KR100552727B1 - A method for fail detecting of water temperature sensor - Google Patents

Abstract

The present invention compares the water temperature value modeled from the gauge unit that sends a signal to the gauge provided in the cluster in front of the driver's seat and the output value of the water temperature sensor to detect that noise is introduced into the water temperature sensor from the outside. For the purpose of determining correct failures;

Receiving water temperature sensor data and gauge unit data in a vehicle in which the engine is started; Comparing the input water temperature sensor data with a set maximum and minimum limit value to determine whether a failure occurs; Modeling and comparing the input gauge unit data and determining whether noise is introduced; In this step, if the water temperature sensor data value is above the set maximum or minimum limit value or noise is detected in the water temperature sensor, it is determined that the water temperature sensor is faulty and outputs a warning lamp lighting request signal. There is no additional cost increase, it is possible to prevent the problem caused by the engine when the water temperature sensor breaks down, and to inform the driver in case of a failure to recognize the maintenance has the effect of providing customers with reliability, satisfaction and convenience.

Description

How to detect water temperature sensor failure {A METHOD FOR FAIL DETECTING OF WATER TEMPERATURE SENSOR}

1 is a general water temperature sensor connector structure diagram.

2 is a block diagram of a water temperature sensor failure detection device according to the present invention.

Figure 3 is a flow chart of the water temperature sensor failure detection method according to the present invention.

4 is a diagram illustrating a memory map for storing a water temperature sensor output value and a gauge unit output value with respect to time according to the present invention.

    <Description of Symbols for Main Parts of Drawings>

100: vehicle operation state detection device

110: water temperature sensor 120: gauge unit

200: control device 300: warning device

The present invention relates to a water temperature sensor failure detection method, and more particularly, to a water temperature sensor failure detection method capable of detecting accurate water temperature when noise is introduced from the outside compared to a water temperature model without adding a new device.

In general, a water temperature sensor (WTS: Water Temperature Sensor) is mounted in the engine block to be in contact with the coolant, and converts the temperature of the coolant into an electrical signal and transmits it. The temperature of the engine coolant measured by this water temperature sensor is used as various information required for the vehicle.

In addition, these cooling water temperature values determine the starting fuel amount and the control fuel amount on the basis of the water temperature at start-up and warm-up, and are an important factor in cooling fan control.

Therefore, water temperature is the most basic in engine control.

The cooling water temperature is measured by the engine controller reading the voltage of the water temperature sensor and converting the voltage into water temperature. Therefore, the engine control device is configured to always detect whether or not the water temperature sensor that detects the coolant temperature, which is an important factor of the engine control. Currently, in most vehicles, the failure detection method of the water temperature sensor is determined to be a failure when the value input from the water temperature sensor exceeds the preset limit.

That is, when the value input from the water temperature sensor is larger than the preset maximum limit value, or when the value input from the water temperature sensor is smaller than the minimum limit value, the engine temperature controller determines that the water temperature sensor has failed. Lights up to alert the driver of water temperature sensor failure.

Therefore, in the related art, various methods for detecting a failure of the water temperature sensor have been proposed. In the case of a water temperature sensor failure, a failure of the water temperature sensor is detected after calculating the water temperature by connecting it to a gauge unit used for displaying the temperature of the instrument panel. The Korean Patent Publication No. 1997-0058808 (Name: water temperature sensor in case of a water temperature sensor failure of the car) and the cooling water temperature value measured by time zone are repeatedly compared with the set temperature by time zone to detect the failure of the water temperature sensor. Korean Patent Publication No. 1996-080633 (name: fault detection method for a water temperature sensor of an automobile) and many other inventions have been presented.

However, among the previously proposed inventions, in particular, the Republic of Korea Patent Publication No. 1997-0058808 because the characteristic curve of the water temperature sensor and the gauge unit is different, the characteristic curve of the gauge unit must be input to the engine control device in advance. In addition, by directly using the temperature information of the gauge unit indicating only the high and low temperature of the water, it is difficult to accurately measure the water temperature.

In addition, other proposals have problems such as cost increase due to additional devices.

In the prior art for determining a failure of the water temperature sensor, when the value input from the water temperature sensor is an input value exceeding a preset limit, it is determined as a failure. However, the above-described conventional technology has a problem that noise signals such as external electromagnetic waves are introduced into the signal input from the water temperature sensor, or incorrect water temperature data is input to the engine control device due to poor contact of the water temperature sensor connector. When the water temperature data values due to this external disturbance are within the maximum / minimum limit, the engine control device does not recognize the sensor as a failure even though an incorrect signal is input, and has a problem of normal processing.

Accordingly, an object of the present invention is to solve the above problems, modeled from the gauge unit for sending a signal to the gauge provided in the cluster in front of the driver's seat to detect that the noise is introduced into the water temperature sensor from the outside to input the false signal It is to provide a water temperature sensor failure detection method for determining whether the water temperature sensor is accurate by comparing the water temperature value and the output value of the water temperature sensor.

The present invention for achieving the above object,

Receiving water temperature sensor data and gauge unit data in a vehicle in which the engine is started;

Comparing the input water temperature sensor data with a set maximum and minimum limit value to determine whether a failure occurs;

Modeling and comparing the input gauge unit data and determining whether noise is introduced;

In this step, if the water temperature sensor data value is greater than the set maximum, minimum limit or noise is determined in the water temperature sensor, it is determined that the water temperature sensor failure is characterized in that the step of outputting a warning lamp lighting request signal.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a water temperature sensor failure detection device according to the present invention. Figure 3 is a flow chart of the water temperature sensor failure detection method according to the present invention. 4 is a diagram illustrating a memory map for storing a water temperature sensor output value and a gauge unit output value with respect to time according to the present invention.

As shown in FIG. 2, the water temperature sensor failure detection device includes a coolant temperature signal detection unit 110 and a coolant temperature signal for detecting a signal applying a change in vehicle coolant temperature, which is varied according to a change in an operating state of the vehicle, to the engine control. A vehicle operation state detection device (100) formed integrally with the detection unit and including a gauge signal detection unit (120) for applying the detected coolant temperature change to a temperature gauge provided in a cluster in front of the driver's seat;

Receives the signal detected by the coolant temperature signal detection unit 110 of the vehicle operation state detection device 100 and performs engine control by a set program, and receives the signal applied by the gauge signal detection unit 120. A control device 200 that determines whether noise is introduced into the water temperature sensor in comparison with the cooling water temperature signal, and outputs a warning light on signal when determining noise inflow;

It is provided with a warning light lighting device 300 to warn the driver of the water temperature sensor failure in synchronization with the warning light lighting signal output from the control device 200.

With reference to the accompanying drawings, a water temperature sensor failure detection method having the above configuration will be described by way of example.

When the engine is started, the water temperature sensor signal detector 110 and the gauge signal detector 120 of the vehicle operation state detection apparatus 100 detect the coolant temperature of the vehicle engine.

Accordingly, the control device 200 receives the water temperature sensor signal detected and applied by the water temperature sensor signal detection unit 110 and determines whether the signal is within the maximum water temperature limit stored in the memory (S100 and S110).

When it is determined that the water temperature value applied by the water temperature sensor signal detector 110 is included in the maximum water temperature limit stored in the memory, the control apparatus 200 determines that the water temperature value applied by the water temperature sensor signal detector 110 is a memory. It is determined whether or not the minimum temperature limit stored in the water (S120).

If it is determined that the water temperature value of the water temperature sensor signal detection unit 110 is included within the maximum and minimum limit values stored in the memory, the control apparatus 200 determines that the water temperature sensor is normal, and whether the water temperature sensor is abnormal. In operation S140, it is determined whether the determination number step_n determining the number is less than or equal to the setting number step_conv (eg, 10 times).

If it is determined that the number of times (step_n) to determine whether the water temperature sensor abnormality is less than the set number (step_conv, for example, 10 times), the control device 200 determines that the water temperature sensor is normal, and returns to the initial step (S100) (S150).

However, if it is determined that the water temperature value of the water temperature sensor signal detection unit 110 applied in the above (S110, S120) is not included in the maximum and minimum limit value range, the control device 200 is a failure of the water temperature sensor signal detection unit 110 In operation S160 and S170, the control signal for turning on the engine check warning lamp is output.

In addition, the controller 200 receives a water temperature value for controlling the engine from the water temperature sensor signal detection unit 110 at step S100 and simultaneously displays a current engine cooling water temperature on a water temperature gauge provided in a cluster in front of the driver's seat. The signal detector 120 receives a signal for each predetermined number of times (step_n) (S200).

eq (n), eq (n + 1), eq (n + 2)

At this time, the controller 200 sequentially stores the water temperature sensor signal value and the signal value detected by the gauge signal detector 120 at a predetermined time in the memory map table as shown in FIG. 4 (S210).

Here, the smaller the setting time, the more accurate modeling values can be obtained. However, since data processing speed and storage have different difficulties, the optimal value is determined through testing.

Thereafter, the control device 200 may obtain the calculated modeling value as a function (S220).

a (n), b (n), c (n) = f [eq (n), eq (n + 1), eq (n + 2)]

Thereafter, the control apparatus 200 calculates a (n), b (n), c by constructing a model equation from the input values stored for each predetermined number of times (step_n) to obtain a modeling value as shown in the following equations. (n) get the value.

In the above formulas 1, 2, and 3 it can be obtained a1, b1, c1 of step 1.

Then, by calculating Equation 4 with the values a1, b1 and c1 calculated in step 1, a2, b2 and c3 in step 2 can be obtained.

Subsequently, a3, b3, and c3 of step 3 may be calculated by calculating Equation 5 from a2, b2, and c3 calculated in step 2 above.

Since each of the steps has three unknowns a, b, and c and three equations, a, b, and c values can be obtained.

If the modeling is made with a higher order, the equations and unknowns required for each step are increased, and more accurate model values are obtained. However, since the data processing speed and storage are difficult, the optimal value is determined according to the system specification.

The model in which the unknowns are set to a, b, and c will be described.

As the number of steps increases, it converges to a constant value of a, b, and c values.

The number of steps (step_conv, for example, 10 times) at which the a, b, and c values are constantly converged is set in advance through experiments.

Here, the predetermined number of steps is exceeded, and the values a, b, and c modeled from the gauge unit, which is the gauge signal detection unit 120, converge to a predetermined value. At this time, each of the converged a, b, and c controls the controller. It is stored at (200), and compares the values of each of a, b, c with the previous step value, if there is a value within the error range determines that the water temperature sensor is normal (S230 ~ S270).

In the above, the error is represented by α, β, and γ.

However, when it is determined that the values of each of the modeled a, b, and c are out of the error range compared to the previous step value, the control apparatus 200 determines that the water temperature sensor signal is a wrong signal due to noise from the outside. (S300, S310).

When noise is input from the outside as described above, the signal from the water temperature sensor does not represent the correct water temperature, so the water temperature is calculated using the equation modeled from the gauge unit, and the controller 200 calculates the water temperature information obtained as described above. It is used to control the engine (S320).

As mentioned above, since external noise may be introduced in an instant or intermittently, the noise does not mean that the water temperature sensor does not work permanently.

However, when such noise is continuously introduced, it is necessary to inform the driver of the failure of the water temperature sensor due to the inflow of external noise.

Therefore, the control apparatus 200 continuously detects whether or not noise inflow occurs and outputs an engine inspection warning lamp lighting signal for requesting the driver to check the water temperature sensor when noise is continuously introduced (S330, S340, and S350).

Thus, it is possible to determine whether the water temperature sensor that detects the engine cooling water temperature by the control logic without installing an additional device.

As described above, the present invention relates to a water temperature sensor failure detection method, wherein a water temperature value modeled from a gauge unit that sends a signal to a gauge provided in a cluster in front of a driver's seat to detect that noise is introduced into the water temperature sensor from the outside and inputs an erroneous signal. It is possible to determine whether the water temperature sensor is accurate by comparing the output value of the water temperature sensor with that of the water temperature sensor. By informing the city driver to be recognized for maintenance, it has the effect of providing the customer with reliability, satisfaction and convenience.

Claims (3)

Receiving water temperature sensor data and gauge unit data in a vehicle in which the engine is started; Comparing the input water temperature sensor data with a set maximum and minimum limit value to determine whether a failure occurs; The input gauge unit data and the water temperature sensor data are sequentially stored in a memory map table every set time and then calculated as a function to calculate a modeling value. Making a step; In the step, if the water temperature sensor data value is out of the set maximum or minimum limit or it is determined that noise is introduced into the water temperature sensor, it is determined that the water temperature sensor is faulty and outputs a warning lamp lighting request signal. Way. delete delete

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