CN116220902A - Crankshaft signal reverse connection diagnosis method, controller, system and motor vehicle - Google Patents

Abstract

The invention relates to a crankshaft signal reverse connection diagnosis method, a controller, a system and a motor vehicle, which comprise the following steps: the time in the signal waveform of the crank sensor is acquired, specifically: time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform; and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent. And the device can judge whether the crankshaft sensor is in a reverse connection state or not according to the signal characteristics obtained by the crankshaft sensor, and send out a fault signal without adding extra hardware.

Description

Crankshaft signal reverse connection diagnosis method, controller, system and motor vehicle

Technical Field

The invention relates to the technical field of vehicles, in particular to a crankshaft signal reverse connection diagnosis method, a controller, a system and a motor vehicle.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

A crank position sensor (crank sensor) is one of the most prominent sensors in an electronic control system of an engine, and provides a signal for determining a crank position at an ignition timing (ignition advance angle) for detecting a piston top dead center, a crank angle, and an engine speed. The structure adopted by the crank shaft position sensor is different according to different vehicle types, and can be divided into three categories of magnetic pulse type, photoelectric type and Hall type, and the crank shaft position sensor is usually arranged at the front end of a crank shaft, the front end of a cam shaft, a flywheel or in a distributor.

The signals collected by the crankshaft sensor are sine wave signals with variable amplitude and period, and the amplitude of the signals is larger and the period is smaller when the engine speed is higher. The crank shaft sensor is divided into a positive pin and a negative pin, the positive pin outputs sine waves, the negative pin outputs cosine waves, and differential signals of the positive signal and the negative signal enter the engine controller for processing.

When the crank sensor is reversely connected, a cosine signal is collected by a positive pin of the sensor, a sine signal is collected by a negative pin of the sensor, and the sine signal is opposite to the sine signal under normal conditions, so that the injection advance angle of the engine is calculated inaccurately, the performance of the engine is influenced, the influence of the problem is often reflected after the engine is assembled to enter a vehicle debugging stage, and the engine performance cannot be debugged according to the injection advance angle at the moment.

Disclosure of Invention

In order to solve the technical problems in the background art, the invention provides a crankshaft signal reverse connection diagnosis method, a controller, a system and a motor vehicle, wherein the reverse connection state (fault report) is firstly identified according to the data acquired by a crankshaft sensor after the data is processed, and then the influence of reverse connection can be minimized by changing the sampling point originally in the falling edge into the rising edge and adding correction based on the engine speed.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a first aspect of the present invention provides a crankshaft signal reverse connection diagnosis method, comprising the steps of:

the time in the signal waveform of the crank sensor is acquired, specifically:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

The signal waveform of the crank sensor is a sine waveform, a section of tooth missing waveform is arranged in the middle of the sine waveform, and the sine waveform is formed by repeatedly and alternately appearing a rising edge and a falling edge.

T1=t2, and t4=t5=3×t3, the crank sensor is not reversely connected.

And in the reverse connection state of the crank sensor, the current position of the engine is obtained based on the data of the rising edge of the signal waveform.

And in the reverse connection state of the crankshaft sensor, the correction value obtained based on the data of the rising edge of the signal waveform and the table lookup is used as angle compensation, so that the calculation of the engine performance is realized.

And in the state that the crankshaft sensor is not reversely connected, acquiring the current position of the engine based on the data of the falling edge of the signal waveform.

The crankshaft sensor is provided with a signal disc with missing teeth, the edge of the signal disc faces towards a permanent magnet and a coil on the crankshaft, and when the crankshaft rotates for one circle, the signal disc emits a missing tooth waveform and a sine waveform corresponding to each tooth.

A second aspect of the present invention provides a controller implementing the above-described false touch prevention method, the controller being configured to:

the time in the signal waveform of the crank sensor is acquired, specifically:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

A third aspect of the present invention provides a crankshaft signal reverse diagnostic system, comprising;

the information acquisition unit acquires time in a signal waveform of the crank sensor, and specifically comprises the following steps:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

a diagnostic unit configured to:

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

A fourth aspect of the present invention provides a motor vehicle comprising a vehicle-mounted computer having the above crankshaft signal reverse connection diagnostic system mounted therein.

Compared with the prior art, the above technical scheme has the following beneficial effects:

1. the data acquired by the crank sensor is processed to identify that the crank sensor is in a reverse connection state (fault is reported), and then the sampling point which is originally in a falling edge is changed into a rising edge to be added with correction based on the engine speed, so that the influence of the reverse connection can be reduced to the minimum.

2. And the method can judge whether the crankshaft sensor is in the reverse connection state or not according to the signal characteristics obtained by the crankshaft sensor without adding extra hardware, send out a fault signal, process an original signal after the fault is reported, and correct errors caused by the reverse connection in an angle compensation mode.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.

FIG. 1 is a waveform diagram of signals obtained when a crankshaft sensor is properly installed in accordance with one or more embodiments of the present invention;

FIG. 2 is a schematic representation of sinusoidal signal processing with a crank sensor properly installed, provided by one or more embodiments of the present invention;

FIG. 3 is a schematic illustration of determining a position of a crankshaft sensor signal disc based on processed signals when the crankshaft sensor is properly installed, as provided by one or more embodiments of the present invention;

FIG. 4 is a signal waveform diagram of a crankshaft sensor in reverse connection provided by one or more embodiments of the present invention;

FIG. 5 is a schematic diagram of data (divided by time T) collected when diagnosing a reverse connection of a crankshaft sensor according to one or more embodiments of the present invention.

Detailed Description

The invention will be further described with reference to the drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

As described in the background art, waveform signals acquired by the positive pin and the negative pin after the crankshaft sensor is reversely connected are opposite, so that the injection advance angle is calculated inaccurately, the performance of the engine is affected, and corresponding diagnosis cannot be performed.

Therefore, the following embodiments provide a crankshaft signal reverse connection diagnosis method, a controller, a system and a motor vehicle, when the crankshaft signal is in reverse connection, the reverse connection judgment is performed through the processing of special teeth, and the advance angle is compensated by changing the identification jump edge and adding the dynamic compensation mode.

Embodiment one:

a crankshaft sensor in the prior art has a signal disc formed of 60-2 teeth (i.e., 58 teeth + two missing teeth), and a sensor senses a missing tooth waveform (one missing tooth waveform corresponds to the crank angle of 2 missing teeth on the signal disc) and a sinusoidal waveform of 58 teeth when the crankshaft rotates one revolution.

When the engine is correctly installed, as shown in fig. 1, the signals collected by the crank sensor are sine wave signals with variable amplitude and period, and the higher the engine speed is, the larger the amplitude and the smaller the period of the signals are. The crank shaft sensor is divided into a positive pin and a negative pin, when the crank shaft sensor is correctly installed, the positive pin outputs sine waves, the negative pin outputs cosine waves, and differential signals of positive and negative signals enter the controller for processing.

As shown in fig. 2, the differential sinusoidal signal entering the controller needs to be processed into a digital signal by a processing chip to be collected and processed by the singlechip, wherein the processing mode is that the positive voltage part of the sinusoidal signal is processed into a rising edge, and the positive voltage part of the sinusoidal signal is processed into a falling edge at a zero crossing point.

As shown in FIG. 3, the positions of the corresponding teeth of the zero crossing points are determined, so that the singlechip can acquire the falling edge (arrow in FIG. 3) of the processed signal, and the position of the current engine can be accurately obtained by using the method.

Since the correspondence between the falling edge and the position of the signal panel is determined, in a steady state, the tooth period at the missing tooth will be 3 times the normal tooth period (from the falling edge to the falling edge)

As shown in fig. 4, when the positive pin and the negative pin of the crank sensor are connected in a wrong way 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, so that the differential signal entering the controller is the cosine signal with the amplitude amplified by two times.

When the engine speed is low, the interval between one waveform and the next waveform is long, and a situation that zero crossing is not occurred for a long time occurs. Especially at missing teeth, the next sine wave signal will be longer from the last sine wave signal, resulting in longer time from rising edge to falling edge.

Therefore, after the reverse connection of the crank sensor occurs, the crank sensor cannot be restored to be correctly installed at the moment, the reverse connection state (failure report) is recognized according to the data acquired by the crank sensor in the reverse connection state after the data are processed, and then the influence of the reverse connection can be minimized by changing the sampling point originally in the falling edge into the rising edge and adding the correction based on the engine speed.

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

as shown in fig. 5, the signal obtained by the crank sensor may be described as a rising edge and a falling edge repeatedly alternating and passing through a missing tooth region (i.e., a sinusoidal waveform having a segment of missing tooth waveform in the middle), where the signal of the missing tooth region is located between the falling edge of the previous tooth and the rising edge of the next tooth.

Five data were collected as T1-T5:

time T1 from the rising edge to the falling edge of the normal tooth;

time T2 from the rising edge to the falling edge of the previous tooth in the tooth-missing section;

time T3 from normal tooth falling edge to falling edge;

the time T4 from the falling edge of the previous tooth to the falling edge of the next tooth in the tooth-missing interval;

the rising edge time T5 from the rising edge of the previous tooth to the rising edge of the next tooth in the tooth-missing interval;

under the condition of no reverse connection, t1=t2, t4=t5=3×t3, when the reverse connection is performed, T2> T1, T4< <3×t3, t5≡3×t3, and when all three conditions are met, a positive pin and negative pin reverse connection fault of the crank sensor is reported.

Wherein T5 is approximately 3 times T3, and the error range is within 3 percent.

With respect to angle compensation

When the fuel injection advance angle is not accurate, the position relation between the fuel injection advance angle and the signal panel is not determined due to the fact that the zero crossing point position is not determined, and if the angle calculation is still carried out according to the falling edge at the moment, the fuel injection advance angle is seriously inaccurate, and the normal sampling point is located at an arrow in fig. 3.

As shown in fig. 4, the calculation of the angle of the engine is based on the falling edge of the crankshaft signal, and for a signal panel of 60-2, the angle from the falling edge to the falling edge is 6 degrees, and when the crankshaft signal is reversely connected, the falling edge which is originally taken as a sampling point is shifted backwards (a box in fig. 4), so that the calculation of the angle of the engine is inaccurate.

The signal in fig. 3 is a normal signal, and fig. 4 is a signal generated by inverting, and it can be seen that if inverting, the rising edge of the signal after inverting is closer to the falling edge of the normal signal than the falling edge, so that the angle calculated by using the rising edge is more accurate than the falling edge after determining inverting. And a small error exists between the reverse rising edge and the normal falling edge, and the faster the engine speed is, the smaller the time of the error is, so that a table look-up mode can be adopted to add an angle compensation based on the speed.

Therefore, in this embodiment, after determining that the reverse connection fault exists in the crank sensor, most of the errors can be eliminated at the position of the arrow in fig. 4, where the signal of the crank sensor is collected at the rising edge, and the influence of the reverse connection can be minimized by adding a correction based on the engine speed.

The process does not need to add extra hardware, can judge whether the crankshaft sensor is in a reverse connection state according to the signal characteristics obtained by the crankshaft sensor, send out a fault signal, process an original signal after the fault is reported, and correct errors caused by the reverse connection in an angle compensation mode.

Embodiment two:

a crankshaft signal reverse diagnostic controller configured to:

the time in the signal waveform of the crank sensor is acquired, specifically:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

Embodiment III:

the crankshaft signal reverse connection diagnosis system comprises;

the information acquisition unit acquires time in a signal waveform of the crank sensor, and specifically comprises the following steps:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

a diagnostic unit configured to:

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

Embodiment four:

a motor vehicle comprises a vehicle-mounted computer, wherein the vehicle-mounted computer is internally provided with the crankshaft signal reverse connection diagnosis system.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The crankshaft signal reverse connection diagnosis method is characterized in that: comprising the following steps:

the time in the signal waveform of the crank sensor is acquired, specifically:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

2. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: the signal waveform of the crank sensor is a sine waveform, a section of tooth missing waveform is arranged in the middle of the sine waveform, and the sine waveform is formed by repeatedly and alternately appearing a rising edge and a falling edge.

3. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: t1=t2, and t4=t5=3×t3, the crank sensor is not reversely connected.

4. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: and in the reverse connection state of the crankshaft sensor, the current position of the engine is obtained based on the data of the rising edge of the signal waveform.

5. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: and in the reverse connection state of the crankshaft sensor, the correction value obtained based on the data of the rising edge of the signal waveform and the table lookup is used as angle compensation to realize the calculation of the engine performance.

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

7. The crankshaft signal reverse connection diagnosis method according to claim 1, characterized in that: the crankshaft sensor is provided with a signal disc with missing teeth, the edge of the signal disc faces to a permanent magnet and a coil on the crankshaft, and when the crankshaft rotates for one circle, the signal disc sends out a missing tooth waveform and a sine waveform corresponding to each tooth.

8. The crankshaft signal reverse connection diagnosis controller is characterized in that: is configured to:

the time in the signal waveform of the crank sensor is acquired, specifically:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

9. The crankshaft signal reverse connection diagnosis system is characterized in that: comprising the following steps:

the information acquisition unit acquires time in a signal waveform of the crank sensor, and specifically comprises the following steps:

time T1 from rising edge to falling edge of normal tooth, time T2 from rising edge to falling edge of previous tooth of missing tooth waveform, time T3 from falling edge to falling edge of normal tooth, time T4 from falling edge of previous tooth to falling edge of next tooth of missing tooth waveform, and time T5 from rising edge of previous tooth to rising edge of next tooth of missing tooth waveform;

a diagnostic unit configured to:

and when T2 is more than 2 x T1, T4 is less than 2 x T3, and T5 is approximately equal to 3 x T3, the positive pin and the negative pin of the crank shaft sensor are reversely connected, and a fault alarm is sent.

10. A motor vehicle comprising a vehicle-mounted computer having the crankshaft signal reverse connection diagnostic system of claim 9 mounted therein.

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