A data synchronization method for an airbag ignition system

Abstract

This invention relates to the field of airbag ignition technology and discloses a data synchronization method for an airbag ignition system. In practical use, this invention first sets a preset interval for sending synchronization pulse signals based on the clock of the main control MCU and the clock of the ignition control chip. Then, the ignition control chip controls the clock frequency of the acceleration sensor on the PSI5 bus based on the preset interval, thereby eliminating the impact of the main control MCU's clock deviation on the communication of the entire ignition system. In addition, the ignition control chip adjusts the preset interval of the synchronization pulse signals by monitoring the interval of sensor data on the PSI5 bus, thereby avoiding excessively short intervals and data corruption on the PSI5 bus. Finally, the main control MCU reads data based on the interval of the heartbeat pulse signals, thereby ensuring the integrity and real-time performance of the read data.

Description

Technical Field

[0001] This invention relates to the field of airbag ignition technology, and more specifically to a data synchronization method for an airbag ignition system. Background Technology

[0002] Car airbags are one of the core components of a vehicle's passive safety system. Their main function is to cushion the impact between the occupants and the vehicle body during a collision, reducing the risk of injury and death, and significantly mitigating damage to critical parts of the body.

[0003] The current structure of the ignition system for car airbags is as follows: Figure 1 As shown, it includes a main control MCU, an ignition control chip, and multiple PSI5 buses, each connected to multiple acceleration sensors. In use... The ignition control chip first interacts with the accelerometer via the PSI5 bus to acquire the data detected by the accelerometer and stores the data in the internal memory array; then the main control MCU communicates with the ignition control chip to obtain the data in the memory array. Combination Figure 1 The specific usage process is as follows: the main control MCU sends a clock signal CLK to the ignition control chip, the ignition control chip counts the time, and after the count value reaches the set time, the ignition control chip sends a synchronization pulse to the PSI5 bus. The acceleration sensor sends data according to the synchronization pulse in a preset order, that is, through time-division multiplexing. At the same time, it also adjusts the internal clock according to the interval of the synchronization pulse.

[0004] for Figure 1 The structure shown has the following problems when used: When the clock difference between the main control MCU and the accelerometer is large, since all clock adjustments are performed only on the accelerometer, as the working time increases, temperature changes, or aging occurs, the clock difference between the main control MCU and the accelerometer may exceed the range that the accelerometer adjusts itself, and bus communication may fail. In addition, the accelerometer follows a clock. Due to the differences between the various accelerometers, the clock adjustment results may be different. This can cause the accelerometers on the PSI5 bus to fail to send data according to the preset time-division multiplexing time, resulting in a communication conflict. Ultimately, this leads to communication failure and the inability to obtain accelerometer data normally. Summary of the Invention

[0005] In view of the shortcomings of the background technology, the present invention provides a data synchronization method for an airbag ignition system. The technical problem to be solved is that the existing airbag ignition control system has the problem that when the clock difference between the main control MCU and the acceleration sensor is too large, the bus communication will fail and the sensor data of the acceleration sensor cannot be obtained normally.

[0006] To solve the above technical problems, the present invention provides the following technical solution: a data synchronization method for an airbag ignition system, wherein the airbag ignition system includes a main control MCU and an ignition control chip, the main control MCU and the ignition control chip communicate via SPI; the ignition control chip is connected to at least one PSI5 bus, and at least one acceleration sensor is connected to each PSI5 bus. Includes the following steps: S1: Based on the clock of the main control MCU and the clock of the ignition control chip, a preset interval for sending synchronization pulse signals is set; specifically as follows: the main control MCU sends initial heartbeat pulses to the ignition control chip multiple times at the set interval, and the ignition control chip counts between two adjacent initial heartbeat pulses, and uses the timing value when the count value is stable as the preset interval. S2: The ignition control chip sends a synchronization pulse signal to the PSI5 bus based on the preset interval, and simultaneously sends a heartbeat pulse signal to the main control MCU; After receiving the synchronization pulse signal, the accelerometer on the PSI5 bus sends sensor data to the ignition control chip in a preset order and adjusts its own clock frequency according to the interval of the synchronization pulse signal; after receiving the sensor data, the ignition control chip stores the sensor data in the storage array. When receiving sensor data from the same PSI5 bus, the ignition control chip also calculates the time interval between two adjacent sensor data and adjusts the value of the preset interval based on the time interval. After receiving the heartbeat pulse signal, the main control MCU starts timing and communicates with the ignition control chip via SPI after the timing reaches a preset time to obtain sensor data from the storage array. In addition, when the main control MCU receives the heartbeat pulse signal, it calculates the time interval between adjacent heartbeat pulse signals and adjusts the preset time based on the time interval between adjacent heartbeat pulse signals.

[0007] In one embodiment, in step S2, the ignition control chip sends a synchronization pulse signal by using a timer. The target value of the timer is the preset interval, and the timer is reset to zero each time the preset interval is reached.

[0008] In one implementation, the set interval is 250µs, 500µs, 750µs, or 1000µs.

[0009] In one implementation, the pin of the main control MCU that sends the initial heartbeat pulse is electrically connected to the pin of the ignition control chip that sends the heartbeat pulse signal, enabling bidirectional communication.

[0010] In one implementation, the pin of the main control MCU that sends the initial heartbeat pulse and the pin of the ignition control chip that sends the heartbeat pulse signal are respectively grounded through a pull-down resistor or connected to the power supply through a pull-up resistor.

[0011] In one implementation, the ignition control chip calculates the time interval between two adjacent sensor data points as follows: The ignition control chip acquires the start and end times of each sensor data, and calculates the time difference between adjacent end and start times, where the time difference is a time interval.

[0012] In one implementation, the trend of change of the preset interval is negatively correlated with the trend of change of the time interval.

[0013] In one implementation, the ignition control chip calculates the clock frequency of the accelerometer based on the start and end times of the sensor data on the PSI5 bus, calculates the difference between the clock frequency of the accelerometer and the clock frequency of the ignition control chip, and adjusts the value of the preset interval based on the difference.

[0014] In one implementation, the ignition control chip adjusts the value of the preset interval based on the difference value as follows: The original value of the preset interval is added to half of the difference value to obtain the new value of the preset interval.

[0015] In one implementation, in step S2, the ignition control chip simultaneously sends a synchronization pulse signal to all PSI5 buses; Alternatively, the ignition control chip may send synchronization pulse signals to all PSI5 buses in a time-sharing manner. At this time, when the ignition control chip receives sensor data on the same PSI5 bus, it also calculates the time interval between two adjacent sensor data and adjusts the value of the preset interval of the corresponding PSI5 bus based on the time interval.

[0016] The beneficial effects of this invention compared to existing technologies are as follows: In practical use, this invention first sets a preset interval for the synchronization pulse signal based on the clocks of the main control MCU and the ignition control chip. Then, the ignition control chip controls the clock frequency of the acceleration sensor on the PSI5 bus based on the preset interval, thereby eliminating the impact of the main control MCU's clock deviation on the communication of the entire ignition system. In addition, the ignition control chip adjusts the preset interval of the synchronization pulse signal by monitoring the interval of the sensor data on the PSI5 bus, thereby avoiding the situation where the interval of the sensor data on the PSI5 bus is too short and data corruption occurs. Finally, the main control MCU reads data based on the interval of the heartbeat pulse signal, thereby ensuring the integrity and real-time performance of the read data. Attached Figure Description

[0017] Figure 1 A schematic diagram of the existing airbag ignition system; Figure 2 This is a schematic diagram of the structure of the airbag ignition system of the present invention in the embodiment; Figure 3 This is a signal waveform diagram of bidirectional communication between the main control MCU and the ignition control chip in the embodiment; Figure 4 This is a schematic diagram of sensor data transmission on the PSI5 bus in the embodiment; Figure 5 This is a comparative schematic diagram showing the magnified sensor data interval on the PSI5 bus in the embodiment. Detailed Implementation

[0018] The illustrative embodiments of this application include, but are not limited to, a data synchronization method for an airbag ignition system.

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0020] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items. Words such as “comprising” or “including” mean that the element or object preceding “comprising” or “including” covers the element or object listed following “comprising” or “including” and its equivalents, and does not exclude other elements or objects. Words such as “connected” or “linked” are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0021] To ensure the accuracy of data acquisition and normal communication of the airbag ignition system, this embodiment provides a data synchronization method for the airbag ignition system. The structure of the airbag ignition system is as follows: Figure 2 As shown, it includes a main control MCU1 and an ignition control chip 2. The main control MCU1 communicates with the ignition control chip 2 via SPI and bidirectional communication. The ignition control chip 2 is connected to at least one PSI5 bus, and at least one acceleration sensor 3 is connected to each PSI5 bus. Data synchronization methods include the following steps: S1: Based on the clock of the main control MCU1 and the clock of the ignition control chip 2, the preset interval for sending synchronization pulse signals is set; S2: Ignition control chip 2 sends a synchronization pulse signal to the PSI5 bus at a preset interval, and simultaneously sends a heartbeat pulse signal to the main control MCU1; After receiving the synchronization pulse signal, the accelerometer 3 on the PSI5 bus sends sensor data to the ignition control chip 2 in a preset order and adjusts its own clock frequency according to the interval of the synchronization pulse signal; after receiving the sensor data, the ignition control chip stores the sensor data in the storage array. When receiving sensor data on the same PSI5 bus, the ignition control chip 2 also calculates the time interval between two adjacent sensor data and adjusts the value of the preset interval based on the time interval. After receiving the heartbeat pulse signal, the main control MCU1 starts timing and communicates with the ignition control chip 2 via SPI to obtain sensor data from the storage array after the timing reaches the preset time. In addition, when the main control MCU1 receives the heartbeat pulse signal, it calculates the time interval between adjacent heartbeat pulse signals and adjusts the preset time based on the time interval between adjacent heartbeat pulse signals.

[0022] In practical use, this invention first sets a preset interval for the synchronization pulse signal based on the clock settings of the main control MCU1 and the ignition control chip 2. Then, the ignition control chip 2 controls the clock frequency of the acceleration sensor 3 on the PSI5 bus based on the preset interval, thereby eliminating the impact of the clock deviation of the main control MCU1 on the communication of the entire ignition system. In addition, the ignition control chip 2 adjusts the preset interval of the synchronization pulse signal by monitoring the interval of the sensor data on the PSI5 bus, thereby avoiding the situation where the interval of the sensor data on the PSI5 bus is too short and data corruption occurs. Finally, the main control MCU1 reads data by using the interval of the heartbeat pulse signal, thereby ensuring the integrity and real-time performance of the read data.

[0023] In this embodiment, step S1 is equivalent to an initialization step. Specifically, in step S1, the method for setting the preset interval for sending the synchronization pulse signal based on the clock of the main control MCU1 and the clock of the ignition control chip 2 is as follows: Reference Figure 3 The main control MCU1 sends initial heartbeat pulses to the ignition control chip 2 multiple times at a set interval. The ignition control chip 2 counts between two adjacent initial heartbeat pulses and uses the time value when the count value is stable as the preset interval. In step S2, the ignition control chip 2 sends a synchronization pulse signal by using a timer. The target value of the timer is a preset interval, and the timer is reset to zero each time the preset interval is reached.

[0024] When the airbag ignition system is first started, the clock of the main control MCU1 will not immediately reach a stable state due to the influence of power supply voltage or other factors. Therefore, the main control MCU1 sends initial heartbeat pulses to the ignition control chip 2 multiple times at set intervals to ensure that the calculated preset interval is accurate.

[0025] For example, assuming the set interval is 500µs and the clock of ignition control chip 2 is 20MHz, when the count value of two stable adjacent initial heartbeat pulses of ignition control chip 2 is 9800, the target value of the timer is 9800. After obtaining the preset interval, i.e. the target value of the timer, in step S2, the timer of the ignition control chip 2 sends a synchronization pulse signal to the PSI5 bus every time it times out to 9800.

[0026] In one implementation, the set interval and number of initial heartbeat pulses sent by the main control MCU1 can be set according to actual needs. The set interval is not necessarily 500us, but can also be 250us, 750us or 1000us, and the number can be 10, 15 or 20.

[0027] in addition Figure 3 The working phase in the above is equivalent to step S2 in the method of this embodiment, at which time the ignition control chip 2 starts to work; however, in this embodiment, by having the main control MCU1 start at different working phases from the ignition control chip 2, time-sharing drive is used to avoid signal conflicts and save resources.

[0028] Specifically, in this embodiment, the method of the present invention further includes electrically connecting the pin of the main control MCU1 that sends the initial heartbeat pulse and the pin of the ignition control chip 2 that sends the heartbeat pulse signal to perform bidirectional communication.

[0029] Furthermore, in this embodiment, the pin of the main control MCU1 that sends the initial heartbeat pulse and the pin of the ignition control chip 2 that sends the heartbeat pulse signal are respectively grounded through a pull-down resistor or connected to the power supply through a pull-up resistor.

[0030] Specifically, in this embodiment, the ignition control chip 2 calculates the time interval between two adjacent sensor data points as follows: For example, refer to Figure 4 There are four accelerometers 3 on the PSI5 bus. After the synchronization pulse signal syncpulse is sent, the time slots of the sensor data of the four accelerometers 3 are slot1, slot2, slot3 and slot4 respectively. The ignition control chip 2 obtains the start time and end time of each sensor data, and calculates the time difference between adjacent end times and start times. The time difference is the time interval GAP.

[0031] Furthermore, in this embodiment, the trend of the preset interval is negatively correlated with the time interval GAP; that is, when the time interval GAP increases, the preset interval can be reduced, thereby increasing the PSI5 bus bandwidth. A schematic diagram of sensor data transmission when the time interval GAP increases is shown below. Figure 5 As shown; When the time interval GAP becomes smaller, the preset interval can be increased. This can adjust the clock frequency of the accelerometer 3, thereby increasing the time interval GAP and ultimately preventing data transmission failure when transmitting sensor data.

[0032] Specifically, in this embodiment, the ignition control chip 2 also calculates the clock frequency of the acceleration sensor 3 based on the starttime and endtime of the sensor data on the PSI5 bus, and calculates the difference between the clock frequency of the acceleration sensor 3 and the clock frequency of the ignition control chip 2, and adjusts the value of the preset interval based on the difference value; in this way, the clock of the acceleration sensor 3 can be continuously adjusted during the control process of the entire airbag ignition control system, so as to avoid the clock difference between the acceleration sensor 3 and the main control MCU 1 being too large.

[0033] Furthermore, in this embodiment, since the accelerometer 3 also has a clock-following function, the ignition control chip 2 adjusts the preset interval value based on the difference value in the following way: The original value of the preset interval is added to half of the difference value to obtain the new value of the preset interval, which can avoid clock adjustment conflicts.

[0034] In addition, in actual implementation, a time monitoring module 20 can be set in the ignition control chip 2. The time monitoring module 20 can be used to calculate the time interval between two adjacent sensor data on the PSI5 bus, calculate the clock frequency of the accelerometer, and calculate the difference between the clock frequency of the accelerometer and the clock frequency of the main control MCU1.

[0035] Specifically, in this embodiment, in step S2, the ignition control chip 2 simultaneously sends a synchronization pulse signal to all PSI5 buses; Alternatively, the ignition control chip can send synchronization pulse signals to all PSI5 buses in a time-sharing manner. At this time, when the ignition control chip 2 receives sensor data on the same PSI5 bus, it also calculates the time interval between two adjacent sensor data and adjusts the value of the preset interval of the corresponding PSI5 bus based on the time interval. In addition, for the main control MCU1, the main control MCU1 can start timing based on the first sent synchronization pulse signal, and then read the sensor data stored in the ignition control chip 2 after the timing time is up. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this invention. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A data synchronization method for an airbag ignition system, characterized in that, The airbag ignition system includes a main control MCU and an ignition control chip. The main control MCU communicates with the ignition control chip via SPI. The ignition control chip is connected to at least one PSI5 bus, and at least one acceleration sensor is connected to each PSI5 bus. The steps include the following: S1: Based on the clock of the main control MCU and the clock of the ignition control chip, a preset interval for sending synchronization pulse signals is set; specifically as follows: the main control MCU sends initial heartbeat pulses to the ignition control chip multiple times at the set interval, and the ignition control chip counts between two adjacent initial heartbeat pulses, and uses the timing value when the count value is stable as the preset interval. S2: The ignition control chip sends a synchronization pulse signal to the PSI5 bus based on the preset interval, and simultaneously sends a heartbeat pulse signal to the main control MCU; After receiving the synchronization pulse signal, the accelerometer on the PSI5 bus sends sensor data to the ignition control chip in a preset order and adjusts its own clock frequency according to the interval of the synchronization pulse signal; after receiving the sensor data, the ignition control chip stores the sensor data in the storage array. When receiving sensor data from the same PSI5 bus, the ignition control chip also calculates the time interval between two adjacent sensor data and adjusts the value of the preset interval based on the time interval. After receiving the heartbeat pulse signal, the main control MCU starts timing and communicates with the ignition control chip via SPI after the timing reaches a preset time to obtain sensor data from the storage array. In addition, when the main control MCU receives the heartbeat pulse signal, it calculates the time interval between adjacent heartbeat pulse signals and adjusts the preset time based on the time interval between adjacent heartbeat pulse signals.

2. The data synchronization method for an airbag ignition system according to claim 1, characterized in that, In step S2, the ignition control chip sends a synchronization pulse signal by using a timer. The target value of the timer is the preset interval, and the timer is reset to zero each time the preset interval is reached.

3. The data synchronization method for an airbag ignition system according to claim 2, characterized in that, The set interval is 250us, 500us, 750us or 1000us.

4. The data synchronization method for an airbag ignition system according to claim 2, characterized in that, The pin that sends the initial heartbeat pulse from the main control MCU is electrically connected to the pin that sends the heartbeat pulse signal from the ignition control chip to enable bidirectional communication.

5. The data synchronization method for an airbag ignition system according to claim 2, characterized in that, The pin that sends the initial heartbeat pulse from the main control MCU and the pin that sends the heartbeat pulse signal from the ignition control chip are respectively connected to the power supply via pull-down resistors or pull-up resistors.

6. A data synchronization method for an airbag ignition system according to any one of claims 2-5, characterized in that, The ignition control chip calculates the time interval between two adjacent sensor data points as follows: The ignition control chip acquires the start and end times of each sensor data, and calculates the time difference between adjacent end and start times, where the time difference is a time interval.

7. The data synchronization method for an airbag ignition system according to claim 6, characterized in that, The preset interval is negatively correlated with the time interval.

8. The data synchronization method for an airbag ignition system according to claim 7, characterized in that, The ignition control chip calculates the clock frequency of the accelerometer based on the start and end times of the sensor data on the PSI5 bus, calculates the difference between the clock frequency of the accelerometer and the clock frequency of the ignition control chip, and adjusts the value of the preset interval based on the difference.

9. A data synchronization method for an airbag ignition system according to claim 8, characterized in that, The ignition control chip adjusts the value of the preset interval based on the difference value in the following way: The original value of the preset interval is added to half of the difference value to obtain the new value of the preset interval.

10. A data synchronization method for an airbag ignition system according to claim 9, characterized in that, In step S2, the ignition control chip simultaneously sends synchronization pulse signals to all PSI5 buses; Alternatively, the ignition control chip may send synchronization pulse signals to all PSI5 buses in a time-sharing manner. At this time, when the ignition control chip receives sensor data on the same PSI5 bus, it also calculates the time interval between two adjacent sensor data and adjusts the value of the preset interval of the corresponding PSI5 bus based on the time interval.

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