Abstract:
A head-up display (HUD) automatic correction method includes: projecting, by a HUD device, a head-up display image onto a windshield of a vehicle; photographing, by a camera disposed outside of the vehicle, the head-up display image; generating, by an image processing unit, a correction signal by analyzing the head-up display image photographed by the camera; and controlling, by a HUD controller, the HUD device to correct the head-up display image using the correction signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0176046 filed in the Korean Intellectual Property Office on Dec. 10, 2015, the entire contents of which are incorporated herein by reference as if fully set forth herein. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    (a) Technical Field 
         [0003]    The present disclosure relates generally to a HUD automatic correction method. More particularly, the present disclosure relates to a head-up display automatic correction method and correction system which efficiently corrects a head-up display screen displayed on a windshield glass of a vehicle. 
         [0004]    (b) Description of the Related Art 
         [0005]    Recent vehicles have been equipped with a driver assistance system (DAS) to enhance convenience and safety for drivers while the vehicles are in motion. The DAS performs functions such as keeping track of the driving lane, generating an alarm when straying from the driving lane, maintaining a safe distance from adjacent vehicles, preventing a collision with adjacent obstacles, and controlling vehicle speed in accordance with traffic situations or road environments, using various cameras, radar sensors, etc., without any instruction from the driver. 
         [0006]    DASs have previously been mounted only in expensive cars, but increasingly have been used in mid- and small-sized cars with a growing focus on eco-friendly, economical driving for protecting the environment and conserving energy resources. For example, the DAS may include a smart cruise control (SCC), a lane departure warning system (LDWS), a blind spot detection (BSD), an around view monitoring system (AVM), a head-up display (HUD), and the like. 
         [0007]    Among those systems, the HUD unit is a system that displays various items of information, such as driving information of the vehicle or navigation information, on the windshield of the vehicle within the main view of the driver while the vehicle is in motion. The HUD unit can display images of various items of information on the windshield by reflecting and enlarging the images with a projector and an optical unit. 
         [0008]    During manufacturing, the HUD unit is typically inspected in a vehicle inspection line. In this inspection process, it can be determined whether distorted images are displayed due to, for example, variation of an anti-double reflection film in the windshield, the quality of the HUD system, and/or assembly variation of the vehicle, when the images are projected to the windshield. Accordingly, since the HUD inspection process is usually performed manually by workers, the inspection cycle time increases, the work efficiency deteriorates, and it is difficult for the inspectors to manage the HUD unit quality. 
         [0009]    The Description of the Related Art is provided above to help understanding the background of the present disclosure and may include matters out of the related art known to those skilled in the art. The information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the related art that is already known to a person of ordinary skill in the art. 
       SUMMARY OF THE DISCLOSURE 
       [0010]    The present disclosure has been made in an effort to provide a head-up display automatic correction method and correction system having advantages of being able to reduce a correction cycle by efficiently correcting the head-up display screen displayed onto the windshield glass of the vehicle and improve operation efficiency. 
         [0011]    According to embodiments of the present disclosure, a HUD automatic correction method includes: projecting, by a HUD device, a head-up display image onto a windshield of a vehicle; photographing, by a camera disposed outside of the vehicle, the head-up display image; generating, by an image processing unit, a correction signal by analyzing the head-up display image photographed by the camera; and controlling, by a HUD controller, the HUD device to correct the head-up display image using the correction signal. 
         [0012]    The generating of the correction signal may include: transforming the photographed head-up display image based on an eye point corresponding to an eye position of a driver viewing the windshield; and generating the correction signal using the transformed image. 
         [0013]    The photographing of the head-up display image may include: moving the vehicle to a predetermined position; moving the camera to a position corresponding to the windshield of the vehicle; and photographing, by the camera, the head-up display image with the camera being in the moved position. 
         [0014]    A moving device may move the camera to the position corresponding to the windshield of the vehicle. 
         [0015]    The image processing unit may perform controller area network (CAN) communication with the HUD controller through an on-board diagnostics (OBD) connector installed in the vehicle. 
         [0016]    The image processing unit and the camera may be connected to each other by a communication device and transmit/receive data to/from each other using the communication device, and the image processing unit and the HUD controller may be connected to each other by the communication device and transmit/receive data to/from each other using the communication device. 
         [0017]    The image processing unit and the camera may be connected to each other by a communication device or an Ethernet connection and transmit/receive data to/from each other using the communication device or the Ethernet connection, and the image processing unit and the HUD controller may be connected to each other by the CAN communication or the Ethernet connection and transmit/receive data to/from each other using the communication device or the Ethernet connection. 
         [0018]    Furthermore, according to embodiments of the present disclosure, a HUD automatic correction system includes: a HUD unit projecting a head-up display image onto a windshield of a vehicle; a camera disposed outside of the vehicle and photographing the head-up display image projected onto the windshield by the HUD unit; an image processing unit generating a correction signal by analyzing the head-up display image photographed by the camera; and a HUD controller controlling the HUD device to correct the head-up display image using the correction signal generated by the image processing unit. The HUD unit may include: a HUD device projecting the head-up display image onto the windshield; and the HUD controller controlling the HUD device to correct the head-up display image using the correction signal generated by the image processing unit. 
         [0019]    The system may further include a communication device wirelessly connecting the camera, the image processing unit, and the HUD controller to each other. 
         [0020]    The image processing unit may transform the photographed head-up display image based on an eye point corresponding to an eye position of a driver viewing the windshield and generates the correction signal using the transformed image. 
         [0021]    The system may further include a moving device moving the camera to a position corresponding to the windshield glass. The HUD controller or the image processing unit may control the moving device to move the camera to the position. 
         [0022]    The system may further include an OBD connector installed in the vehicle. The image processing unit may perform CAN communication with the HUD controller through the OBD connector. 
         [0023]    The camera and the image processing unit may wirelessly transmit/receive data to/from each other using an Ethernet connection or CAN communication. 
         [0024]    Accordingly, by detecting the head-up display screen displayed on the windshield of the vehicle through an external camera and correcting the head-up display screen using the detected data, it is possible to efficiently perform the correction rather than performing the correction in the vehicle. 
         [0025]    Further, according to embodiments of the present disclosure, it is possible to prevent precision deterioration resulting from the worker&#39;s manual operation, and reduce inspection time and correction time as compared to performing the correction in the vehicle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a schematic diagram of a HUD automatic correction system according to embodiments of the present disclosure. 
           [0027]      FIG. 2  is a flowchart showing a HUD automatic correction method according to embodiments of the present disclosure. 
           [0028]      FIG. 3  is a flowchart showing a part of a HUD automatic correction method according to embodiments of the present disclosure. 
           [0029]      FIG. 4  is a drawing showing a glass image corresponding to an eye point of a driver in a HUD automatic correction method according to embodiments of the present disclosure. 
       
    
    
       [0030]      
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                 &lt;Description of symbols&gt; 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 102: HUD device 
                 104: HUD controller 
               
               
                   
                 110: OBD connector 
                 120: image processing unit 
               
               
                   
                 150: vehicle 
                 140: windshield glass 
               
               
                   
                 130: camera 
                 135: moving device 
               
               
                   
                   
               
             
          
         
       
     
       DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0031]    Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. Further, throughout the specification, like reference numerals refer to like elements. 
         [0032]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0033]    It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
         [0034]    Additionally, it is understood that one or more of the below methods, or aspects thereof, may be executed by at least one controller. The term “controller” may refer to a hardware device that includes a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute the program instructions to perform one or more processes which are described further below. Moreover, it is understood that the below methods may be executed by an apparatus comprising the controller in conjunction with one or more other components, as would be appreciated by a person of ordinary skill in the art. 
         [0035]    Furthermore, the controller of the present disclosure may be embodied as non-transitory computer readable media containing executable program instructions executed by a processor, controller or the like. Examples of the computer readable mediums include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable recording medium can also be distributed throughout a computer network so that the program instructions are stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN). 
         [0036]    Embodiments of the present disclosure will hereinafter be described in detail with reference to the accompanying drawings. 
         [0037]      FIG. 1  is a schematic diagram of a HUD automatic correction system according to embodiments of the present disclosure. 
         [0038]    As shown in  FIG. 1 , the head-up display (HUD) automatic correction system includes a vehicle  150 , a windshield  140 , a HUD unit  100 , an on-board diagnostics (OBD) connector  110 , an image processing unit  120 , a camera  130 , and a moving device  135 . 
         [0039]    The HUD unit  100  includes a HUD device  102  and a HUD controller  104  according to embodiments of the present disclosure. The HUD controller  104  controls the HUD device  102 , and the HUD device  102  is disposed in the vehicle to project an image onto the windshield  140 . The HUD controller  104  is disposed in the vehicle with the HUD device  102  or is disposed outside of the vehicle. The HUD controller  104  is configured to control the HUD device  102 . 
         [0040]    The camera  130  is disposed outside of the vehicle  150 . The camera  130  is disposed on the windshield  140 , and the moving device  135  moves the camera  130  to a predetermined position. Herein, the moving device  135  may be moved to a predetermined position by the HUD controller  104  or the image processing unit  120 . 
         [0041]    A head-up display image (alternatively referred to herein as a “glass image”) projected from the HUD device  102  and formed on the windshield  140  is photographed by the camera  130  positioned outside of the vehicle  150 . The image photographed by the camera  130  is wirelessly transmitted to the image processing unit  120  through an Ethernet connection. 
         [0042]    The image processing unit  120  analyzes the image photographed by the camera  130 , and generates a correction signal on the basis of the analyzed data. The correction signal is transmitted to the OBD connector  110  through controller area network (CAN) communication. The HUD controller  104  controls the HUD device  102  using the correction signal transmitted to the OBD connector  110 , and corrects the glass image projected onto the windshield  140 . The image processing unit  120  transforms the image photographed by the camera  130  to an eye point image based on an eye point of a driver by a predetermined program or method, and generates the correction signals by using the eye point image. When the photographed image is transformed to the eye point image, the image processing unit  120  considers the type of the windshield  140  and the position of the eye point of the driver. 
         [0043]      FIG. 2  is a flowchart showing a HUD automatic correction method according to embodiments of the present disclosure. 
         [0044]    As shown in  FIG. 2 , control starts in step S 200  and the vehicle  150  is entered and arranged to the predetermined position in step S 205 . 
         [0045]    In step S 210 , the HUD device  102  is turned on by the HUD controller  104 , and a predetermined image is projected onto the windshield  140  by the HUD device  102 . 
         [0046]    The camera  130  disposed outside of the vehicle  150  photographs the glass image projected onto the windshield  140  in step S 215 , and the image photographed by the camera  130  is transmitted to the image processing unit  120  in step S 220 . 
         [0047]    The image processing unit  120  analyzes the photographed image transmitted from the camera  130  in step S 225 , and generates the correction signal on the basis of the analyzed data in step S 230 . Herein, the image processing unit  120  may transform the photographed image based on an eye point of a driver, and generate the correction signals by using the eye point image. 
         [0048]    The image processing unit  120  transmits the correction signals to the HUD controller  104  through the OBD connector  110  using the CAN communication in step S 235 . 
         [0049]    The HUD controller  104  controls the HUD device  102  using the correction signals received through the OBD connector  110  and corrects the glass image formed onto the windshield  140  in step S 240 . 
         [0050]    Further, the camera  130  photographs the corrected glass image again and the image processing unit  120  determines whether the corrected glass image is passed or performs correction work again in step S 245 , and the control ends in step S 250 . 
         [0051]      FIG. 3  is a flowchart showing a part of a HUD automatic correction method according to embodiments of the present disclosure. 
         [0052]    As shown in  FIG. 3 , the image processing unit  120  analyzes the photographed image transmitted from the camera  130  at step S 225 . 
         [0053]    Then, the image processing unit  120  receives the photographed image from the camera  130  at step S 300 , and transforms the photographed image to the eye point image based on an eye point corresponding to an eye position of a driver at step S 305 . The image processing unit  120  analyzes the eye point image at step S 310 , and generates the correction signals on the basis of the analyzed data at step S 320 . 
         [0054]    In an exemplary embodiment of the present disclosure, since the image photographed by the camera  130  is changed according to the curvature of the windshield  140  and the position of the driver&#39;s eye, the image processing unit  120  changes the photographed image to the eye point image and performs the correction work in the same condition as the state which views the glass image by the driver. Therefore, when the photographed image is transformed to the eye point image, the image processing unit  120  considers the type of the windshield glass  140  and the position of the eye point of the driver. 
         [0055]      FIG. 4  is a drawing showing a glass image corresponding to an eye point of a driver in a HUD automatic correction method according to embodiments of the present disclosure. The left side of  FIG. 4  shows the eye point image before correction, and the right side of  FIG. 4  shows the eye point image after correction. 
         [0056]    Before the correction, an error  420  is generated between a reference lattice point  400  and an actual lattice point  410 , an error angle occurs between a reference angle  450  and an actual angle  440 . However, after the correction, the error between the reference lattice point and the actual lattice point is eliminated, and the error angle between the reference angle and the actual angle does not occur. 
         [0057]    While this disclosure has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.