An online performance detection method and system of an engine ignition system

Abstract

The application discloses an online performance detection method and system of an engine ignition system, which comprises outputting a driving signal to a measured ignition system; collecting a current signal of the measured ignition system to generate a current waveform and extracting a characteristic parameter according to the current waveform; comparing the characteristic parameter with a preset standard parameter range and outputting a diagnosis result of the measured ignition system according to a comparison result; and the characteristic parameter comprises a current amplitude, a response time and a spark duration. By collecting a current waveform of a secondary loop of an ignition coil and extracting three characteristic parameters of the response time, the current amplitude and the spark duration, and comparing the three characteristic parameters with a preset standard range, the ignition voltage, the response time and the spark duration of the ignition system can be detected without disassembling and contacting a spark plug on an engine assembly production line.

Description

Technical Field

[0001] This invention relates to the field of engine ignition system testing, and in particular to an online performance testing method and system for engine ignition systems. Background Technology

[0002] On the engine assembly line, after the ignition system is assembled, its spark plugs are installed inside the engine block and are tightly wrapped by metal parts such as covers, cylinder heads, and cylinder blocks. This makes it impossible to measure the ignition voltage, response time, and spark duration by directly contacting the spark plug electrodes with conventional test probes.

[0003] Existing technologies typically employ random sampling to disassemble and measure engines after they have come off the assembly line. This method is inefficient and costly, and it cannot test all ignition systems. As a result, substandard ignition systems can affect the overall quality of the engine. Therefore, there is a need to solve the technical problem of online testing of ignition system performance on the engine assembly line without direct contact with the spark plugs. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is: no need to disassemble the detection ignition system.

[0005] The above-mentioned technical problems are solved by the following technical solution: The present invention proposes an online performance testing method for an engine ignition system, which includes outputting a drive signal to the ignition system under test; The current signal of the ignition system under test is acquired, a current waveform is generated, and feature parameters are extracted based on the current waveform. The characteristic parameters are compared with a preset standard parameter range, and the diagnostic results of the tested ignition system are output based on the comparison results. The characteristic parameters include current amplitude, response time, and spark duration.

[0006] In a preferred embodiment of the online performance testing method for the engine ignition system of the present invention: the step of extracting feature parameters based on the current waveform includes: Record the starting moment when the drive signal transitions from high to low level; The time difference between the start time and the first time is calculated as the response time, and the first time is obtained when the current value is not less than the first preset threshold. The peak value of the current waveform is obtained as the current amplitude; After obtaining the second moment when the current value first drops to no more than a second preset threshold after the first moment, calculate the time difference between the first moment and the second moment as the spark duration.

[0007] In a preferred embodiment of the online performance testing method for the engine ignition system of the present invention: outputting the performance diagnosis result of the tested ignition system based on the comparison result includes: In response to the response time being within a preset response time range, it is determined whether the current amplitude is within a preset amplitude range; In response to the current amplitude being within a preset amplitude range, it is determined whether the spark duration is within a preset duration range; In response to the spark duration being within a preset duration range, a qualified diagnostic result is output; If any of the response time, current amplitude, or spark duration is not within the corresponding preset range, an unqualified diagnostic result is output.

[0008] In a preferred embodiment of the online performance testing method for the engine ignition system of the present invention: the high-level holding time of the drive signal, the preset standard parameter range of the response time, and the preset standard parameter range of the spark duration are all calibrated and set according to the charging time, secondary high voltage, and internal resistance of the ignition system under test.

[0009] The present invention also proposes an electronic device, characterized in that it includes: a processor and a memory, wherein the memory stores a computer program, and the processor is configured to execute the computer program to implement the above-described method for online performance testing of the engine ignition system.

[0010] The present invention also proposes an online performance testing system for an engine ignition system, including a drive module for outputting drive signals to the ignition system under test; A current sampling module is connected in series in the secondary circuit of the ignition coil in the ignition system under test, and is used to collect the current signal of the secondary circuit. The processing module, connected to the current sampling module, is used to receive the current signal, generate a current waveform, extract feature parameters based on the current waveform, and compare the feature parameters with a preset standard parameter range to output a performance diagnosis result.

[0011] In a preferred embodiment of the online performance testing system for the engine ignition system described in this invention: the current sampling module includes, A sampling resistor is connected in series in the secondary circuit of the ignition coil; A differential amplifier circuit, connected in parallel with the sampling resistor, is used to acquire the differential voltage across the sampling resistor and convert the differential voltage into a current signal of the secondary circuit, which is then input to the processing module.

[0012] In a preferred embodiment of the online performance testing system for the engine ignition system of the present invention: the processing module includes a field-programmable gate array (FPGA), which is used to perform the generation of the current waveform, the extraction of feature parameters, and comparison and diagnosis.

[0013] In a preferred embodiment of the online performance testing system for the engine ignition system of the present invention, a display module is further included, which is connected to the processing module and is used to receive and display the current waveform and the performance diagnostic results generated by the processing module.

[0014] In a preferred embodiment of the online performance testing system for the engine ignition system described in this invention: the drive module includes a power output terminal, a drive signal output terminal, and a ground terminal.

[0015] The beneficial effects of this invention are as follows: by collecting the current waveform of the secondary circuit of the ignition coil and extracting three characteristic parameters—response time, current amplitude, and spark duration—and comparing them with a preset standard range, it is possible to detect the ignition voltage, response time, and spark duration of the ignition system without disassembling or contacting the spark plug on the engine assembly line. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A flowchart of an online performance testing method for an engine ignition system is shown. Figure 2 The overall structural diagram of the online performance testing system for the engine ignition system is shown. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0019] Reference Figure 1This embodiment provides an online performance testing method for an engine ignition system, including the following steps: S1: Outputs a drive signal to the ignition system under test; S2: Acquire the current signal of the secondary circuit 5 of the ignition coil in the ignition system under test, generate the current waveform, and extract the characteristic parameters based on the current waveform; S3: Compare the characteristic parameters with the preset standard parameter range, and output the diagnostic results of the tested ignition system based on the comparison results; It should be noted that existing technologies typically use a sampling inspection method to disassemble the engine after it comes off the production line and then measure it. This method is inefficient and costly, and it cannot test all ignition systems. As a result, substandard ignition systems affect the overall quality of the engine. Therefore, it is necessary to solve the technical problem of online testing of ignition system performance on the engine assembly line without direct contact with the spark plugs.

[0020] This invention acquires the current waveform of the secondary circuit of the ignition coil and extracts three characteristic parameters: response time, current amplitude, and spark duration. By comparing these parameters with a preset standard range, it enables the detection of the ignition voltage, response time, and spark duration of the ignition system without disassembling or contacting the spark plugs on the engine assembly line.

[0021] Specifically, S1: outputs a drive signal to the ignition system under test; In this embodiment, step S1 specifically involves the test equipment outputting a drive signal to the ignition system under test to simulate the control behavior of the engine control unit on the ignition coil. Specifically, before outputting the drive signal, the test equipment needs to be connected to the ignition system under test. The test equipment includes at least a signal output terminal and a ground terminal. The signal output terminal is connected to the control signal input terminal of the ignition coil, i.e., the drive terminal of the IGBT, and the ground terminal is connected to the ECU ground of the ignition coil. After completing the wiring, the test equipment can send a drive signal to the ignition coil.

[0022] Specifically, the drive signal is a square wave signal, which includes two stages: a high-level stage and a low-level stage. The high-level stage corresponds to the charging stage, during which the IGBT is turned on and the primary coil of the ignition coil begins to store energy. The low-level stage corresponds to the turn-off stage, during which the IGBT is turned off, the current in the primary coil changes abruptly, and the secondary coil induces a high voltage, which breaks down the spark plug 52 gap to generate a spark.

[0023] In this embodiment, the drive signal parameters output by the test device are as follows: the high-level voltage is set to 5V, the low-level voltage is set to 0V, and the holding time of the high level is recorded as T1. It needs to be set according to the energy storage characteristics of the ignition coil under test. For example, for the ignition coil in this embodiment, T1 is set to 4ms. This time is sufficient for the primary coil current to reach the saturation value so as to store enough energy.

[0024] Through the above steps, the test equipment successfully outputs a drive signal with charging time and shutdown time to the ignition system under test, providing a timing reference for acquiring the secondary circuit 5 current signal.

[0025] S2: Acquire the current signal of the secondary circuit 5 of the ignition coil in the ignition system under test, generate the current waveform, and extract the characteristic parameters based on the current waveform; In this embodiment of the application, after generating a current waveform, the test equipment needs to extract three characteristic parameters from the current waveform: response time, current amplitude, and spark duration. Specifically, this includes the following steps S2.1 to S2.4: S2: Acquire the current signal of the secondary circuit 5 of the ignition coil in the ignition system under test, generate the current waveform, and extract the characteristic parameters based on the current waveform; In this embodiment of the application, after generating a current waveform, the test equipment needs to extract three characteristic parameters from the current waveform: response time, current amplitude, and spark duration. Specifically, this includes the following steps S2.1 to S2.4.

[0026] S2.1: Record the starting moment when the drive signal transitions from high level to low level; The test equipment's internal timer precisely records the instant the drive signal transitions from high to low, marking this instant as the start time. This start time serves as the reference point for calculating all subsequent time parameters.

[0027] For example, suppose the test device pulls the drive signal from high level to low level 4 milliseconds after the start of the test. The start time is recorded as 4 milliseconds. In order to facilitate subsequent calculations with microsecond-level precision, the test device internally converts this time into microsecond units, such as 4000 microseconds.

[0028] S2.2: Obtain the first moment when the current value is not less than the first preset threshold, and calculate the time difference between the start time and the first moment as the response time; The testing equipment reads the current value of the current waveform point by point at fixed time intervals, starting from the initial moment. A first preset threshold is set, denoted as I. 1， When the current value is first detected to be greater than or equal to I1, this moment is recorded as the first moment. The response time is the difference between the first moment and the initial moment.

[0029] The setting of the first preset threshold I1 needs to be determined based on the breakdown characteristics of the ignition system. For example, in the engine ignition system of this embodiment, the response time ranges from 10 to 20 microseconds. I1 is set to 10 amperes. Taking the generated current waveform data as an example, the current value is 0 amperes at the initial time of 0 microseconds, and the current value first reaches 10 amperes 12 microseconds after the initial time. Therefore, the first moment is 12 microseconds. The response time is equal to 12 microseconds minus 0 microseconds, resulting in a calculated response time of 12 microseconds.

[0030] S2.3: Obtain the peak value of the current waveform as the current amplitude; The testing equipment searches for the maximum value of the current waveform within the entire sampling window after the start time, that is, the time period from the start time to the time corresponding to the sum of the start time and the sampling duration. This maximum value is recorded as the current amplitude. The current amplitude is used to indirectly characterize the ignition voltage of the ignition system. The larger the current amplitude, the higher the corresponding ignition voltage.

[0031] For example, using the current waveform data described above, within a sampling window from 0 microseconds to 200 microseconds at the start time, the current waveform reaches its maximum value of 120 amperes 15 microseconds after the start time. Thereafter, the current value gradually decreases, so the current amplitude is equal to 120 amperes.

[0032] S2.4: Obtain the second moment after the first moment when the current value first drops to no more than the second preset threshold, and calculate the time difference between the first moment and the second moment as the spark duration; The testing equipment continues to read the current value of the current waveform point by point, starting from the first moment. A second preset threshold is set, denoted as I. 1， When the current value is first detected to be less than or equal to I1, this moment is recorded as the second moment. The spark duration is the difference between the second moment and the first moment.

[0033] The setting of the second preset threshold I1 needs to be determined based on the residual current when the spark extinguishes. For example, the spark duration ranges from 120 to 150 microseconds. In this embodiment, I1 is set to 2 amperes. Taking the above current waveform data as an example, the first moment is 12 microseconds. After that, the current value gradually decreases. 118 microseconds after the first moment, that is, at a total time of 130 microseconds, the current value drops to 2 amperes. The first time it is not greater than 2 amperes, so the second moment is 130 microseconds. The spark duration is equal to 130 microseconds minus 12 microseconds, and the calculated spark duration is 118 microseconds.

[0034] S3: Compare the characteristic parameters with the preset standard parameter range, and output the diagnostic results of the tested ignition system based on the comparison results; In this embodiment of the application, after the test equipment extracts the response time, current amplitude and spark duration, it needs to compare these three characteristic parameters with the preset standard parameter ranges respectively, and output the diagnostic results of the ignition system under test based on the comparison results. The preset standard parameter ranges include the response time range, current amplitude range and spark duration range. These standard ranges are pre-calibrated and stored in the test equipment according to the design parameters of the ignition system under test.

[0035] For example, in the engine ignition system of this embodiment, the response time is set to 10 microseconds to 20 microseconds, the current amplitude is set to 100 amperes to 150 amperes, and the spark duration is set to 120 microseconds to 150 microseconds.

[0036] The specific diagnostic process is as follows: If the response time is within the preset response time range, then the system continues to determine whether the current amplitude is within the preset amplitude range. If the response time is not within the preset response time range, then the system directly outputs a non-compliance diagnosis result and does not perform any further judgment.

[0037] If the current amplitude is within the preset range, the system continues to determine if the spark duration is within the preset range. If the current amplitude is not within the preset range, an unqualified diagnostic result is output, and no further judgment is made.

[0038] If the spark duration is within the preset duration range, a qualified diagnostic result is output; otherwise, an unqualified diagnostic result is output.

[0039] Taking the feature parameters extracted in step S2 above as an example, the response time is 12 microseconds, which is within the response time range of 10 to 20 microseconds. Therefore, the current amplitude is further judged. The current amplitude is 120 amperes, which is within the amplitude range of 100 to 150 amperes. Therefore, the spark duration is further judged. The spark duration is 130 microseconds, which is within the duration range of 120 to 150 microseconds. Therefore, a qualified diagnostic result is output.

[0040] If a parameter is not up to standard, for example, if the response time is assumed to be 25 microseconds and exceeds the range of 10 to 20 microseconds, then the response time is not within the preset response time range. The test equipment will directly output a failure diagnosis result and can indicate on the display that the response time exceeds the standard. It will no longer judge the current amplitude and spark duration.

[0041] Through the above S3 steps, the testing equipment realizes online detection and diagnosis of the engine ignition system performance, and can automatically determine whether the response time, ignition voltage and spark duration of the ignition system meet the requirements.

[0042] In one embodiment of this application, an electronic device is also provided, which is applicable to the online performance testing method of the engine ignition system described above. The electronic device includes a memory and a processor, wherein the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the online performance testing method of the engine ignition system described above.

[0043] Please refer to Figure 2 In one embodiment of this application, an online performance testing system for an engine ignition system is also provided. This system is used to implement the online performance testing method of the above method embodiment. The system includes a drive module 1, a current sampling module 2, and a processing module 3.

[0044] Specifically, the drive module 1 is used to output a drive signal to the ignition system under test. The drive module 1 can generate a square wave signal, which includes a high level phase and a low level phase. The high level phase corresponds to the charging phase, and the low level phase corresponds to the shutdown phase, simulating the engine control unit's control of the ignition coil.

[0045] The current sampling module 2 is connected in series in the secondary circuit 5 of the ignition coil in the ignition system under test. It is used to collect the current signal of the secondary circuit 5. This module can acquire the current change of the secondary coil in the ignition process in real time and convert the current signal into an electrical signal that can be processed. The output terminal of the current sampling module 2 is electrically connected to the input terminal of the processing module 3.

[0046] The processing module 3 is connected to the current sampling module 2 and is used to receive current signals, generate current waveforms, extract feature parameters based on the current waveforms, and compare the feature parameters with preset standard parameters to output diagnostic results.

[0047] In another embodiment, the current sampling module 2 includes a sampling resistor 21 and a differential amplifier circuit 22. The sampling resistor 21 is connected in series in the secondary circuit 5 of the ignition coil. The secondary circuit 5 refers to the complete path from the high-voltage end of the secondary winding 51 of the ignition coil through the spark plug 52, the engine block 53, the engine ground wire, and back to the low-voltage end of the secondary winding 51. One end of the sampling resistor 21 is connected to the low-voltage end of the secondary winding 51 of the ignition coil, and the other end is connected to the engine ground wire.

[0048] The differential amplifier circuit 22 is connected in parallel with the sampling resistor 21 to collect the differential voltage across the sampling resistor 21 and convert the differential voltage into a current signal of the secondary circuit 5, which is then input to the processing module 3. The positive input terminal of the differential amplifier circuit 22 is connected to the high potential terminal of the sampling resistor 21, the negative input terminal is connected to the low potential terminal of the sampling resistor 21, and the output terminal is connected to the processing module 3.

[0049] The voltage output by the differential amplifier circuit 22 and the secondary current satisfy the following relationship: the secondary current equals the differential voltage divided by the sampling resistor 21. For example, if the sampling resistor 21 is R_s, the gain of the differential amplifier circuit 22 is 1 or appropriately set according to the signal amplitude, after the processing module 3 acquires the differential voltage, it restores the secondary current value according to the formula that the current equals the differential voltage divided by the sampling resistor 21, thus forming a current waveform.

[0050] By combining the sampling resistor 21 and the differential amplifier circuit 22, the current sampling module 2 can convert the transient current signal in the secondary circuit 5 of the ignition coil into a low-voltage signal that can be collected by the processing module 3, while avoiding interference from the high-voltage circuit to the low-voltage circuit.

[0051] As an optional embodiment, the processing module 3 includes a field-programmable gate array 31, which is used to perform current waveform generation, feature parameter extraction, and comparison diagnosis.

[0052] The field-programmable gate array 31 integrates programmable logic units, block memory, digital signal processing units, and input / output interfaces. In this embodiment, the field-programmable gate array is connected to the driver module 1 through its output pin module 32 to output drive signals. At the same time, the field-programmable gate array is connected to the current sampling module 2 through its internal analog-to-digital converter interface or an external analog-to-digital converter to receive the current signal of the secondary circuit 5.

[0053] The field-programmable gate array (FPGA) is internally configured with waveform generation logic. When the falling edge of the drive signal is detected, the analog-to-digital converter is started to continuously sample and the sampled data is stored in the block memory in sequence to form a complete current waveform. The FPGA is also internally configured with feature parameter extraction logic. This logic reads the current waveform data from the block memory and extracts the response time, current amplitude and spark duration according to a preset algorithm. For the specific extraction method, please refer to the aforementioned step S2.

[0054] The field-programmable gate array (FPGA) is also equipped with comparison and diagnostic logic. This logic compares the extracted feature parameters with a preset standard parameter range in sequence, and outputs a pass or fail diagnostic signal based on the comparison result. As an optional embodiment, the system also includes a display module 4, which is connected to the processing module 3 and is used to receive and display the current waveform and performance diagnostic results generated by the processing module 3.

[0055] Specifically, the display module 4 can be an LCD screen, a touch screen, or an OLED screen. The display module 4 is connected to the processing module 3 via a parallel bus, a serial peripheral interface, or a low-voltage differential signal interface. The processing module 3 packages and sends the collected current waveform data, calculated characteristic parameters, and diagnostic results to the display module 4 for presentation.

[0056] As an optional embodiment, the drive module 1 includes a power output terminal, a drive signal output terminal, and a ground terminal. The power output terminal is connected to the positive power supply of the ignition system under test, the drive signal output terminal is connected to the control signal input terminal of the ignition system under test, and the ground terminal is connected to the ground terminal of the ignition system under test to simulate the electrical interface of the engine control unit.

[0057] Specifically, the engine control unit, or ECU for short, provides power, drive signals, and grounding circuits to the ignition coil in a real vehicle environment. In order to simulate the working state of the ECU on the production line, the drive module 1 in this embodiment integrates these three interfaces.

[0058] The power output terminal is used to provide DC operating voltage to the ignition coil, and the drive signal output terminal is used to output a square wave drive signal. The high and low level voltage values ​​and the high level holding time of this signal can be configured according to the requirements of the ignition system under test. The ground terminal is used to connect to the ECU ground of the ignition system under test to form a complete electrical circuit. The ground terminal is connected to the internal reference ground of the test equipment to ensure that the reference potential of the drive signal and the current sampling signal are consistent.

[0059] Through the above three-terminal interface, the test equipment can completely simulate the ECU's control method of the ignition coil. Without modifying the original wiring harness of the engine under test, the performance of the ignition system can be detected online. The drive module 1 can be integrated with the processing module 3 on the same circuit board, or it can be a separate signal conditioning board.

[0060] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A method for online performance testing of an engine ignition system, characterized in that: include, Output drive signal to the ignition system under test; The current signal of the ignition system under test is acquired, a current waveform is generated, and feature parameters are extracted based on the current waveform. The characteristic parameters are compared with a preset standard parameter range, and the diagnostic results of the tested ignition system are output based on the comparison results. The characteristic parameters include current amplitude, response time, and spark duration.

2. The online performance testing method for an engine ignition system according to claim 1, characterized in that: The step of extracting feature parameters based on the current waveform includes: Record the starting moment when the drive signal transitions from high to low level; The time difference between the start time and the first time is calculated as the response time, and the first time is obtained when the current value is not less than the first preset threshold. The peak value of the current waveform is obtained as the current amplitude; After obtaining the second moment when the current value first drops to no more than a second preset threshold after the first moment, calculate the time difference between the first moment and the second moment as the spark duration.

3. The online performance testing method for an engine ignition system according to claim 2, characterized in that: Based on the comparison results, the performance diagnostic results of the tested ignition system are output, including: In response to the response time being within a preset response time range, it is determined whether the current amplitude is within a preset amplitude range; In response to the current amplitude being within a preset amplitude range, it is determined whether the spark duration is within a preset duration range; In response to the spark duration being within a preset duration range, a qualified diagnostic result is output; If any of the response time, current amplitude, or spark duration is not within the corresponding preset range, an unqualified diagnostic result is output.

4. The online performance testing method for an engine ignition system according to claim 2, characterized in that: The high-level holding time of the drive signal, the preset standard parameter range of the response time, and the preset standard parameter range of the spark duration are all calibrated and set according to the charging time, secondary high voltage, and internal resistance of the ignition system under test.

5. An electronic device, characterized in that, include: A processor and a memory, wherein the memory stores a computer program, and the processor is configured to execute the computer program to implement the method as described in any one of claims 1 to 4.

6. An online performance testing system for an engine ignition system, characterized in that, include: The drive module (1) is used to output drive signals to the ignition system under test; The current sampling module (2) is connected in series in the secondary circuit (5) of the ignition coil in the ignition system under test, and is used to collect the current signal of the secondary circuit (5). The processing module (3) is connected to the current sampling module (2) and is used to receive the current signal to generate a current waveform, extract feature parameters based on the current waveform, and compare the feature parameters with a preset standard parameter range to output a performance diagnosis result.

7. The online performance testing system for an engine ignition system according to claim 6, characterized in that: The current sampling module (2) includes, The sampling resistor (21) is connected in series in the secondary circuit (5) of the ignition coil; The differential amplifier circuit (22) is connected in parallel with the sampling resistor (21) to collect the differential voltage across the sampling resistor (21) and convert the differential voltage into a current signal of the secondary circuit (5) and input it to the processing module (3).

8. The online performance testing system for an engine ignition system according to claim 6, characterized in that: The processing module (3) includes a field-programmable gate array (31), which is used to perform the generation of the current waveform, the extraction of characteristic parameters, and the comparison and diagnosis.

9. The online performance testing system for an engine ignition system according to claim 6, characterized in that: It also includes a display module (4), which is connected to the processing module (3) and is used to receive and display the current waveform and the performance diagnosis results generated by the processing module (3).

10. The online performance testing system for an engine ignition system according to claim 6, characterized in that: The drive module (1) includes a power output terminal, a drive signal output terminal, and a ground terminal.

Images