KR20070024072A - Diagnosis method for malfunction of a output shaft speed sensor under 1st speed for automatic transmission - Google Patents

Abstract

A method of diagnosing a trouble of an output shaft speed sensor at a first speed for an automatic transmission is provided to determine the trouble by using a wheel speed sensor or an input shaft speed sensor. A vehicular speed is computed with receiving a detected signal from a wheel speed sensor(S12). The vehicular speed is compared by a speed of an output shaft detected by an output shaft speed sensor of an automatic transmission to determine trouble of the output shaft speed sensor(S22). A difference between an input shaft speed detected by an input shaft speed sensor and revolutions of an engine is compared with a reference value.

Description

Diagnosis method for malfunction of a output shaft speed sensor under 1st speed for automatic transmission}

1 is a view illustrating sensors connected to a control unit of a vehicle in general.

       Showing drawings,

2 is a view illustrating a control unit and sensors for implementing a fault diagnosis method of the present invention;

       Drawing showing configuration,

Figure 3 is a failure diagnosis method of the automatic transmission output shaft speed sensor of the present invention

       A flowchart showing a first preferred embodiment,

Figure 4 is a failure diagnosis method of the automatic transmission output shaft speed sensor of the present invention

        Flow chart showing the second preferred embodiment.

<Explanation of symbols for the main parts of the drawings>

10: control unit 20: display unit

31: vehicle speed sensor 32: inhibitor switch

33: engine speed detection unit 34: throttle position sensor

35: speed sensor of input shaft 36: speed sensor of output shaft

37: Wheel Speed Sensor

The present invention relates to a first-speed failure diagnosis method of the output shaft speed sensor of the automatic transmission, and more particularly to a failure diagnosis method that can diagnose the failure of the output shaft speed sensor in the automatic transmission in which the vehicle speed sensor is deleted.

In general, the vehicle is equipped with various sensors for detecting the driving information or vehicle information of the vehicle and connected to the control unit, and the detection signals of these sensors are transmitted to the control unit so that the vehicle can perform the best driving performance under the optimal conditions. To help.

On the other hand, in the vehicle, various sensors always need to detect and transmit accurate information. Therefore, the control unit determines whether the sensors are broken and if necessary, outputs a fault code to warn the driver to take appropriate measures. .

The present invention proposes a method for diagnosing a failure of an output shaft speed sensor of an automatic transmission among the sensors provided in the vehicle, and a brief description will now be made of a failure diagnosis of an output shaft speed sensor of a conventional automatic transmission.

1 is a view showing some sensors connected to a control unit of a vehicle in general, the control unit 10 is connected to a variety of sensing means and the display unit 20 that can inform the driver of the failure as needed.

The sensing means includes a vehicle speed sensor 31 for detecting a moving speed of the vehicle, an inhibitor switch 32 for detecting an operation position of the shift lever, and an engine speed detector for detecting an engine speed. 33), a throttle position sensor (hereinafter referred to as "TPS") 34 for detecting the opening degree of the throttle valve, and an input shaft speed sensor (hereinafter referred to as "PG") for detecting the input shaft speed of the automatic transmission. And an output shaft speed sensor (hereinafter also referred to as a "PG-B sensor") 36 for detecting the output shaft speed of the automatic transmission.

In particular, the PG-B sensor transmits the current operating status of the transmission to the control unit and transmits important information in automatic transmission control such as shift command, line pressure control and shift clutch pressure command at each stage. .

Therefore, the failure detection of the PG-B sensor that performs this important function can be said to be very important for the stability of the vehicle and the protection of the transmission system.

On the other hand, the failure detection of the conventional PG-B sensor has been using a vehicle speed sensor, but in the automatic transmission system in which the vehicle speed sensor of the automatic transmission has been deleted, there is a difficult problem of diagnosing the failure of the PG-B sensor.

Specifically, 1) whether the rotation speed of the engine is detected by the engine speed detection unit 33 and the speed is 3500rpm or more, 2) whether the opening rate is 15% or more from the TPS 34, and 3) After determining the 1 st speed entry condition to determine whether the condition is maintained for 6 seconds or more, the detection signal of the PG-B sensor was judged to diagnose the failure of the PG-B sensor. That is, if the detection signal of the PG-B sensor is transmitted as "0" under the 1-speed entry condition, the control unit determines that the PG-B sensor has failed and generates a failure code.

However, in the determination of the failure of the conventional PG-B sensor, since the first speed entry condition must be driven at a high rpm for a long time, the failure condition determination entry condition of the PG-B sensor is often not satisfied. There is a problem that the reliability of the detection of failure is reduced.

The present invention is to solve the above-described drawbacks, and to provide a first-speed failure diagnosis method of the output shaft speed sensor of the automatic transmission that can diagnose the failure of the output shaft speed sensor in the automatic transmission system in which the vehicle speed sensor is deleted.

The first-speed fault diagnosis method of the output shaft speed sensor of the automatic transmission according to the present invention includes a first step of calculating a vehicle speed by receiving a signal detected from a wheel speed sensor; A second step of determining whether the output shaft speed sensor is broken by comparing the vehicle speed detected in the first step and the output shaft speed detected from the output shaft speed sensor of the automatic transmission is achieved.

In addition, the first-speed fault diagnosis method of the output shaft speed sensor of the automatic transmission of the present invention, the first step of comparing the signal detected from the input shaft speed sensor of the automatic transmission with a reference value; Calculating a vehicle speed from an input shaft speed of the input shaft speed sensor of the automatic transmission when the input shaft speed detected by the input shaft speed sensor in the first step is within a reference value range; Comparing the output shaft speed detected from the output shaft speed sensor and the calculated vehicle speed can be achieved by a third step of determining whether or not the output shaft speed sensor failure.

2 to 4 are diagrams for explaining a failure diagnosis method of the output shaft speed sensor of the present invention, Figure 2 is a view showing the configuration of the control unit and sensors to which the failure diagnosis method of the present invention is applied, Figure 3 4 is a flowchart showing a first preferred embodiment of a failure diagnosis method of an automatic transmission output shaft speed sensor of the present invention, and FIG. 4 is a flowchart showing a second preferred embodiment of a failure diagnosis method of an automatic transmission output shaft speed sensor of the present invention.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the following description, the same reference numerals are used for the same components as the prior art, and descriptions that may overlap may be omitted.

2 is a view showing the configuration of the control unit and the sensors for implementing the fault diagnosis method of the present invention, the vehicle speed sensor described in the prior art is deleted, the wheel speed sensor 37 is used in the automatic transmission system of the present invention.

The wheel speed sensor 37 is a well-known detection means mounted on a vehicle, and is mounted on each wheel of the vehicle to detect the rotation speed of the wheel. The wheel speed sensor 37 is connected to the control unit 10 and transmits the detected wheel rotation speed.

First Embodiment

The first-speed failure diagnosis method of the output shaft speed sensor of the automatic transmission in the automatic transmission system configured as described above comprises: a first step (S10) of receiving a signal detected from the wheel speed sensor 37 and calculating a vehicle speed; Comprising a second step (S20) for determining the failure of the PG-B sensor 36 by comparing the vehicle speed detected in the first step (S10) and the output shaft speed detected from the PG-B sensor 36 of the automatic transmission. It is a technical characteristic to do it.

In the first step S10, the vehicle receives a signal detected from the wheel speed sensor 37 of each wheel in the first speed driving state (S11), and the control unit 10 calculates the vehicle speed Vc from the transmitted signal. (S12). The process of calculating the vehicle speed from the transmitted wheel speed may be calculated by averaging the speed values detected from each wheel speed sensor 37 and multiplying the coefficient determined empirically or experimentally.

In the second step S20, the control unit 10 obtains the output shaft speed Vb detected from the PG-B sensor 36 of the automatic transmission (S21), and compares it with the vehicle speed Vc calculated from the wheel speed. Determine the presence (S22).

The determination of the presence or absence of a failure is performed by comparing the difference between the calculated vehicle speed Vc and the detected output shaft speed Vb, when the control unit 10 determines the failure, and the display unit 20 operates to the driver. Ensure that appropriate measures are taken.

Second Embodiment

On the other hand, some vehicles do not have a wheel speed sensor for detecting the wheel speed. In this case, a PG-A sensor for detecting the input shaft speed of the automatic transmission can be used.

According to another embodiment of the present invention, a first speed failure diagnosis method of an output shaft speed sensor of an automatic transmission may include a first step S30 of comparing a signal detected from the PG-A sensor 35 of the automatic transmission with a reference value; When the input shaft speed detected from the PG-A sensor 35 in the first step (S30) is within the reference value range, the vehicle speed Vc is calculated from the input shaft speed Va of the PG-A sensor 35 of the automatic transmission. A second step (S40); And a third step S50 of comparing the output shaft speed Vb detected from the PG-B sensor 36 with the calculated vehicle speed Vc to determine whether or not the PG-B sensor 36 is broken. do.

In the first step S30, the vehicle detects a signal from the PG-A sensor 35 in the first speed driving state to determine the validity of the detection value of the PG-A sensor 35.

There may be various methods for this determination, but preferably, the engine speed Ve detected from the engine speed detection unit 33 may be used. That is, the input shaft speed Va may be detected by the PG-A sensor 35, and the engine speed Ve may be detected, and the difference may be determined by comparing the difference with a reference value (determined in approximately 400 rpm).

In the second step S40, if the input shaft speed Va detected by the PG-A sensor 35 is within the reference value range, the vehicle speed Vc is calculated from the detected input shaft speed Va.

The calculation of the vehicle speed Vc from the input shaft speed Va can determine the vehicle speed within a certain error range from empirical or experimental data that can be determined according to the applied automatic transmission.

The third step S50 detects the output shaft speed Vb from the PG-B sensor 36 (S51), and then compares the difference between the calculated vehicle speed Vc and the output shaft speed Vb with a reference value to determine the PG-B. It is determined whether the B sensor 36 is broken.

That is, when the difference between the calculated vehicle speed Vc and the output shaft speed Vb is equal to or greater than the reference value, the control unit 10 makes a failure determination, generates a failure code, and outputs a warning signal through the display unit 20.

As described above, the first-speed failure diagnosis method of the output shaft speed sensor of the automatic transmission according to the present invention may be performed by using a known wheel speed sensor mounted on a wheel in an automatic transmission system in which a vehicle speed sensor is deleted, or using an input shaft speed sensor (PG-A). By determining the failure of the output shaft speed sensor (PG-B sensor) of the automatic transmission by using a sensor), it is an invention having the effect of increasing the reliability of the failure diagnosis of the sensor compared with the conventional.

Claims (3)

A first step of receiving a signal detected from the wheel speed sensor and calculating a vehicle speed; And comparing the vehicle speed detected in the first step with the output shaft speed detected from the output shaft speed sensor of the automatic transmission to determine whether the output shaft speed sensor has a failure. Fault diagnosis method. A first step of comparing the signal detected from the input shaft speed sensor of the automatic transmission with a reference value; Calculating a vehicle speed from an input shaft speed of the input shaft speed sensor of the automatic transmission when the input shaft speed detected by the input shaft speed sensor in the first step is within a reference value range; And a third step of comparing the output shaft speed detected from the output shaft speed sensor with the calculated vehicle speed to determine whether the output shaft speed sensor is faulty. 2. The method of claim 1, wherein the input shaft speed detected by the input shaft speed sensor is compared with a reference value to a difference between the engine speed and a reference value.

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