KR20080053591A - Image-recognizing apparatus which is easy to adjust angle for a moving object - Google Patents

Abstract

An angle adjustment-facilitated apparatus for recognizing an image of a moving object is provided to reduce a unit cost of a product by removing the necessity of adding an acceleration sensor when applied for a high-end security vehicle device or a car black box. A camera unit(10) includes a camera(11) for capturing an image, and an acceleration sensor(15) mounted at the camera to sense acceleration. An image acquiring unit(21) acquires digital image data from the image captured by the camera unit. An image processing unit(22) receives the image data from the image acquiring unit and processes it. An output unit(80) outputs information required for a user through a voice or an image. An angle calculating unit(40) calculates an installation angle of the camera by using an acceleration value of the acceleration sensor and a pre-set reference acceleration value. A main processing unit(50) controls the entire device, and provides information about the installation angle of the camera through the output unit.

Description

Image-recognizing apparatus which is easy to adjust angle for a moving object}

1 is a view showing a coordinate system applied to the image recognition device for a moving object according to an embodiment of the present invention.

2 is a view showing a two-dimensional road image taken by the camera.

Figure 3 is a block diagram showing the configuration of an image recognition device for a moving object easy to adjust the angle according to an embodiment of the present invention.

4 is a diagram illustrating a configuration of a camera unit shown in FIG. 3.

FIG. 5 is a diagram illustrating a method of calculating a forward and backward rotation angle of a camera in the angle calculation unit shown in FIG. 3.

FIG. 6 is a diagram illustrating a method of calculating a left and right rotation angle of a camera in the angle calculation unit shown in FIG. 3.

7 is a block diagram showing a configuration of an image recognition device for easily adjusting the angle according to another embodiment of the present invention.

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

10: camera portion 11: camera

12: mounting portion 15: acceleration sensor

21: image acquisition unit 22: image processing unit

50: main processor 60: memory

80: output 81: speaker

82: display device 90: motor unit

91: motor 92: motor drive unit

The present invention relates to an image recognition device for a moving object that is easy to adjust the angle, and more particularly includes a camera equipped with an acceleration sensor, and the reference of the acceleration sensor set in advance when setting the device and the acceleration detected by the acceleration sensor The present invention relates to an image recognition device for a moving object that calculates a camera installation angle from acceleration and informs a user so that the user can more easily and accurately adjust the camera installation angle of the image recognition device.

In general, the image recognition device mounted on a moving object such as a vehicle detects the surrounding roads, other driving vehicles, and obstacles of the driving vehicle by using image recognition technology, and converts the information into helpful information to the driver. This is to improve the safety and convenience of passengers.

In particular, advanced safety vehicle (ASV) related fields, which are currently being highly functionalized and intelligent, are the main applications of image recognition devices, such as lane departure warning devices, advanced vehicle collision warning devices to prevent inadvertent driving, and beginners. It is expected that the relevant market will expand further in the future as the range of automobile makers in each country is expanding its application range, such as rear parking guides to assist parking and anti-collision devices that operate the brakes in dangerous situations to prevent collisions.

The image recognition apparatus acquires an image of a target to be recognized using a dedicated camera, and then performs a video recognition process of extracting a feature of the target using digital image processing technology and identifying the target using the feature. Therefore, in order for the image recognition device to perform the image recognition function smoothly, it is essential to accurately adjust the position and angle of the camera so that the image of the target can be captured at a desired position.

In the case of an image recognition device for a vehicle, an error in the installation angle of the camera may be represented to the extent that the image of the target deviates from the design position in the screen, and preferably, the value does not exceed 5% of the screen size. For example, in the case of a VGA format image having a resolution of 640x480, the deviation degree based on the diagonal of the screen is 40 pixels or less, and in the case of a QVGA image having 320 × 240 resolution, the deviation degree is preferably 20 pixels or less.

Conventional vehicle image recognition device is mainly provided with a guide for adjusting the angle by allowing the user to adjust the installation angle of the camera to match the guide line set the angle adjustment guide, thereby ensuring the accuracy of the installation angle of the camera.

However, if the camera installation angle is adjusted according to the user's vision, an error may occur in the process of processing the captured image due to a deviation in the camera installation angle depending on the user, and in some cases, a target in the screen. There is a problem that the degree of departure for the image of the excessively large image recognition function can not operate properly.

The present invention is to solve the problem of the image recognition apparatus for a moving object according to the prior art. That is, an object of the present invention is to provide an image recognition device by providing a camera equipped with an acceleration sensor and calculating the camera installation angle from the reference acceleration of the acceleration sensor set at the initial setting of the device and informing the user. It is to make it easy to adjust the camera installation angle of the camera, and to install the camera at a more accurate angle than simply adjusting the instructions depending on the user's naked eye.

The present invention as a technical idea for achieving the above object, the camera unit is composed of a camera for photographing the image, and an acceleration sensor mounted on the camera to detect the acceleration; An image acquisition unit for acquiring digital image data from an image captured by the camera unit; An image processor for receiving and processing image data from the image acquisition unit; An output unit for outputting information required by the user through audio or video; An angle calculator configured to calculate an installation angle of the camera by using an acceleration value of the acceleration sensor and a preset reference acceleration value; And a main processor configured to control the entire apparatus and notify the user of the information on the installation angle of the camera calculated by the angle calculator through the output unit. Provide a recognition device.

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

An image recognition apparatus for a moving object according to an embodiment of the present invention is a device mounted on a vehicle for recognizing a front image. First, a coordinate system applied to the present embodiment, a horizon and a camera installation position and angle within a shooting screen. The relationship between the following will be briefly described.

1 is a view showing a coordinate system applied to the camera of the image recognition device for a moving object according to an embodiment of the present invention, Figure 2 is a view showing a two-dimensional road image taken by the camera.

In FIG. 1, the X, Y, and Z axes are three-dimensional coordinate axes of a global coordinate system, and the x, y, and z axes are three-dimensional coordinate axes of a local coordinate system set in the camera 11. Here, the X axis is a fixed coordinate axis indicating the left and right direction of the vehicle, the Y axis is the front and rear direction of the vehicle, and the Z axis is the vertical direction of the vehicle, and the road surface is positioned on the XY plane, and the x, y, and z axes are the rotations of the camera 11. Alternatively, a variable coordinate axis whose direction and origin change according to the movement is located at the center of the camera.

The camera 11 is installed so that the shooting direction is inclined at an angle with respect to the road surface at a point of height H on the road where the lane is formed, so that the z-axis of the local coordinate system and the Z-axis of the global coordinate system form an angle of θ. .

On the other hand, when photographing the ground surface with the lane formed by the camera 11 of the image recognition device is converted to a planar image frame as shown in Figure 2, the coordinates on the two-dimensional plane to match the x, z axis of the local coordinate system do.

The coordinate values (x, z) on the plane shown in FIG. 2 correspond to the global coordinate values (X, Y, Z) by Equations 1 and 2 below.

Here, F is the focal length of the camera 11, H is the installation height of the camera, θ is the installation angle of the camera.

When Equation 2 is solved with respect to Y, the following Equation 3 is obtained. Since the horizon L3 is infinitely spaced toward the front of the vehicle, the z coordinate value in which the Y coordinate value becomes infinity in Equation 3, The z coordinate value of which the denominator is 0 becomes the z coordinate value of the horizon L3, which is represented by Equation 4.

Here, z _∞ means the z value of the horizon L3, and the z value of the horizon L3 appearing in the camera image is a function that is independent of the height H of the camera 11 and depends on the installation angle θ of the camera 11. It can be seen that.

Since the vehicle image recognition device mainly targets objects on the road, the vanishing point (P1) where the two lanes (L1, L2) and the horizon (L3) of the road meet with the horizon (L3) always appears in the image. Since the positions of the lanes L1 and L2 and the object on the road are calculated based on the L3 and the vanishing point P1, the camera 11 matches the z value of the horizon L3 on the image frame with a preset value. Should be installed correctly.

Therefore, the accuracy of the image recognition device can be ensured only when the installation angle θ of the camera 11 is exactly matched with a preset angle (hereinafter, referred to as a design angle), and the image recognition device for a moving object according to the present invention has such an angle. It provides a function to notify the user by measuring the angle for easy adjustment.

Hereinafter, a configuration of an image recognition device for easily adjusting an angle according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is a block diagram illustrating a configuration of an image recognition device for easily adjusting an angle according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating a configuration of a camera unit illustrated in FIG. 3.

As shown in FIG. 3, an image recognition device for easily adjusting an angle according to an embodiment of the present invention is mounted on a moving object and mounted on a camera 11 and a camera 11 for capturing an image. From the camera unit 10 is composed of an acceleration sensor 15 for sensing the acceleration, the image acquisition unit 21 for obtaining digital image data from the image captured by the camera unit 10, and from the image acquisition unit 21 Image processor 22 for receiving the image data and processing the image data, memory 60 for storing the data, an output unit 80 for outputting the information required by the user through the voice or video, and acceleration sensor 15 Control the angle calculation unit 40 and the whole device to calculate the installation angle of the camera 11 by processing the acceleration signal output from the), and outputs information on the installation angle of the camera calculated by the angle calculation unit 40 To the user via section 80 It is configured to include a main processor 50, which notice.

As shown in FIG. 4, the camera unit 10 is coupled to the mounting unit 12 attached to the moving object and the hinge 13 so as to be rotatable in the front-rear direction with respect to the mounting unit 12 to capture an image. 11 and an acceleration sensor 15 provided inside the camera 11 to detect the acceleration. Here, although the CMOS camera is preferably used as the camera 11, a CCD image sensor, an IR camera, or the like may be used. The acceleration sensor 15 is fixed inside the camera 11 to rotate integrally with the camera 11, and in the direction of each axis (x, y, z) of the local coordinate system of the camera 11 in a state of rotating at an arbitrary angle. The acceleration is detected.

When the camera unit 10 is installed, the user attaches the mounting unit 12 to the windshield 100 of the vehicle such that the photographing direction of the camera 11 faces the front of the vehicle, and the left and right directions of the camera 11 are road surfaces. It is necessary to adjust the angle of rotation of the front and rear direction of the camera 11, that is, the angle between the y-axis and the Y-axis, to be the design angle while being installed so as to be horizontal to the horizontal direction, that is, the x-axis parallel to the X-axis.

The image acquisition unit 21 receives an analog image signal photographed from the camera unit 10 and converts the analog image signal into a digital image signal having a preset frame per second and resolution.

The image processor 22 processes the image data received from the image acquisition unit 21 to obtain information about a subject in the image, or compresses the image data and stores the image data in the memory 60. When the image recognition apparatus for moving object is applied to the lane departure detecting apparatus, the vehicle recognizes that the lane is leaving the lane by recognizing the lane in the image and calculating the relative position of the vehicle from the lane width and the lane.

The output unit 80 includes a speaker 81 for outputting voice and a display device 82 for outputting an image. The output unit 80 may include only one of a speaker or a display device.

The angle calculator 40 calculates an installation angle of the camera 11 by using an acceleration value detected by the acceleration sensor 15 and a preset reference acceleration value when the camera is installed. More details according to the calculation will be described later.

As the user rotates the camera 11 and changes the installation angle of the camera 11, the main processing unit 50 designates the installation angle received from the angle calculation unit 40 in advance in the memory 60. Compared with, the output unit 80 notifies whether the installation angle of the camera 11 is set correctly from the match of two values, and preferably the user can approach the current installation angle or design angle. By notifying the rotation direction of (11), it is good to allow the user to easily adjust the installation angle of the camera (11).

Here, the main processor 50 checks the installation angle of the camera 11 at the time of starting the device or periodically, and when the installation angle of the camera 11 does not match the design angle, the camera is provided to the user through the output unit 80. You can request the angle of (11). In addition, an operation unit (not shown) including an angle setting button may be further provided to enable the user to activate the angle calculation and notification function of the image recognition apparatus by pressing the angle setting button before adjusting the installation angle of the camera. .

Hereinafter, a method of calculating the installation angle of the camera 11 in the angle calculation unit 40 will be described in detail.

FIG. 5 is a diagram illustrating a method of calculating a front and rear rotation angle of a camera in the angle calculation unit shown in FIG. 3.

First, Figure 5 (a) is a state in which the front, rear, left and right directions of the camera 11 is fixed to be parallel to the road surface in the initial setting step of the device before shipping the image recognition device for a moving object according to the present embodiment And a side view of the camera 11. At this time, each axis (x, y, z) of the local coordinate system is parallel to each axis (X, Y, Z) of the global coordinate system, and the camera 11 is in an equilibrium state where the sum of external forces is 0 The acceleration value measured by the sensor 15 becomes zero.

In this case, if the acceleration value in the z-axis direction is set to an arbitrary value by adjusting the setting of the acceleration sensor 15, an effect similar to that in which the acceleration in the z-axis direction exists is present. The acceleration in the direction is defined as the z-axis reference acceleration a _zref .

In the process of installing the image recognition device for a moving object according to the present embodiment, the user installs the left and right directions of the camera 11 in parallel with the left and right directions of the road as shown in FIG. When (11) is rotated in the front-rear direction, the z-axis and y-axis of the local coordinate system form an angle of θ with the Z-axis and Y-axis of the global coordinate system, respectively, and the acceleration actually acting on the camera 11 is shown in FIG. ) with the same z-axis reference acceleration (a _zref) set in the relation of the z-axis direction acceleration, and z-axis reference acceleration (a _zref) measured at the acceleration sensor 15 it is expressed as shown in equation (5) below, Can be.

When the front and rear rotation angle θ of the camera 11 is obtained from Equation 5, Equation 6 below is obtained.

Therefore, by using Equation 6, the angle of forward and backward rotation of the camera 11, that is, the angle at which the camera 11 is rotated around the X axis of the global coordinate system, may be calculated.

FIG. 6 is a diagram illustrating a method of calculating left and right rotation angles of a camera in the angle calculation unit shown in FIG. 3.

First, Figure 6 (a) is a state in which the front, rear, left and right directions of the camera 11 is fixed to be parallel to the road surface in the initial setting step of the device before shipping the image recognition device for a moving object according to the present embodiment , The rear of the camera 11 is shown.

Here, as described above with reference to FIG. 5 (a), by adjusting the setting of the acceleration sensor 15 to set the acceleration value in the x-axis direction to an arbitrary value, the effect as if the acceleration in the x-axis direction actually exists. The acceleration in the x-axis direction, which is _{initially set in this way} , is defined as the x-axis reference acceleration a _xref .

의 각도를 이루게 되며, 카메라(11)에 실제로 작용하는 가속도는 도 6의 (a)에서 설정된 x축 방향 기준 가속도(a_xref)와 동일하므로, 가속도센서(15)에서 측정되는 x축 방향 가속도와 x축 방향 기준 가속도(a_zref)의 관계는 아래의 수학식 5와 같이 표현될 수 있다.In the process of installing the image recognition device for the moving object according to the present embodiment, the user does not parallel the mounting surface of the mounting portion 12 of the camera unit 10 to the road surface as shown in FIG. When installed, the x and z axes of the local coordinate system are the X and X axes of the global coordinate system, respectively.

Since the acceleration actually acting on the camera 11 is the same as the x-axis reference acceleration a _xref set in FIG. 6 (a), the acceleration in the x-axis direction measured by the acceleration sensor 15 The relationship between the x-axis direction reference acceleration a _zref may be expressed by Equation 5 below.

를 구하면 아래의 수학식 8과 같다.Left and right rotation angle of the camera 11 from the equation (7)

To obtain Equation 8 below.

Therefore, by using Equation 8, the left and right rotation angles of the camera 11, that is, the angle at which the camera 11 is rotated around the Y axis of the global coordinate system, may be calculated.

In this way, after setting the reference acceleration of the acceleration sensor 15 in a state where the front, rear, left and right directions of the camera 11 are fixed to be parallel to the road surface at the initial setting of the device, the user calculates the angle when installing the device. When the installation angle calculated by calculating the installation angle of the camera 11 in the unit 40 coincides with the design angle, the user is notified through the output unit 80, so that the user can easily install the image recognition device. .

In general, high-tech safety vehicle devices or vehicle black boxes, which are the main applications of image recognition devices, are equipped with an acceleration sensor in addition to the image recognition device to determine the driving state of the vehicle. Using the provided image recognition device, it is possible to lower the unit cost of the product because there is no need to provide an additional acceleration sensor.

In the above-described embodiment of the present invention, the acceleration sensor 15 and the angle calculator 40 are configured to notify the user of the installation angle of the camera calculated by the angle calculator 40. The angle calculator Removing the 40 and comparing the acceleration value received through the acceleration sensor from the main processor 50 with the reference acceleration value preset in the initial setting of the device, and outputting the output unit to the user when the measured acceleration and the reference acceleration coincide with each other. By notifying through 80, the user may be configured to accurately adjust the installation angle of the camera.

Meanwhile, as shown in FIG. 7, the motor shaft 90 includes a motor 91 connected to the hinge 13 shaft of the camera unit 10 and a motor driver 92 driving the motor 91. ) May be further provided to adjust the installation angle by automatically rotating the camera 11. Here, the main processor 50 is the user's request or when the installation angle of the camera 11 does not match the design angle, the front and rear rotation angle of the camera calculated through the angle calculation unit 40 coincides with the design angle By controlling the motor driving unit 92, it is possible to automatically adjust the forward and backward rotation angle of the camera without the need for the user to manually adjust.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the image recognition device for easily adjusting the angle according to the present invention calculates the installation angle of the camera using the acceleration sensor provided in the camera, and informs the user of the calculated angle, so that the user It is effective to provide an image recognition device that can adjust the installation angle accurately and conveniently.

In addition, when applied to a high-tech safety vehicle device or a black box for a vehicle, there is no need to additionally provide an acceleration sensor, thereby reducing the cost of the product.

Claims (5)

A camera unit 10 comprising an camera 11 for capturing an image and an acceleration sensor 15 mounted on the camera 11 to detect acceleration; An image acquisition unit 21 for acquiring digital image data from an image captured by the camera unit 10; An image processor 22 for receiving and processing image data from the image acquisition unit 21; An output unit 80 for outputting information required by the user through audio or video; An angle calculation unit 40 for calculating an installation angle of the camera 11 by using an acceleration value of the acceleration sensor 15 and a preset reference acceleration value; And A main processor 50 for controlling the entire apparatus and notifying the user of the installation angle of the camera calculated by the angle calculator 40 through the output unit 80; Image recognition device for easy angle adjustment characterized in that it comprises a. The method of claim 1, It further comprises a motor unit 90 for rotating the camera 11, The main processor 50 controls the motor unit 90 to automatically adjust the installation angle of the camera, characterized in that the angle adjustment easy image recognition device for moving objects. The method according to claim 1 or 2, The angle calculation unit, An image recognition device for easily adjusting the angle, characterized in that for calculating the forward and backward rotation angle of the camera according to the following formula. <Formula>

(θ: forward and backward rotation angle, a _z : acceleration in z-axis, a _zref : acceleration in z-axis direction) The method according to claim 1 or 2, The angle calculation unit, The image recognition device for easily adjusting the angle, characterized in that for calculating the left and right rotation angle of the camera according to the following formula. <Formula>

(

: Left and right rotation angle, a _x : acceleration in x axis, a _xref : acceleration in x axis direction) A camera unit 10 comprising an camera 11 for capturing an image and an acceleration sensor 15 mounted on the camera 11 to detect acceleration; An image acquisition unit 21 for acquiring digital image data from an image captured by the camera unit 10; An image processor 22 for receiving and processing image data from the image acquisition unit 21; An output unit 80 for outputting information required by the user through audio or video; A main processor which controls the entire apparatus and compares the acceleration value detected by the acceleration sensor 15 with a preset reference acceleration value, and notifies the user when the detected acceleration value and the reference acceleration value coincide with each other. 50; Image recognition device for easy angle adjustment characterized in that it comprises a.

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