JP2010234856A - On-vehicle display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide "an on-vehicle display device" capable of a proper top view display in response to a tire installed in a vehicle. <P>SOLUTION: This on-vehicle display device includes an imaging part 60 for displaying imaging data of imaging the one's own vehicle periphery by being converted as coordinates into an image looked down from a virtual view point above the vehicle and outputting the imaging data of imaging the one's sown vehicle periphery, a storage part 40 storing tire outer diameter information corresponding to a tire classification, a control part 70 for converting the imaging data into the coordinates based on an extracted tire outer diameter by extracting the tire outer diameter corresponding to the tire classification replaced based on tire information stored in the storage part 40 when the tire of one's own vehicle is replaced, and an image display part 50 for displaying the coordinate-converted imaging data as the image looked down from the virtual view point. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an in-vehicle display device that displays an image around a host vehicle captured by an imaging camera mounted on a vehicle, and in particular, a technique for converting a captured image into an image looking down from a viewpoint above the vehicle and displaying the image. About.

  With the improvement of the mounting rate of imaging cameras in automobiles, applications using image composition are rapidly expanding. Many of these applications assist the driver's driving and improve the safety of the vehicle during travel. For example, an in-vehicle image system that provides images of obstacles around a vehicle includes a camera system (such as a corner monitor system or a rear view camera system) that captures distant obstacles, and a system that captures blind spot obstacles in the vicinity of the vehicle ( Side view camera system). Further, in a system using an imaging camera with a narrow angle of view, the direction of the imaging camera can be changed by a driving device so that obstacles around the vehicle are projected. Furthermore, in a system using an ultra-wide-angle imaging camera, it is possible to synthesize the captured image data and project 360 degrees around the vehicle, and cut out the image data in the required horizontal range from that. Or crop and view the image.

  In addition, the image data captured by multiple imaging cameras on the front, back, left and right of the host vehicle is converted into viewpoints (coordinate conversion), and the image around the host vehicle is displayed on the monitor as if viewed from directly above. View display has also been put to practical use. Patent Document 1 discloses a technique for coordinate conversion according to the slope change point and the slope change amount of the road surface when it is detected that the road surface is inclined with respect to such top view display.

JP 2007-318460 A

  FIG. 1 is an explanatory diagram of top view display. An imaging camera is attached to each of the front, rear, left and right sides of the host vehicle, and the top view display T displays a front image A, left and right images B and C, and a rear image D of the host vehicle from a virtual viewpoint above the host vehicle. Display as if looking down. In the center of the top view display T, a plane image of the host vehicle is displayed, and 1 is a joint between the images.

  FIG. 2 is a diagram illustrating the positional relationship between the virtual viewpoint of the top view display and the imaging camera. As shown in the figure, the optical axis O of the imaging camera is at a height Hs from the ground surface or road surface (hereinafter, Hs is referred to as a reference height), and the imaging camera has a viewing angle in the vertical direction around the optical axis O. Take an image at θ. Further, the virtual viewpoint P of the top view display T is set to the height Ht from the ground surface or the road surface. The top view display T displays the image data captured at the reference height Hs after coordinate conversion to the height Ht of the virtual viewpoint P.

  For example, if the mounting position accuracy of the imaging camera decreases, the reference height Hs changes, and the distance Hd between the imaging camera and the virtual viewpoint P changes. As a result, the coordinate-converted imaging data includes an error. End up. This error appears, for example, as distortion of the image of the top view display, or causes discontinuity in the joint 1 of the images to be combined.

  Furthermore, even if the mounting position accuracy of the imaging camera is maintained, the reference height Hs of the imaging camera can change if the vehicle height changes later. Factors that change the vehicle height include the number of people on the vehicle, the weight to be loaded, and the tire pressure. In the conventional in-vehicle display device, the reference height Hs is set so as to be an average value or a median value of the predicted maximum vehicle height and the minimum vehicle height in consideration of these vehicle height changes.

  However, the conventional in-vehicle display device has the following problems. Tires mounted on vehicles may be changed depending on the season or may be changed to new ones. For example, in the season from spring to autumn, normal tires for normal driving (hereinafter referred to as summer tires for convenience) are mounted, and in the winter season, studless tires for driving on snowy roads, etc. (Hereinafter referred to as winter tire for convenience). Such a summer tire and a winter tire have different vehicle outer diameters, so the vehicle height varies. Furthermore, the outer diameter is subtly different depending on the tire manufacturer. Of course, the vehicle height also changes when the tire size is changed. Once the tire is replaced, the vehicle height will continue to change over a long period of time, but conventional vehicle-mounted display devices have not taken into account such changes in vehicle height due to the tire. Accordingly, the distortion of the top view display caused by tire replacement or the like continues for a long time, and during that time, the user feels uncomfortable or stressed.

  The present invention solves such a conventional problem, and provides a vehicle-mounted display device, a vehicle-mounted image correction method, and a program capable of performing an appropriate top-view display according to a tire mounted on a vehicle. With the goal.

  The in-vehicle display device according to the present invention displays image data obtained by imaging the periphery of the vehicle by converting the coordinates into an image looking down from a virtual viewpoint above the vehicle, and images the periphery of the vehicle and outputs the image data. Imaging means, tire information storage means for storing tire outer diameter information corresponding to the tire type, and when the vehicle tire is replaced, the tire information storage means is replaced based on the tire outer diameter information stored in the tire information storage means. Extraction means for extracting tire outer diameter information corresponding to the tire type, coordinate conversion means for coordinate conversion of the imaging data based on the extracted tire outer diameter information, and imaging data converted by the coordinate conversion means. Display means for displaying as an image looking down from the virtual viewpoint.

  Preferably, the in-vehicle display device further includes input means for inputting a tire type when the tire is replaced, and the extraction means extracts tire outer diameter information based on the input tire type. Preferably, the coordinate conversion unit performs coordinate conversion of the imaging data based on a difference between a predetermined reference value and tire outer diameter information extracted by the extraction unit. Preferably, the coordinate conversion unit corrects the position of the virtual viewpoint whose coordinates are converted based on the difference. Preferably, the coordinate conversion unit corrects the position of the imaging data to be trimmed from the imaging unit based on the difference.

  According to the present invention, in the method for displaying the image data obtained by imaging the periphery of the vehicle by converting the coordinates into an image looking down from the virtual viewpoint above the vehicle, the step of inputting the replaced tire type when the tire of the vehicle is replaced And a step of extracting tire outer diameter information corresponding to the input tire type with reference to a table that prescribes a relationship between a prepared tire type and tire outer diameter information, and the extracted tire outer diameter information A step of transforming the image data based on the coordinates; and a step of displaying the image data subjected to the coordinate conversion as an image looking down from the virtual viewpoint.

  Preferably, the display method further includes a step of detecting a difference between the extracted tire outer diameter information and the reference tire outer diameter information, and the step of performing the coordinate conversion includes the position of the virtual viewpoint based on the detected difference. Is corrected. Preferably, the display method further includes a step of detecting a difference between the extracted tire outer diameter information and the reference tire outer diameter information, and the step of performing the coordinate conversion trims the imaging data based on the detected difference. Correct the position.

  According to the present invention, when the tire of the host vehicle is replaced, the coordinate conversion of the imaging data is performed according to the tire type, so even if the vehicle height changes due to the tire type, it looks down from the appropriate virtual viewpoint. An image can be displayed.

It is a figure explaining a top view display. It is a figure explaining the positional relationship of the virtual viewpoint of a top view display, and an imaging camera. It is a block diagram which shows the structure of the vehicle-mounted display apparatus which concerns on the Example of this invention. It is a figure which shows the example of the tire information which registered the relationship between a tire classification and a tire outer diameter. It is an example of installation of an imaging camera. It is a functional block diagram for performing the top view display of the control part shown in FIG. It is an operation | movement flowchart of the top view display by 1st Example of this invention. It is an example of a display of the input screen for inputting the information regarding a tire. It is a figure explaining the method of correct | amending the reference | standard height Hs of an imaging camera. It is a figure explaining the method of correct | amending the reference | standard height Hs of the imaging camera by 2nd Example of this invention.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 3 is a block diagram illustrating the configuration of the in-vehicle display device according to the embodiment of the present invention. The in-vehicle display device 10 includes an input unit 20 for inputting information from a user and a contact for detecting attachment / detachment of a tire. A vehicle state sensor 30 that detects a vehicle state such as a sensor and a gear position, a storage unit 40 that stores data necessary for the operation of the in-vehicle display device, and an image that displays a top view display T, a rear view display, and the like on the display The display unit 50 is configured to include an imaging unit 60 that images the vicinity of the host vehicle, and a control unit 70 that controls the operation of each unit.

  The input unit 20 includes input keys, a touch panel, voice input, and the like, and provides various information from the user to the control unit 70. For example, the control unit 70 can output the top view display T in response to an input from the user. The storage unit 40 includes a tire information table 42, a tire information input screen unit 44, and a tire information update unit 46. As shown in FIG. 4, the tire information table 42 includes tire outer diameter information corresponding to the tire type for each manufacturer. The tire type is, for example, a standard normal summer tire or a winter tire such as studless. The tire information input screen unit 44 holds an input screen for prompting the user to input tire information at the time of tire replacement. The tire information update unit 46 stores tire information currently mounted on the vehicle, and updates the tire information when the tire information is input from the user.

  The imaging unit 60 includes imaging cameras 62, 64, 66, and 68, and the imaging cameras 62 to 68 include, for example, an optical system including a CCD imaging device and a wide-angle fisheye lens. FIG. 5 shows an arrangement example of the imaging cameras 62 to 68. The imaging camera 62 is installed near the license plate of the front bumper and images the front in the range of the viewing angle θ1. The imaging cameras 66 and 68 are installed on the left and right door mirrors, respectively, and image the left and right direction of the host vehicle in the range of viewing angles θ2 and θ3. The imaging camera 64 is installed in the rear bumper and images the rear in the range of the viewing angle θ4. The viewing angles θ1 to θ4 of the imaging cameras are adjusted so as to partially overlap with the adjacent viewing angles, and the four imaging cameras 62 to 68 capture the entire periphery of the vehicle. However, the number and installation positions of the imaging cameras are arbitrary, and are not necessarily limited to the above-described mode.

  FIG. 6 is a functional block diagram for executing the top view display in the control unit 70. The control unit 70 refers to the tire information setting unit 72 that enables the setting of tire information based on the input screen read from the tire information input screen unit 44 and the tire information table 42 and is held in the tire information update unit 46. A tire outer diameter extraction unit 74 that extracts a tire outer diameter corresponding to the tire type, and a difference detection unit 76 that detects a difference between the tire outer diameter extracted by the tire outer diameter extraction unit 74 and a preset reference tire outer diameter. A coordinate conversion unit 78 that performs coordinate conversion of the imaging data using the difference detected by the difference detection unit 76, and an image synthesis unit that combines the imaging data converted by the coordinate conversion unit 78 to generate an image for top view display. 80.

  Next, the top view display operation in the in-vehicle display device of this embodiment will be described with reference to the flowchart of FIG. First, the tire of the own vehicle is exchanged, for example, from a summer tire to a winter tire or from a winter tire to a summer tire, or to a new tire (step S101). When the tire replacement is performed, a detection signal for detecting the attachment / detachment of the tire is output from the vehicle state sensor 30 to the control unit 70. Alternatively, the user inputs that the tire has been changed through the input unit 20. When the tire information setting unit 72 detects that the tire has been changed, the tire information setting unit 72 reads the input screen information from the tire information input screen unit 44 and displays an input screen for inputting information about the tire on the display (step S102).

  FIG. 8A is an example of an input screen for information related to tires. An input instruction 90 such as “Please select manufacturer and tire type” is displayed on the input screen of FIG. 6A, and a tire list 92 of summer tires and winter tires for each manufacturer is displayed. Is done. The user can select a corresponding tire from the tire list 92. When the input in FIG. 8A is completed, a screen for inputting the tire size as shown in FIG. 8B is displayed. Here, for example, an input instruction 94 such as “Please input tire size” is displayed, and a size list 96 indicating a plurality of tire sizes is further displayed. However, when the tire is an imported product or a new product and is not registered in the tire list, the user may directly input information on the tire.

  Information on the tire is input from the user with reference to the input screen as described above (step S103). When the information related to the tire is input, the tire information setting unit 72 stores the information related to the tire in the tire information update unit 46 and updates the information related to the tire (step S104). Next, the tire outer diameter extraction unit 74 refers to the tire information table 42 shown in FIG. 4 and extracts the tire outer diameter Dx from the information about the tire held in the tire information update unit 46 (step S105). The tire outer diameter Dx determines the vehicle height, that is, the height from the ground surface of the imaging camera shown in FIG. Next, the difference detection unit 76 detects a difference S (S = | Ds−Dx |) between the extracted tire outer diameter Dx and a predetermined reference tire outer diameter Ds (step S106). Here, the reference tire outer diameter Ds is an outer diameter at the reference height Hs of the imaging camera.

  Next, the coordinate conversion unit 78 corrects the coefficient based on the detected difference S, and performs coordinate conversion of the imaging data (step S107). As shown in FIG. 9, at the reference tire outer diameter Ds, the reference height of the imaging camera is Hs. When the tire outer diameter Dx1 is larger than the reference tire outer diameter Ds (Dx1> Ds), the height of the imaging camera from the ground surface is Hs1 (Hs1> Hs), and the distance Hd1 between the virtual viewpoint P and the imaging camera is greater than Hd. Becomes smaller. Accordingly, the coordinate conversion unit 78 corrects the virtual viewpoint P to P1 and converts the coordinates so that the distance between the virtual viewpoint P and the imaging camera is Hd.

  Conversely, when the tire outer diameter Dx2 is smaller than the reference tire outer diameter Ds (Dx2 <Ds), the height of the imaging camera from the ground surface is Hs2 (Hs2 <Hs), and the distance Hd2 between the virtual viewpoint P and the imaging camera. Becomes larger than Hd. Therefore, the coordinate conversion unit 78 corrects the virtual viewpoint P to P2 and converts the coordinates so that the distance between the virtual viewpoint P and the imaging camera is Hd.

  Next, the image synthesizing unit 80 synthesizes the imaging data of the imaging cameras on the front, rear, left and right of the vehicle (step S108), and the image display unit 50 outputs the top view display T on the display (step S109).

  In this way, by correcting the virtual viewpoint and performing coordinate transformation so as to compensate for the difference with respect to the reference height Hs according to the tire outer diameter to be mounted, the distortion of the top view display due to the vehicle height change is eliminated. In addition, it is possible to reduce discomfort and discomfort to the user.

  Next, a second embodiment of the present invention will be described. In the above embodiment, the compensation is made by changing the virtual viewpoint based on the reference height Hs of the imaging camera based on the difference in the tire outer diameter. However, in the second embodiment, the reference of the imaging camera based on the difference S in the tire outer diameter. The height Hs is corrected by the imaging camera itself.

  FIG. 10 schematically illustrates a two-dimensional range that can be imaged by the imaging camera. The imaging data 100 of the imaging camera using the wide-angle lens can capture a wide range of surrounding situations with a constant aspect ratio, but distortion occurs at the end of the imaging data 100, so the central rectangular area with little distortion. 102 is trimmed and used as a top-view display image. Here, the rectangular portion 102 is an image cut out at the reference height Hs of the imaging camera. When the tire outer diameter Dx1 is larger than the reference tire outer diameter Ds, the vehicle height increases according to the difference S, and thus the height of the imaging camera also increases. The coordinate conversion unit 78 can compensate the difference S of the tire outer diameter by shifting the rectangular region 102A to be trimmed from the imaging data 100 downward by a distance T1 corresponding to the difference S.

  Similarly, when the tire outer diameter Dx2 is smaller than the reference tire outer diameter Ds, the vehicle height decreases according to the difference S, and thus the height of the imaging camera also decreases. The coordinate conversion unit 78 can compensate the difference S of the tire outer diameter by shifting the rectangular region 102B to be trimmed from the imaging data 100 to the upper T2 by a distance corresponding to the difference S.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims. Deformation / change is possible.

  In the first and second embodiments, the method for correcting the top view display T has been exemplified. However, in addition to such a method, the top view display T is compensated by using the vehicle height value stored in the memory. Alternatively, the size change due to tire replacement may be reflected in the vehicle height value.

10: In-vehicle display device 20: Input unit 30: Vehicle state sensor 40: Storage unit 50: Image display unit 60: Imaging unit 70: Control unit T: Top view display A: Front image B, C of own vehicle Left and right image D: Rear image of own vehicle

Claims (8)

An in-vehicle display device that displays image data obtained by imaging the periphery of the vehicle by converting coordinates into an image looking down from a virtual viewpoint above the vehicle,
Imaging means for imaging the periphery of the vehicle and outputting imaging data;
Tire information storage means for storing tire outer diameter information corresponding to the tire type;
An extraction means for extracting tire outer diameter information corresponding to the tire type replaced based on the tire outer diameter information stored in the tire information storage means when the tire of the host vehicle is replaced;
Coordinate conversion means for performing coordinate conversion of the imaging data based on the extracted tire outer diameter information;
Display means for displaying the imaging data converted by the coordinate conversion means as an image looking down from the virtual viewpoint;
A vehicle-mounted display device comprising: The in-vehicle display device further includes input means for inputting a tire type when a tire is replaced, and the extraction means extracts tire outer diameter information based on the input tire type. In-vehicle display device. The in-vehicle display device according to claim 1, wherein the coordinate conversion unit performs coordinate conversion of the imaging data based on a difference between a predetermined reference value and tire outer diameter information extracted by the extraction unit. The in-vehicle display device according to claim 3, wherein the coordinate conversion unit corrects a position of the virtual viewpoint whose coordinates are converted based on the difference. The in-vehicle display device according to claim 3, wherein the coordinate conversion unit corrects a position of imaging data to be trimmed from the imaging unit based on the difference. A method for displaying image data obtained by imaging the periphery of the vehicle by converting the coordinates into an image looking down from a virtual viewpoint above the vehicle,
A step of inputting the replaced tire type when the own tire is replaced;
A step of extracting tire outer diameter information corresponding to the input tire type with reference to a table that defines a relationship between a tire type and tire outer diameter information prepared in advance;
Transforming the imaging data based on the extracted tire outer diameter information;
Displaying coordinate-converted imaging data as an image looking down from the virtual viewpoint;
Display method. The display method further includes a step of detecting a difference between the extracted tire outer diameter information and the reference tire outer diameter information, and the coordinate conversion step corrects the position of the virtual viewpoint based on the detected difference. The display method according to claim 6, wherein coordinate conversion is performed. The display method further includes a step of detecting a difference between the extracted tire outer diameter information and the reference tire outer diameter information, and the step of performing the coordinate conversion includes a position for trimming the imaging data based on the detected difference. The display method according to claim 6, wherein correction is performed.

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