KR20130051702A - Method for diagnosing pressure sensor for engine clutch - Google Patents

Abstract

PURPOSE: A diagnosing method of an engine clutch pressure sensor for hybrid vehicles is provided to increase reliability on the protection of an engine and a driving system, and capability of a car by grasping troubles of the pressure sensor based on the output signal from the pressure sensor. CONSTITUTION: A diagnosing method of an engine clutch pressure sensor for hybrid vehicles comprises the following steps: a step of checking a gear to determine whether the gear position is parking shift(S100); a step of checking EOP(elctric-powered oil pump) to determine whether the EOP of the engine clutch is in the stationary state(S200); a step of checking the soaking to determine whether the soaking time is over the first time(S300); a step of checking a car speed to determine whether the car is in the stationary state(S400); and a step of determining a malfunction of the pressure sensor in case that the output signal is over a fixed standard by checking the output signal from the engine clutch pressure sensor when the gear position is parking shift(S610). The first time in the step of checking the soaking is 8 hours, and the output signal in the determining step of is output voltage. The diagnosing method also comprises a step of checking a voltage to determine whether the input voltage of the engine clutch pressure sensor is under a fixed voltage(S10). The determining step checks the output signal of the engine clutch sensor in case that the input voltage is under the fixed voltage. The diagnosing method also comprises a step of checking the communication to determine whether the CAN communication of a hybrid controlling part or an engine controlling part(S20). The determining step checks the output signal of the engine clutch pressure sensor in case that the CAN communication of the hybrid controlling part or the engine controlling part is normal. [Reference numerals] (AA) Start; (BB) End; (S10) Pressure voltage > 10V ?; (S100) Gear position = P gear ?; (S20) HUC/ECU CAN normal?; (S300) Soaking time > 8 hours ?; (S40) Is TM manipulation impossible?; (S400) Vehicle speed = 0 ?; (S500) Output voltage > 0.7V ?; (S610) Determine the malfunction of sensor offset; (S620) Store malfunction information; (S630) Stop correcting the sensor offset; (S640) Control limp home; (S650) Warning lamp

Description

How to diagnose engine clutch pressure sensor in hybrid vehicle {METHOD FOR DIAGNOSING PRESSURE SENSOR FOR ENGINE CLUTCH}

The present invention relates to a failure diagnosis method of an engine clutch pressure sensor of a hybrid vehicle for measuring a pressure of an oil pump for operating the engine clutch of the hybrid vehicle.

Hybrid vehicles allow the engine and motor to be used simultaneously as the driving force. For this purpose, the engine clutch is connected between the shaft and the engine and the motor, and the engine clutch is operated by oil pressure and it is the pressure sensor of the engine clutch that measures the oil pressure of the oil pump.

The pressure sensor periodically corrects the zero point to correct the point where the actual pressure is recognized as 0 bar. If this zero correction is incorrect, it causes many problems due to malfunction of the engine clutch.

The present invention relates to a method for determining the reliability of the output of the sensor when one pressure sensor is applied to the hybrid vehicle. The method for determining the reliability of the offset output due to the change in the characteristics of the pressure sensor is a factor determined in the transmission system. Currently, there is no diagnostic method for the case where one sensor is applied.

Therefore, when the pressure sensor offset output, the clutch state can be misjudged when controlling the engine clutch, so a method for determining the reliability of the sensor unit is required. In addition, there is a need for a diagnostic method for determining whether or not a failure occurs with respect to the pressure sensor offset output.

For this purpose, it is necessary to clarify the basis of the judgment on the failure of the pressure sensor offset output. In order to support this, it is necessary to implement a diagnosis method considering the conditions in which the pressure in the transmission cannot occur in the actual vehicle conditions.

In addition, conditions where no pressure can occur at the actual transmission pressure port require experimental evidence as to what conditions the residual pressure in the transmission is eliminated. If the diagnosis is made in a section other than the operating condition of the oil pump, it will be possible to judge the normal / abnormal state of the offset characteristics of the sensor unit.

1 is for explaining a phenomenon that occurs when a conventional pressure sensor offset adjustment failure, the engine clutch slips when the output voltage of the pressure sensor is recognized as 0 bar because the offset correction of the pressure sensor is incorrect. It can be seen that a problem occurs for 30 seconds without escape. Therefore, it is necessary to prevent the application of such a wrong offset from the beginning.

It should be understood that the foregoing description of the background art is merely for the purpose of promoting an understanding of the background of the present invention and is not to be construed as an admission that the prior art is known to those skilled in the art.

The present invention has been proposed to solve this problem, to provide a method for diagnosing the engine clutch pressure sensor of the hybrid vehicle to determine the normal operation by determining the pressure sensor of the engine clutch of the hybrid vehicle under various conditions. There is this.

Engine clutch pressure sensor diagnostic method of a hybrid vehicle according to the present invention for achieving the above object, the gear check step of determining whether the gear position of the vehicle (P stage); An EOP checking step of determining whether the engine clutch EOP (electric oil pump) is stopped; A soaking checking step of determining whether a soaking time is equal to or greater than a first time; A vehicle speed checking step of determining whether the vehicle is stationary; And when the gear position of the vehicle is in the parking stage, the EOP is stopped, the soaking time is greater than or equal to the first hour, and the vehicle is in the stopped state, the output signal of the engine clutch pressure sensor is checked and the output signal is above a certain standard. Determination step of determining that the sensor failure.

The first time of the soaking checking step may be 8 hours, and the output signal of the determining step may be an output voltage.

And a voltage checking step of determining whether an input voltage of the engine clutch pressure sensor is lower than or equal to a predetermined voltage. The determining step includes checking an output signal of the engine clutch pressure sensor when the input voltage of the engine clutch pressure sensor is lower than or equal to a predetermined voltage. Can be.

And a communication checking step of determining whether CAN communication of the hybrid control unit or the engine control unit is normal. The determining step includes output signals of the engine clutch pressure sensor when CAN communication of the hybrid control unit or the engine control unit is normal. You can check

And an ignition checking step of determining whether the IG of the vehicle is in an ON state, wherein the determining step checks the output signal of the engine clutch pressure sensor when the IG is in the ON state. can do.

The determining step may further include a correction stop step of stopping the offset correction of the pressure sensor when determining the failure of the engine clutch pressure sensor.

The determining step may further include an emergency control step of controlling the engine clutch by loading a separate engine clutch control logic in which the control of the pressure sensor is excluded when determining the failure of the engine clutch pressure sensor.

According to the method for diagnosing the engine clutch pressure sensor of the hybrid vehicle having the above-described structure, it is possible to increase the reliability of the protection of the engine and the drive system and the vehicle performance by identifying whether the sensor is in advance based on the output signal of the pressure sensor. .

In addition, since the failure determination is made under a plurality of valid conditions, the reliability of the failure determination is increased.

1 is a graph showing the phenomenon when the offset failure of the conventional engine clutch pressure sensor.
2 is a flow chart of a method for diagnosing the engine clutch pressure sensor of a hybrid vehicle according to an exemplary embodiment of the present invention.

Hereinafter, a method for diagnosing an engine clutch pressure sensor of a hybrid vehicle according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a flowchart of a method for diagnosing an engine clutch pressure sensor of a hybrid vehicle according to an exemplary embodiment of the present invention. In the method of diagnosing an engine clutch pressure sensor of a hybrid vehicle of the present invention, whether the gear position of the vehicle is a parking stage (P stage). Gear check step (S100) to determine; EOP check step (S200) of determining whether the engine oil clutch EOP (electric oil pump) is stopped; A soaking check step S300 of determining whether a soaking time is equal to or greater than a first time; A vehicle speed checking step (S400) for determining whether the vehicle is in a stopped state; And when the gear position of the vehicle is in the parking stage, the EOP is in the stopped state, the soaking time is greater than or equal to the first hour, and the vehicle is in the stopped state, the output signal of the engine clutch pressure sensor is checked and the output signal is above a certain standard. It includes a determination step (S610) for determining the failure of the sensor.

The pressure sensor for measuring the pressure of the engine clutch hydraulic pressure of the vehicle may be operated in a variety of ways, but typically a method of applying the operating voltage and outputting the formation of pressure as the output voltage. Therefore, in order to accurately measure the pressure sensor, it is necessary to determine how much output voltage is formed in a situation where it can be actually seen as 0 bar and periodically correct it. This is called offset correction.

However, when the offset correction function of the pressure sensor fails, the output accuracy is sometimes formed as 0 bar because the accuracy of the offset is lowered even though the actual pressure is formed.

Therefore, in order to check the failure of the pressure sensor, it is necessary to implement a situation in which pressure is not detected by the pressure sensor, and measure the minimum output voltage in this state and observe how much the output voltage appears at 0 bar. .

To this end, it implements a condition that no pressure is formed in the pressure sensor. To this end, a gear check step (S100) of determining whether the vehicle gear position is the parking stage (P stage) is performed to determine whether the current gear stage is the parking stage. If it is not the parking stage, the clutch hydraulic pressure can be formed by the transmission.

In addition, the EOP check step (S200) of determining whether the engine clutch EOP (electric oil pump) is stopped. Through this it is determined that the clutch pressure is not formed.

On the other hand, a soaking check step (S300) of determining whether the soaking time is more than the first time; Soaking is the process of minimizing the action of heat by cooling the engine completely for a certain period of time. Therefore, the measurement of the pressure sensor by the engine heat is accurate only when the soaking time is secured to some extent.

Then, the vehicle speed check step (S400) for determining whether the vehicle is in a stopped state. This is because a mechanical pump is also used in the case of an oil pump. Since the mechanical pump is directly connected to the shaft of the vehicle, if the vehicle speed is 0, the mechanical pump also has a speed of 0, and thus it is possible to check that no pressure is generated. .

Meanwhile, the first time of the soaking checking step S300 is 8 hours, and the output signal of the determining step S610 may be set to an output voltage. In addition, although there may be a difference depending on the actual vehicle, it may be desirable to set the minimum output voltage, that is, the constant reference of the output signal as 0.7 V as the margin line.

In conclusion, when the gear position of the vehicle is the parking stage, the EOP is stopped, the soaking time is more than the first time, and the vehicle is stopped, the output signal of the engine clutch pressure sensor is checked and the output signal In case of abnormality, it is possible to determine whether the pressure sensor indicates the correct pressure by performing the determination step (S610) of determining the failure of the pressure sensor. If the output signal of the pressure sensor exceeds a predetermined standard, the zero point is adjusted. That is, it is determined that the offset correction function has been lost, and the final conclusion is concluded as a failure and stored (S610, S620).

On the other hand, the engine clutch pressure sensor diagnosis method of the hybrid vehicle of the present invention, the voltage check step (S10) of determining whether the input voltage of the engine clutch pressure sensor is less than a predetermined voltage; and the determination step (S610) When the input voltage of the engine clutch pressure sensor is below a certain voltage, the output signal of the engine clutch pressure sensor may be checked. If the normal voltage is not applied to the pressure sensor, the measurement may be incorrect due to the risk of malfunction. The reference of this input voltage may be set to 10V or more.

In addition, the engine clutch pressure sensor diagnosis method of the hybrid vehicle of the present invention, the communication check step (S20) of determining whether the CAN communication of the hybrid control unit (HCU) or the engine control unit (ECU) is normal; The determination step (S610) may check the output signal of the engine clutch pressure sensor when CAN communication of the hybrid controller or the engine controller is normal.

The engine clutch pressure sensor diagnosis method of the hybrid vehicle of the present invention further includes an ignition check step (S50) for determining whether the IG of the vehicle is in an ON state, and the determination step (S610). When the ignition (IG) is ON (ON) may check the output signal of the engine clutch pressure sensor. This is because the pressure sensor measures the pressure normally to generate an output signal only when the drive system controller of the vehicle performs normal operation and is performed while the ignition is turned on.

On the other hand, the engine clutch pressure sensor diagnostic method of the hybrid vehicle of the present invention determines whether the state of the HCU and ECU is in a normal state (READY) (S30), the transmission (TM) is a situation that can not be operated (S40) If the hybrid vehicle is not in the ready state (S60), it may be desirable to perform the determination of the failure of the pressure sensor, that is, the determination step.

Further, the determining step (S610), further comprising a correction stop step (S630) for stopping the offset correction of the pressure sensor when determining the failure of the engine clutch pressure sensor, so as not to perform a wrong correction, the determination step (S610) The emergency control step (S640) of controlling the engine clutch by loading a separate engine clutch control logic in which the control of the pressure sensor is excluded when determining the failure of the engine clutch pressure sensor is preferable.

Emergency control step is to prepare the control logic that clutch control can be done regardless of the pressure of engine clutch, and load it when judging the failure of pressure sensor to run the vehicle in emergency to support the stability (limform control). Say.

And, when the pressure sensor is broken, it is preferable to guide the user to service the pressure sensor by lighting a warning light on the cluster of the vehicle (S650).

According to the method for diagnosing the engine clutch pressure sensor of the hybrid vehicle having the above-described structure, it is possible to increase the reliability of the protection of the engine and the drive system and the vehicle performance by identifying whether the sensor is in advance based on the output signal of the pressure sensor. .

In addition, since the failure determination is made under a plurality of valid conditions, the reliability of the failure determination is increased.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be apparent to those of ordinary skill in the art.

S100: Gear check step S200: EOP check step
S300: Soking check step S400: Vehicle speed check step
S610: judgment step

Claims (7)

A gear check step (S100) of determining whether the vehicle gear position is the parking stage (P stage);
EOP check step (S200) of determining whether the engine oil clutch EOP (electric oil pump) is stopped;
A soaking check step S300 of determining whether a soaking time is equal to or greater than a first time;
A vehicle speed checking step (S400) for determining whether the vehicle is in a stopped state; And
When the gear position of the vehicle is the parking stage, the EOP is stopped, the soaking time is more than the first hour, and the vehicle is stopped, the output signal of the engine clutch pressure sensor is checked and the output signal is above a certain standard. Determination step (S610) of determining as a failure of the engine clutch pressure sensor diagnostic method of a hybrid vehicle comprising a. The method according to claim 1,
The first time of the soaking check step (S300) is 8 hours, the output signal of the determination step (S610) is the engine clutch pressure sensor diagnostic method of the hybrid vehicle, characterized in that the output voltage. The method according to claim 1,
And a voltage checking step (S10) for determining whether an input voltage of the engine clutch pressure sensor is lower than or equal to a predetermined voltage.
The determination step (S610) is the engine clutch pressure sensor diagnostic method of the hybrid vehicle, characterized in that for checking the output signal of the engine clutch pressure sensor when the input voltage of the engine clutch pressure sensor is below a predetermined voltage. The method according to claim 1,
And a communication check step (S20) for determining whether CAN communication of the hybrid controller or the engine controller is normal.
The determining step (S610) is a method of diagnosing the engine clutch pressure sensor of a hybrid vehicle, characterized in that for checking the CAN signal of the hybrid control unit or the engine control unit is normal the output signal of the engine clutch pressure sensor. The method according to claim 1,
An ignition check step (S50) for determining whether the ignition (IG) of the vehicle is on (ON);
The determination step (S610) is the engine clutch pressure sensor diagnostic method of the hybrid vehicle, characterized in that for checking the output signal of the engine clutch pressure sensor when the ignition (IG) is ON (ON). The method according to claim 1,
The determination step (S610), the engine stop of the clutch clutch pressure sensor of the hybrid vehicle, characterized in that it further comprises a correction stop step (S630) for stopping the offset correction of the pressure sensor when determining the failure of the engine clutch pressure sensor. The method according to claim 1,
The determining step (S610), the emergency control step (S640) for controlling the engine clutch by loading a separate engine clutch control logic to exclude the control of the pressure sensor when determining the failure of the engine clutch pressure sensor; Engine clutch pressure sensor diagnostic method for a hybrid vehicle.

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