JP2007040844A - On-vehicle navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle navigation device capable of providing high-quality guidance information to drivers. <P>SOLUTION: The on-vehicle navigation device, implementing guidance to display on a displaying section by superimposing content information on landscape imageries ahead, is equipped with an image acquiring section 6 acquiring landscape imageries of landscape ahead photoed with a camera; a landscape information filtering section 8 which discriminates landscape images that are suitable as a background images from landscape images acquired at the image acquiring section to output landscape information containing the discriminated landscape images and information used for deciding whether it is suitable as the background image; a landscape information accumulating section accumulating landscape information outputted from the landscape information filtering section; an optimal landscape information selecting section 10 selecting landscape information, on which content information is superimposed, from landscape information accumulated in the landscape information accumulating section; and a content combining section 11 for combining the landscape imageries included in landscape information selected at the optimal landscape information selecting section and content information to display on displaying section as guidance information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle navigation device that displays guidance information on a landscape image in front of a vehicle.

  Conventionally, an on-vehicle display that displays a landscape image in front of a vehicle photographed by a vehicle-mounted camera on a vehicle-mounted display and displays a separately-created guidance arrow on the landscape image. Navigation devices are known. For example, Patent Document 1 discloses an in-vehicle navigation device that provides guidance by displaying an arrow graphic indicating a course at an intersection where a driver should travel on a landscape image including an intersection in front of a vehicle photographed by an in-vehicle camera. A driving guidance image display method is disclosed.

  Further, Patent Document 2 discloses the direction of shooting of the in-vehicle camera when the guidance is given to the driver by superimposing an arrow graphic indicating the course of the driver on a landscape image in front of the vehicle captured by the in-vehicle camera. A vehicle front image capturing device and a vehicle guidance display device that acquire a desired front image by directing in a direction along a road shape instead of a traveling direction of a vehicle when changing or traveling on a curve are disclosed.

  Furthermore, Patent Document 3 is equipped with a plurality of in-vehicle cameras when guiding the driver by displaying an arrow graphic indicating the driver's path superimposed on a landscape image in front of the vehicle photographed by the in-vehicle camera. Thus, a vehicle travel guide device is disclosed that switches a vehicle-mounted camera to be used and obtains a desired forward image when a front landscape is obstructed by a front vehicle.

JP-A-7-63572 Japanese Patent Laid-Open No. 10-287177 Japanese Patent Laid-Open No. 11-023305

  By the way, in the case where information for various guidance for the driver is superimposed and displayed at a corresponding position on the landscape image in front of the vehicle photographed by the camera, there are the following problems regarding the superposition.

  If the landscape image taken by the camera is blurred due to the vibration of the vehicle, turning left and right, turning of the vehicle due to unevenness on the road surface, etc., guidance is provided by other traveling vehicles appearing in the landscape image When the target to be hidden is hidden, the background image on which the guidance information is superimposed may be inappropriate, for example, when the guidance target is not clearly photographed due to rain, snow, nighttime, backlight, or the like. Such a landscape image is called an “inappropriate image”.

  In addition, the degree of accuracy of the position and posture of the vehicle calculated by the vehicle position detection unit built in the vehicle-mounted navigation device and / or the accuracy of the position and posture of the camera measured by the camera position and posture measurement unit. Depending on the degree, the information for guidance and guidance superimposed on the landscape image may deviate from the originally superimposed position. This is called “inappropriate position and orientation”.

  Furthermore, although the composition of a landscape image as an optimal background can be considered depending on the type of information such as guidance and guidance provided to the driver, the acquired landscape image may not satisfy the composition. This is called “inappropriate composition”. The driver is always required to provide high-quality information that avoids the above-described inappropriate image, inappropriate position and orientation, and inappropriate composition as much as possible.

  In a conventional in-vehicle navigation device, in an acquired landscape image, an object to be superimposed, such as an intersection, is hidden or not photographed due to the presence of another vehicle or the traveling direction of the own vehicle, or superimposed even if photographed. In order to avoid taking inappropriate landscape images for driver guidance, such as the display target being the peripheral part of the image, as shown in Patent Document 2 and Patent Document 3 described above, A control device that controls the shooting direction or a plurality of cameras are provided.

  However, these methods are expensive because it is necessary to install a camera control device and multiple cameras, but only inappropriate landscape images can be taken due to weather conditions such as shooting under backlight, snowfall, or rain. The effect is very limited.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an in-vehicle navigation device capable of providing high-quality guidance information to a driver.

  The in-vehicle navigation device according to the present invention is an in-vehicle navigation device that performs guidance by superimposing content information on a front landscape image and displaying the content information on a display unit, and acquires a landscape image obtained by capturing the front landscape with a camera. Information that is selected from the landscape image acquired by the image acquisition unit and the landscape image suitable for the background image and used for determining whether the image is suitable for the background image. Landscape information filter unit that outputs image, a landscape information storage unit that stores landscape information output from the landscape information filter unit, and a landscape that is optimal for superimposing content information from the landscape information stored in the landscape information storage unit The optimal landscape information selection unit for selecting information and the landscape image included in the landscape information selected by the optimal landscape information selection unit are combined with the content information. To and a content combining unit for displaying on the display unit as guidance information.

  According to the present invention, a background image suitable for superimposing content information to be presented to a user can be overlaid with high-accuracy content from landscape images accumulated as a result of traveling in the past. Since an appropriate landscape image such as a landscape image or a landscape image having a desirable composition for providing information can be selected, the quality of the guidance information provided to the driver can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing the configuration of the in-vehicle navigation device according to Embodiment 1 of the present invention. This in-vehicle navigation device includes a navigation control unit 1, a vehicle position detection unit 2, a map database 3, an input operation unit 4, a camera 5, a video acquisition unit 6, a camera position / orientation measurement unit 7, a landscape information filter unit 8, and landscape information. The storage unit 9, the optimum landscape information selection unit 10, the content composition unit 11, and the display unit 12 are included.

  The navigation control unit 1 controls the entire in-vehicle navigation device. For example, the navigation control unit 1 calculates a guidance route from the current position of the vehicle acquired from the vehicle position detection unit 2 to the destination input from the input operation unit 4 with reference to the map database 3. Processing for providing basic functions for guiding the driver to the destination, such as calculation and generation of guidance information along the guidance route obtained by the calculation, is performed.

  In addition, the navigation control unit 1 searches for traffic information related to the current position of the vehicle, the destination or the guidance route, information on sightseeing spots, restaurants, merchandise stores, etc., and searches for facilities that match the conditions entered by the user. The process is performed. Further, the navigation control unit 1 displays information (hereinafter referred to as “content information”) representing content to be provided to the user in a superimposed manner on a landscape image, such as an arrow graphic, for example, the landscape information filter unit 8, the optimum landscape information. This is provided to the selection unit 19 and the content composition unit 11.

  The own vehicle position detection unit 2 detects the current position and posture of the own vehicle. The vehicle position detection unit 2 uses, for example, GPS (Global Positioning System), D-GPS (differential GPS) that corrects the positioning result by GPS using error information provided by FM multiplex broadcasting, or other artificial satellites. Based on the constraints such as positioning method, position information supplied from optical beacon and radio wave beacon installed on the road, autonomous navigation to obtain the position from the traveling direction and distance of the vehicle, and the vehicle traveling on the road Various position detection methods such as a map matching method for correcting the vehicle position to the road position registered in the map database 3 can be realized by combining one or two or more. Information representing the current position and posture of the vehicle detected by the vehicle position detection unit 2 is sent to the navigation control unit 1, the camera position / orientation measurement unit 7, and the landscape information filter unit 8.

  The map database 3 stores 3D shape information, 3D landscape information, and facility information in addition to 2D map information. The three-dimensional shape information includes information obtained by modeling a three-dimensional shape such as a ground, a terrain such as a pond, a lake, a mountain, and a valley, a building, a structure such as a road, a railway overpass, and a tunnel. The three-dimensional landscape information consists of information obtained by adding data relating to the color and image of the surface constituting the three-dimensional shape to the three-dimensional shape information. The facility information includes information such as the position, name, telephone number, and address of structures, facilities, and tourist attractions. The map database 3 is referred to by the navigation control unit 1 and the camera position / orientation measurement unit 7.

  The input operation unit 4 includes a remote controller, a touch panel, a voice recognition device, and the like, and is used for a driver or a passenger who is a user to input a destination or to select information provided by an in-vehicle navigation device. Is done. Information indicating the destination and selection result input from the input operation unit 4 is sent to the navigation control unit 1.

  The camera 5 is installed at a predetermined position of the vehicle and captures a landscape in front of the vehicle. A video signal obtained by photographing with the camera 5 is sent to the video acquisition unit 6. The video acquisition unit 6 converts the video signal sent from the camera 5 into image information that can be processed by a computer. The landscape image represented by the image information obtained by the conversion in the video acquisition unit 6 is sent to the camera position / orientation measurement unit 7 and the landscape information filter unit 8.

  The camera position / orientation measurement unit 7 includes information indicating the position and orientation of the camera 5 in a coordinate system with reference to the vehicle, and the latitude and longitude of the vehicle obtained from the vehicle position detection unit 2. The position and orientation of the camera 5 in the ground surface coordinate system are calculated using information representing the position and orientation of the vehicle in the ground surface coordinate system. Information representing the position and orientation of the camera 5 in the coordinate system of the ground surface (hereinafter referred to as “camera position and orientation information”) calculated by the camera position and orientation measurement unit 7 is a landscape information filter unit 8 and an optimum landscape information selection unit. 10 is sent.

  The camera position / orientation measurement unit 7 is provided with a function for performing image recognition processing on a landscape image sent as image information from the video acquisition unit 6 so that a center line, a stop line, and a building on the road in the landscape image are displayed. By extracting a contour and the like, and further performing a matching process with road information and three-dimensional shape information acquired from the map database 3, it is possible to improve the measurement accuracy of the position and orientation of the camera 5.

  The landscape information filter unit 8 includes content information obtained from the navigation control unit 1 and camera position and orientation information obtained from the camera position and orientation measurement unit 7 (if image recognition processing is performed, accuracy correction by the image recognition processing is performed). Information indicating the state), information indicating the position and posture of the host vehicle obtained from the host vehicle position detection unit 2 and accuracy thereof, and image information of a landscape image serving as a background to superimpose content from the video acquisition unit 6 To get. Using this information, it is possible to properly overlay this landscape image, the quality of the landscape image itself, whether the subject to be superimposed is taken, whether it is desirable as a composition, etc. Are selected, landscape images satisfying these determination criteria are selected, the selected landscape images and information used as the determination criteria are set as one set, and stored as landscape information in the landscape information storage unit 9. Details of the processing performed in the landscape information filter unit 8 will be described later.

  The optimum landscape information selection unit 10 matches or approaches the content information and the position and orientation of the camera 5 based on the content information obtained from the navigation control unit 1 and the camera position and orientation information obtained from the camera position and orientation measurement unit 7. The landscape information to be searched is searched from the landscape information storage unit 9, the most suitable landscape image is selected and sent to the content composition unit 11. Details of processing performed in the optimum landscape information selection unit 10 will be described later.

  The landscape information storage unit 9 organizes and stores the landscape information in which the landscape image selected by the landscape information filter unit 8 and the information used as the selection criterion are arranged as one set. In response to the request, the corresponding landscape information is searched and sent to the optimum landscape information selection unit 10 on condition that the position and orientation of the camera 5 and the content information match or approach each other.

  The content synthesizing unit 11 synthesizes the content information obtained from the navigation control unit 1 and the image information representing the landscape image using the optimal landscape information selected by the optimal landscape information selecting unit 10, and sends it to the display unit 12. . The display unit 12 is composed of, for example, a liquid crystal panel, and in accordance with the information sent from the content synthesis unit 11, displays a superimposed image of various guidance and guidance content on the landscape image and presents it to the driver. To do.

  Next, an example of landscape information filter processing performed in the landscape information filter unit 8 will be described with reference to the flowchart shown in FIG. In the landscape information filtering process described below, as acquisition information, as shown in FIG. 3, “acquisition time”, “landscape image”, “camera position and orientation”, “degree of accuracy of camera position and orientation”, It is assumed that “content information” and “composition evaluation value” are used.

  First, the latest landscape information, that is, landscape information at the current time is constructed (step ST11). Specifically, first, the current time is acquired from a clock mechanism (not shown), and a landscape image is acquired from the video acquisition unit 6. Next, camera position and orientation information is acquired from the camera position and orientation measurement unit 7. Next, information used to calculate the vehicle position obtained from the vehicle position detection unit 2 and information used to correct the camera position and posture by image recognition processing obtained from the camera position and orientation measurement unit 7. From this, the degree of accuracy of the camera position and orientation is calculated as follows.

That is, when measuring the position and orientation of the vehicle using GPS, a vehicle speed sensor, a direction sensor, and map matching, the number of satellites used for positioning by GPS is ns, and the direction change speed measured by the direction sensor is Sd (deg / sec). In general, the accuracy of the position and orientation of the camera 5 increases as the number of satellites used increases. When the direction changes, such as when turning left or right or turning, the direction sensor measurement time is delayed or map matching is performed. This is considered to be low due to the characteristics of Also, a value indicating whether or not the camera position and orientation can be corrected by the image recognition processing in the camera position and orientation measurement unit 7 is Cc (“1” if corrected, “0” if not corrected). Using these values, the accuracy Ccp of the camera position and orientation is obtained according to the following equation (1).
Ccp = k * ns−1 * Sd + m * Cc (1)
Here, k, l, and m are parameters for adjusting the influence on Ccp, and are adjusted by the system designer. By these parameters k, l and m, fine adjustment of the degree of accuracy of the camera position and orientation is performed.

  Next, the landscape information filter unit 8 receives the content information from the navigation control unit 1, that is, the type of information to be presented to the driver (for example, the direction of turning to an intersection, guidance for a store in a building, guidance for a distant mountain or lake) Etc.) and the position (for example, latitude, longitude, altitude) based on the target ground surface indicated by the type. The information acquired or calculated as described above is constructed as landscape information having a structure as shown in FIG.

  When the construction of the landscape information described above is completed, the landscape information is then stored in a primary storage location for use in later processing (step ST12). The primary storage location preferably has a structure in which landscape information for the past several minutes to several tens of minutes is stored and deleted in order from the oldest.

  Next, the degree of accuracy is checked (step ST13). That is, first, the accuracy Ccp of the camera position and orientation included in the landscape information is extracted and compared with a constant Acc that is a predetermined threshold value. In this comparison, when the camera position / posture accuracy degree Ccp is equal to or less than the constant Acc, that is, when the camera position / posture accuracy degree Ccp is less accurate than the reference, step ST14 for the landscape information is performed. To ST19 are not performed, and the landscape information filter process is terminated.

  The above-described constant Acc can be configured to be determined by trial and error of the system developer, noting that the operation result of the optimum landscape information selection unit 10 is affected. Moreover, it can also comprise so that the driver | operator who is a user may input from the input operation part 4. FIG. Further, the constant Acc can be properly used depending on the type of content information. By passing through this step ST13, in step ST14 and subsequent steps, processing is performed only for landscape information in which the position and posture of the camera 5 are somewhat accurate.

  If it is determined in step ST13 that the degree of accuracy Ccp of the camera position and orientation is larger than the constant Acc, image determination processing is then performed (step ST14). That is, in this image determination process, it is determined whether or not the quality of the image information constituting the landscape information has reached a certain level as a material for superimposition. Details of the image determination processing in step ST14 will be described with reference to the flowchart shown in FIG.

  In the image determination process, first, brightness distribution calculation is performed (step ST21). That is, paying attention to the brightness of each pixel constituting the landscape image included in the current landscape information to be processed, statistical values such as a median value and a variance value for the entire landscape image are calculated. Next, it is checked whether or not the brightness distribution is appropriate (step ST22). When the median calculated in step ST21 is extremely bright, the image is too bright, when the median is extremely dark, the image is too dark, and when the variance is extremely small, the contrast is low. It is determined that it is not appropriate as a landscape image. If it is determined in this step ST22 that the brightness distribution is not appropriate, it is stored that the result of the image determination is NG (step ST23), and then the sequence returns to step ST15 in FIG. In this way, the system designer can select a landscape image as an appropriate material by adjusting the threshold values for these statistical values.

  If it is determined in step ST22 that the brightness distribution is appropriate, brightness distribution correction processing is performed (step ST24). As described above, by excluding extremely bad image information (landscape image) and correcting an image having an appropriate brightness distribution, the quality of the image information can be improved. In this example, the statistical processing of brightness is performed on a pixel-by-pixel basis. However, in addition to this, various existing image processing techniques are used to improve quality by eliminating or correcting poor quality images. Can be configured.

  Next, blur calculation is performed (step ST25). The “blurring” in the first embodiment is caused by the turning of the own vehicle or the unevenness of the road surface even if the image becomes unclear due to the vibration or turning of the own vehicle in which the camera 5 is installed. This is when the landscape image moves greatly. As described above, when the landscape image moves greatly, the result of measuring the position and orientation of the camera 5 is often obtained later than the actual movement of the own vehicle, and as a result, There is a time lag between the position and orientation of the camera 5 and a situation where a display lag is likely to occur during superimposed display.

  In step ST25, in order to detect such a situation, image recognition processing is performed on the past landscape image stored in step ST12 of the flowchart shown in FIG. 2 and the image being processed. Then, the degree of movement of the corresponding characteristic point between the two images is calculated. Then, a statistical value such as the average value or median value of the calculated movement amount of the corresponding feature point is used as the blur evaluation point. If the corresponding point cannot be recognized, the evaluation score is the lowest score.

  In addition to using the image recognizing process described above, for example, these blurring states are also estimated by measuring a vehicle state such as a turning angle of a steering wheel or a displacement state of a suspension supporting each wheel. It is possible. In this case, the magnitude of the turning angle of the steering wheel, the average value of the displacement amount or the displacement speed of the suspension, and the like can be used as the evaluation points for blurring.

  Next, it is checked whether or not the blur is within an allowable range (step ST26). That is, it is checked whether or not the blur evaluation score calculated in step ST24 is greater than or equal to a predetermined threshold value. If it is determined in step ST26 that the blur is not within the allowable range, the sequence proceeds to step ST23, and as described above, the fact that the result of the image determination is NG is stored, and then the sequence is as shown in FIG. Return to step ST15 of the flowchart shown in FIG.

  On the other hand, if it is determined in step ST26 that the blur is within the allowable range, then it is stored that the result of the image determination is OK (step ST27), and then the sequence is the step of the flowchart shown in FIG. Return to ST15.

  In step ST15 of the flowchart shown in FIG. 2, it is checked whether the image information is appropriate. That is, based on the image determination result obtained in step ST14, it is determined whether or not the image information constituting the current landscape image is appropriate as a material. If it is determined that the image information is not appropriate, the process from step ST16 to step ST19 is not performed on the landscape information, and the landscape information filter process ends.

On the other hand, if it is determined in step ST15 that the image information is appropriate, then target concealment determination processing is performed (step ST16). In the target concealment determination process, a process for determining whether or not the image information includes a target on which content information is superimposed (hereinafter referred to as “target”) is performed. This process has the following process pattern.
(A) A fixed building such as that stored in advance in the map database 3 is present in front of the content position, so that the target cannot be seen. (B) The content position deviates from the viewing angle of the camera 5. (C) When the target is concealed by a dynamically changing object such as a surrounding car (d) When the field of view is concealed by snowfall or rain on the windshield

  Regarding (a) and (b) above, the position of the content and the camera position and orientation, the geometric calculation based on the three-dimensional shape data of other buildings, or the position and the camera position and orientation of the content, and the viewing angle of the camera 5 Judgment can be made by geometrical calculation. Further, (c) and (d) can be detected by an image recognition method for the video from the camera 5. For example, using the image information of the past landscape information and the current landscape information for a certain period stored in step ST12, the correspondence between the feature points between the image information is clarified. If the movement of the feature point between the image information and the movement of the camera position and posture are combined, the movement of the feature point relating to the static building corresponds to the movement of the camera position and posture.

  On the other hand, since the movement of the feature point related to the other vehicle in (c) is also affected by the movement of the other vehicle itself, it does not correspond only to the movement of the camera position and posture. Such a region including feature points that cannot be explained by the movement of the host vehicle can be regarded as the presence of another vehicle. For (d), since the image is fixed without being affected at all by the camera position and orientation, such a region can also be specified. If the position of the content matches the area identified in (c) and (d), it can be determined that the other vehicle is hiding.

  In this case, the target concealment is determined using an image recognition method. However, the present invention is not limited to this. For example, the vehicle includes a sensor such as a radar device, and the detection result by the sensor is displayed. It can also be configured to determine whether or not the target is concealed.

  Next, based on the result of the target concealment determination process in step ST16, it is checked whether or not the target is concealed (step ST17). Here, if it is determined that the target is concealed, the process of step ST18 and step ST19 is not performed on the landscape information, and the landscape information filter process is terminated.

On the other hand, if it is determined in step ST17 that the target is not concealed, composition evaluation processing is then performed (step ST18). That is, the quality of the composition is quantified as an evaluation point of the composition from the distance between the position of the content to be superimposed and the camera position and the position of the target on the image. For example, when guiding a left or right turn at an intersection, it is desirable that the camera 5 captures the center of the intersection in the center of the image and includes a building around the intersection for the landmark in the image. Therefore, on the image, the distance on the screen between the center of the intersection and the center of the image is p in terms of the number of pixels. The evaluation point E of the composition is calculated using the following equation (2), where Dbest is the optimum distance between the camera 5 and the object (in this case, the center of the intersection), and D is the actual distance between the camera 5 and the object. To do.
E = k * p + (1-k) | D-Dbest | ... (2)
Here, k is determined in consideration of an evaluation score of an appropriate composition within a range of 0 <k <1. The smaller the evaluation score E, the better the composition.

  In the case of buildings and shops around the road, it is important to get close enough to recognize the target, or in the case of landmarks such as mountains and lakes, it is far away. The system developer adjusts k and Dbest in the above formula (2) according to the type of information to be presented and the size of the target. The evaluation point E of this composition is stored in the landscape information as shown in FIG.

  Next, the landscape information created by the above-described processing is stored in the landscape information storage unit 9 (step ST19). Thus, the landscape information filter process in the landscape information filter unit 8 ends.

  The landscape information filtering process in the landscape information filter unit 8 can be performed periodically at regular intervals. Moreover, it can also comprise so that it may implement at the timing which the image | video acquisition part 6 acquired the image | video.

  Next, details of the optimum landscape information selection process performed by the optimum landscape information selection unit 10 will be described with reference to the flowchart shown in FIG.

  First, based on the camera position / orientation information representing the current camera position and orientation obtained from the camera position / orientation measurement unit 7 and the content information obtained from the navigation control unit 1, a plurality of available landscape information is stored in the landscape information storage unit. 9 is selected and read (step ST31). In other words, the optimal landscape information selection unit 10 acquires the current camera position and posture that are close within a certain range from the landscape information that matches the target. This range can be determined after adjusting an appropriate value.

  Next, from the plurality of read landscape information, the one having the best composition evaluation point is selected as the best landscape information (step ST32). In step ST31, in addition to past landscape information that is very close to several seconds ago, for example, landscape information accumulated when a similar guidance is given several months ago may be obtained. As the optimal landscape information, the distant past landscape information may not be frequently switched between the near past landscape information and the distant past landscape information. It can be configured to be used only when it is not visible at night. The best landscape information selected in step ST32 is sent to the content composition unit 11 as a processing result of the optimum landscape information selection unit 10, and the content is synthesized based on this best landscape information and provided to the user.

  The optimum landscape information selection unit 10 can be configured to repeatedly execute the optimum landscape information selection process at a predetermined cycle. Moreover, it can also be configured such that the content displayed by the navigation control unit 1 is changed, the timing at which the video acquisition unit 6 acquires the video, or a combination thereof.

  As described above, according to the in-vehicle navigation device according to the first embodiment of the present invention, the background image suitable for superimposing the content information to be presented to the user is accumulated as a result of traveling in the past. From the landscape image, it is possible to select an appropriate landscape image such as a landscape image capable of overlaying highly accurate content and a landscape image having a desirable composition for providing information, so that the quality of the guidance information provided to the driver can be improved. Can be increased.

Embodiment 2. FIG.
The in-vehicle navigation device according to the first embodiment described above is configured to provide high-quality information that avoids “inappropriate image”, “inappropriate position and orientation”, and “inappropriate composition”. The in-vehicle navigation device according to the second embodiment further avoids inappropriate image updating.

  During driving, the driver usually has to monitor the surroundings directly around the front of the vehicle, and it is dangerous to watch the image of the in-vehicle navigation device. Therefore, it is necessary to control the update cycle of the landscape image in order to update the image frequently like a moving image and avoid attracting the driver's attention to the screen more than necessary (inappropriate image update). Therefore, in the in-vehicle navigation device according to the second embodiment, in addition to the “inappropriate image”, “inappropriate position and orientation”, and “inappropriate composition” shown in the first embodiment, “Update” is also controlled so that it can be avoided.

  The configuration of the in-vehicle navigation device according to the second embodiment is the same as the configuration of the in-vehicle navigation device according to the above-described first embodiment except for the processing performed by the optimum image information selection unit 10. Hereinafter, only the optimum image information selection process executed by the optimum image information selection unit 10 will be described.

  FIG. 6 is a flowchart showing details of the optimum image information selection process performed by the optimum image information selection unit 10 of the in-vehicle navigation device according to the second embodiment. Step ST31 and step ST32 are the same as the processing shown in the flowchart of FIG. That is, first, based on the camera position / orientation information indicating the current camera position and orientation obtained from the camera position / orientation measurement unit 7 and the content information obtained from the navigation control unit 1, a plurality of available landscape information is obtained as landscape information. It is selected and read from the storage unit 9 (step ST31). Next, from the plurality of read landscape information, the one having the best composition evaluation point is selected as the best landscape information (step ST32).

  Next, the adoption time Tdisp of the scenery currently used is acquired (step ST33). This time Tdisp is the time when the optimum landscape information selection unit 10 updates the landscape information. Next, it is checked whether or not the difference between the current time t and the time Tdisp exceeds the minimum image update time Tmin (step ST34). The latest image update time Tmin is provided in order to prevent frequent image update, and a value such as 1 second or 5 seconds is given in advance. The value of the latest image update time Tmin can be configured to be set by the driver.

  If it is determined in step ST34 that the difference between the current time t and the time Tdisp exceeds the minimum image update time Tmin, then the best landscape information selected in step ST32 is the optimum landscape information selection unit 10's optimum. Adopted as landscape information (step ST35), the adopted optimal landscape information is provided to the content composition unit 11. Also, the current time t is substituted for the time Tdisp. Thus, the optimum landscape information selection process ends. If it is determined in step ST34 that the difference between the current time t and the time Tdisp does not exceed the minimum image update time Tmin, the process in step ST35 is skipped, and the optimum landscape information selection process ends.

  As described above, according to the vehicle-mounted navigation device according to Embodiment 2 of the present invention, the overlay accuracy is high, and the overlay display of the desired composition can be provided to the driver at the desired update cycle.

Embodiment 3 FIG.
FIG. 7 is a diagram showing a configuration of a navigation system including an in-vehicle navigation device according to Embodiment 3 of the present invention. This navigation system includes a plurality of in-vehicle navigation devices and a center 19 that are respectively mounted on a plurality of automobiles A16, B17, and C18.

  Since the configurations of the in-vehicle navigation devices mounted on the automobiles A16, B17, and C18 are the same, only the in-vehicle navigation device mounted on the automobile A16 will be described below. The in-vehicle navigation device mounted on the automobile A16 is configured by adding the communication unit 13 to the in-vehicle navigation device according to the first embodiment. The communication unit 13 controls communication between the in-vehicle navigation device and the center 19. Specifically, the communication unit 13 transmits the landscape information stored in the landscape information storage unit 9 to the center 19 and receives the landscape information transmitted from the center 19 and stores it in the landscape information storage unit 9. .

  The center 19 includes a communication unit 14 and a common landscape information storage unit 15. The communication unit 14 controls communication between the center 19 and the in-vehicle navigation devices mounted on the automobiles A16 to C18. Specifically, the communication unit 14 transmits the landscape information stored in the common landscape information storage unit 15 to the in-vehicle navigation device mounted on each of the cars A16 to C18, and the onboard mounted on each of the cars A16 to C18. The landscape information sent from the navigation device is received and stored in the common landscape information storage unit 15.

  The communication between the communication unit 13 and the communication unit 14 described above is performed by wireless such as a wireless LAN or a cellular phone, light such as infrared rays transmitted and received between an optical beacon installed on the road side, the Internet, a dedicated line, etc. It can be performed using a cable or a combination of these.

  In the in-vehicle navigation device according to the third embodiment of the present invention configured as described above, the landscape information filter unit 8 and the optimum landscape information selection unit 10 perform the same processing as that described in the first embodiment. However, the landscape information stored in the landscape information storage unit 9 is sent to the common landscape information storage unit 15 of the center 19 at regular intervals or triggered by the timing at which the engine is started or the communication path is secured.

  If the landscape information requested by the optimal landscape information selection unit 10 does not exist in the landscape information storage unit 9, the landscape information provided by another vehicle is acquired from the common landscape information storage unit 15, and the optimal landscape information selection unit 10 Provided to. Such acquisition of the landscape information stored in the common landscape information storage unit 15 can be performed when necessary. In addition, when a communication path is secured, scenery information that is likely to be required in the future route is collectively acquired from the common scenery information accumulation unit 15 and stored in the scenery information accumulation unit 9. It can also be configured. Furthermore, it is also possible to obtain landscape information from the common landscape information storage unit 15 according to an operation by the driver and store it in the landscape information storage unit 9.

  As described above, according to the in-vehicle navigation device according to the third embodiment, the in-vehicle navigation devices of a plurality of automobiles store the landscape information in the center 19, and the in-vehicle navigation devices of each automobile are stored in the center 19. The vehicle-mounted navigation device installed in each vehicle uses the landscape information stored in the center 19 by other vehicles, even for local landscapes that have never traveled. By doing so, it is possible to display the content superimposed on the landscape image.

It is a block diagram which shows the structure of the vehicle-mounted navigation apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the procedure of the landscape information filter process performed in the landscape information filter part of the vehicle-mounted navigation apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the example of the structure of the landscape information used with the vehicle-mounted navigation apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the detail of the image determination process performed by step ST14 of FIG. It is a flowchart which shows the procedure of the optimal landscape information selection process performed in the optimal landscape information selection part of the vehicle-mounted navigation apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the procedure of the optimal scenery information selection process performed in the optimal scenery information selection part of the vehicle-mounted navigation apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the vehicle-mounted navigation apparatus which concerns on Embodiment 3 of this invention, and a navigation system using the same.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation control part, 2 Own vehicle position detection part, 3 Map database, 4 Input operation part, 5 Camera, 6 Image | video acquisition part, 7 Camera position and orientation measurement part, 8 Landscape information filter part, 10 Optimal scenery information selection part, 11 Content composition unit, 12 display unit, 13 communication unit, 14 communication unit, 15 common landscape information storage unit, 16 car A, 17 car B, 18 car C, 19 center.

Claims (5)

In an in-vehicle navigation device that performs guidance by superimposing content information on a front landscape image and displaying it on a display unit,
A video acquisition unit for acquiring a landscape image obtained by photographing the landscape in front with a camera;
A landscape image suitable as a background image is selected from the landscape image acquired by the video acquisition unit, and landscape information including the selected landscape image and information used to determine whether the image is suitable as a background image is output. A landscape information filter section
A landscape information storage unit for storing landscape information output from the landscape information filter unit;
An optimal landscape information selection unit for selecting optimal landscape information for superimposing the content information from the landscape information stored in the landscape information storage unit;
A vehicle-mounted navigation device comprising: a content synthesis unit that synthesizes a landscape image included in the landscape information selected by the optimum landscape information selection unit and the content information and displays the synthesized information as guidance information on the display unit. A vehicle position detector for detecting the position and posture of the vehicle;
A camera position and orientation measurement unit that measures the position and orientation of the camera;
A navigation control unit that provides content information,
The landscape information filter section
From the landscape image acquired by the video acquisition unit, the position and orientation of the own vehicle detected by the own vehicle position detection unit, the position and orientation of the camera measured by the camera position and orientation measurement unit, and the navigation control unit The vehicle-mounted navigation device according to claim 1, wherein a landscape image suitable as a background image is selected based on each state of the content provided from. The optimal landscape information selection section
Selecting optimal landscape information for superimposing content information based on content information provided from a navigation control unit and information representing a camera position and orientation measured by a camera position and orientation measurement unit The in-vehicle navigation device according to claim 2.   The optimal landscape information selection unit selects and updates the optimal landscape information for superimposing content from the landscape information stored in the landscape information storage unit at a period of a predetermined time or more. The vehicle-mounted navigation device according to 1. 2. The communication device according to claim 1, further comprising: a communication unit that transmits the landscape information stored in the landscape information storage unit to the outside, and receives the landscape information from the outside and stores it in the landscape information storage unit. 4. The in-vehicle navigation device according to 4.

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