A vehicle misfire detection method

Abstract

The application discloses a kind of vehicle point fire detection methods.Method comprising the following steps: MCU is collected to the voltage Vb of vehicle battery;MCU is compared with the threshold voltage Vt to the battery voltage Vb collected, and it is judged as vehicle type;Set off fire voltage initial value is Vb1, ignition voltage initial value is Vb2, voltage rising speed initial value is Sv1, MCU continuously detects battery voltage Vb, and rising speed is used to judge whether vehicle is ignited;Detection voltage drop speed Sv2 is used to judge whether vehicle is extinguished.The application obtains the voltage value of vehicle battery by accessing to vehicle cigarette lighter interface, without professional personnel connecting installation ignition line, and the point fire detection of vehicle can be realized;And through the determination of threshold voltage and the real-time updating of ignition voltage and extinguishing voltage, the misjudgment problem caused by the aging of vehicle generator and battery is avoided, and the detection accuracy is improved.

Description

Technical Field

[0001] This invention belongs to the field of vehicle inspection technology, and in particular relates to a method for detecting vehicle engine start-stop. Background Technology

[0002] Normally, when a vehicle is turned off, in order to minimize battery drain and prevent the vehicle's electrical systems from depleting the battery, the vehicle's electrical system will determine the vehicle's ignition state and enter a low-power mode to reduce battery consumption.

[0003] Currently, common methods for detecting a vehicle's ignition status using automotive electrical products include two approaches. One is to connect a separate signal detection cable from the automotive electrical system to the vehicle's ignition cable. By detecting the voltage on the ignition cable, the system can determine whether the vehicle is off or ignited. The other approach is for the automotive electrical system to directly detect the vehicle's battery voltage. Typically, when the vehicle is ignited, the alternator charges the battery, resulting in a higher battery voltage than when the engine is off. By setting a voltage threshold, the system can determine whether the vehicle has started.

[0004] Vehicle electrical appliances can be easily plugged into the cigarette lighter socket, but the ignition signal wire needs to be connected to the vehicle's own ignition wire. The location of the ignition wire varies from vehicle to vehicle, and professional wire cutting and installation are required, which is cumbersome and carries certain risks.

[0005] The method of directly detecting the vehicle's battery voltage through the power cord and judging whether the detected voltage is close to the set threshold voltage has certain differences in parameters for each vehicle. Furthermore, as the vehicle ages, the output voltage of the vehicle's alternator and battery may also change, which may lead to misjudgment. Summary of the Invention

[0006] The purpose of this invention is to provide a vehicle start-stop detection method. By connecting to the vehicle's cigarette lighter interface to obtain the vehicle's battery voltage value, the vehicle can be started-stop detected without the need for professional personnel to connect and install the ignition wires. Furthermore, by determining the threshold voltage and updating the ignition and shutdown voltages in real time, the method solves the problem of misjudgment caused by battery aging.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0008] This invention relates to a method for detecting vehicle engine start-stop, comprising the following steps:

[0009] Stp1 and MCU collect and detect the voltage Vb of the vehicle battery;

[0010] Stp2, Determine Vehicle Type

[0011] The MCU compares the collected battery voltage Vb with the threshold voltage Vt. When Vb is less than Vt, it is determined to be a small vehicle; when Vb is greater than Vt, it is determined to be a medium or large vehicle.

[0012] Stp3, Vehicle Ignition Check

[0013] The initial values ​​for the shutdown voltage, ignition voltage, and voltage rise rate are set to Vb1, Vb2, and Sv1, respectively.

[0014] The MCU continuously monitors the battery voltage Vb. If Vb is less than Vb2, it uses the rolling average of Vb over a period of time to update Vb1. At the same time, it calculates the rate of increase of the battery voltage Vb. When the rate of increase is greater than Sv1, it can be determined that the vehicle has been started.

[0015] Stp4, Vehicle Off-Roll Detection

[0016] After the vehicle is ignited, the MCU continues to monitor the battery voltage Vb and updates Vb2 with its rolling average over a period of time. At the same time, it updates Sv1 based on the newly acquired values ​​of Vb2 and Vb1, and uses the updated Vb2 in the comparison with Vb in the next loop.

[0017] Based on Vb2 and Vb1, calculate the voltage drop rate and store the midpoint in Sv2. Continuously monitor the battery voltage Vb. When the voltage drop rate reaches Sv2, it is determined that the vehicle has been turned off.

[0018] Preferably, the threshold voltage Vt is set to 17V. When Vb is detected to be less than 17V, it is determined to be a small vehicle; when Vb is detected to be greater than 17V, it is determined to be a medium or large vehicle.

[0019] Preferably, the initial value of the shutdown voltage Vb1 set for the small vehicle is 12.5V, the initial value of the ignition voltage Vb2 is 13V, and the initial value of the voltage rise rate Sv1 is 1V / 5S.

[0020] Preferably, the initial value of the shutdown voltage Vb1 for the medium and large vehicles is 25V, the initial value of the ignition voltage Vb2 is 27V, and the initial value of the voltage rise rate Sv1 is 2V / 5S.

[0021] Preferably, the MCU obtains the vehicle battery voltage Vb by connecting to the vehicle's cigarette lighter interface.

[0022] The present invention has the following beneficial effects:

[0023] This invention obtains the vehicle battery voltage value by connecting to the vehicle's cigarette lighter interface, enabling vehicle ignition and shutdown detection without requiring professional personnel to connect and install the ignition wires. By determining threshold voltages and updating the ignition and shutdown voltages in real time, it avoids misjudgment problems caused by the aging of the vehicle's alternator and battery, thereby improving detection accuracy.

[0024] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart of a vehicle start-up detection method according to the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1 As shown, the present invention is a method for detecting vehicle engine stall, comprising the following steps:

[0029] Stp1, the MCU collects and detects the vehicle battery voltage Vb; the MCU obtains the vehicle battery voltage Vb by connecting to the vehicle's cigarette lighter interface.

[0030] Stp2, Determine Vehicle Type

[0031] The MCU compares the collected battery voltage Vb with the threshold voltage Vt. When Vb is less than Vt, it is identified as a small vehicle; when Vb is greater than Vt, it is identified as a medium or large vehicle. The threshold voltage Vt is set to 17V. When Vb is less than 17V, it is identified as a small vehicle; when Vb is greater than 17V, it is identified as a medium or large vehicle.

[0032] Stp3, Vehicle Ignition Check

[0033] The initial values ​​for the shutdown voltage, ignition voltage, and voltage rise rate are set to Vb1, Vb2, and Sv1, respectively. For small vehicles, the initial values ​​for the shutdown voltage (Vb1) are 12.5V, Vb2 (13V), and Sv1 (1V / 5S). For medium and large vehicles, the initial values ​​for the shutdown voltage (Vb1) are 25V, Vb2 (27V), and Sv1 (2V / 5S).

[0034] The MCU continuously monitors the battery voltage Vb. If Vb is less than Vb2, it uses the rolling average of Vb over a period of time to update Vb1. At the same time, it calculates the rate of increase of the battery voltage Vb. When the rate of increase is greater than Sv1, it can be determined that the vehicle has been started.

[0035] Stp4, Vehicle Off-Roll Detection

[0036] After the vehicle is ignited, the MCU continues to monitor the battery voltage Vb and updates Vb2 with its rolling average over a period of time. At the same time, it updates Sv1 based on the newly acquired values ​​of Vb2 and Vb1, and uses the updated Vb2 in the comparison with Vb in the next loop.

[0037] Based on Vb2 and Vb1, calculate the voltage drop rate and store the midpoint in Sv2. Continuously monitor the battery voltage Vb. When the voltage drop rate reaches Sv2, it is determined that the vehicle has been turned off.

[0038] Example 1:

[0039] This embodiment describes the workflow of the detection device when the vehicle is identified as a small vehicle: The initial values ​​of the shutdown voltage (Vb1) and ignition voltage (Vb2) are set to 12.5V and 13V respectively, with an initial voltage rise rate of Sv1. The battery voltage (Vb) is continuously monitored. If Vb is less than Vb2, its rolling average over a period of time is used to update Vb1. This means the shutdown voltage is dynamically changing to accommodate differences between different vehicle batteries. Simultaneously, the voltage rise rate is calculated. Since the vehicle battery voltage does not fluctuate significantly during normal operation, when the rise rate exceeds Sv1, the vehicle is considered to have started. After the vehicle is identified as started, the battery voltage is continuously monitored, and its rolling average over a period of time is used to update Vb2 and Sv1. This accommodates differences between different vehicles (vehicle alternators). Vb2 is then used in the next cycle for comparison with Vb. Based on Vb2 and Vb1, the voltage drop rate is calculated, and its value is stored in Sv2. The battery voltage is continuously monitored, and when the voltage drop rate reaches Sv2, the vehicle is considered to have stopped.

[0040] For example, if the initial value of the vehicle shutdown voltage Vb1 is updated to 13.5V and the updated value of the vehicle ignition voltage Vb2 is 14V, then the rate of decrease Sv2 is updated to 0.5V / 5S. The MCU checks the battery voltage every 5S. When the next detection cycle is completed, if the MCU detects that the real-time battery voltage Vb is 13V, then the rate of decrease is greater than the previous 0.5V / 5S, and the vehicle is determined to be off.

[0041] Example 2:

[0042] This embodiment describes the workflow of the detection device when the vehicle is a medium or large-sized vehicle: The main difference between small and medium / large-sized vehicles in this invention is the voltage. When determining if a vehicle is a medium or large-sized vehicle, the initial values ​​of the shutdown voltage Vb1 and ignition voltage Vb2 are set to 25V, and the initial voltage rise rate is set to Sv1. The battery voltage Vb is continuously monitored. If Vb is less than Vb2, its rolling average over a period of time is used to update Vb1. That is, the shutdown voltage value is dynamically changing to adapt to the differences between batteries in different vehicles. At the same time, the voltage rise rate is calculated. Since the vehicle battery voltage does not fluctuate significantly during normal operation, when the rise rate is greater than Sv1, it can be determined that the vehicle has been ignited. After determining that the vehicle has been ignited, the battery voltage continues to be monitored, and its rolling average over a period of time is used to update Vb2 and Sv1. This adapts to the differences between different vehicles (vehicle alternators), and Vb2 is used in the comparison with Vb in the next cycle. Based on Vb2 and Vb1, calculate the voltage drop rate and store the value in Sv2. Continuously monitor the battery voltage. When the voltage drop rate reaches Sv2, it is determined that the vehicle has been turned off.

[0043] It is worth noting that the various units included in the above system embodiments are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0044] Furthermore, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware, and the corresponding program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, or optical disk.

[0045] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A vehicle misfire detection method, characterized by, It comprises the following steps: Stp1, the MCU collects and detects the voltage Vb of the vehicle storage battery; Stp2, determine the vehicle type The MCU compares the collected storage battery voltage Vb with the threshold voltage Vt, when Vb is less than Vt, it is determined to be a small vehicle; when Vb is greater than Vt, it is determined to be a medium or large vehicle; Stp3, vehicle ignition detection The initial value of the off voltage is Vb1, the initial value of the ignition voltage is Vb2, and the initial value of the voltage rising speed is Sv1, The MCU continues to detect the storage battery voltage Vb, if Vb is less than Vb2, its rolling average value for a period of time is used to update Vb1, and the rising speed of the storage battery voltage Vb is calculated, when the rising speed is greater than Sv1, it is determined that the vehicle has been ignited; Stp4, vehicle off detection After determining the vehicle ignition, the MCU continues to detect the storage battery voltage Vb, and updates Vb2 with its rolling average value for a period of time, and updates Sv1 according to the values of Vb2 and Vb1, and uses the updated Vb2 in the comparison with Vb in the next cycle; According to Vb2 and Vb1, the voltage drop speed is calculated and the number is stored in Sv2, and the storage battery voltage Vb is continuously detected, when the voltage drop speed reaches Sv2, it is determined that the vehicle has been turned off.

2. The vehicle misfire detection method of claim 1, wherein The threshold voltage Vt is set to 17V, when Vb is less than 17V, it is determined to be a small vehicle; when Vb is greater than 17V, it is determined to be a medium or large vehicle.

3. The vehicle misfire detection method of claim 2, wherein The initial value of the off voltage Vb1 of the small vehicle is 12.5V, the initial value of the ignition voltage Vb2 is 13V, and the initial value of the voltage rising speed Sv1 is 1V / 5S.

4. The vehicle misfire detection method of claim 2, wherein The initial value of the off voltage Vb1 of the medium or large vehicle is 25V, the initial value of the ignition voltage Vb2 is 27V, and the initial value of the voltage rising speed Sv1 is 2V / 5S.

5. The method of claim 1, wherein, The MCU is connected with the cigarette lighter interface of the vehicle to obtain the voltage Vb of the vehicle storage battery.

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