KR101667236B1

KR101667236B1 - Device and method for correcting stereo vision sensor by considering time delay

Info

Publication number: KR101667236B1
Application number: KR1020150076002A
Authority: KR
Inventors: 허건수; 김승기; 박장희
Original assignee: 한양대학교 산학협력단
Priority date: 2015-05-29
Filing date: 2015-05-29
Publication date: 2016-10-18

Abstract

A stereo vision sensor correcting apparatus considering a time delay according to an embodiment of the present invention includes a setting unit for measuring a first relative distance between the vehicle and a stopped forward object in a state where the vehicle is stationary and setting the first relative distance as an initial value; And estimating a moving distance of the vehicle by using at least one of a speed and an acceleration of the vehicle when the vehicle moves, calculating a second distance between the vehicle and the forward object based on the set initial value and the predicted traveling distance, An operation unit for calculating a relative distance; And calculating a time delay value of the vision sensor based on the second relative distance, a third relative distance obtained through a vision sensor mounted on the vehicle, and a velocity of the vehicle, and using the calculated time delay value And a correction unit for correcting the vision sensor.

Description

TECHNICAL FIELD [0001] The present invention relates to a device and a method for compensating a stereo vision sensor,

Embodiments of the present invention relate to sensor calibration techniques and, more particularly, to an apparatus and method for calibrating a stereo vision sensor in consideration of time delay.

The Stereo Vision Sensor requires image processing to determine the object ahead and measure the distance, which results in a time delay.

That is, the positional information of the currently obtained forward object is actually the positional information of the previous object by a predetermined delay time. In addition, the position information of the forward object provided by the stereo vision sensor is updated in a long time period.

In general, when the position of a forward object is acquired using the stereo vision sensor and the vehicle is controlled based on the position, the position information without considering the time delay is used as it is.

Therefore, a method of correcting the position in consideration of the time delay among the existing techniques has been proposed. However, in the first method, there is a limitation that the time delay value can be directly calculated only when the stereo vision sensor supports a time sync function and a time stamp (Time Stamp) function. Also, in the second method, a memory space equivalent to a delay time is required to express the position information of an object, and there is a limit in that a large amount of calculation occurs when estimating the time delay value.

Therefore, even when the stereo vision sensor does not support the time sync and time stamp functions, the development of a technology capable of calculating the delay time of the stereo vision sensor with a small amount of calculation and correcting the stereo vision sensor using the delay time It is necessary.

A related prior art is Korean Patent Registration No. 10-1194115 entitled " Vehicle Distance Control System, Registered Date: October 17, 2012 ".

One embodiment of the present invention is a stereo vision sensor correction device that calculates a time delay value using a predicted value and an estimated value of a relative distance between a vehicle and a forward object and considers a time delay in which the vision sensor can be corrected using the time delay value, &Lt; / RTI >

The problems to be solved by the present invention are not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be clearly understood by those skilled in the art from the following description.

Wherein the setting unit detects the position of the vehicle and the forward object using the vision sensor, measures the first relative distance using the sensed position, and sets the measured first relative distance as the initial value .

The setting unit estimates the position of the vehicle and the front object using an IMU (Inertial Measurement Unit) mounted on the vehicle, measures the first relative distance using the estimated position, The relative distance can be set to the initial value.

The calculation unit obtains at least one of a speed and an acceleration of the vehicle using an IMU (Inertial Measurement Unit) mounted on the vehicle, and estimates a moving distance of the vehicle using at least one of the obtained speed and acceleration have.

The operation unit may obtain the yaw rate of the vehicle using the IMU, and may further estimate the movement distance of the vehicle using the obtained yaw rate.

The correcting unit may calculate the time delay value of the vision sensor by dividing the difference between the second relative distance and the third relative distance by the speed of the vehicle.

The second relative distance may be the information without influence of the time delay by the vision sensor, and the third relative distance may be the information including the influence of the time delay by the vision sensor.

The correcting unit may apply the weight to the time delay value according to the speed of the vehicle, considering that an offset error due to the time delay value increases in proportion to the speed of the vehicle.

The correction unit periodically cumulatively calculates a time delay value of the vision sensor, updates the time delay value to select a final sensor time delay value when the preset time condition is satisfied, So that the vision sensor can be corrected.

The final sensor time delay value may be an accumulated time delay value generated by accumulating the time delay value for the predetermined time.

The correction unit reflects a current time delay value (Time delay T _{cd (k)} ) to a preset cumulative time delay value (Time delay T _{d (k-1)} Value (Time delay T _{d (k)} ).

[Equation 1]

The apparatus for correcting a stereovision sensor considering time delay according to an embodiment of the present invention further includes a control unit for controlling the driving of the vehicle using the third relative distance measured by the vision sensor after the correction of the vision sensor can do.

The vision sensor may be a stereo vision sensor that does not support time synchronization and time stamping.

A stereo vision sensor correction method considering time delay according to an embodiment of the present invention includes the steps of measuring a first relative distance between the vehicle and a stopped forward object in a state where the vehicle is stopped and setting the first relative distance as an initial value; Estimating a moving distance of the vehicle using at least one of a speed and an acceleration of the vehicle when the vehicle moves; Calculating a second relative distance between the vehicle and the forward object based on the set initial value and the predicted traveling distance; Calculating a time delay value of the vision sensor based on the second relative distance, a third relative distance obtained through a vision sensor mounted on the vehicle, and a velocity of the vehicle; And correcting the vision sensor using the calculated time delay value.

The step of calculating the time delay value of the vision sensor may include calculating a time delay value of the vision sensor by dividing the difference between the second relative distance and the third relative distance by the speed of the vehicle.

Wherein the step of calibrating the vision sensor includes periodically accumulating the time delay value of the vision sensor; Updating the time delay value to select a final sensor time delay value when a predetermined time condition is satisfied; And correcting the vision sensor using the selected final sensor time delay value, wherein the final sensor time delay value may be an accumulated time delay value generated by accumulating the time delay value during the predetermined time .

The details of other embodiments are included in the detailed description and the accompanying drawings.

According to an embodiment of the present invention, a time delay value may be calculated using a predicted value and an estimated value of a relative distance between a vehicle and a forward object, and the vision sensor may be corrected using the calculated time delay value.

According to an embodiment of the present invention, the relative distance between the vehicle and the forward object can be more accurately calculated by correcting the vision sensor in consideration of the time delay, and thereby the operation of the vehicle can be more precisely controlled.

According to an embodiment of the present invention, since a large amount of calculation does not occur when calculating the time delay value, the computation amount and the computational complexity can be reduced, and the relative distance between the vehicle and the forward object can be accurately calculated at a faster cycle.

According to an embodiment of the present invention, the time delay value of the vision sensor can be directly calculated even when the vision sensor does not support the time sync and the time stamp function.

FIG. 1 is a block diagram for explaining a stereo vision sensor correcting apparatus considering a time delay according to an embodiment of the present invention. Referring to FIG.
2 is a block diagram showing the detailed configuration of the setting unit of FIG.
3 is a block diagram showing the detailed configuration of the operation unit of FIG.
Fig. 4 is a diagram showing the detailed configuration of the correction unit of Fig. 1. Fig.
FIG. 5 is a flowchart illustrating a stereo vision sensor correction method considering time delay according to an exemplary embodiment of the present invention. Referring to FIG.
6 is a flowchart illustrating a process of correcting a vision sensor using a time delay value according to an exemplary embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

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

FIG. 1 is a block diagram for explaining a stereo vision sensor correcting apparatus considering a time delay according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, a stereo vision sensor correction apparatus 100 considering a time delay according to an embodiment of the present invention includes a setting unit 110, an operation unit 120, a correction unit 130, and a control unit 140 .

The setting unit 110 measures a first relative distance between the vehicle and the stopped forward object in a state where the vehicle is stopped and sets the first relative distance as an initial value. Here, the forward object may include a forward vehicle.

2, the setting unit 110 may include a position sensing unit 210, a distance measuring unit 220, and an initial value setting unit 230. 2 is a block diagram showing the detailed configuration of the setting unit 110 of FIG.

The position sensing unit 210 may sense the position of the vehicle and the front object using a vision sensor mounted on the vehicle.

To this end, the vision sensor can acquire position information of the forward object by imaging the forward object using the camera module, image processing the identified forward object, and acquiring the position information of the forward object.

The position sensing unit 210 may sense the position of the forward object through the position information obtained by the vision sensor.

At this time, the vision sensor can periodically perform the image processing to acquire the position information at predetermined time intervals. Accordingly, the position sensing unit 210 may periodically sense the position of the forward object.

The distance measuring unit 220 can measure the first relative distance using the position sensed by the position sensing unit 210. [

That is, the distance measuring unit 220 may compare the position information of the forward object with the position information of the vehicle, and measure the first relative distance based on the difference value according to the comparison result.

The initial value setting unit 230 may set the first relative distance measured by the distance measuring unit 220 to the initial value.

Here, the first relative distance may be an actual distance that does not include a distance error due to a time delay or a value that is very close to an actual distance because the first relative distance is a value measured while the vehicle and the forward object are stationary.

Therefore, in an embodiment of the present invention, the first relative distance may be set as the initial value, and thus the first relative distance may be used as a reference value for correcting the error of the vision sensor according to the time delay.

For reference, in one embodiment of the present invention, a stereo vision sensor that does not support a time sync function and a time stamp function may be used as the vision sensor.

There has been a limitation in calculating the error of the vision sensor, that is, the time delay value only when the vision sensor supports the time sink and the time stamp function. However, in one embodiment of the present invention, the time delay value may be calculated based on the initial value even when the time sensor and the time stamp function are not supported by the vision sensor.

Meanwhile, as another embodiment, the setting unit 120 may estimate the position of the vehicle and the forward object using an IMU (Inertial Measurement Unit) mounted on the vehicle. The setting unit 120 may measure the first relative distance using the estimated position. The setting unit 120 may set the measured first relative distance to the initial value.

When the vehicle moves, the calculation unit 120 may predict the moving distance of the vehicle using at least one of the speed and the acceleration of the vehicle.

3, the operation unit 120 may include an IMU 310, an information obtaining unit 320, and a distance predicting unit 330. 3 is a block diagram showing the detailed configuration of the calculation unit 120 of FIG.

The IMU 310 senses the speed, acceleration, yaw rate, and the like of the vehicle according to the movement of the vehicle to generate sensing data. The sensing data is transmitted to the information acquiring unit 320).

The information obtaining unit 320 may obtain the sensing data from the IMU 310.

The distance predicting unit 330 may predict the moving distance of the vehicle using at least one of the velocity and the acceleration of the vehicle among the sensor data.

At this time, the distance predicting unit 330 can predict the moving distance of the vehicle more accurately in consideration of the straight running of the vehicle as well as the curve running.

For this, the distance predicting unit 330 may predict the moving distance of the vehicle by further using the yaw rate of the vehicle from the sensing data. That is, the distance predicting unit 330 can estimate the moving distance of the vehicle using at least one of the speed and the acceleration of the vehicle and the yaw rate of the vehicle.

As such, the distance predicting unit 330 predicts the traveling distance of the vehicle in consideration of the traveling trajectory of the vehicle, thereby accurately estimating the traveling distance of the vehicle not only in the straight traveling but also in the curved traveling.

For reference, the movement of the vehicle may be determined by the sensing data of the IMU 310, that is, the speed or acceleration of the vehicle. In other words, the distance predicting unit 330 may determine whether the vehicle is moving using the sensing data sensed by the IMU 310. [

The distance predicting unit 330 calculates a second relative distance between the vehicle and the forward object based on the predicted traveling distance and an initial value set by the setting unit 110. [

That is, the distance predicting unit 330 calculates a value obtained by subtracting a moving distance corresponding to the movement of the vehicle from a first relative distance (initial value) measured in a state where the vehicle is stopped, Can be calculated as the relative distance.

Based on the second relative distance calculated by the distance predicting unit 330, the third relative distance obtained through the vision sensor, and the speed of the vehicle, the correcting unit 130 corrects the time delay value .

Specifically, the correction unit 130 may calculate the time delay value of the vision sensor by dividing the difference between the second relative distance and the third relative distance by the speed of the vehicle.

Here, the second relative distance may be the information without influence of the time delay by the vision sensor, and the third relative distance may be information including the influence of the time delay by the vision sensor.

The correction unit 130 subtracts the information (second relative distance) not included in the information (the third relative distance) included in the influence of the time delay by the vision sensor and divides the information by the speed of the vehicle , The calculation result can be calculated as the time delay value of the vision sensor.

The correcting unit 130 corrects the vision sensor using the calculated time delay value. Here, the time delay value may increase in proportion to the speed of the vehicle. Therefore, in one embodiment of the present invention, the vision sensor can be corrected in consideration of the time delay value according to the speed ratio of the vehicle.

Hereinafter, the correction unit 130 will be described in more detail with reference to FIG. 4 is a diagram showing the detailed configuration of the correction unit 130 of FIG.

4, the correction unit 130 may include an accumulation unit 410, an update unit 420, a sensor correction unit 430, and a weight application unit 440.

The accumulation unit 410 periodically accumulates the time delay value of the vision sensor.

To this end, the cumulative calculation unit 410 obtains the third relative distance through the vision sensor, subtracts the second relative distance calculated by the calculation unit 120 from the third relative distance, The speed of the operation can be reduced.

Thus, the cumulative calculation unit 410 can calculate the time delay value of the vision sensor at predetermined time intervals, and can calculate the cumulative time delay value by cumulatively calculating all of the calculated time delay values.

At this time, the accumulation unit 410 _{multiplies the} current time delay T _{cd (k} ) by a predetermined reflection ratio G in the existing cumulative time delay value T _{d (k-1} ) And the current cumulative time delay value (Time delay T _{d (k)} ) can be calculated. That is, the cumulative time delay value can be calculated by the following equation (1).

[Equation 1]

Here, if G is large, the reflection ratio of the current time delay value T _cd _(k) is high. If G is small, the reflection rate of the current time delay value is low. That is, the rate of reflection of the time delay value is proportional to the value of G.

Further, the time delay value may have a positive value or a negative value. Accordingly, the cumulative time delay value may be continuously increased, or may be decreased continuously, or may be increased or decreased.

If the preset time condition is satisfied, the update unit 420 may update the time delay value to select the last sensor time delay value.

For example, it is assumed that the time delay value of the vision sensor is calculated at an interval of time '1', and the time condition is preset at an interval of time '5'. In this case, the update unit 420 may update the current time delay value to a first cumulative time delay value accumulated up to time '5' at a time '5', and select the latest time delay value as a final sensor time delay value.

Then, when the time reaches a time point '10', the update unit 420 outputs a second cumulative time delay value reflecting the accumulated time delay value between the time '5' and the time '10' The final sensor time delay value may be updated. The update unit 420 may repeat the updating process.

As the updating process is repeated, the difference between the predicted value (second relative distance) and the estimated value (third relative distance) is reduced. As a result, the accumulated time delay value gradually decreases and converges to a certain value.

The weight applying unit 430 may calculate the time delay value (including the accumulated time delay value) according to the speed of the vehicle, considering an increase in the offset error due to the time delay value in proportion to the speed of the vehicle. ). &Lt; / RTI >

For this, the weight application unit 430 may assign a rating according to the speed of the vehicle, and may generate a weight according to the rating and apply the weight to the time delay value.

The sensor correcting unit 440 may correct the vision sensor using the last sensor time delay value selected by the updater 420.

That is, the sensor correcting unit 440 can correct the vision sensor by compensating the time delay value of the vision sensor by the final sensor time delay value.

Alternatively, the sensor correction unit 440 may correct the vision sensor using the weighted time delay value.

The control unit 140 may control the driving of the vehicle using the third relative distance measured by the vision sensor after the correction of the vision sensor.

For example, when the vehicle is likely to hit the forward object (another vehicle in front), the control unit 140 detects the collision with the forward object based on the detection result using the third relative distance, The operation of the vehicle can be controlled so as to be avoided.

The control unit 1400 includes a stereo vision sensor correcting apparatus 100 considering the time delay according to an embodiment of the present invention, that is, the setting unit 110, the calculating unit 120, the correcting unit 130, The operation can be controlled as a whole.

FIG. 5 is a flowchart illustrating a stereo vision sensor correction method considering time delay according to an exemplary embodiment of the present invention. Referring to FIG. The stereo vision sensor correcting method may be performed by the stereo vision sensor correcting apparatus 100 of FIG.

Referring to FIG. 5, in step 510, the stereo vision sensor correction device measures a first relative distance between the vehicle and a stopped forward object in a state where the vehicle is stationary.

Next, in step 520, the stereo vision sensor correction apparatus sets the measured first relative distance as an initial value.

Next, in step 530, the stereo vision sensor correction device predicts the moving distance of the vehicle using the velocity, acceleration, and yaw rate of the vehicle when the vehicle is moving.

Next, in step 540, the stereo vision sensor correction device calculates a second relative distance between the vehicle and the forward object based on the set initial value and the predicted traveling distance.

Next, in step 550, the stereo vision sensor correction device acquires a third relative distance through a vision sensor mounted on the vehicle.

Here, the third relative distance is an estimated distance between the vehicle and the forward object, and represents a distance including an influence of the error (time delay) of the vision sensor according to the speed of the vehicle.

Next, in step 560, the stereo vision sensor correction device calculates the time delay value of the vision sensor based on the second and third relative distances, the speed of the vehicle.

Next, in step 570, the stereo vision sensor correction apparatus uses the calculated time delay value to correct the vision sensor. Hereinafter, the step 570 will be described in detail with reference to FIG. 6 is a flowchart illustrating a process of correcting a vision sensor using a time delay value according to an exemplary embodiment of the present invention.

Referring to FIG. 6, in step 610, the stereo vision sensor correction device periodically cumulatively calculates a time delay value of the vision sensor.

Thereafter, in step 620, the stereo vision sensor correction device determines whether or not a preset time condition is satisfied.

As a result of the determination, if the time condition is satisfied (the "Yes" direction of 620), the stereo vision sensor correction apparatus updates the time delay value in step 630, And the cumulative time delay value generated as a final sensor time delay value is selected.

On the other hand, if it is determined that the time condition is not satisfied (No in step 620), the stereo vision sensor correction apparatus returns to step 610.

Thereafter, in step 640, the stereo vision sensor correction device corrects the vision sensor using the selected final sensor time delay value.

As described above, in one embodiment of the present invention, the time delay value is calculated using the predicted value and the estimated value of the relative distance between the vehicle and the forward object, and the vision sensor can be corrected using the calculated time delay value.

Therefore, according to one embodiment of the present invention, the relative distance between the vehicle and the forward object can be more accurately calculated by correcting the vision sensor in consideration of the time delay. Thus, according to an embodiment of the present invention, the vehicle can be controlled more precisely through the relative distance between the vehicle and the forward object, thereby enabling a higher performance driver's convenience or a vehicle safety system to be constructed .

Also, according to the embodiment of the present invention, since a large amount of computation does not occur when calculating the time delay value, the amount of computation and the computational complexity can be reduced. Therefore, according to one embodiment of the present invention, the relative distance between the vehicle and the forward object can be accurately calculated at a faster cycle.

In addition, according to an embodiment of the present invention, the time delay value of the vision sensor can be directly calculated even when the vision sensor does not support the time sync and time stamp functions.

Embodiments of the present invention include computer readable media including program instructions for performing various computer implemented operations. The computer-readable medium may include program instructions, local data files, local data structures, etc., alone or in combination. The media may be those specially designed and constructed for the present invention or may be those known to those skilled in the computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floppy disks, and ROMs, And hardware devices specifically configured to store and execute the same program instructions. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible. Accordingly, the spirit of the present invention should be understood only in accordance with the following claims, and all equivalents or equivalent variations thereof are included in the scope of the present invention.

110: Setting section
120:
130:
140:
210:
220:
230: initial value setting unit
310: IMU
320: Information obtaining unit
330: Distance estimation unit
410: cumulative calculation unit
420:
430: weight application unit
440:

Claims

A setting unit for measuring a first relative distance between the vehicle and a stopped forward object in a state in which the vehicle is stopped and setting the first relative distance as an initial value;
And estimating a moving distance of the vehicle by using at least one of a speed and an acceleration of the vehicle when the vehicle moves, calculating a second distance between the vehicle and the forward object based on the set initial value and the predicted traveling distance, An operation unit for calculating a relative distance; And
Calculating a time delay value of the vision sensor based on the second relative distance, a third relative distance acquired through a vision sensor mounted on the vehicle, and a velocity of the vehicle, and using the calculated time delay value A correction unit
Lt; / RTI >
The correction unit
Existing cumulative time delay value _{(Time delay T d (k-} 1)) the current time delay value of the (Time delay T _{cd (k))} in advance to reflect as set reflection ratio (G) are accumulated time delay value (Time delay T _{d (k)} ) is calculated.
[Equation 1]

The method according to claim 1,
The setting unit
Detecting the position of the vehicle and the forward object using the vision sensor, measuring the first relative distance using the sensed position, and setting the measured first relative distance as the initial value And the time delay of the stereo vision sensor.

The method according to claim 1,
The setting unit
Estimating a position of the vehicle and the forward object using an IMU (Inertial Measurement Unit) mounted on the vehicle, measuring the first relative distance using the estimated position, and calculating the measured first relative distance Wherein the initial value is set to the initial value.

The method according to claim 1,
The operation unit
Wherein at least one of the speed and the acceleration of the vehicle is obtained using an IMU (Inertial Measurement Unit) mounted on the vehicle, and the moving distance of the vehicle is predicted using at least one of the obtained speed and acceleration A stereo vision sensor correction device that takes into account time delays.

5. The method of claim 4,
The operation unit
Acquiring a yaw rate of the vehicle using the IMU, and estimating a moving distance of the vehicle by further using the obtained yaw rate.

The method according to claim 1,
The correction unit
And calculates the time delay value of the vision sensor by dividing the difference between the second relative distance and the third relative distance by the speed of the vehicle.

The method according to claim 6,
The second relative distance
The influence of the time delay caused by the vision sensor is not included,
The third relative distance
Wherein the information is information including an effect of time delay caused by the vision sensor.

The method according to claim 1,
The correction unit
And a weight is applied to the time delay value in accordance with the speed of the vehicle in consideration of an increase in an offset error due to the time delay value in proportion to the speed of the vehicle. Vision sensor compensation device.

The method according to claim 1,
The correction unit
Periodically accumulating the time delay value of the vision sensor and updating the time delay value to select a final sensor time delay value when the preset time condition is satisfied, And the vision sensor is corrected.

10. The method of claim 9,
The final sensor time delay value
And the cumulative time delay value is generated by accumulating the time delay value during the predetermined time.

delete

The method according to claim 1,
And a control unit for controlling the driving of the vehicle by using the third relative distance measured by the vision sensor after the correction of the vision sensor
Further comprising a time delay detector for detecting the time delay of the stereo vision sensor.

The method according to claim 1,
The vision sensor
Wherein the stereo vision sensor is a stereo vision sensor that does not support a time sync function and a time stamp function.

Measuring a first relative distance between the vehicle and a stopped forward object in a state where the vehicle is stopped, and setting the measured first relative distance as an initial value;
Estimating a moving distance of the vehicle using at least one of a speed and an acceleration of the vehicle when the vehicle moves;
Calculating a second relative distance between the vehicle and the forward object based on the set initial value and the predicted traveling distance;
Calculating a time delay value of the vision sensor based on the second relative distance, a third relative distance obtained through a vision sensor mounted on the vehicle, and a velocity of the vehicle; And
Correcting the vision sensor using the calculated time delay value
Lt; / RTI >
The step of calculating the time delay value of the vision sensor
Existing cumulative time delay value _{(Time delay T d (k-} 1)) the current time delay value of the (Time delay T _{cd (k))} in advance to reflect as set reflection ratio (G) are accumulated time delay value (Time delay T _{d (k)} ) is calculated.
[Equation 1]

15. The method of claim 14,
The step of calculating the time delay value of the vision sensor
Calculating a time delay value of the vision sensor by dividing the difference between the second relative distance and the third relative distance by the speed of the vehicle
And calculating a time delay of the stereo vision sensor.