JP2008202987A - On-vehicle navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To select properly on which of a landscape image in front of a vehicle and a drawn map image generated based on map images stored beforehand navigation information is to be displayed in the superimposed state. <P>SOLUTION: This on-vehicle navigation device for displaying the navigation information in the superimposed state by a display means by using an imaged image by an imaging means or a drawn map image as a background image includes the imaging means for imaging a landscape in front of the vehicle, a drawn map image generation means for generating the drawn map image based on map information stored beforehand in a map information storage means and on a present position of the vehicle acquired by a present position acquiring means capable of acquiring the present position of the vehicle, and the display means for performing display visible in a cabin. The device also includes a traveling environment acquiring means for acquiring the traveling environment of the vehicle, and a background image selection means for selecting on which of the imaged image by the imaging means and the drawn map image the navigation information is to be displayed in the superimposed state, based on the traveling environment of the vehicle acquired by the traveling environment acquiring means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-vehicle navigation device that displays navigation information superimposed on a landscape image in front of a vehicle or a drawn map image generated based on a map image stored in advance.

Conventionally, a display mode in which a landscape in the traveling direction of the host vehicle is captured by a camera, and navigation information elements are superimposed and displayed on the captured image, and navigation information elements are superimposed on a map image generated based on drawing map information. An invention relating to a car navigation system that can be switched between display modes to be displayed is disclosed (see, for example, Patent Document 1). In this system, the user manually switches the display mode, or when the vehicle reaches a landmark, it automatically switches so that the navigation information element is displayed superimposed on the captured image.
JP-A-11-108684

  However, as in the conventional car navigation system, it is troublesome for the user to manually switch the display mode, and it is not preferable to perform operations related to driving from the viewpoint of safe driving. Therefore, it is preferable to automatically switch the display mode, but it is not sufficient to automatically switch the display mode when the landmark is reached. Depending on the actual driving environment, it may be preferable to display the navigation information superimposed on the drawn map image generated based on the map image, rather than displaying the navigation information superimposed on the landscape captured by the imaging means. It is.

  The present invention is for solving such a problem, and it is appropriate to appropriately determine which navigation information is to be superimposed and displayed on a landscape image in front of the vehicle or a drawn map image generated based on a map image stored in advance. The main purpose is to provide an in-vehicle navigation device that can be selected.

  In order to achieve the above object, one aspect of the present invention is an imaging unit that captures a landscape in front of a vehicle, map information stored in advance in a map information storage unit, and a current position of the vehicle acquired by a current position acquisition unit. A drawing map image generation means for generating a drawing map image based on the display, and a display means for performing a display that can be visually recognized in the passenger compartment. The display means uses the captured image of the imaging means or the drawing map image as a background image for navigation information. Is a vehicle-mounted navigation device that superimposes and displays a driving environment acquisition unit that acquires the driving environment of the vehicle, a captured image of the imaging unit, and a drawn map image based on the driving environment of the vehicle acquired by the driving environment acquisition unit And background image selection means for selecting which of the navigation information is to be displayed in a superimposed manner.

  According to this aspect of the present invention, it is possible to appropriately select which of the captured image of the imaging unit and the drawn map image is to be displayed with the navigation information superimposed based on the traveling environment of the vehicle.

  In one aspect of the present invention, for example, the traveling environment acquisition unit includes a current position acquisition unit, and the background image selection unit displays the current position acquisition unit while the navigation information is superimposed on the captured image of the imaging unit. By referring to the map information using the current position of the vehicle acquired by the above, when the current position of the vehicle corresponds to a predetermined position preset in the map information, the navigation information is superimposed and displayed on the drawn map image. This is means for switching the display contents of the display means. In this case, the predetermined position is, for example, a position in the downtown area.

  In one aspect of the present invention, for example, the traveling environment acquisition unit is a unit that performs captured image analysis of the imaging unit and acquires an analysis result obtained by the captured image analysis as a traveling environment, and the background image selection unit includes While the navigation information is superimposed and displayed on the captured image of the imaging means, the captured image of the imaging means displays the navigation information superimposed by a predetermined determination method based on the analysis result acquired by the traveling environment acquisition means. Means for switching the display content of the display means so as to superimpose and display the navigation information on the drawn map image when it is determined whether or not the captured image is suitable for superimposing and displaying the navigation information It is. In this case, for example, the traveling environment acquisition unit is a unit that derives the complexity of the captured image of the imaging unit and acquires it as the traveling environment, and the predetermined determination method uses the complexity acquired by the traveling environment acquisition unit as a reference level. In this case, this is a method for determining that the captured image is not suitable for displaying the navigation information in a superimposed manner.

  Further, in one aspect of the present invention, for example, the traveling environment acquisition unit is a unit that can detect the presence of an obstacle present on the course of the vehicle, and the background image selection unit stores the captured image navigation information of the imaging unit. Display contents of the display means so that the navigation information is superimposed and displayed on the drawn map image when the traveling environment acquisition means detects the presence of an obstacle present on the course of the vehicle during the superimposed display. Is a means for switching.

  In one aspect of the present invention, for example, the traveling environment acquisition unit is a unit that can acquire weather information, and the background image selection unit is displaying the navigation information superimposed on the captured image of the imaging unit. When the information indicating that the weather is bad is acquired by the traveling environment acquisition unit, the display content of the display unit is switched so that the navigation information is superimposed on the drawn map image.

  In one aspect of the present invention, for example, the traveling environment acquisition unit is a unit capable of detecting a road surface state, and the background image selection unit is displaying the navigation information superimposed on the captured image of the imaging unit. When the traveling environment acquisition unit detects that the vehicle is traveling on a rough road, the display content of the display unit is switched so that navigation information is superimposed on the drawn map image.

  In one embodiment of the present invention, when the background image selection unit selects the captured image of the imaging unit, a process of associating unnecessary image elements included in the captured image of the imaging unit with the background color is performed. It is characterized by.

  According to the present invention, there is provided an in-vehicle navigation device capable of appropriately selecting which of the landscape image in front of the vehicle and the drawn map image generated based on the previously stored map image is to be displayed with the navigation information superimposed. Can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  Hereinafter, an in-vehicle navigation device 1 according to an embodiment of the present invention will be described. The in-vehicle navigation device 1 selects either a landscape in front of the vehicle imaged by the camera or a drawn map image generated based on the map information as a background image, and navigation information (vehicles) on the selected background image. And the like, an arrow indicating a traveling direction to be traveled, a highlighted display indicating a destination, and the like.

[Constitution]
FIG. 1 is a diagram illustrating an example of the overall configuration of the in-vehicle navigation device 1. The in-vehicle navigation device 1 includes, as main components, a front camera 10, a GPS antenna 20, an HMI (Human Machine Interface) 30, a memory 40, a communication device 50, a G sensor 60, a display device 70, navigation, and the like. And a computer 80. The arrows in the figure indicate the main information communication flow in the apparatus performed using an appropriate communication protocol such as CAN (Controller Area Network), BEAN, AVC-LAN, or FlexRay.

  The front camera 10 is, for example, a camera that uses an image sensor such as a CCD or a CMOS disposed in the upper center of the windshield, and has an optical axis directed toward the front of the vehicle and images the front of the vehicle. The captured image of the front camera 10 is transmitted to the navigation computer 80 as an image signal generated by an interlace method such as NTSC (National Television Standards Committee). In addition, the front camera 10 used for well-known LKA (Lane Keeping Assist) control may be shared.

  The GPS antenna 20 receives a radio signal including satellite orbit and time data from a GPS satellite, and transmits the radio signal to the navigation computer 80.

  The HMI 30 is, for example, a liquid crystal display device arranged as a touch panel, a microphone for a voice input / output, a microphone, a speaker, a buzzer, etc. disposed at a position easily visible from the driver and passenger in the center of the instrument panel. Including.

  As the memory 40, for example, a storage medium such as a hard disk, a DVD, or a CD-ROM is used, and map information is stored. In the map information, the road shape is represented by node points representing intersections and the like and links connecting the node points, and information such as road width, curvature, and number of lanes is stored along with each link. ing. In addition, main buildings and place names, characteristic terrain, coordinates thereof, location areas such as downtown areas (specifically, coordinates of extended lines), and the like are stored.

  The communication device 50 is a device capable of communicating with a wireless communication station using, for example, a mobile phone radio network, and can be connected to an Internet provider or an information service facility via the wireless communication station. Moreover, you may include a beacon receiver and FM multiplex broadcast receiver. The communication device 50 periodically transmits the current position of the vehicle to the information service facility, and acquires weather information at the point from the information service facility.

  The G sensor 60 is, for example, a three-axis acceleration sensor attached below the center console portion of the vehicle, and according to the longitudinal, lateral, vertical, and vertical accelerations of the vehicle (in the present invention, particularly the vertical accelerations). The generated distortion of the beam in the sensor is measured, replaced with an electrical signal, and output to the navigation computer 80.

  The display device 70 is, for example, a HUD (Head Up Display) device. In other words, by projecting the image to the display position on the windshield, the content of the image as a virtual image as if it exists at the position on the extension line (position outside the vehicle) when viewing the display position from the driver's viewpoint Is displayed.

  The entire display device 70 is accommodated in a recess formed on the upper surface of the instrument panel, for example. And a dedicated liquid crystal display device that is disposed on the back side of the combination meter and performs light emission display in the traveling direction of the vehicle, and a reflecting mirror that reflects light emitted from the dedicated liquid crystal display device and projects it onto the windshield. Prepare. In addition, a focus adjustment mechanism is provided between the dedicated liquid crystal display and the reflecting mirror so that the perspective of the virtual image reflected in the eyes of the driver can be adjusted. The display contents that are projected to the eyes of the driver when the display device projects onto the windshield are determined by the navigation computer 80.

  Note that the display device 70 is not limited to the HUD device, and even if a liquid crystal display device or the like exemplified as being included in the HMI 30 is used as the display device 70, a particular problem occurs in the application of the present invention. Absent.

  The navigation computer 80 is, for example, a computer unit in which a ROM, a RAM, and the like are connected to each other via a bus with a CPU as a center, and includes an I / O port, a timer, a counter, and the like. The ROM stores programs and data executed by the CPU. The navigation computer 80 has a current position specifying unit 81 and a drawn map image generating unit 82 as main functional blocks that function when the CPU stores (executes) a program stored in the ROM and executes it. An image analysis unit 83, a background image selection unit 84, and a route guidance unit 85.

  The current position specifying unit 81 specifies the current position (latitude, longitude, altitude) of the host vehicle by a calculation based on the time difference of the radio signal from the satellite received by the GPS antenna 20. Note that the current position of the host vehicle may be corrected based on outputs from various sensors such as a vehicle speed sensor and a gyro sensor, and various information received via the beacon receiver and the FM multiplex broadcast receiver.

  The drawn map image generation unit 82 is, for example, a functional block that operates according to an operation request from the background image selection unit 84, and uses the current position and traveling direction of the host vehicle specified by the current position specifying unit 81 to map on the memory 40. With reference to the information, a drawn map image simulating the scenery in front of the vehicle is generated. FIG. 2 is a diagram illustrating a state in which a drawn map image is generated. The drawn map image is generated by converting a road shape on a two-dimensional plane obtained from map information into a bird's eye view. When displaying a drawn map image, it is possible to stably display an overview of the road shape to the driver without being affected by the degree of congestion of the buildings or imaging conditions. On the other hand, as compared with the case where the captured image of the front camera 10 is displayed as it is, there is a demerit that a difference from the actual landscape may be caused due to the above-described conversion error and the like. It is considered preferable to display the captured image of the front camera 10 as it is, as long as the contrast can be secured.

  The image analysis unit 83 analyzes the captured image of the front camera 10 and transmits it to the background image selection unit 84. In the image analysis of the image analysis unit 83, for example, the complexity of the captured image of the front camera 10 is quantified. Here, the complexity can be defined as the number of image elements that are elementized when the captured image of the front camera 10 is elementized based on luminance or color.

  As will be described later, the background image selection unit 84 is either a captured image of the front camera 10 or a drawn map image generated by the drawn map image generation unit 82 as a background image of navigation information superimposed and displayed by the route guidance unit 85. Is transmitted to the route guide unit 85. The selection method will be described below.

[Select background image]
FIG. 3 is a flowchart showing a flow of characteristic processing executed by the background image selection unit 84 regarding selection of the background image. This flow is repeatedly executed with a predetermined cycle, for example.

  First, the background image selection unit 84 refers to the current position of the host vehicle specified by the current position specifying unit 81 and the map information stored in the memory 40, and determines whether or not the current position of the host vehicle corresponds to a predetermined position. (S100; Condition 1). Here, the predetermined position is, for example, a position in a downtown area or a mountainous area, and the captured image of the front camera 10 is because the scenery in front of the vehicle is complicated (because there are many buildings, trees, etc.). A position that has been previously found to be inappropriate as the background of navigation information. When the current position of the host vehicle corresponds to the predetermined position, the drawing map image generated by the drawing map image generation unit 82 is selected as the background image of the navigation information (S112). This is because the image captured by the front camera 10 is not appropriate as the background of the navigation information at such a position.

  If the current position of the host vehicle does not correspond to the predetermined position, it is determined whether or not the complexity of the captured image of the front camera 10 is equal to or greater than a predetermined value (S102; condition 2). When the complexity is equal to or greater than a predetermined value, the drawing map image generated by the drawing map image generation unit 82 is selected as the background image of the navigation information (S112). This is because when the complexity is greater than or equal to a predetermined value, the captured image of the front camera 10 is not appropriate as the background of the navigation information.

  When the complexity is less than a predetermined value, it is determined whether or not there is a shield on the course of the host vehicle (S104; Condition 3). Here, the shielding object refers to a large building, mountain, hill, or the like that makes it impossible to visually recognize the curved road ahead when the traveling direction of the host vehicle is curved. The map information stored in the memory 40 is referred to for the traveling direction of the host vehicle being curved and the position coordinates of the building or the like. When there is an obstruction on the course of the host vehicle, the drawing map image generated by the drawing map image generation unit 82 is selected as the background image of the navigation information (S112). This is because, in a scene where a curved road ahead cannot be visually recognized due to the presence of an obstruction, it is better to display the drawn map image as illustrated in FIG. .

  When there is no shielding object on the course of the host vehicle, it is determined whether or not the current weather is bad weather (S106; condition 4). The current weather is acquired using the communication device 50. Or you may estimate the weather using the output value of the sensor etc. which detect the operating condition of the wiper of the own vehicle, and the light quantity outside a vehicle. If the current weather is bad weather, the drawing map image generated by the drawing map image generation unit 82 is selected as the background image of the navigation information (S112). This is because when it is raining or snowing, it is difficult to visually recognize the scenery in front of the vehicle, and the captured image of the front camera 10 is not appropriate as the background of the navigation information.

  If the current weather is not bad, it is determined whether or not the vehicle is traveling on a bad road (S108; Condition 5). Whether or not the vehicle is traveling on a rough road is determined by referring to the output value of the G sensor 60. For example, it is determined whether or not the vehicle is traveling on a rough road by applying a predetermined threshold value to the vibration frequency and the vibration amplitude per predetermined time of the vertical acceleration of the vehicle. If the vehicle is traveling on a rough road, the drawing map image generated by the drawing map image generation unit 82 is selected as the background image of the navigation information (S112). This is because when the vehicle is traveling on a rough road, the captured image of the front camera 10 is blurred and is not appropriate as a background of navigation information.

  And when negative determination is acquired in any of S100-S108, the picked-up image of the front camera 10 is selected as a background image of navigation information.

  The route guide unit 85 generates a recommended route from the current position of the host vehicle specified by the current position specifying unit 81 to the destination input by the user using the HMI 30, and is selected by the background image selection unit 84. The display device 70 is controlled to display the navigation information superimposed on the image (see FIG. 4). In addition, at a branch point or the like, the speaker of the HMI 30 is controlled so that voice guidance is performed.

  As described above, the background image selection unit 84 appropriately determines whether or not the captured image of the front camera 10 is suitable as the navigation information according to the determination procedure illustrated in FIG. As a result, as long as the visibility and the contrast with the navigation information can be ensured, the captured image of the front camera 10 is used as the background image of the navigation information, and in other scenes, the drawn map generated by the drawn map image generating unit 82 The image becomes the background image of the navigation information. Therefore, the driver can grasp the situation ahead of the vehicle more accurately.

  According to the vehicle-mounted navigation device 1 of the present embodiment, it is possible to appropriately select which of the captured image of the front camera and the drawn map image generated by the drawn map image generation unit 82 is to display the navigation information superimposed.

  Note that the flowchart of FIG. 3 is merely an example, and some of the above conditions 1 to 5 may be arbitrarily selected, and a drawn map image may be selected when any of the selected conditions is met. Good. For example, a drawn map image is selected when the current position of the host vehicle corresponds to a predetermined position, or when there is an obstacle on the course of the host vehicle. A selection procedure for selecting an image may be used. If it is not determined whether the weather is bad during the selection procedure, the communication device 50 is not an essential configuration. Further, when it is not determined whether the vehicle is traveling on a rough road, the G sensor 60 is not an essential configuration.

  Moreover, it is good also as what selects some conditions among the said conditions 1-5 arbitrarily, and selects a drawing map image, when it corresponds to all the selected conditions. For example, a drawn map image is selected when the current position of the host vehicle corresponds to a predetermined position and the complexity of the captured image of the front camera 10 is equal to or greater than a predetermined value, and otherwise, the captured image of the front camera 10 A selection procedure such as selecting

  Further, at night when it is difficult to visually recognize the front of the vehicle, other conditions such as selecting a drawn map image generated by the drawn map image generation unit 82 may be added (as an or condition or an or condition). ).

  The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. And substitutions can be added.

  For example, when navigation information is superimposed and displayed on the captured image of the front camera 10, unnecessary image elements (electric poles, electric wires, etc.) in the captured image may be assimilated to the background color (see FIG. 5). Regarding the recognition of the electric wire in the captured image, for example, a straight line (curve) having a certain area or less in consideration of sagging can be recognized as the electric wire. Alternatively, an image pattern composed of utility poles and electric wires may be stored in the memory 40 in advance, and when a similar pattern is found in the captured image, it may be assimilated to the background color.

  The present invention can be used in the automobile manufacturing industry, the automobile parts manufacturing industry, and the like.

It is a figure which shows an example of the whole structure of the vehicle-mounted navigation apparatus. It is a figure which shows a mode that a drawing map image is produced | generated. It is a flowchart which shows the flow of the characteristic process which the background image selection part 84 performs regarding selection of a background image. It is a figure which shows a mode that navigation information is superimposed and displayed on the image which the background image selection part 84 selected. It is a figure which shows a mode that the unnecessary image element in the captured image of the front camera 10 is assimilated with a background color.

Explanation of symbols

1 On-vehicle navigation device 10 Front camera 20 GPS antenna 30 HMI
40 memory 50 communication device 60 G sensor 70 display device 80 navigation computer 81 current position specifying unit 82 drawn map image generating unit 83 image analyzing unit 84 background image selecting unit 85 route guiding unit

Claims (9)

An imaging means for imaging a landscape in front of the vehicle; a map information generating means for generating a drawing map image based on the map information stored in advance in the map information storage means and the current position of the vehicle acquired by the current position acquisition means; And display means for performing a display visible in the passenger compartment,
An in-vehicle navigation device that displays navigation information superimposed on the display unit using a captured image of the imaging unit or the drawn map image as a background image,
Driving environment acquisition means for acquiring the driving environment of the vehicle;
Background image selection means for selecting which of the captured image of the imaging means and the drawn map image is to be displayed with the navigation information superimposed based on the traveling environment of the vehicle acquired by the traveling environment acquisition means;
An in-vehicle navigation device comprising: The in-vehicle navigation device according to claim 1,
The traveling environment acquisition means includes the current position acquisition means,
The background image selection means includes
While the navigation information is being superimposed and displayed on the captured image of the imaging means, the map information is referred to using the current position of the vehicle acquired by the current position acquisition means, and the current position of the vehicle is the map. A means for switching display contents of the display means so that navigation information is superimposed and displayed on the drawn map image when the information corresponds to a predetermined position set in advance in the information;
Car navigation system. The in-vehicle navigation device according to claim 2,
The predetermined position is a position in a downtown area.
Car navigation system. The in-vehicle navigation device according to any one of claims 1 to 3,
The traveling environment acquisition unit is a unit that performs captured image analysis of the imaging unit and acquires an analysis result obtained by the captured image analysis as a traveling environment.
The background image selection means includes
While the navigation information is superimposed and displayed on the captured image of the imaging unit, the captured image of the imaging unit displays the navigation information superimposed by a predetermined determination method based on the analysis result acquired by the traveling environment acquisition unit. The display means so that the navigation information is superimposed and displayed on the drawn map image when it is determined that the captured image is not suitable for the superimposed display of the navigation information. It is a means to switch display contents.
Car navigation system. The in-vehicle navigation device according to claim 4,
The traveling environment acquisition unit is a unit that derives the complexity of the captured image of the imaging unit and acquires it as a traveling environment,
The predetermined determination method is a method of determining that the captured image is not suitable for displaying navigation information in a superimposed manner when the complexity acquired by the traveling environment acquisition unit is greater than or equal to a reference level.
Car navigation system. The in-vehicle navigation device according to any one of claims 1 to 5,
The travel environment acquisition means is a means capable of detecting the presence of a shield present on the course of the vehicle,
The background image selection means includes
Navigation information is displayed on the drawn map image when the traveling environment acquisition means detects the presence of an obstacle present on the course of the vehicle while the navigation information is superimposed on the captured image of the imaging means. Is a means for switching the display content of the display means so as to be superimposed.
Car navigation system. The in-vehicle navigation device according to any one of claims 1 to 6,
The travel environment acquisition means is means capable of acquiring weather information,
The background image selection means includes
While navigation information is superimposed on the captured image of the imaging unit, navigation information is superimposed and displayed on the drawn map image when the information indicating that the driving environment acquisition unit is in bad weather is acquired. And means for switching the display content of the display means.
Car navigation system. The in-vehicle navigation device according to any one of claims 1 to 7,
The traveling environment acquisition unit is a unit capable of detecting a road surface state,
The background image selection means includes
While the navigation information is being superimposed and displayed on the captured image of the imaging unit, the navigation information is superimposed and displayed on the drawn map image when the driving environment acquisition unit detects that the vehicle is traveling on a rough road. The means for switching the display content of the display means,
Car navigation system. The in-vehicle navigation device according to any one of claims 1 to 8,
When the background image selection unit selects a captured image of the imaging unit, a process of associating an unnecessary image element included in the captured image of the imaging unit with a background color is performed.
Car navigation system.

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