KR20090011725A - Offset correction and trouble detection method of yaw rate sensor - Google Patents

Abstract

An offset correction and trouble detection method of a yaw rate sensor is provided to detect accurately a trouble of a sensor by acquiring a moving average for a difference between a calculated sensor value and a measured sensor value and comparing the moving average with a trouble detection reference value. A difference between a calculated yaw rate and a measured yaw rate is set as a yaw rate offset(S1). A moving average is acquired with respect to the set yaw rate offset(S2). A trouble detection is detected by determining whether a result value of the moving average is larger than a trouble detection reference value or not(S5).

Description

Offset correction and trouble detection method of yaw rate sensor

1 is a block diagram showing the configuration of a system used in the present invention.

Figure 2 is a flow chart illustrating the operation of the yaw rate sensor offset correction and failure detection method according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: control unit 11: offset correction and fault determination unit

12: Stopping / starting section 13: Straight driving section

14: forward driving judgment 15: front wheel speed sensor

16: Rear wheel speed sensor 17: Lateral acceleration sensor

18: steering angle sensor 19: yaw rate sensor

20: display unit 21: main control unit

The present invention relates to a yaw rate sensor offset correction and fault detection method in a vehicle, and more particularly to a yaw rate sensor offset correction and fault detection method for correcting the yaw rate offset or failure detection of the yaw rate sensor.

In general, the yaw rate sensor for detecting the rotational angular velocity is widely used not only for automobiles but also for navigation devices and camcorders of ships and aircrafts. The yaw rate sensor, also called an angular velocity sensor, detects the angular velocity in the vertical axis direction of the vehicle.

The ESP system (vehicle stability control system) using the yaw rate sensor is not only a yaw rate sensor but also a plurality of sensors and a hydro unit, an actuator for controlling the braking force of each wheel, and an electronic control unit (ECU), which is an electronic controller. It is composed.

The yaw rate is the basis for controlling the ESP system, and the accuracy of the yaw rate sensor is a very important factor in the ESP system.

However, in the related art, there is a problem in that an offset failure of the yaw rate sensor is not suggested, and thus an offset failure occurs in the yaw rate sensor, thereby causing a risk of malfunction.

In order to solve this problem, if the vehicle is driving, the yaw rate measured during the stop is set to the yaw rate offset depending on whether the vehicle has been stopped before the second predetermined time or the yaw rate difference between the calculated yaw rate and the measured yaw rate A method of setting an offset, comparing the set yaw rate offset with a reference value, and correcting the yaw rate offset or determining a failure according to the result of the comparison has been introduced (Publication 10-2006-0033058, 10-2006-0077822). And 10-2005-0046240).

However, in the above-described method, the difference between the calculated sensor value and the measured sensor value is used for offset correction or fault detection of the sensor. In addition, this difference is detected by detecting the abnormal offset of the sensor by comparing with the fault detection reference value considering the specifications provided by the sensor manufacturer. Here, the above technique detects the offset failure of the sensor by comparing the difference between the calculated sensor value and the measured sensor value with the reference value, but this method basically takes into account the uncertainty of the calculated sensor value. When comparing the dispersion, there is a problem that frequently occurs even if the failure detection reference value is exceeded even under normal circumstances.

Accordingly, the present invention has been made to solve the problems of the prior art, and the fault detection of the sensor is performed by taking a moving average of the difference between the calculated sensor value and the measured sensor value and comparing the result with the fault detection reference value. It is an object of the present invention to provide a yaw rate sensor offset correction and a failure detection method that enables accurate detection of a failure of a sensor.

The present invention relates to sensor values calculated in relation to signal abnormality failures (sensor offsets, gains, code differences, etc., which may occur due to deterioration of the sensor, mounting failure, sensor itself defect, etc.) of the sensor disclosed in the above-mentioned prior art publication. It is an object of the present invention to provide a yaw rate sensor offset correction and a failure detection method that can reduce the dispersion and increase the reliability of failure detection by taking a moving average with respect to a difference from the measured sensor value.

In order to achieve the above object, the yaw rate sensor offset correction and fault detection method according to the present invention includes the steps of setting the difference between the calculated yaw rate and the measured yaw rate as the yaw rate offset; Obtaining a moving average with respect to the set yaw rate offset; And detecting a failure according to whether the result value of the moving average is greater than a failure detection reference value.

Hereinafter, a yaw rate sensor offset correction and a failure detection method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, the system for the present invention includes a front wheel speed sensor 15 for detecting a speed of a front wheel of a vehicle, a rear wheel speed sensor 16 for detecting a speed of a rear wheel of a vehicle, and a lateral acceleration sensor 17 for detecting a lateral acceleration. And a steering angle sensor 18 for detecting a steering angle, and a yaw rate sensor 19 for detecting an angular velocity of the vehicle.

In addition, the control unit 10 for controlling the overall operation of the system is the stop / start determination unit 12, the straight running determination unit 13, the forward driving determination unit 14, the offset correction and failure determination unit 11, And the main control part 21 is provided.

The stop / start judging unit 12 is installed to determine the stop / start state of the vehicle by using the result of sensing the speed of the wheel. The straight traveling judging unit 13 is a device for determining whether the vehicle is traveling straight, using front / rear wheel speed sensors 15 and 16, a steering angle sensor 18, a lateral acceleration sensor 17, and a yaw rate sensor 19. If the front / rear wheel speed difference, steering angle, lateral acceleration, and yaw rate are each less than the predetermined value, it is regarded as going straight. That is, in the case of going straight, ideally, the speed of the front / rear wheels is the same, the steering angle or the lateral acceleration is 0, and the yaw rate is 0. The above predetermined value can be arbitrarily set.

The forward traveling judging portion 14 is the yaw rate and yaw rate sensor 19 calculated as a result detected by the front / rear wheel speed sensors (15, 16), steering angle sensor (18), transverse acceleration sensor (17) Judging forward driving by using the measured yaw rate. This means that the yaw rate calculated by each sensor when the vehicle reverses and the yaw rate measured by the yaw rate sensor 19 have opposite signs, and the yaw rate calculated and the measured yaw rate have the same sign when moving forward. Using points.

The yaw rate is calculated by (front right wheel speed-front left wheel speed) / distance between wheels, (rear right wheel speed-rear left wheel speed) / distance between wheels, (vehicle speed * steering angle) / (steering ratio * axis distance) ( The steering ratio is the steering angle required for the front wheel to rotate 1 degree and the distance between the axles is the front / rear axle distance) and the lateral acceleration / vehicle formula.

The offset correction and fault determination unit 11 compares the set yaw rate offset with each reference value, which will be described later, and determines that the yaw rate offset is correct or is a failure.

The main controller 21 controls the operation of each determination unit and the sensor.

The display unit 20 is a warning lamp for displaying the externally when the offset correction and the failure determination unit 11 determines that the yaw rate sensor is out of order.

Next, a yaw rate sensor offset correction and a failure detection method according to the present invention will be described with reference to FIG. 2.

Here, as disclosed in Patent Publication Nos. 10-2005-0046240 and the like, the calculated yaw rate sensor value and the measured yaw rate sensor value are stored in the main control unit 21.

The offset correction and failure determination unit 11 obtains the calculated yaw rate sensor value and the measured yaw rate sensor value stored in the main controller 21, obtains the difference between the calculated sensor and the measured sensor, and the difference Is set to the yaw rate offset (step S1).

That is, yaw rate offset (Ryaw) = | calculated sensor value (Cyaw) -measured sensor value (Myaw) |

Then, the moving average value MRyaw is calculated for the set yaw rate offset Ryaw (step S2). In other words,

It is checked whether the calculated moving average value MRyaw is larger than the failure detection reference value (step S3).

If it is larger than the reference value in step S3, it is detected as a failure, and if it is not large, it is detected as normal (S5, S4).

That is, the difference between the calculated sensor value and the measured sensor value is filtered again using the moving average, thereby reducing the scattering and increasing the reliability of the failure detection.

On the other hand, the present invention is not limited to the above specific embodiments, but can be modified and modified in various ways without departing from the gist of the present invention. If such changes and modifications fall within the scope of the appended claims, it will be apparent that they are included in the present invention.

As described above, according to the present invention, the sensor value calculated in relation to the signal abnormality failure of the sensor (sensor offset, gain, code difference, etc., which may occur due to deterioration of the sensor, mounting failure, defective sensor itself, etc.) and By taking a moving average with respect to the difference from the measured sensor value, the dispersion can be reduced to increase the reliability of the fault detection.

Claims (1)

Setting the difference between the calculated yaw rate and the measured yaw rate as the yaw rate offset; Obtaining a moving average with respect to the set yaw rate offset; Yaw rate sensor offset correction and failure detection method comprising the step of detecting a failure according to whether or not the result value of the moving average is greater than the failure detection reference value.

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