Crankshaft Signal Reverse Connection Diagnosis Method, Controller, System and Motor Vehicle

Abstract

The present invention relates to a method for diagnosing reverse connection of a crankshaft signal, a controller, a system and a motor vehicle, and includes the following steps: obtaining the time in the signal waveform of the crankshaft sensor, specifically: the time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth; when T2 > 2 * T1, and T4 < 2 * T3, and at the same time T5 ≈ 3 * T3, the positive and negative pins of the crankshaft sensor are reversely connected, and a fault alarm is issued. Without adding additional hardware, it can judge whether the crankshaft sensor is in a reverse connection state according to the signal characteristics obtained by the crankshaft sensor and issue a fault signal.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and specifically to a crankshaft signal reverse connection diagnosis method, a controller, a system, and a motor vehicle. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] The crankshaft position sensor (crankshaft sensor) is one of the most important sensors in the engine electronic control system. It provides signals for ignition timing (ignition advance angle) and confirms the crankshaft position, and is used to detect the top dead center of the piston, the crankshaft angle, and the engine speed. The structure adopted by the crankshaft position sensor varies with different vehicle models and can be divided into three categories: magnetic pulse type, photoelectric type, and Hall type. It is usually installed at the front end of the crankshaft, the front end of the camshaft, on the flywheel, or in the distributor.

[0004] The signal collected by the crankshaft sensor is a sine wave signal with variable amplitude and period. The higher the engine speed, the larger the amplitude and the smaller the period of the signal. The crankshaft sensor is divided into positive and negative pins. The positive pin outputs a sine wave, and the negative pin outputs a cosine wave. The differential signal of the positive and negative signals enters the engine controller for processing.

[0005] When the crankshaft sensor is reversely connected, the positive pin of the sensor collects the cosine signal, while the negative pin collects the sine signal, which is opposite to the normal situation, resulting in inaccurate calculation of the injection advance angle of the engine and affecting the engine performance. Such problems often become apparent only after the engine is assembled and enters the vehicle debugging stage, and at this time, it is no longer possible to debug the engine performance based on the injection advance angle. Summary of the Invention

[0006] In order to solve the technical problems existing in the above background technique, the present invention provides a crankshaft signal reverse connection diagnosis method, a controller, a system, and a motor vehicle. After processing the data obtained from the crankshaft sensor, it first identifies its reverse connection state (reports a fault), and then changes the sampling points originally at the falling edge to the rising edge plus a correction based on the engine speed, so as to minimize the impact of the reverse connection.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The first aspect of the present invention provides a crankshaft signal reverse connection diagnosis method, including the following steps:

[0009] Obtain the time in the signal waveform of the crankshaft sensor, specifically:

[0010] The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth;

[0011] When T2 > 2 * T1, T4 < 2 * T3, and T5 ≈ 3 * T3, the positive and negative pins of the crankshaft sensor are reversed, and a fault alarm is issued.

[0012] The signal waveform of the crankshaft sensor is a sine waveform with a missing tooth waveform in the middle, and the sine waveform repeatedly alternates between the rising edge and the falling edge.

[0013] When T1 = T2, T4 = T5 = 3 * T3, the crankshaft sensor is not reversed.

[0014] In the state where the crankshaft sensor is reversed, the current position of the engine is obtained based on the data of the rising edge of the signal waveform.

[0015] In the state where the crankshaft sensor is reversed, the data of the rising edge of the signal waveform and the correction value obtained by looking up the table are used as the angle compensation to realize the engine performance calculation.

[0016] In the state where the crankshaft sensor is not reversed, the current position of the engine is obtained based on the data of the falling edge of the signal waveform.

[0017] The crankshaft sensor has a signal disk with missing teeth, the edge of the signal disk faces the permanent magnet and coil on the crankshaft, and when the crankshaft rotates one circle, the signal disk emits a missing tooth waveform and a sine waveform corresponding to each tooth.

[0018] The second aspect of the present invention provides a controller for implementing the above anti-misoperation method, and the controller is configured to:

[0019] Obtain the time in the signal waveform of the crankshaft sensor, specifically:

[0020] The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth;

[0021] When T2 > 2 * T1, T4 < 2 * T3, and T5 ≈ 3 * T3, the positive and negative pins of the crankshaft sensor are reversed, and a fault alarm is issued.

[0022] The third aspect of the present invention provides a crankshaft signal reverse connection diagnosis system, including;

[0023] An information acquisition unit that obtains the time in the signal waveform of the crankshaft sensor, specifically:

[0024] The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth;

[0025] A diagnosis unit configured to:

[0026] When T2 > 2*T1, T4 < 2*T3, and at the same time T5 ≈ 3*T3, the positive and negative pins of the crankshaft sensor are reversed, and a fault alarm is issued.

[0027] The fourth aspect of the present invention provides a motor vehicle, including an on-vehicle computer, and the above-mentioned crankshaft signal reverse connection diagnosis system is installed in the on-vehicle computer.

[0028] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0029] 1. After processing the data obtained from the crankshaft sensor, first identify that it is in the reverse connection state (report a fault), and then change the sampling points that were originally at the falling edge to the rising edge plus a correction based on the engine speed, so as to minimize the impact of the reverse connection.

[0030] 2. Without adding additional hardware, it is possible to determine whether it is in the reverse connection state according to the signal characteristics obtained from the crankshaft sensor, issue a fault signal, and process the original signal after reporting the fault to correct the error caused by the reverse connection in the form of angle compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0032] Figure 1 is a signal waveform diagram obtained when the crankshaft sensor is correctly installed according to one or more embodiments of the present invention;

[0033] Figure 2 is a schematic diagram of the sine signal processing when the crankshaft sensor is correctly installed according to one or more embodiments of the present invention;

[0034] Figure 3 is a schematic diagram of determining the position of the crankshaft sensor signal disk according to the processed signal when the crankshaft sensor is correctly installed according to one or more embodiments of the present invention;

[0035] Figure 4It is a signal waveform diagram when the crankshaft sensor is reversely connected provided by one or more embodiments of the present invention;

[0036] Figure 5 It is a schematic diagram for collecting data (divided by time T) when diagnosing the reverse connection of the crankshaft sensor provided by one or more embodiments of the present invention. Specific Embodiments

[0037] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0038] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] As described in the background art, after the crankshaft sensor is reversely connected, the waveform signals obtained by the positive and negative pins are opposite, resulting in inaccurate calculation of the injection advance angle, affecting the engine performance, and also unable to perform corresponding diagnosis.

[0041] Therefore, the following embodiments provide a crankshaft signal reverse connection diagnosis method, controller, system, and motor vehicle. When the crankshaft signal is reversely connected, the reverse connection is judged by processing special teeth, and the advance angle is compensated by changing the identified edge and adding dynamic compensation.

[0042] Embodiment 1:

[0043] A crankshaft sensor in the prior art has a signal disk composed of 60 - 2 teeth (i.e., 58 teeth + two missing teeth). When the crankshaft rotates one circle, the sensor will sense a missing tooth waveform (one missing tooth waveform corresponds to the crankshaft rotation angle of 2 missing teeth on the signal disk), and 58 tooth sine waveforms.

[0044] As Figure 1 shown, when correctly installed, the signal collected by the crankshaft sensor is a sine wave signal with variable amplitude and period. The higher the engine speed, the larger the amplitude and the smaller the period of the signal. The crankshaft sensor is divided into positive and negative pins. When correctly installed, the positive pin outputs a sine wave, and the negative pin outputs a cosine wave. The differential signal of the positive and negative signals enters the controller for processing.

[0045] As Figure 2 shown, the differential sine signal entering the controller needs to be processed by a processing chip into a digital signal before it can be collected and processed by the single-chip microcomputer. The processing method is to process the positive voltage part of the sine signal into a rising edge and the zero-crossing point into a falling edge.

[0046] As Figure 3 shown, since the position of the tooth corresponding to the zero-crossing point is determined, the single-chip microcomputer can collect the falling edge of the processed signal ( Figure 3 at the arrow in), and using this method, the current position of the engine can be accurately obtained.

[0047] Since the correspondence between the falling edge and the signal disk position is determined, in the stable state, the tooth cycle at the missing tooth will be 3 times the normal tooth cycle (from falling edge to falling edge)

[0048] As Figure 4 shown, when the positive and negative pins of the crankshaft sensor are connected reversely due to human error, the signal collected by the positive pin becomes a cosine signal, and the signal collected by the negative pin becomes a sine signal, making the differential signal entering the controller a cosine signal with an amplitude amplified by two times.

[0049] When the engine speed is low, the interval between one waveform and the next is long, and there will be a situation where the zero-crossing point does not appear for a long time. Especially at the missing tooth, the time of the next sine wave signal from the previous sine wave signal is longer, resulting in a longer time from the rising edge to the falling edge.

[0050] Therefore, after the crankshaft sensor is reversely connected, if it is no longer possible to restore the crankshaft sensor to the correct installation, it is necessary to first identify its reversely connected state (report a fault) based on the data obtained in the reversely connected state of the crankshaft sensor after processing, and then change the sampling point originally at the falling edge to a rising edge plus a correction based on the engine speed, so as to minimize the impact of the reverse connection.

[0051] The judgment of the reverse connection of the crankshaft signal is specifically as follows:

[0052] As Figure 5 shown, the signal obtained by the crankshaft sensor can be described as the rising edge and the falling edge alternating repeatedly and passing through the missing tooth interval (that is, there is a section of missing tooth waveform in the middle of the sine waveform), and the signal in the missing tooth interval is between the falling edge of the previous tooth and the rising edge of the next tooth.

[0053] The five collected data are T1 - T5:

[0054] The time T1 from the rising edge to the falling edge of the normal tooth;

[0055] The time T2 from the rising edge to the falling edge of the tooth before the missing tooth interval;

[0056] The time T3 from the falling edge to the falling edge of the normal tooth;

[0057] The time T4 from the falling edge of the tooth before the missing tooth interval to the falling edge of the next tooth;

[0058] The time T5 from the rising edge of the tooth before the missing tooth interval to the rising edge of the next tooth;

[0059] When there is no reverse connection, T1 = T2, T4 = T5 = 3 * T3 should hold. When there is a reverse connection, T2 >> T1, T4 << 3 * T3, T5 ≈ 3 * T3. When all three conditions are met, a fault indicating reverse connection of the positive and negative pins of the crankshaft sensor is reported.

[0060] Among them, T5 ≈ 3 * T3, and the error range is within 3%.

[0061] Regarding angle compensation

[0062] When there is a reverse connection, due to the uncertain zero-crossing position and the uncertain positional relationship with the signal disk, if the angle is still calculated based on the falling edge at this time, it will cause the fuel injection advance angle to be seriously inaccurate. The normal sampling point should be at Figure 3 the arrow in.

[0063] The waveform diagram after reverse connection is as shown in Figure 4 . The angle calculation of the engine is based on the falling edge of the crankshaft signal. For a 60 - 2 signal disk, the angle from the falling edge to the falling edge is 6°. When the crankshaft signal is reversely connected, the falling edge that was originally used as the sampling point moves backward ( Figure 4 the square box in) will cause inaccurate angle calculation of the engine.

[0064] Figure 3 The signal in is the normal signal, Figure 4 is the signal generated by reverse connection. It can be seen that if there is a reverse connection, the rising edge of the signal after reverse connection is closer to the falling edge of the normal signal than the falling edge. Therefore, after determining the reverse connection, the angle calculated using the rising edge will be more accurate than using the falling edge. There is still a small error between the rising edge after reverse connection and the normal falling edge, and the faster the engine speed, the smaller this error time. Therefore, a table - look - up method can be used to add an angle compensation based on the engine speed.

[0065] Therefore, in this embodiment, after determining that there is a reverse connection fault in the crankshaft sensor, the signal of the crankshaft sensor is collected at the rising edge, that is, Figure 4 at the arrow in, which can eliminate most of the errors. Adding a correction based on the engine speed can minimize the influence of reverse connection.

[0066] The above process does not require additional hardware. It can determine whether the crankshaft sensor is in the reverse connection state according to the signal characteristics obtained by the crankshaft sensor, send a fault signal, and process the original signal after reporting the fault to correct the error caused by the reverse connection in the form of angle compensation.

[0067] Embodiment 2:

[0068] A crankshaft signal reverse connection diagnosis controller, which is configured to:

[0069] Obtain the time in the crankshaft sensor signal waveform, specifically:

[0070] The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth;

[0071] When T2 > 2*T1, and T4 < 2*T3, and at the same time T5 ≈ 3*T3, the positive and negative pins of the crankshaft sensor are reversely connected, and a fault alarm is issued.

[0072] Embodiment 3:

[0073] A crankshaft signal reverse connection diagnosis system, including;

[0074] An information acquisition unit, which obtains the time in the crankshaft sensor signal waveform, specifically:

[0075] The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth;

[0076] A diagnosis unit, which is configured to:

[0077] When T2 > 2*T1, and T4 < 2*T3, and at the same time T5 ≈ 3*T3, the positive and negative pins of the crankshaft sensor are reversely connected, and a fault alarm is issued.

[0078] Embodiment 4:

[0079] A motor vehicle, including an on-vehicle computer, and the above-mentioned crankshaft signal reverse connection diagnosis system is installed in the on-vehicle computer.

[0080] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for diagnosing reverse connection of crankshaft signals, characterized in that: Including: Obtain the time in the signal waveform of the crankshaft sensor, specifically: The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth; Among them, the signal waveform of the crankshaft sensor is a sine waveform with a section of missing tooth waveform in the middle. The rising edge and the falling edge of the sine waveform alternate repeatedly, and the signal in the missing tooth interval is located between the falling edge of the previous tooth and the rising edge of the next tooth; When T2 > 2 * T1, and T4 < 2 * T3, and at the same time T5 ≈ 3 * T3, the positive and negative pins of the crankshaft sensor are reversely connected, and a fault alarm is issued.

2. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: When T1 = T2, and T4 = T5 = 3 * T3, the crankshaft sensor is not reversely connected.

3. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: In the state where the crankshaft sensor is reversely connected, obtain the current position of the engine based on the data of the rising edge of the signal waveform.

4. The crankshaft signal reverse connection diagnosis method according to claim 1, wherein: In the state where the crankshaft sensor is reversely connected, use the data of the rising edge of the signal waveform and the correction value obtained by looking up the table as the angle compensation to realize the engine performance calculation.

5. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: In the state where the crankshaft sensor is not reversely connected, obtain the current position of the engine based on the data of the falling edge of the signal waveform.

6. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: The crankshaft sensor has a signal disk with missing teeth. The edge of the signal disk faces the permanent magnet and the coil on the crankshaft. When the crankshaft rotates one circle, the signal disk emits a missing tooth waveform and a sine waveform corresponding to each tooth.

7. Crankshaft signal reverse connection diagnosis controller, characterized in that: Configured to: Obtain the time in the signal waveform of the crankshaft sensor, specifically: The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth; among them, the signal waveform of the crankshaft sensor is a sine waveform with a section of missing tooth waveform in the middle. The rising edge and the falling edge of the sine waveform alternate repeatedly, and the signal in the missing tooth interval is located between the falling edge of the previous tooth and the rising edge of the next tooth; When T2 > 2 * T1, and T4 < 2 * T3, and at the same time T5 ≈ 3 * T3, the positive and negative pins of the crankshaft sensor are reversely connected, and a fault alarm is issued.

8. Crankshaft signal reverse connection diagnosis system, characterized in that: Including: An information acquisition unit that obtains the time in the signal waveform of the crankshaft sensor, specifically: The time T1 from the rising edge to the falling edge of a normal tooth, the time T2 from the rising edge to the falling edge of the tooth before the missing tooth waveform, the time T3 from the falling edge to the falling edge of a normal tooth, the time T4 from the falling edge of the tooth before the missing tooth waveform to the falling edge of the next tooth, and the time T5 from the rising edge of the tooth before the missing tooth waveform to the rising edge of the next tooth; among them, the signal waveform of the crankshaft sensor is a sine waveform with a section of missing tooth waveform in the middle. The rising edge and the falling edge of the sine waveform alternate repeatedly, and the signal in the missing tooth interval is located between the falling edge of the previous tooth and the rising edge of the next tooth; A diagnosis unit configured to: When T2 > 2 * T1, T4 < 2 * T3, and T5 ≈ 3 * T3, the positive and negative pins of the crankshaft sensor are reversely connected, and a fault alarm is issued.

9. A motor vehicle, characterized in that, It includes an on-vehicle computer, and the on-vehicle computer is equipped with the crankshaft signal reverse connection diagnosis system described in claim 8.

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