WO2015115770A1 - Calibration device and camera system - Google Patents

Abstract

According to one embodiment of the present invention, a calibration device comprises: a first reflection member arranged in a first element; a second reflection member arranged in a second element; a light source unit for emitting a first beam; a beam splitter for dividing the first beam into a second beam and a third beam which are different from each other in a propagation path, and if a first reflected beam in which the second beam is reflected by the first reflection member and a second reflected beam in which the third beam is reflected by the second reflection member are projected, coupling the first reflected beam and the second reflected beam as a forth beam; a detector for detecting an image signal corresponding to the fourth beam; and a displacement detection unit for detecting an interference pattern from the image signal and calculating displacement information between the first and second elements by comparing the interference pattern and a pre-stored interference pattern.

Description

Calibration device and camera system

The present invention relates to a calibration apparatus and a camera system, and to a calibration apparatus of a stereo camera system and a stereo camera system including the same.

Stereo camera system that detects objects from images taken in front of or behind the vehicle to help the driver to drive safely, and extracts distance information between the vehicle and the objects in front of the vehicle using two cameras ) Has been proposed.

In a stereo camera system, in order to acquire accurate distance information, a calibration process according to a distance between cameras and a relative posture needs to be performed at initial installation.

In general, calibration of a stereo camera system is performed using a checker board on which a specific pattern is drawn. In the calibration process using a checker board, a checker board is photographed from different angles with a stereo camera to acquire 10 or more stereo camera images, which are different scenes, and a displacement parameter between the two cameras is derived through mathematical calculations using the acquired images. In order.

In this calibration process, the distance between the checker board and the stereo camera system needs to satisfy the actual usage distance of 5m to 100m of the vehicle stereo camera system. This requires a large space for calibration.

In addition, since a displacement parameter is derived by substituting the captured image into a calculation program after capturing 10 or more images, a large amount of time is required for calibration.

In addition, even when the calibration parameter is changed due to the mechanical and thermal deformation of the vehicle while mounting and using the stereo camera system in which the calibration is completed, real-time calibration is difficult.

An embodiment of the present invention provides a calibration apparatus and a camera system capable of real-time calibration of a stereo camera system.

According to an embodiment of the present invention, a first reflecting member disposed on the first element, a second reflecting member disposed on the second element, a light source unit emitting the first beam, and a traveling path different from each other in the first beam When the first and second reflecting beams reflected by the first reflecting member and the second reflecting beam reflected by the second reflecting member are incident, A beam splitter for combining the first and second reflection beams into a fourth beam, a detector for detecting an image signal corresponding to the fourth beam, and

And a displacement detection unit for detecting an interference pattern from the image signal, and comparing displacement patterns with previously stored interference patterns to calculate displacement information between the first element and the second element.

A mirror disposed on an optical path between the third beam and the second reflecting beam, the mirror configured to transmit the third beam to the second reflecting member, and to transfer the second reflecting beam to the beam splitter. have.

The apparatus may further include a case accommodating the light source unit, the beam splitter, and the detector.

The apparatus may further include a case accommodating the light source unit, the beam splitter, the mirror, the detector, and the second reflecting member.

The first element and the second element may include a camera.

The displacement information may include distance movement information between the first element and the second element, and the displacement detection unit may obtain the distance movement information based on a circular fringe included in the interference pattern.

The displacement information may include relative rotation information between the first element and the second element, and the displacement detection unit may acquire the rotation information based on a straight fringe included in the interference pattern.

The camera system according to an embodiment of the present invention includes a camera housing including a first camera and a second camera spaced apart from each other, and a calibration device for calculating displacement information between the first camera and the second camera. The calibration apparatus includes a first reflecting member disposed on the first camera, and a second reflecting member disposed on the second camera.

The controller may further include a controller for correcting a displacement parameter used to calculate distance information with respect to the object based on the calculated displacement information.

The calibration device includes an interferometer for obtaining an image signal including an interference pattern between a plurality of beams reflected by the first and second reflecting members, and detecting the interference pattern from the image signal. And a displacement detector configured to compare the previously stored interference pattern to calculate displacement information between the first camera and the second camera.

The interferometer may further include a light splitter and a beam splitter which separates the beam irradiated from the light source into a plurality of beams having different optical paths and transmits the beam to the first reflecting member and the second reflecting member, respectively.

The interferometer may further include a mirror that transmits the beam separated by the beam splitter to the second reflecting member.

The light source unit may include a laser or a laser diode.

The displacement information may include distance movement information between the first camera and the second camera, and the displacement detection unit may acquire the distance movement information based on a circular fringe included in the interference pattern.

The displacement information may include relative rotation information between the first camera and the second camera, and the displacement detection unit may acquire the rotation information based on a straight fringe included in the interference pattern.

The camera system may be configured to acquire a plurality of image data through the plurality of cameras, and calculate a distance information with respect to an object detected from the plurality of image data based on distance information and relative rotation information between the plurality of cameras. The control apparatus may further update the distance information and the rotation information based on the displacement information.

1 is a block diagram schematically illustrating a camera calibration apparatus according to an embodiment of the present invention.

2 is a block diagram schematically illustrating an interferometer according to an exemplary embodiment of the present invention.

3 is a view for explaining a method of obtaining displacement information from an interference pattern in a calibration device according to an embodiment of the present invention.

4 is a block diagram schematically illustrating a stereo camera system including a calibration device according to an exemplary embodiment.

5 and 6 illustrate examples in which a calibration device according to an embodiment of the present invention is coupled to a camera.

7 is a diagram for describing a method of calculating a distance from an object in a stereo camera system according to an exemplary embodiment.

8 is a flowchart illustrating a calibration method of a stereo camera system including a calibration device according to an exemplary embodiment.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers, such as second and first, may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

In addition, the suffixes "module" and "unit" for the components used in the following description are given or mixed in consideration of ease of specification, and do not have distinct meanings or roles from each other.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

Since the components described below with reference to the drawings are not essential, the camera system and the calibration device according to the embodiment of the present invention may be provided to include more or fewer components.

1 is a block diagram schematically illustrating a camera calibration apparatus according to an embodiment of the present invention. 2 is a block diagram schematically illustrating an interferometer according to an embodiment of the present invention. 3 is a view for explaining a method of obtaining displacement information from an interference pattern in a calibration device according to an embodiment of the present invention.

1 and 2, the calibration device 10 according to an embodiment of the present invention may include an interferometer 11, a displacement detector 12, and the like.

The interferometer 11 includes a plurality of reflecting members 114 and 115 disposed on each of the plurality of elements spaced apart from each other, and separates the beams emitted from one light source unit 111 into a plurality of beams (or a plurality of light beams). The light source is incident on each of the reflective members 114 and 115, and an image signal is obtained in response to an interference pattern in which a plurality of beams reflected by the reflective members 114 and 115 interfere. The element may be a plurality of cameras mounted on a stereo camera or a component having a predetermined distance and angle, such as a vehicle head lamp. Hereinafter, the camera will be described as an example.

The interferometer 11 may be a configuration of a Michelson interferometer.

The interferometer 11 may include a light source 111, a beam splitter 112, a plurality of reflectors 114 and 115, a detector 116, and the like. In addition, the interferometer 11 may further include a mirror 113.

The light source unit 111 emits a beam L1.

In order to detect displacement from the interference pattern detected by the interferometer 11, the beam emitted from the light source unit 111 may include a coherent beam. Herein, the displacement is a parameter indicating a change in relative position between two objects, and a parameter indicating how much of the other object is rotated and how much is translated relative to which one of the two objects.

In an embodiment of the present invention, the displacement is a parameter indicating how much the remaining camera is rotated and how much the other camera is rotated based on one of the plurality of cameras.

The light source unit 111 may include a laser, a laser diode, and the like, which emit a coherent beam.

The beam L1 emitted from the light source unit 111 may enter the beam splitter 112. To this end, the emission surface of the light source unit 111 is disposed to face the beam splitter 112.

The beam splitter 112 may split the matching beam L1 emitted from the light source unit 111 into a plurality of beams L11 and L12 having different travel directions. For example, the beam splitter 112 may transmit a portion L11 of the beam L1 incident from the light source unit 111 to the beam splitter 112, and reflect the remaining portion L12 to separate the plurality of beams. have. In this case, the beam splitter 112 may include a translucent dielectric thin plate such as a translucent mirror.

The beams L11 and L12 separated by different beam paths by the beam splitter 112 may be transmitted to the first and second reflecting members 114 and 115, respectively. For example, the beam transmitted by the beam splitter 112 may be transmitted to the first reflecting member 114, and the beam reflected by the beam splitter 112 may be transmitted to the second reflecting member 115.

When the beams L11 and L12 separated by the beam splitter 112 are incident, the first and second reflecting members 114 and 115 may reflect the beams to the beam splitter 112.

On the other hand, depending on the characteristics of the beam splitter 112, in general, the beams separated by the beam splitter 112 proceeds to form a predetermined angle and not parallel to each other. For example, the beams separated by the beam splitter 112 may proceed to be orthogonal to each other. Therefore, when the first and second reflecting members 114 and 115 are respectively disposed in a plurality of cameras (not shown) spaced apart in a line, and the beam splitter 112 is disposed therebetween for space efficiency, The interferometer 11 may further include a mirror 113 to allow the beams separated from the beam splitter 112 to be incident on the first and second reflecting members 114 and 115, respectively.

The mirror 113 is disposed on an optical path of the beam splitter 112 and the second reflecting member 115, and may perform a function of transferring a beam between the beam splitter 112 and the second reflecting member 115. have.

Referring to FIG. 2, the mirror 113 is disposed on a path of the beam L12 reflected by the beam splitter 112, and reflects the beam reflected by the beam splitter 112 to reflect the second reflecting member. Proceed to 115. In addition, when the beam L22 reflected by the second reflecting member 115 is incident, the mirror 114 may reflect the incident light and enter the beam splitter 112.

That is, the beam L11 transmitted by the beam splitter 112 proceeds directly to the first reflecting member 114, but the beam L12 reflected by the beam splitter 112 is once again reflected by the mirror 113. The reflection may proceed to the second reflecting member 115. In addition, the beam L21 reflected by the first reflecting member 114 proceeds directly to the beam splitter 112, but the beam L22 reflected by the second reflecting member 115 is reflected by the mirror 113. Once again reflected it may proceed to the beam splitter 112.

As described above, the beam emitted from one light source unit 111 is separated by the beam splitter 112, and a difference occurs in the traveling path, and is reflected by the first and second reflecting members 114 and 115 and the beam Interference occurs in the splitter 112.

The beams L21 and L22 interfering in the beam splitter 112 may be combined into one beam L2 by the beam splitter 112, and the beam splitter 112 may transmit it to the detector 116.

When the detector 116 receives the beam L2 reflected and recombined from the beam splitter 112, the detector 116 receives the beam L2 to obtain an image signal. The image signal obtained by the detector 116 includes an interference fringe. Here, the interference pattern represents a pattern of light and dark shades formed in a lattice or concentric shape caused by the interference of the beam.

The beams reflected by the first reflecting member 114 and the second reflecting member 115 generate interference when they are met at the beam splitter 112 due to the difference in optical paths. This interference generates contrast patterns in the image signal of the beam incident on the detector 116.

Referring again to FIG. 1, the displacement detector 12 processes the image signal obtained through the interferometer 11 to obtain image data, and extracts an interference pattern therefrom.

In addition, the displacement detection unit 12 may calculate displacement information including a change in distance and rotation between the first and second reflecting members 114 and 115 by comparing the previously stored interference pattern with the newly extracted interference pattern. Here, the pre-stored interference pattern used for comparison is an interference pattern which is a reference for detecting displacement information, and is referred to as a 'reference interference pattern' for convenience of description below.

The reference interference pattern may be an interference pattern acquired by the displacement detector 12 using the interferometer 11 when the calibration apparatus 10 is initially mounted in a camera system (not shown). In addition, the reference interference pattern may be an interference pattern obtained by the displacement detector 12 using the interferometer 11 during the previous calibration. In the former case, the displacement detector 12 may use the internal memory (not shown) or the external memory (not shown) to acquire an interference pattern obtained by using the interferometer 11 when the calibration apparatus 10 is initially installed in a camera system (not shown). ) Can be used as a reference interference pattern. In addition, in the latter case, the displacement detection unit 12 stores the interference pattern obtained through the interferometer each time in an internal memory (not shown) or an external memory (not shown), or only when there is a displacement change. Alternatively, it may be stored in an external memory (not shown) and used as a reference interference pattern.

Meanwhile, the relationship between the interference pattern detected by the displacement detection unit 12 and the displacement of the measurement target may be expressed by Equation 1 below.

Here, d represents the displacement of the measurement object, that is, the displacement between the first reflecting member 114 and the second reflecting member 115, n is the number of changes of the fringe in the interference pattern, λ is the light source unit 111 It represents the wavelength of the beam emitted from.

Referring to FIG. 3A, when the position of the first reflecting member 114 moves from M ₁ to M ₂ ′, that is, the position of the first reflecting member 114 is far from the second reflecting member 115. Ground, the position of the virtual image of the source beam (source beam) emitted from the light source unit 111 is changed from S ₁ 'to S ₂ ' due to the path change of the beam. As a result, at least some circular fringes in the image signal detected by the detector 116 spread out and change.

On the other hand, when the position of the first reflecting member 114 moves from M ₂ ′ to M ₁ , that is, when the position of the first reflecting member 114 approaches the second reflecting member 115, the beam path changes. Therefore, the position of the virtual image of the source beam emitted from the light source 111 is changed from S ₂ ′ to S ₁ ′. Accordingly, at least some of the circular fringes in the image signal detected by the detector 116 converge while changing.

Accordingly, the displacement detector 12 may detect a change in relative distance between the first reflecting member 114 and the second reflecting member 115 based on the change of the circular fringe pattern in the image signal detected by the detector 116. .

Referring to FIG. 3B, when the angle of the first reflecting member 114 rotates from M ₁ to M ₂ ′, the position of the virtual image of the source beam emitted from the light source unit 111 is S ₁ ′ to S _2. Is changed to '. As a result, the linear fringe near the optical axis is shifted to the right (or left) in the image signal detected by the detector 116.

On the other hand, when the angle of the first reflecting member 114 rotates from M ₂ ′ to M ₁ , the position of the virtual image of the source beam emitted from the light source unit 111 is changed from S ₂ ′ to S ₁ ′. As a result, the linear fringe near the optical axis is shifted to the left (or right) in the image signal detected by the detector 116.

Accordingly, the displacement detector 12 may detect a change in the relative inclination between the first reflective member 114 and the second reflective member 115 based on the change of the linear fringe pattern in the image signal detected by the detector 116.

On the other hand, the wavelength of a laser is generally 400 nm-800 nm. In the case of UV lasers, wavelengths of approximately 400 nm or less are possible.

Therefore, when the beam irradiated from the light source unit 111 is a laser, referring to Equation 1, the resolution of the interferometer 11 may satisfy 10 nm or less. That is, if the phase is changed by half wavelength due to the optical path difference, one fringe in the interference pattern may change.

Therefore, when the above-described interferometer 11 is used, displacement information between the first and second reflecting members 114 and 115 can be detected in units of 10 nm or less.

As described above, the calibration device 10 may detect displacement information between the first and second reflecting members 114 and 115 spaced apart from each other using the interferometer 11. In addition, displacement information between a plurality of cameras (not shown) in which the first and second reflection members 114 and 115 are disposed may be detected based on the displacement information between the first and second reflection members 114 and 115.

When the above-described calibration device 10 is applied to a stereo camera system, real time camera calibration of the stereo camera system is possible.

Hereinafter, a case in which the calibration device according to an embodiment of the present invention is applied to a stereo camera system will be described with reference to FIGS. 4 to 6.

4 is a block diagram schematically illustrating a stereo camera system including a calibration device according to an exemplary embodiment. 5 and 6 illustrate examples in which a calibration device according to an embodiment of the present invention is coupled to cameras of a stereo camera system. FIG. 7 is a diagram for describing a method of calculating a distance from an object in a stereo camera system according to an exemplary embodiment.

Referring to FIG. 4, the stereo camera system according to an exemplary embodiment may include a plurality of cameras 21 and 22, a calibration device 10, a control device 30, and the like.

The plurality of cameras 21 and 22 may be spaced apart from each other by a predetermined interval, and may acquire image data outside the object. For example, when the object is a vehicle, the plurality of cameras 21 and 22 may be mounted before or after the vehicle to acquire image data in front of or behind the vehicle.

The calibration device 10 includes an interferometer (see reference numeral 11 of FIG. 1), as described with reference to FIGS. 1 to 3, and between the plurality of cameras 21 and 22 using the interferometer 11. Obtain displacement information. Here, the displacement information may include a relative distance translation between the plurality of cameras 21 and 22 and a relative angular rotation.

On the other hand, in order to detect the relative displacement information between the plurality of cameras 21, 22 through the interferometer 11, the reflecting member of the interferometer 11 (reference numeral 114, It is necessary to arrange them in one piece.

5 and 6 show examples of coupling the interferometer 11 with the cameras 21 and 22.

Referring to FIG. 5, the first camera 21 and the second camera 22 are spaced apart by a predetermined interval by the camera housing 200. If necessary, three or more cameras may be mounted in the camera housing 200. In this case, the reflective members may also be arranged in the same number.

The first and second reflecting members 114 and 115 of the interferometer 11 are disposed in the bodies of the cameras 21 and 22, respectively. The first and second reflecting members 114 and 115 may be integrally coupled to the bodies of the cameras 21 and 22 so as to move or rotate in response to the body movements of the cameras 21 and 22.

In addition, an interferometer case 100 is disposed on the optical path between the first and second reflecting members 114 and 115, and the interferometer case 100 has a light source unit 111 and a beam splitter () of the interferometer 11 therein. 112, mirror 113, detector 116, and the like.

Specifically, the interferometer case 100 in which the light source unit 111, the beam splitter 112, the mirror 113, and the detector 116 are integrally accommodated is disposed between the first camera 21 and the second camera 22. The first reflecting member 114 and the second reflecting member 115 may be disposed independently of the first camera 21 and the second camera 22, respectively.

However, the present invention is not limited thereto, and as shown in FIG. 6, the first reflecting member 114 of the interferometer 11 is disposed on the body of the first camera 21, and the interferometer case 100 ′ is provided on the second camera 22. ) May be arranged.

In this case, the interferometer case 100 ′ may include a light source unit 111, a beam splitter 112, a mirror 113, a second reflecting member 115, a detector 116, and the like of the interferometer 11. . That is, the light source unit 111, the beam splitter 112, the mirror 113, the second reflecting member 115, and the detector 116 may be integrally coupled by the interferometer case 100.

Again, referring to FIG. 4, the controller 30 continuously receives image data outside the object through the plurality of cameras 21 and 22. In addition, the controller 30 detects an object from image data received from the plurality of cameras 21 and 22 through image recognition.

When the object is detected from the image data, the controller 30 obtains object position information in each image data, and controls the position information of the object in each image data and distance information between the plurality of cameras 21 and 22. Based on the distance information with the object can be obtained.

Referring to FIG. 7, the focal length of each of the first and second cameras 21 and 22 is f, and the distance between the first and second cameras 21 and 22 is b, the first and second cameras 21 and 22. When the distance between the point corresponding to the center of the first and second cameras 21 and 22 and the object OB is defined as DL and DR, respectively, on the image data input through the plurality of cameras 21 and 22, The distance information Z between the objects OB may be obtained as in Equation 2 below.

In Equation 2, the focal length f of each of the first and second cameras 21 and 22 may be a preset value according to the specifications of the first and second cameras 21 and 22.

In addition, the distance d between the first and second cameras 21 and 22 is a distance between the center points of the first and second cameras 21 and 22, and is installed when the first and second cameras 21 and 22 are installed. The set value can be used as the initial value.

Meanwhile, after the first and second cameras 21 and 22 are installed in the vehicle that is the object, the position and the posture of the first and second cameras 21 and 22 may be changed due to vehicle vibration and temperature change. . Therefore, without using the process of reflecting the position or attitude change of the first and second cameras 21 and 22, the stereo parameters set at the time of initial installation of the first and second cameras 21 and 22 are used as they are. When the distance information with respect to the object is calculated, the accuracy of the distance information is reduced.

Here, the stereo parameter used to calculate distance information with the object may include distance information between the first and second cameras 21 and 22 and relative tilting information between the first and second cameras 21 and 22. Can be. The relative inclination information of the first and second cameras 21 and 22 may indicate the degree of inclination of the other cameras with respect to the optical axis of any one of the first and second cameras 21 and 22.

The control device 30 is obtained through the calibration device 10 in order to prevent the accuracy of calculating the distance information with the object as the position, posture, etc. of the first and second cameras 21 and 22 are changed. Based on the displacement information, the displacement parameter used to calculate distance information with the object may be corrected and used. That is, the controller 30 may update the stereo parameter between the first and second cameras 21 and 22 that are stored in advance based on the displacement information obtained by the calibration device 10.

On the other hand, the above-described displacement detection unit 12 of the calibration device 10 may be implemented in the control device 30, may be implemented separately from the control device 30.

8 is a flowchart illustrating a calibration method of a stereo camera system including a calibration device according to an exemplary embodiment.

Referring to FIG. 8, when calibration is started, the light source unit 111 of the interferometer 11 irradiates a beam for generating an interference pattern (S110).

After that, when the beam irradiated from the light source unit 111 is reflected by different light paths by the first and second reflecting members 114 and 115, the calibration device 10 passes through the detector 116 of the interferometer 11. In operation S120, the detector 116 outputs an image signal corresponding to the reflected beam.

In step S120, the beam irradiated from the light source unit 11 is separated into a plurality of beams (or a plurality of light beams) having different propagation paths by the beam splitter 112. The plurality of beams separated by the beam splitter 112 proceed to the first and second reflecting members 114 and 115, respectively, and are reflected by the first and second reflecting members 114 and 115 to reflect the beam splitter 112. Are combined again in. The beam splitter 112 combines the reflected beams and proceeds to the detector 116, which receives the output and outputs a corresponding image signal.

The video signal generated in step S120 is input to the displacement detector 12 of the calibration device 10.

The displacement detector 12 obtains image data by signal processing the image signal input from the detector 16, and detects an interference pattern between the reflected beams (S130).

In addition, the displacement detection unit 12 obtains displacement information by analyzing a circular fringe or a straight fringe of the detected interference pattern (S140). Since the displacement information detection method has been described in detail with reference to FIG. 3, the detailed description will be omitted below.

In step S140, the displacement information obtained by the displacement detection unit 12 is transmitted to the control device 30.

When the displacement information is received from the displacement detector 12, the controller 30 corrects the stereo parameter used to detect the distance to the object based on the displacement information (S150). That is, distance information and slope information between the first and second cameras 21 and 22 are corrected based on the displacement information.

The stereo parameter corrected in step S150 is stored in an internal memory (not shown) or an external memory (not shown) of the control device 30.

The stereo camera system according to an exemplary embodiment of the present invention described above may detect in real time that a distance and a slope between a plurality of cameras change due to vibration, temperature change, etc. generated during driving of a vehicle. Further, accuracy of calculating distance information with an object may be improved by acquiring displacement information between a plurality of cameras in real time and correcting a stereo parameter used to calculate distance information with an object based on the obtained displacement information.

In addition, due to the characteristics of the interferometer does not require a lot of installation space, it is possible to use integrally mounted to the camera system.

The calibration apparatus and the camera system disclosed in this document may perform calibration of the camera system in real time while driving a vehicle.

The term '~ part' used in the present embodiment refers to software or a hardware component such as a field-programmable gate array (FPGA) or an ASIC, and '~ part' performs certain roles. However, '~' is not meant to be limited to software or hardware. May be configured to reside in an addressable recording medium or may be configured to reproduce one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and the 'parts' may be combined into a smaller number of components and the 'parts' or further separated into additional components and the 'parts'. In addition, the components and '~' may be implemented to play one or more CPUs in the device or secure multimedia card.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (16)

1. A first reflecting member disposed on the first element,

   A second reflecting member disposed on the second element,

   A light source unit emitting the first beam,

   The first beam is divided into a second beam and a third beam having different propagation paths, and the first reflecting beam and the third beam reflecting the second beam by the first reflecting member are the second reflecting member. A beam splitter for combining the first reflection beam and the second reflection beam into a fourth beam when the second reflection beam reflected by the light is incident;

   A detector for detecting an image signal corresponding to the fourth beam, and

   A displacement detector which detects an interference pattern from the image signal and compares the interference pattern with previously stored interference patterns to calculate displacement information between the first element and the second element.

   Calibration device comprising a.
2. The method of claim 1,

   And a mirror disposed on an optical path between the third beam and the second reflecting beam, the mirror configured to transmit the third beam to the second reflecting member and to transmit the second reflecting beam to the beam splitter. Device.
3. The method of claim 2,

   And a case accommodating the light source unit, the beam splitter, and the detector.
4. The method of claim 2,

   And a case accommodating the light source unit, the beam splitter, the mirror, the detector, and the second reflecting member.
5. The method of claim 1,

   The first element and the second element calibration device comprising a camera.
6. The method of claim 1,

   The displacement information includes distance movement information between the first element and the second element,

   And the displacement detection unit obtains the distance movement information based on a circular fringe included in the interference pattern.
7. The method of claim 1,

   The displacement information includes relative rotation information between the first element and the second element,

   And the displacement detection unit obtains the rotation information based on a straight fringe included in the interference pattern.
8. A camera housing including a first camera and a second camera spaced apart from each other, and

   It includes a calibration device for calculating displacement information between the first camera and the second camera,

   The calibration device includes a first reflecting member disposed on the first camera, and a second reflecting member disposed on the second camera.

   Camera system comprising a.
9. The method of claim 8,

   And a controller for correcting a displacement parameter used to calculate distance information with respect to an object based on the calculated displacement information.
10. The method of claim 8,

    The calibration device,

    An interferometer for acquiring an image signal including an interference pattern between a plurality of beams reflected by the first reflecting member and the second reflecting member, and

    And a displacement detector configured to detect the interference pattern from the image signal and compare displacement patterns with previously stored interference patterns to calculate displacement information between the first camera and the second camera.
11. The method of claim 10,

    The interferometer,

    A light source unit, and

    And a beam splitter which separates the beam irradiated from the light source into a plurality of beams having different optical paths and transmits the beam to the first reflecting member and the second reflecting member, respectively.
12. The method of claim 11,

    The interferometer,

    And a mirror for transferring the beam separated by the beam splitter to the second reflecting member.
13. The method of claim 11,

    The light source unit comprises a laser or a laser diode.
14. The method of claim 10,

    The displacement information includes distance movement information between the first camera and the second camera,

    And the displacement detection unit obtains the distance movement information based on a circular fringe included in the interference pattern.
15. The method of claim 10,

    The displacement information includes relative rotation information between the first camera and the second camera,

    The displacement detection unit is a camera system for obtaining the rotation information based on a straight fringe included in the interference pattern
16. The method of claim 15,

    The camera system may be configured to acquire a plurality of image data through the plurality of cameras, and calculate a distance information with respect to an object detected from the plurality of image data based on distance information and relative rotation information between the plurality of cameras. More,

    And the control device updates the distance information and the rotation information based on the displacement information.

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