurately judges the severity of the collision and promptly triggers the airbags to deploy, thus protecting the safety of the occupants.

[0003] With the increasing development of automotive safety, there is a need to support the deployment of more airbags. Currently, ignition chips such as CG904 only support 16 ignition circuits. If a vehicle needs to be equipped with 17 ignition circuits, an additional ignition chip is required, which increases the cost and correspondingly increases the size and weight of the controller. Utility Model Content

[0004] This application provides an airbag ignition channel control circuit, an airbag controller, and a vehicle to solve the problems of increased cost and increased size and weight of the controller due to the need to add an ignition chip to the airbag controller by adding an ignition circuit. This application adds an airbag ignition circuit through circuit logic, which can reduce the unit cost of the controller and the airbag controller, and avoid chip risks.

[0005] The first aspect of this application provides an airbag ignition channel control circuit, including:

[0006] A first control circuit for issuing a first control signal;

[0007] A second control circuit for issuing a second control signal;

[0008] A constant current source control circuit, the constant current source control circuit including a first switch, one end of the first switch being connected to a first power supply access node, the control terminal of the first switch being connected to the first control circuit, the first switch closing when receiving a first closing signal;

[0009] The second switch has one end connected to the grounding node and the control terminal of the second switch connected to the second control circuit. The second switch closes when it receives the second closing signal.

[0010] The ignition circuit has a bursting tube resistor, one end of which is connected to the first switch and the other end of which is connected to the second switch. When the first switch is closed and the second switch is closed, the heat generated by the ignition current flowing through the bursting tube resistor will activate the gas generator and complete the gasbag detonation.

[0011] Optionally, the first control circuit includes:

[0012] The NOR gate has its first input connected to the ignition chip, its second input connected to the main control chip, its power input connected to the second power access node, and its power input connected to the ground node.

[0013] The first resistor (R3) has one end connected to the second power supply node and the other end connected to the first input terminal of the NOR gate.

[0014] The second resistor (R4) has one end connected to the second power supply access node and the other end connected to the second input terminal of the NOR gate.

[0015] The first transistor has its base connected to the output of the NOR gate and its emitter connected to the ground node.

[0016] The third resistor (R_LIMIT) has one end connected to the collector of the first transistor and the other end connected to the constant current source control circuit.

[0017] Optionally, the first transistor is an NPN transistor.

[0018] Optionally, the first switch is a PNP transistor.

[0019] Optionally, the constant current source control circuit further includes:

[0020] A reference resistor (R_REFERENCE) is connected at one end to the first power access node and at the other end to the emitter of the PNP transistor.

[0021] A reference diode (D_REFERENCE) is provided, wherein the anode of the reference diode is connected to the connection node between one end of the reference resistor and the first power access node, and the cathode of the reference diode is connected to the connection node between the other end of the third resistor and the base of the PNP transistor.

[0022] Optionally, the second control circuit includes:

[0023] The fourth resistor (R2) has one end connected to the main control chip and the other end connected to the control terminal of the second switch.

[0024] Optionally, a protection circuit for preventing accidental ignition, wherein the protection circuit includes:

[0025] The second transistor (Q1) has its base connected to the ignition chip, its collector connected to the connection node between the fourth resistor and the control terminal of the second switch, and its emitter connected to the ground node.

[0026] The fifth resistor (R1) has one end connected to the connection node between the fourth resistor and the control terminal of the second switch, and the other end connected to the grounding node.

[0027] Optionally, the second switch is an NMOS transistor, the gate of which is connected to the other end of the fourth resistor, the source of which is connected to the ground node, and the drain of which is connected to the other end of the bursting resistor.

[0028] A second aspect of this application provides an airbag controller, including: an airbag ignition channel control circuit as described above.

[0029] A third aspect of this application provides a vehicle including an airbag controller as described above.

[0030] Therefore, a first control signal is issued through the first control circuit, and a second control signal is issued through the second control circuit. The first switch of the constant current source control circuit closes when it receives the first closing signal; the second switch closes when it receives the second closing signal. When both the first and second switches are closed, the heat generated by the ignition current flowing through the detonating tube resistor activates the gas generator, completing the airbag deployment. This solves the problems of increased cost, larger size, and heavier controller caused by adding an ignition chip to the airbag controller by adding an ignition circuit. This application adds an airbag ignition circuit through circuit logic, which can reduce the unit cost of the controller and the airbag controller itself, and avoid chip-related risks.

[0031] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0032] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic diagram of the airbag ignition channel control circuit provided according to an embodiment of this application. Detailed Implementation

[0034] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0035] The following description, with reference to the accompanying drawings, describes an airbag ignition channel control circuit, an airbag controller, and a vehicle according to embodiments of this application. Addressing the issues mentioned in the background art, such as the increased cost and increased controller size and weight due to the need to add an ignition chip to the airbag controller by adding an ignition circuit, this application provides an airbag ignition channel control circuit. In this circuit, a first control circuit sends a first control signal, and a second control circuit sends a second control signal. A first switch of a constant current source control circuit closes upon receiving the first closing signal; a second switch closes upon receiving the second closing signal. When both the first and second switches are closed, the ignition current flowing through the detonating tube resistor generates heat, which activates the gas generator, completing airbag deployment. This solves the problems of increased cost and increased controller size and weight caused by adding an ignition chip to the airbag controller by adding an ignition circuit. This application reduces the unit cost of the controller and the airbag controller itself by adding an airbag ignition circuit through circuit logic, thus mitigating chip-related risks.

[0036] Specifically, Figure 1 This is a block diagram of an airbag ignition channel control circuit provided in an embodiment of this application.

[0037] like Figure 1 As shown, the airbag ignition channel control circuit 10 includes: a first control circuit 100, a second control circuit 200, a constant current source control circuit 300, a second switch 400, and a burst tube resistor 500.

[0038] The system includes a first control circuit 100 for issuing a first control signal, a second control circuit 200 for issuing a second control signal, a constant current source control circuit 300 including a first switch (Q_HS), one end of which is connected to a first power input node (VH), and the control terminal of which is connected to the first control circuit 100. The first switch (Q_HS) closes when it receives a first closing signal. A second switch 400 is connected to a ground node (GND), and the control terminal of which is connected to the second control circuit 200. The second switch 400 closes when it receives a second closing signal. A detonating tube resistor 500 on the ignition circuit is connected to the first switch (Q_HS) and to the second switch 400. When the first switch (Q_HS) and the second switch 400 are both closed, the heat generated by the ignition current flowing through the detonating tube resistor 500 activates the gas generator, thus detonating the airbag.

[0039] Among them, the first switch (Q_HS) is a PNP transistor, the second switch 400 is an NMOS transistor (Q_LS), the gate of the NMOS transistor is connected to the other end of the fourth resistor R2, the source of the NMOS transistor is connected to the ground node (GND), and the drain of the NMOS transistor is connected to the other end of the bursting resistor 500 (R_SQUIB).

[0040] Specifically, the 500Ω detonator resistor (R_SQUIB) in the ignition circuit is typically integrated inside the airbag gas generator and connected to the ACU via the vehicle wiring harness. When the ACU determines that a collision has occurred and decides to deploy the airbag, it sends an ignition current (1.2A / 2ms). The heat generated by the ignition current flowing through the R_SQUIB activates the gas generator, completing the airbag deployment.

[0041] Optionally, in some implementations, the first control circuit 100 includes: a NOR gate (U1), a first resistor (R3), a second resistor (R4), and a third resistor (R_LIMIT).

[0042] In this circuit, the first input terminal (DIS_AHP_From_ASIC) of the NOR gate (U1) is connected to the ignition chip, the second input terminal (DIS_HS_From_MCU) of the NOR gate (U1) is connected to the main control chip, the power input terminal of the NOR gate (U1) is connected to the second power access node (VCC), and the power input terminal of the NOR gate (U1) is connected to the ground node (GND); one end of the first resistor (R3) is connected to the second power access node (VCC), and the other end of the first resistor (R3) is connected to the NOR gate (U1). 1) The first input terminal is connected to the second resistor (R4). One end of the second resistor (R4) is connected to the second power supply access node (VCC), and the other end of the second resistor (R4) is connected to the second input terminal of the NOR gate (U1). The base of the first transistor (Q2) is connected to the output terminal of the NOR gate (U1), and the emitter of the first transistor (Q2) is connected to the ground node (GND). One end of the third resistor (R_LIMIT) is connected to the collector of the first transistor (Q2), and the other end of the third resistor (R_LIMIT) is connected to the constant current source control circuit 300.

[0043] Among them, the first transistor (Q2) is an NPN transistor.

[0044] Specifically, the second input terminal (DIS_HS_From_MCU) is connected to the I / O pin of the main control chip MCU. Its default output state is high, meaning the high-side first switch (Q_HS) is off by default. When the ACU detects a collision and decides to deploy the airbag, it can pull the second input terminal (DIS_HS_From_MCU) low. However, due to the presence of the NOR gate U1, the first switch (Q_HS) cannot be turned on at this time, and the ACU cannot deploy the airbag. Only when both the first input terminal (DIS_AHP_From_ASIC) and the second input terminal (DIS_HS_From_MCU) are low can the NOR gate output a high level, thereby turning on the first transistor (Q2) and turning on the high-side first switch (Q_HS), thus completing the airbag deployment function.

[0045] The first input terminal (DIS_AHP_From_ASIC) is connected to the DIS_AHP pin of the ignition chip ASIC. The voltage level of this pin is related to the Security Core (SCON) inside the ASIC. The SCON can work with the MCU to obtain the current collision sensor data and determine whether the current collision intensity has reached the preset ignition threshold. If the SCON detects that the current collision sensor data has reached the preset ignition threshold, the first input terminal (DIS_AHP_From_ASIC) will be pulled low. At this time, if the MCU also determines that the airbag needs to be deployed based on the collision sensor data, it will pull the second input terminal (DIS_HS_From_MCU) low, thereby realizing the airbag deployment function. If the SCON detects that the current collision sensor data has not reached the preset ignition threshold, the first input terminal (DIS_AHP_From_ASIC) will remain at a low level. At this time, even if the MCU determines that the airbag needs to be deployed based on the collision sensor data, pulling the second input terminal (DIS_HS_From_MCU) low will not deploy the airbag.

[0046] Optionally, in some implementations, the second control circuit 200 includes a fourth resistor R2.

[0047] One end of the fourth resistor R2 is connected to the main control chip, and the other end of the fourth resistor R2 is connected to the control terminal of the second switch 400.

[0048] Specifically, EN_LS_From_MCU is connected to the IO pin of the main control chip MCU, and its default output state is low level, that is, the second switch 400 (Q_LS) on the low side is in the off state by default; when the ACU detects a collision and decides to deploy the airbag, it can turn on the second switch (Q_LS) on the low side by pulling EN_LS_From_MCU to a high level.

[0049] Optionally, in some implementations, the constant current source control circuit 300 may also include a reference resistor (R_REFERENCE) and a reference diode (D_REFERENCE).

[0050] The reference resistor (R_REFERENCE) has one end connected to the first power input node (VH), and the other end connected to the emitter of the PNP transistor. The reference diode (D_REFERENCE) has its anode connected to the connection node between one end of the reference resistor (R_REFERENCE) and the first power input node (VH), and its cathode connected to the connection node between the other end of the third resistor (R_LIMIT) and the base of the PNP transistor.

[0051] The reference resistor R_REFERENCE, the reference diode D_REFERENCE, and the high-side switch Q_HS constitute a constant current source control circuit, which is used to set the magnitude of the ignition current.

[0052] Specifically, when the ACU deploys the airbag, the first switch (Q_HS), i.e. the high-side switch, and the second switch 400 (Q_LS), i.e. the low-side switch, need to be closed simultaneously. This ensures that the first power supply node (VH), the reference resistor (R_REFERENCE), the first switch (Q_HS), the detonation tube resistor 500 (R_SQUIB), the second switch 400 (Q_LS), and the ground node (GND) of the ignition circuit power supply form a complete circuit in order to complete the deployment function.

[0053] Optionally, in some implementations, a protection circuit is used to prevent accidental ignition, wherein the protection circuit includes: a second transistor Q1 and a fifth resistor R1.

[0054] Among them, the base of the second transistor Q1 is connected to the ignition chip, the collector of the second transistor Q1 is connected to the connection node between the fourth resistor R2 and the control terminal of the second switch 400, and the emitter of the second transistor Q1 is connected to the ground node (GND); the fifth resistor R1 has one end connected to the connection node between the fourth resistor R2 and the control terminal of the second switch 400, and the other end connected to the ground node (GND).

[0055] Specifically, the first input terminal (DIS_AHP_From_ASIC) is connected to the DIS_ALP pin of the ignition chip ASIC. The level of this pin is related to the watchdog timer inside the ASIC and the system power state. When the watchdog timer fails to feed or the system power supply has abnormal states such as overvoltage or undervoltage, the DIS_ALP pin will output a high level. At this time, the second switch 400 (Q_LS) on the low side of the second transistor Q1 is locked in the off state. Even if the EN_LS_From_MCU signal is pulled high, the second switch 400 (Q_LS) cannot be turned on. This can effectively prevent the airbag from being accidentally deployed due to system abnormalities such as MCU malfunction or power supply failure. When the system is running normally, the DIS_ALP pin outputs a low level. At this time, the second switch 400 (Q_LS) is completely controlled by the MCU. That is, the MCU can freely control the on and off state of the second switch 400 (Q_LS) through the EN_LS_From_MCU signal level.

[0056] As can be seen from the above, this hardware circuit can only realize the detonation function when both the MCU and the SCON inside the ASIC believe that the current collision intensity has reached the preset detonation threshold. This can effectively prevent the airbag from accidentally detonating.

[0057] In summary, the procedure for deploying an airbag is as follows:

[0058] (1) ASIC pulls DIS_ALP_From_ASIC low (no system abnormalities such as MCU crash or power supply failure occur).

[0059] (2) MCU pulls EN_LS_From_MCU high (MCU determines that the current collision intensity has reached the detonation threshold).

[0060] (3) After steps (1) and (2), the second switch 400 (Q_LS) on the lower side is turned on.

[0061] (4) ASIC lowers DIS_AHP_From_ASIC (ASIC determines that the current collision intensity has reached the detonation threshold).

[0062] (5) MCU pulls DIS_HS_From_MCU low (MCU determines that the current collision intensity has reached the detonation threshold).

[0063] (6) After steps (4) and (5), the first switch (Q_HS) on the high side is turned on and is in constant current control state. After waiting for 2ms, the power consumption of the ignition current on the airbag burst tube resistor 500 (R_SQUIB) will ignite the airbag.

[0064] After the airbag deploys, the MCU can shut off the ignition circuit by pulling DIS_HS_From_MCU high and pulling EN_LS_From_MCU low.

[0065] According to the airbag ignition channel control circuit proposed in this application, a first control signal is issued through a first control circuit, and a second control signal is issued through a second control circuit. A first switch of the constant current source control circuit closes upon receiving the first closing signal; a second switch closes upon receiving the second closing signal. When both the first and second switches are closed, the heat generated by the ignition current flowing through the detonating tube resistor activates the gas generator, completing airbag deployment. This solves the problems of increased cost, larger size, and heavier controller caused by adding an ignition chip to the airbag controller. This application adds an airbag ignition circuit through circuit logic, reducing the unit cost of the controller and mitigating chip-related risks.

[0066] This application also provides an airbag controller, including: the airbag ignition channel control circuit as described above.

[0067] This application also provides a vehicle, including: an airbag controller as described above.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0070] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0071] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0072] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0073] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An airbag ignition channel control circuit, characterized in that, include: A first control circuit for issuing a first control signal; A second control circuit for issuing a second control signal; A constant current source control circuit, the constant current source control circuit including a first switch, one end of the first switch being connected to a first power supply access node, the control terminal of the first switch being connected to the first control circuit, the first switch closing when receiving a first closing signal; The second switch has one end connected to the grounding node and the control terminal of the second switch connected to the second control circuit. The second switch closes when it receives the second closing signal. The ignition circuit has a bursting tube resistor, one end of which is connected to the first switch and the other end of which is connected to the second switch. When the first switch is closed and the second switch is closed, the heat generated by the ignition current flowing through the bursting tube resistor will activate the gas generator and complete the gasbag detonation.

2. The airbag ignition channel control circuit according to claim 1, characterized in that, The first control circuit includes: The NOR gate has its first input connected to the ignition chip, its second input connected to the main control chip, its power input connected to the second power access node, and its power input connected to the ground node. A first resistor, one end of which is connected to the second power supply node, and the other end of which is connected to the first input terminal of the NOR gate. The second resistor has one end connected to the second power supply node and the other end connected to the second input terminal of the NOR gate. The first transistor has its base connected to the output of the NOR gate and its emitter connected to the ground node. The third resistor has one end connected to the collector of the first transistor and the other end connected to the constant current source control circuit.

3. The airbag ignition channel control circuit according to claim 2, characterized in that, The first transistor is an NPN transistor.

4. The airbag ignition channel control circuit according to claim 2, characterized in that, The first switch is a PNP transistor.

5. The airbag ignition channel control circuit according to claim 4, characterized in that, The constant current source control circuit further includes: A reference resistor, one end of which is connected to the first power access node, and the other end of which is connected to the emitter of the PNP transistor; A reference diode, wherein the anode of the reference diode is connected to a connection node between one end of the reference resistor and the first power access node, and the cathode of the reference diode is connected to a connection node between the other end of the third resistor and the base of the PNP transistor.

6. The airbag ignition channel control circuit according to claim 1, characterized in that, The second control circuit includes: The fourth resistor has one end connected to the main control chip and the other end connected to the control terminal of the second switch.

7. The airbag ignition channel control circuit according to claim 6, characterized in that, Also includes: A protection circuit for preventing accidental ignition, wherein the protection circuit includes: The base of the second transistor is connected to the ignition chip, the collector of the second transistor is connected to the connection node between the fourth resistor and the control terminal of the second switch, and the emitter of the second transistor is connected to the ground node. The fifth resistor has one end connected to the connection node between the fourth resistor and the control terminal of the second switch, and the other end connected to the grounding node.

8. The airbag ignition channel control circuit according to claim 7, characterized in that, The second switch is an NMOS transistor. The gate of the NMOS transistor is connected to the other end of the fourth resistor, the source of the NMOS transistor is connected to the ground node, and the drain of the NMOS transistor is connected to the other end of the bursting resistor.

9. An airbag controller, characterized in that, include: The ignition channel control circuit as described in any one of claims 1-8.

10. A vehicle, characterized in that, include: The airbag controller as described in claim 9.

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