Airbag application safety logic circuit
By introducing redundant modules into the airbag ignition system, it is ensured that the discrete airbag chip only reaches the arming state when certain conditions are met, which solves the problem of the discrete airbag chip causing the error of the airbag explosion caused by the lack of safety logic modules, and improves the reliability of the system.
Patent Information
- Application Number
- CN202420904593.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-27
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-04-27
AI Technical Summary
The discrete airbag chip lacks safety logic modules, which may cause the microcontroller software to accidentally explode the airbag when the logic is inconsistent, reducing the reliability of the airbag ignition system.
The redundant module is used to prevent the microcontroller from directly contacting the discrete airbag chip from reaching the arming state. Only when the ARMX pin or the ARMY pin drives the redundant module will the high-level ARM_FIRE signal be output to the discrete airbag chip, thereby ensuring the safety of the airbag ignition.
Through the design of redundant modules, the microcontroller logic disorder is avoided and the airbag explodes by mistake, the reliability of the airbag ignition system is improved, and a safety logic module is established without using a fully integrated airbag chip.
Smart Images
Figure CN222600081U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of airbag control circuits, and in particular to a safety logic circuit for airbag applications. Background Art
[0002] Reference Figure 1 The fully integrated airbag chip has its own safety logic module, which can monitor the data of the acceleration sensor through SPI. When the threshold is reached, the device reaches the arming state. Similarly, the microcontroller also obtains the acceleration data through SPI to reach the threshold and receives the ARMX or ARMY signal. When the three devices reach the threshold at the same time, the algorithm is started at this time. If it meets the characteristic algorithm, the ignition command is sent through SPI to detonate the airbag.
[0003] However, since the dedicated airbag chips are currently strictly controlled and difficult to obtain, other methods are needed to achieve safe airbag deployment. Discrete airbag chips lack safety logic modules, and there is a probability that the airbag will be deployed by mistake, especially when the microcontroller software logic is disordered. Utility Model Content
[0004] In order to improve the reliability of the airbag ignition system, the present application provides an airbag application safety logic circuit.
[0005] The airbag application safety logic circuit provided in this application adopts the following technical solution:
[0006] An airbag application safety logic circuit comprises an acceleration chip and a single-chip microcomputer, wherein the output end of the acceleration chip is electrically connected to the input end of the single-chip microcomputer, and further comprises a redundant module and a discrete airbag chip, wherein the output end of the single-chip microcomputer is electrically connected to the input end of the discrete airbag chip, the ARMX pin of the acceleration chip and the ARMY pin of the acceleration chip are respectively connected to the control end of the redundant module, the input end of the redundant module is electrically connected to the ARM pin of the single-chip microcomputer, the output end of the redundant module is electrically connected to the signal receiving end of the discrete airbag chip, and the output end of the redundant module is used to output an ARM_FIRE signal; when the discrete airbag chip receives the ARM_FIRE signal of a high level, the discrete airbag chip is triggered to reach an arming state.
[0007] By adopting the above technical solution and utilizing the redundant module, the single-chip microcomputer cannot directly trigger the discrete airbag chip to reach the arming state; only when the ARMX pin or the ARMY pin drives the redundant module, if the acceleration value obtained by the single-chip microcomputer through SPI exceeds the threshold, the redundant module receives the high level output by the ARM pin of the single-chip microcomputer, and outputs a high-level ARM_FIRE signal to the discrete airbag chip, thereby avoiding the occurrence of the airbag being misfired due to logic confusion of the single-chip microcomputer, improving the reliability of the airbag ignition system, and thus being able to establish a safety logic module without using a fully integrated airbag chip.
[0008] Preferably, the redundancy module includes a diode D11, a diode D12 and a composite transistor Q1, the ARMX pin is electrically connected to the anode of the diode D11, the ARMY pin is electrically connected to the anode of the diode D12, and the cathodes of the diode D11 and the diode D12 are both electrically connected to the control end of the composite transistor Q1, the input end of the composite transistor Q1 is connected to the ARM pin, the output end of the composite transistor Q1 is grounded, and the output end of the composite transistor Q1 is also electrically connected to the signal input end of the discrete airbag chip.
[0009] By adopting the above technical solution, when the X-axis of the acceleration chip reaches the threshold, the corresponding ARMX pin outputs a high level, and the diode D11 is turned on; when the Y-axis of the acceleration chip reaches the threshold, the corresponding ARMY pin outputs a high level, and the diode D12 is turned on. When the diode D11 or the diode D12 is turned on, the composite transistor Q1 is in the on state; if the acceleration value obtained by the single-chip microcomputer through SPI exceeds the threshold at this time, the ARM pin of the single-chip microcomputer outputs a high level, so that the redundant module can output a high-level ARM_FIRE signal to the discrete airbag chip.
[0010] Preferably, the composite transistor Q1 includes an NPN transistor Q11 and a PNP transistor Q12, the cathode of the diode D11 is electrically connected to the base of the NPN transistor Q11, the emitter of the NPN transistor Q11 is grounded, the collector of the NPN transistor Q11 is electrically connected to the base of the PNP transistor Q12, the emitter of the PNP transistor Q12 is electrically connected to the ARM pin of the microcontroller, the collector of the PNP transistor Q12 is grounded, and the collector of the PNP transistor Q12 is also electrically connected to the input signal input terminal of the discrete airbag chip.
[0011] By adopting the above technical solution, the use of composite triodes can reduce the number of independent components in the circuit, thereby simplifying the circuit design and layout. This not only reduces the complexity of the circuit, but also helps to improve the stability and reliability of the circuit.
[0012] Preferably, the collector of the PNP transistor Q12 is grounded via a pull-down resistor R1.
[0013] By adopting the above technical solution, the pull-down resistor R1 can be used to keep the collector voltage as stable as possible, which helps to improve the performance and reliability of the circuit.
[0014] Preferably, the NPN transistor Q11 and the transistor Q12 are both configured as band-stop transistors.
[0015] By adopting the above technical solution, the voltage drop of the band-stop transistor is lower than that of the traditional transistor, which means that when the circuit is working, it can realize energy conversion more efficiently and reduce energy loss.
[0016] Preferably, the diode D11 and the diode D12 are integrated into a common cathode diode D1.
[0017] By adopting the above technical solution, the consistency of the specifications of the diode D11 and the diode D12 can be simply and conveniently achieved.
[0018] To summarize, the present application includes at least one of the following beneficial technical effects: by setting up a redundant module, the single-chip microcomputer cannot directly trigger the discrete airbag chip to reach the arming state, thereby avoiding the situation where the single-chip microcomputer logic is confused and the airbag is accidentally detonated, thereby improving the reliability of the airbag ignition system and thus being able to establish a safety logic module without using a fully integrated airbag chip. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a circuit diagram of an existing air bag ignition system;
[0020] Figure 2 It is a circuit diagram of an embodiment of the present application. DETAILED DESCRIPTION
[0021] The following is combined with Figure 1-2 This application is described in further detail.
[0022] refer to Figure 1The existing airbag circuit includes a unit machine, an acceleration chip and a fully integrated airbag chip, wherein the fully integrated airbag chip has its own safety logic module. The CS pin, MOSI pin, MISO pin and SCK pin of the acceleration chip are electrically connected to the input end of the unit machine and the input end of the fully integrated airbag chip, respectively, and the ARMX pin and ARMY pin of the acceleration chip are electrically connected to the input end of the single-chip microcomputer. The safety logic module monitors the data of the acceleration sensor through SPI. When the threshold is reached, the device reaches the arming state. Similarly, the single-chip microcomputer also obtains the acceleration data through SPI to reach the threshold and receives the ARMX or ARMY signal. When the three devices reach the threshold at the same time, the algorithm is started at this time. If it meets the characteristic algorithm, the ignition command is sent through SPI to detonate the airbag.
[0023] The embodiment of the present application discloses an airbag application safety logic circuit.
[0024] Reference Figure 2 , an airbag application safety logic circuit includes an acceleration chip, a single-chip microcomputer, a discrete airbag chip and a redundant module, the CS pin, MOSI pin, MISO pin and SCK pin of the acceleration chip are electrically connected to the input end of the unit machine, and the CS pin, MOSI pin, MISO pin and SCK pin of the single-chip microcomputer are electrically connected to the input end of the discrete airbag chip. The ARMX pin and ARMY pin of the acceleration chip are electrically connected to the input end of the single-chip microcomputer and the first connection end of the redundant module, the second connection end of the redundant module is electrically connected to the input end of the single-chip microcomputer, and the output end of the redundant module is electrically connected to the input end of the discrete airbag chip. Since the discrete airbag chip lacks a safety logic module, the use of a redundant module can improve the reliability of the airbag ignition system and avoid the occurrence of accidental detonation of the airbag due to the confusion of the single-chip microcomputer software logic.
[0025] The redundancy module includes a common cathode diode D1, a composite transistor Q1 and a pull-down resistor R1, wherein the common cathode diode D1 includes a diode D11 and a diode D12, and the composite transistor integrates a band-blocking NPN transistor Q11 and a band-blocking PNP transistor Q12. The ARMX pin of the acceleration chip is electrically connected to the anode of the diode D11, and the ARMY pin of the acceleration chip is electrically connected to the anode of the diode D12. The cathode of the common cathode diode D1 is electrically connected to the base of the NPN transistor Q11, the emitter of the NPN transistor Q11 is grounded, the collector of the NPN transistor Q11 is electrically connected to the base of the PNP transistor Q12, the emitter of the PNP transistor Q12 is electrically connected to the ARM pin of the microcontroller, and the collector of the PNP transistor Q12 is also electrically connected to the input end of the discrete airbag chip for transmitting the ARM_FIRE signal.
[0026] When the X-axis of the acceleration chip reaches the threshold, the corresponding ARMX pin outputs a high level, and the diode D11 is turned on; when the Y-axis of the acceleration chip reaches the threshold, the corresponding ARMY pin outputs a high level, and the diode D12 is turned on. When diode D11 or diode D12 is turned on, the base voltage of NPN transistor Q11 is raised, so that NPN transistor Q11 is turned on, and at this time, the base of PNP transistor Q12 is grounded through NPN transistor Q11, so that PNP transistor Q12 is in the on state; if the acceleration value obtained by the MCU through SPI exceeds the threshold at this time, the ARM pin of the MCU outputs a high level, so that the redundant module can output a high-level ARM_FIRE signal to the discrete airbag chip, that is, ARM_FIRE=ARM&(ARMX|ARMY). After receiving the high-level ARM_FIRE signal, the discrete airbag chip reaches the arming state and waits for the MCU to send an ignition command.
[0027] The implementation principle of an airbag application safety logic circuit in an embodiment of the present application is as follows: by setting a redundant module, the single-chip microcomputer cannot directly trigger the discrete airbag chip to reach the arming state, thereby avoiding the situation where the single-chip microcomputer logic is confused and the airbag is accidentally detonated, thereby improving the reliability of the airbag ignition system and thus being able to establish a safety logic module without using a fully integrated airbag chip.
[0028] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A safety logic circuit for airbag application, comprising an acceleration chip and a single-chip microcomputer, wherein the output end of the acceleration chip is electrically connected to the input end of the single-chip microcomputer, characterized in that: It also includes a redundant module and a discrete airbag chip, the output end of the single-chip microcomputer is electrically connected to the input end of the discrete airbag chip, the ARMX pin of the acceleration chip and the ARMY pin of the acceleration chip are respectively connected to the control end of the redundant module, the input end of the redundant module is electrically connected to the ARM pin of the single-chip microcomputer, the output end of the redundant module is electrically connected to the signal receiving end of the discrete airbag chip, and the output end of the redundant module is used to output an ARM_FIRE signal; when the discrete airbag chip receives the ARM_FIRE signal of a high level, the discrete airbag chip is triggered to reach an arming state.
2. The airbag application safety logic circuit according to claim 1, characterized in that: The redundancy module includes a diode D11, a diode D12 and a composite transistor Q1, the ARMX pin is electrically connected to the anode of the diode D11, the ARMY pin is electrically connected to the anode of the diode D12, and the cathodes of the diode D11 and the diode D12 are both electrically connected to the control end of the composite transistor Q1, the input end of the composite transistor Q1 is connected to the ARM pin, the output end of the composite transistor Q1 is grounded, and the output end of the composite transistor Q1 is also electrically connected to the signal input end of the discrete airbag chip.
3. The airbag application safety logic circuit according to claim 2, characterized in that: The composite transistor Q1 includes an NPN transistor Q11 and a PNP transistor Q12, the cathode of the diode D11 is electrically connected to the base of the NPN transistor Q11, the emitter of the NPN transistor Q11 is grounded, the collector of the NPN transistor Q11 is electrically connected to the base of the PNP transistor Q12, the emitter of the PNP transistor Q12 is electrically connected to the ARM pin of the single-chip microcomputer, the collector of the PNP transistor Q12 is grounded, and the collector of the PNP transistor Q12 is also electrically connected to the input signal input end of the discrete airbag chip.
4. The airbag application safety logic circuit according to claim 3, characterized in that: The collector of the PNP transistor Q12 is grounded via a pull-down resistor R1.
5. The airbag application safety logic circuit according to claim 3, characterized in that: The NPN transistor Q11 and the transistor Q12 are both configured as band-stop transistors.
6. The airbag application safety logic circuit according to claim 2, characterized in that: The diode D11 and the diode D12 are integrated to form a common cathode diode D1.