JP2006153565A - In-vehicle navigation device and own car position correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the own vehicle position highly accurately even when the state where reception of a signal from a GPS satellite is difficult continues. <P>SOLUTION: When a dashed-line lane mark is laid on a traveling road where the own vehicle is traveling, an image including the dashed-line lane mark is photographed by an in-vehicle camera, and the dashed-line interval of the dashed-line lane mark is measured by performing image recognition processing of the image photographed by the in-vehicle camera, and the number of unit lines passed by the own vehicle is counted. Then, a mileage of the own vehicle is calculated based on the dashed-line interval of the dashed-line lane mark and the number of passed unit lines, and the own position is corrected based on the calculated mileage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle navigation device that guides the traveling of a vehicle while displaying a mark or the like representing the vehicle position on a map, and in particular, the vehicle position detected using a GPS (Global Positioning System) receiver or the like. The present invention relates to a technique for correcting errors.

In an in-vehicle navigation system that guides the driving of the vehicle while displaying a mark representing the vehicle position on the map, the detection of the absolute position using a positioning system such as GPS (Global Positioning System), the wheel speed sensor, In general, a vehicle position can be detected with high accuracy by combining with a travel position estimation technique based on self-contained navigation using a steering angle sensor, a gyro sensor, or the like. In such an in-vehicle navigation device, for example, when the vehicle is traveling in the vicinity of a tunnel, mountain road, or high-rise building, it is difficult to receive a signal from a GPS satellite with a GPS receiver. In such a place, the position of the own vehicle is detected only by self-contained navigation (see, for example, Patent Document 1).
JP-A-9-280877

  By the way, when the position of the own vehicle is detected only by the self-contained navigation, due to the detection error of the wheel speed sensor, the variation in tire size, etc. It tends to decrease. For this reason, in the conventional technology including the above-described Patent Document 1, when a situation where it is difficult to receive a signal from a GPS satellite continues, the distance between the travel distance calculated by the self-contained navigation and the actual travel distance. An error of about several tens of meters may occur, and as a result, the mark of the vehicle position superimposed on the map is greatly deviated from the actual position, which is a big obstacle in properly guiding the vehicle's travel There was a problem of becoming.

  The present invention was devised to solve the above-described problems of the prior art, and even when the situation where it is difficult to receive signals from GPS satellites continues, the position of the vehicle is increased. It is an object of the present invention to provide an in-vehicle navigation device and a vehicle position correction method that can detect with high accuracy and can appropriately guide the traveling of the vehicle.

  In the present invention, in order to achieve the above object, when a broken line lane mark is laid on the traveling road on which the vehicle is traveling, an image including the broken line lane mark is captured by the in-vehicle camera, Based on the image taken by the camera, the distance between the broken lines, which is the length from the leading position of one unit line constituting the broken lane mark to the leading position of the next adjacent unit line, is measured, and the own vehicle Counting the number of unit lines passed by the vehicle, and calculating the travel distance of the vehicle based on the distance between the broken lines measured based on the images taken by these in-vehicle cameras and the number of unit lines counted Yes. Then, based on the calculated travel distance, the vehicle position detected by the vehicle position detection means is corrected.

  According to the present invention, the travel distance of the vehicle is calculated by image recognition processing using an image photographed by the in-vehicle camera, and the host vehicle position detected by the host vehicle position detection unit is corrected based on the calculated travel distance. Therefore, if the detection error of the own vehicle position detection means is large, for example, a GPS receiver is used as the own vehicle position detection means, and the vehicle continuously detects areas where it is difficult to receive signals from GPS satellites. Even when the vehicle is running, the vehicle position can be detected with high accuracy. Therefore, according to the present invention, it is possible to effectively avoid the problem that the mark of the vehicle position superimposed on the map due to the detection error of the vehicle position greatly deviates from the actual position, and appropriately guide the traveling of the vehicle. be able to.

  Hereinafter, a specific embodiment of an in-vehicle navigation device to which the present invention is applied will be described in detail with reference to the drawings.

  The in-vehicle navigation device of the present embodiment guides the traveling of the vehicle while displaying a mark representing the position of the vehicle on a map in a superimposed manner, and in particular, a broken lane on the traveling path on which the vehicle is traveling When the mark is laid, the image is taken, and the vehicle's position is corrected by calculating the mileage of the vehicle through image recognition processing. Can be performed.

  FIG. 1 is a diagram illustrating a schematic configuration of the in-vehicle navigation device of the present embodiment. As shown in FIG. 1, the in-vehicle navigation device of the present embodiment includes a control unit 11 that comprehensively controls each unit, an in-vehicle camera 12 that captures an image of the traveling path of the host vehicle, and a GPS (Global Positioning System) GPS receiver 13 for receiving signals from satellites, various sensor groups 14 constituting a self-contained navigation system, a map storage unit 15 for storing map data, an input device 16 as a user interface, and various information The display control part 17 which performs display control of this, and the display 18 which displays various information as a navigation screen are provided.

  The control unit 11 is configured as a microcomputer in which peripheral circuits such as a CPU, a ROM, a RAM, and an input / output interface are connected via a bus, and the CPU uses the RAM as a work area and is stored in the ROM. By executing this program, the respective units in the in-vehicle navigation of this embodiment are comprehensively controlled. In the in-vehicle navigation device, the control unit 11 controls the respective units in this way, thereby displaying a map display function for displaying a mark representing the vehicle position superimposed on a map image around the vehicle position, Various navigation functions such as a route search function for searching for an optimum route to reach the destination and a route guidance function for performing various guidance so that the vehicle can travel along the searched route are realized. Become.

  In particular, in the in-vehicle navigation device of the present embodiment, the control unit 11 performs an image recognition process using an image including a dashed lane mark photographed by the in-vehicle camera 12, and calculates the travel distance of the vehicle. Processing such as correcting the position of the host vehicle using information on the calculated travel distance of the host vehicle is also performed. Specifically, when an image including a broken lane mark is sent from the in-vehicle camera 12, the control unit 11 extracts the broken lane mark from the image by a known edge detection process or the like. Then, the extracted broken lane mark is analyzed, and a broken line interval that is a length from the leading position of one unit line constituting the broken lane mark to the leading position of the next adjacent unit line is measured. (Measuring means). In addition, the control unit 11 recognizes the relative movement of the lane mark with respect to the traveling of the host vehicle from images continuously sent from the in-vehicle camera 12, and counts the number of unit lines that the host vehicle has passed (counting). means). Then, the travel distance of the host vehicle is calculated based on the measured information on the distance between the broken lines and the information on the number of passing unit lines counted (the travel distance calculation means), and the calculated travel distance information is used to calculate the position of the host vehicle. Correction is performed (vehicle position correction means). Details of the travel distance calculation process and the vehicle position correction process by the control unit 11 will be described later.

  The in-vehicle camera 12 is composed of, for example, a CCD (Charge Coupled Device) camera, a CMOS (Complementary Metal Oxide Semiconductor) camera, or the like, and an appropriate position of the vehicle body of the own vehicle so that an image of the traveling road on which the own vehicle is traveling can be taken. Is attached. The photographing of the image by the in-vehicle camera 12 is controlled by the control unit 11. For example, when the reception sensitivity of the GPS receiver 13 is deteriorated, the in-vehicle camera 12 is activated according to the control of the control unit 11, and the own vehicle travels. An image of the running road is taken. Data of images taken by the in-vehicle camera 12 is sequentially sent to the control unit 11.

  The GPS receiver 13 receives a GPS signal sent from a GPS satellite. The GPS signal includes position information and time information for determining the absolute position of the vehicle, and the GPS receiver 13 receives the GPS signal sent from the GPS satellite to determine the absolute position of the vehicle. The information is detected and the information is supplied to the control unit 11.

  The sensor group 14 detects information necessary for estimating the traveling position of the own vehicle by self-contained navigation. For example, various gyroscopes for detecting the orientation of an optical fiber gyroscope, a piezoelectric vibration gyroscope, a semiconductor gyroscope, etc. , A geomagnetic sensor, a rudder angle sensor, a vehicle speed sensor that detects a vehicle speed and a travel distance based on a vehicle speed pulse signal obtained by rotation of a wheel, and the like. Information detected by these sensor groups 14 is supplied to the control unit 11.

  The map storage unit 15 stores link data for drawing a map, node data, and other map data including various accompanying information. The map storage unit 15 includes, for example, a DVD (Digital Versatile Disc) or a hard disk. The The reading of the map data from the map storage unit 15 is controlled by the control unit 11, and the map data necessary for displaying the desired navigation screen on the display 18 is read from the map storage unit 15 as needed, and the control unit 11 is supplied.

  The input device 16 is a user interface for a user to perform an input operation, and includes, for example, a centralized switch device having operation switches and a joystick. When the user performs an operation input for instructing a desired operation using the input device 16, a control signal corresponding to the operation input is supplied to the control unit 11.

  The display control unit 17 creates display data of a navigation screen to be displayed on the display 18 under the control of the control unit 11 and supplies the display data to the display to control the display operation of the display 18. . Specifically, the display control unit 17 develops the map data read from the map storage unit 15 by the control unit 11 using a video RAM (not shown), and displays the map data on the map image drawn by the video RAM. For example, a mark indicating the position of the vehicle, a name such as a place name, a road name, a landmark that serves as a landmark, and when a travel route of the vehicle is set, various information such as a line representing the route is superimposed on the navigation screen. Create display data.

  The display 18 displays a desired navigation screen based on the display data of the navigation screen created by the display control unit 17. For example, the display 18 is a liquid crystal display (LCD) or a windshield of a vehicle body. It is comprised from the projector apparatus etc. which utilize as a screen.

  In the in-vehicle navigation device of the present embodiment configured as described above, basically, the absolute position detection based on the GPS signal received by the GPS receiver 13 and the traveling position based on the self-contained navigation based on the information from the sensor group 14. The vehicle position is detected with high accuracy in combination with the estimation of the vehicle (vehicle position detection means), but the reception sensitivity of the GPS receiver 13 deteriorates and the detection accuracy of the absolute position of the vehicle decreases. In the case where the detection of the absolute position of the vehicle itself becomes difficult, in addition to the estimation of the traveling position by the self-contained navigation, the traveling distance of the own vehicle is determined by the image recognition processing of the image captured by the in-vehicle camera 12. The vehicle position is calculated based on this calculation. Specifically, in the in-vehicle navigation device of this embodiment, when the reception sensitivity of the GPS receiver 13 is deteriorated, the control unit 11 performs a series of processes shown in FIG. I am doing so. Hereinafter, the processing of the control unit 11 executed when the reception sensitivity of the GPS receiver 13 is deteriorated will be described with reference to the flowchart of FIG.

  When it is detected that the reception sensitivity of the GPS receiver 13 has dropped below a predetermined value, the control unit 11 first activates the in-vehicle camera 12 and captures the image captured by the in-vehicle camera 12 in step S1. Capture the image of the car's driving path. And the process which extracts the lane mark which divides the lane of a driving path from the taken-in image by known methods, such as edge detection, is performed.

  Next, the control part 11 determines whether the lane mark extracted from the image of the vehicle-mounted camera 12 is a broken lane mark. If the extracted lane mark is not a dashed lane mark, or if no lane mark is extracted, the process proceeds to step S15. On the other hand, if it is determined that the lane mark extracted from the image of the in-vehicle camera 12 is a broken lane mark, the control unit 11 analyzes the broken line lane mark image in step S3 and analyzes the broken line lane mark. The distance between the broken lines, which is the length from the head position of one unit line constituting the lane mark to the head position of the next adjacent unit line, is measured.

  Usually, the format of the broken lane mark laid on the road is a predetermined format for each of the general road and the expressway. That is, as shown in FIG. 3A, the broken line lane mark on a general road is provided with unit lines having a length of 5 m at intervals of 5 m, and the next adjacent line from the head position of one unit line. The distance between the broken lines to the head position of the unit line is 10 m. On the other hand, as shown in FIG. 3B, broken line lane marks on the highway are provided with unit lines of 8 m in length at intervals of 12 m, and the distance between broken lines is 20 m.

  For example, the control unit 11 stores in advance standard patterns of such general road lane marks and expressway lane marks, and stores in advance the broken line lane marks extracted from the image of the in-vehicle camera 12. By performing pattern matching with the standard pattern of the existing lane mark, it is possible to determine whether the interval between the broken line lane marks extracted from the image of the in-vehicle camera 12 is 10 m or 20 m. . The processing for measuring the interval between the broken lines of the lane marks is not limited to such a pattern matching method, and various methods such as a method of estimating the length from the mounting angle of the in-vehicle camera 12 and the coordinate position of the image are applied. Is possible.

  As a result of the processing in step S3, when it is determined that the broken line interval between the broken lane marks extracted from the image of the in-vehicle camera 12 is 10 m (step S4), the control unit 11 next in step S5 Whether the traveling position of the vehicle is recognized on a general road, that is, whether the mark representing the vehicle position is superimposed on the general road on the navigation screen displayed on the display 18 Determine if. Here, when it is recognized that the traveling position of the host vehicle is on the highway, the host vehicle is actually traveling on a general road where lane marks are formed with a 10 m broken line interval. Regardless, since the vehicle is misrecognized as traveling on the highway, the process proceeds to step S14 to perform processing for correcting the vehicle position on the general road. On the other hand, when it is recognized that the traveling position of the host vehicle is on a general road, the control unit 11 determines the lane for the traveling of the host vehicle from images continuously sent from the in-vehicle camera 12 in the next step S6. Recognize the relative movement of the mark and count the number of unit lines that the vehicle has passed. In step S7, the travel distance of the vehicle from the start of the process is calculated based on the broken line interval of the broken lane mark measured in step S3 and the number of passing unit lines counted in step S6, and step S8. In step S7, the travel position of the host vehicle is specified using the travel distance information calculated in step S7, and the process proceeds to step S14.

  Further, when it is determined as a result of the processing in step S3 that the interval between the dashed lane marks extracted from the image of the in-vehicle camera 12 is 20 m (step S9), the control unit 11 then proceeds to step S10. In FIG. 5, whether or not the traveling position of the vehicle is recognized as being on the highway, that is, on the navigation screen displayed on the display 18, a mark representing the vehicle position is superimposed on the highway. Determine if it exists. Here, when it is recognized that the traveling position of the vehicle is on a general road, the vehicle is actually traveling on a highway on which lane marks are formed at intervals of a broken line of 20 m. Regardless, since the vehicle is misrecognized as traveling on a general road, the process proceeds to step S14 to perform processing for correcting the vehicle position on the expressway. On the other hand, when it is recognized that the traveling position of the own vehicle is on the highway, the control unit 11 determines the lane for traveling of the own vehicle from images continuously sent from the in-vehicle camera 12 in the next step S11. Recognize the relative movement of the mark and count the number of unit lines that the vehicle has passed. In step S12, the travel distance of the vehicle from the start of processing is calculated based on the broken line interval of the broken lane mark measured in step S3 and the number of passing unit lines counted in step S11, and step S13. In step S12, the travel position of the host vehicle is specified using the travel distance information calculated in step S12, and the process proceeds to step S14.

  Then, in step S14, the control unit 11 detects based on the traveling position of the own vehicle specified in step S8 or step S13 by a combination of absolute position detection by GPS and estimation of traveling position by self-contained navigation, or by self-contained navigation only. The corrected vehicle position is corrected, and mismatching of a mark representing the vehicle position on the navigation screen displayed on the display 18 is corrected. As for the correction of the vehicle position, the vehicle travel distance calculated in step S7 or step S12, that is, the travel distance calculated by the image recognition processing of the image of the broken lane mark, and the vehicle speed in the sensor group 14 are calculated. The average value of the travel distance based on the vehicle speed pulse signal detected by the sensor is obtained as the correct travel distance of the host vehicle, and the travel position of the host vehicle is specified using the travel distance information. May be corrected. In this case, the error of the travel distance calculated by the image recognition process of the image of the broken lane mark and the error of the travel distance based on the vehicle speed pulse signal can be compensated for both, and the accuracy of the vehicle position is further improved. be able to.

  The above process is continuously repeated while the reception sensitivity of the GPS receiver 13 is less than a predetermined value. Then, when the reception sensitivity of the GPS receiver 13 is restored to a predetermined value or higher (step S15), a series of vehicle position correction processing by the control unit 11 is completed.

  As described above in detail, in the in-vehicle navigation device of the present embodiment, when the reception sensitivity of the GPS receiver 13 deteriorates, the traveling of the host vehicle photographed by the in-vehicle camera 2 under the control of the control unit 11. When a road image is captured and the traveling road of the vehicle is a road with a dashed lane mark, the traveling distance of the vehicle is calculated by image recognition processing of an image captured by the in-vehicle camera 12. I am doing so. Then, using the information on the travel distance of the own vehicle calculated in this way, a combination of absolute position detection by GPS and travel position estimation by self-contained navigation, or the self-vehicle position detected only by self-contained navigation is corrected. ing. Therefore, according to the in-vehicle navigation device of the present embodiment, when the reception sensitivity of the GPS receiver 13 is deteriorated and the detection accuracy of the absolute position of the own vehicle is lowered, or the detection of the absolute position of the own vehicle is difficult. Specifically, even when the vehicle is continuously traveling in an area where it is difficult to receive signals from GPS satellites, such as in the vicinity of tunnels, mountain roads, and high-rise buildings, It is possible to detect the position with high accuracy, effectively avoiding the problem that the mark of the vehicle position superimposed on the map due to the detection error of the vehicle position greatly deviates from the actual position, and driving the vehicle Can be guided appropriately.

  Further, according to the in-vehicle navigation device of the present embodiment, the road type of the traveling road on which the vehicle is actually traveling is determined based on the broken line interval of the broken lane mark, and the vehicle is traveling on a general road. If you are misrecognizing that you are traveling on a highway, or if you are misrecognizing that you are traveling on a general road even though you are traveling on a highway, Since the position is corrected to the correct position on the road, the travel guidance of the vehicle can be performed more appropriately.

  That is, in a conventional general vehicle-mounted navigation device, for example, when the vehicle is traveling in a place where a general road and a highway are parallel, any road is limited by the limit performance of the GPS receiver. It may be difficult to determine whether you are traveling on the road, it appears on the display as if you are traveling on a highway even though you are getting off the highway and traveling on a general road, While driving on the road, the location of the vehicle was sometimes suddenly mapped to the highway. On the other hand, in the in-vehicle navigation device of the present embodiment, the image taken by the in-vehicle camera 2 is analyzed, the distance between the broken lane marks included in the image is measured, and the vehicle travels based on the measured distance. Since the road type of the running road is determined, using this information, it is possible to effectively correct mismatching to parallel roads, and to more appropriately guide the driving of the vehicle. Can do.

  The on-vehicle navigation device described above exemplifies an embodiment of the present invention, and the present invention is not limited to the above example, and various modifications are of course possible. . For example, in the on-vehicle navigation device described above, a series of processes for correcting the vehicle position is performed only when the reception sensitivity of the GPS receiver 13 is less than a predetermined value. It may be performed not only when reception sensitivity is deteriorated but also when a dashed lane mark is detected. In this case, the in-vehicle camera 2 periodically takes an image of the traveling path of the vehicle to determine whether there is a broken lane mark, or if there is lane mark information in the map data, use this What is necessary is just to start the process for correct | amending the own vehicle position by judging the lane mark of a broken line on the running path of the own vehicle. As described above, when a series of processes for correcting the vehicle position is performed not only when the reception sensitivity of the GPS receiver 13 is deteriorated but also when a broken lane mark is detected, It is possible to further improve the vehicle position detection accuracy and perform more appropriate traveling guidance of the host vehicle.

It is a block diagram which shows schematic structure of the vehicle-mounted navigation apparatus to which this invention is applied. It is a flowchart which shows the flow of a series of processes for correct | amending the own vehicle position. It is a figure explaining the standard pattern of a dashed lane mark, (a) is a figure which shows the standard pattern of the dashed lane mark in a general road, (b) is a figure which shows the standard pattern of the dashed lane mark in a highway.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Control part 12 Car-mounted camera 13 GPS receiver 14 Sensor group 15 Map memory | storage part 16 Input device 17 Display control part 18 Display

Claims (4)

Own vehicle position detecting means for detecting the own vehicle position;
When a broken lane mark is laid on the traveling road on which the vehicle is traveling, an in-vehicle camera that captures an image including the broken lane mark;
Measurement that measures the distance between broken lines, which is the length from the leading position of one unit line constituting the broken lane mark to the leading position of the next adjacent unit line, based on an image taken by the in-vehicle camera Means,
Counting means for counting the number of unit lines that the vehicle has passed, based on an image taken by the in-vehicle camera;
A travel distance calculating means for calculating a travel distance of the vehicle based on the interval between the broken lines measured by the measuring means and the number of the unit lines counted by the counting means;
An in-vehicle navigation device comprising: a vehicle position correction unit that corrects the vehicle position detected by the vehicle position detection unit based on the travel distance calculated by the travel distance calculation unit.   The in-vehicle navigation device according to claim 1, further comprising a road type determining unit that determines a road type of a traveling road on which the host vehicle is traveling based on the interval between the broken lines measured by the measuring unit. . The own vehicle position detecting means has a traveling distance detecting means for detecting a traveling distance of the own vehicle based on a vehicle speed pulse signal obtained by rotation of a wheel,
The own vehicle position correcting means calculates the own vehicle position based on an average value of the travel distance calculated by the travel distance calculating means and the travel distance based on the vehicle speed pulse signal detected by the travel distance detecting means. The in-vehicle navigation device according to claim 1, wherein correction is performed. When a broken line lane mark is laid on the traveling road on which the vehicle is traveling, a step of taking an image including the broken line lane mark with an in-vehicle camera;
A step of measuring an interval between broken lines, which is a length from the leading position of one unit line constituting the broken lane mark to the leading position of the next adjacent unit line, based on an image photographed by the in-vehicle camera. When,
Counting the number of unit lines that the vehicle has passed, based on an image captured by the in-vehicle camera;
Calculating the travel distance of the vehicle based on the measured distance between the broken lines and the counted number of unit lines;
And correcting the vehicle position detected by the vehicle position detection means based on the calculated travel distance.

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