JP2005291732A - Navigation device, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device for performing highly accurate calculation and display on the position of an own vehicle. <P>SOLUTION: This navigation device comprises: a first vehicle speed detection part for calculating own vehicle speed through the processing of vehicle speed pulses performed by a vehicle speed detection part provided in the navigation device equipped with the function of displaying the present position of a movable body based on previously provided road map data; a second vehicle speed detection part comprising an image data processing part for processing image data obtained from a camera attached to the own vehicle at its prescribed position and a vehicle speed calculation part for calculating vehicle speed from data obtained by the data processing part; and a vehicle speed correction part for correcting a vehicle speed found by the first vehicle speed detection part by using a vehicle speed found by the second vehicle speed detection part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a navigation technology, that is, a navigation device, a method, and a navigation program, which are improved to improve the accuracy of the vehicle position displayed on a map by improving the detection accuracy of the vehicle speed.

  In recent years, with the generalization of automobiles and the development of information processing technology, navigation devices represented by in-vehicle use are rapidly spreading. This navigation device uses the road map data stored in a DVD, HDD, etc. to detect the current position (latitude, longitude, etc.) of the vehicle that is sequentially detected by a geomagnetic sensor, a vehicle speed sensor, a GPS sensor, etc. In addition to displaying above, based on the route data included in the road map data, it calculates the optimal guidance route from the current position to the specified destination, and guides it with specific display or voice synthesis. is there.

  Such a navigation apparatus is generally configured as shown in FIG. 4, and is an autonomous system that calculates the own vehicle position based on other navigation methods that measure the own vehicle position by a GPS receiver and detection values of various sensors. By combining with navigation, map matching on the map is developed to display the vehicle position.

  That is, the absolute position / orientation detection unit 1 calculates the absolute position coordinates and direction on the ground surface with respect to the current position of the automobile (referred to as the own vehicle) on which the navigation device is mounted, that is, the own vehicle position. For example, it is a part for receiving GPS radio waves transmitted from GPS satellites with an antenna or a receiver. The relative azimuth detection unit 2 is a part for detecting the relative azimuth of the host vehicle using a gyroscope or the like. Moreover, the vehicle speed detection part 3 is a part which calculates the speed of the own vehicle by processing the vehicle speed pulse obtained from a motor vehicle.

  The main CPU and its peripheral circuit 4 are parts that serve as a control circuit that controls the entire navigation device. The memory group M is various memories necessary for the operation of the navigation apparatus. For example, the ROM 5 for storing programs is accessed by the main CPU when the apparatus is activated. A main program is loaded into a dynamic RAM (DRAM) 6 that provides a work area and the like.

  An SRAM (static RAM) 7 is a storage means for acquiring and storing various settings such as the current position, destination, route, and information included in the road map data, and a display VRAM (video RAM) 8. Is means for storing bitmap data of an image to be displayed on the display unit 10.

  The display unit 10 is a part that displays various types of information such as a map, an operation menu, a search list, and point information on a liquid crystal display screen (not shown). The voice output means can be used together with the guidance by the synthesized voice. The input unit 11 is a part for a user to input information such as a command from a switch, and the user interface unit 9 uses an I / O control circuit, a device driver, or the like to display the display unit 10 and the input unit. 11 and a user interface that connects the main CPU and its peripheral circuit 4.

  The HDD control unit 12 is means for reading various data such as a navigation program recorded in a hard disk (mass storage device) from a database. The FM multiplex reception and processing unit 13 is a part that receives FM broadcast waves and extracts desired data such as VICS service traffic information from the broadcast waves, and the traffic information includes traffic jam information. The optical / radio wave beacon reception and processing unit 14 is a part that receives and processes information such as identification information of each beacon and traffic information of the VICS service from an optical beacon or a radio beacon installed on a shoulder or the like.

  Further, the main CPU and its peripheral circuit 4 are configured to realize the roles as the following parts shown in FIG. That is, the current position detection unit 40 is means for sequentially calculating the own vehicle position, and specifically, is configured to calculate the own vehicle position by combining GPS navigation positioning and autonomous navigation positioning. .

  Here, in GPS navigation positioning, the current position is calculated using information obtained by the absolute position / orientation detection unit 1 based on radio waves from an artificial satellite. In the autonomous navigation positioning, the current position is calculated using information obtained from the relative bearing detection unit 2 and the vehicle speed detection unit 3 based on the geomagnetism and the speed of the host vehicle.

  The destination designation unit 41 is means for receiving designation of a destination, that is, input by facility search from a database in which the road map data is recorded or cursor designation on a map. The route setting unit 42 calculates a route from the current position detected by the current position detecting unit 40 to the destination specified by the destination specifying unit 41 based on the road map data, and obtains the result. It is a means for setting a given route.

  In addition, the map display unit 43 displays a map around the vehicle position or a map displayed in a wide area on the display unit 10 in a three-dimensional display or other manner based on the calculated vehicle position, route, and road map data. It is means to do.

  The guidance control unit 44 is a means for controlling guidance guidance by determining elements to be displayed in the route, elements such as blinking emphasis, and using combined speech. That is, the current position detection unit 40, the route setting unit 42, the map display unit 43, and the guidance control unit 44 are based on the road map data read from the HDD control unit 12 and are routed to the designated destination. Navigation means for searching for and guiding guidance.

Further, Patent Document 1 separately filed by the present applicant discloses a technique relating to correction of a dead reckoning positioning solution in a navigation system.
JP 2002-2131979 A

However, in the conventional navigation apparatus as described above, the vehicle position may not be displayed correctly for the reasons described below.
In other words, the GPS receiver is difficult to receive radio waves from satellites in a densely built-up area or under a highway, which causes a deterioration in positioning accuracy. Furthermore, there is a problem that positioning cannot be performed because radio waves cannot be received in the tunnel.

  Further, when traveling on highways and toll roads, the speed of the traveling vehicle is high, and the display position of the positioning result is delayed with respect to the actual vehicle position. Further, the vehicle speed sensor has a problem in that the distance characteristic accuracy with respect to the vehicle speed is lowered because the vehicle speed pulse output varies depending on the road surface condition and the tire condition.

  If the vehicle position shift due to such a cause (here, “displacement” is “shift” with respect to the map) is a certain amount of shift, the map is positioned to the correct position on the map by positioning the vehicle position on the map. The result is a convergent display that results in a problem-free display.

  However, in a situation where the vehicle is traveling on a general road, for example, an intersection or the like is used as a link node point that is a target of map matching. Since a parking area or an interchange is used as the link node point, the number of link node points is smaller than that of a general road. As a result, the accuracy of the map matching process may be reduced.

  For example, as shown in FIG. 5, when traveling on a highway or traveling on a densely built building, the actual vehicle position (in the figure, road It is often found that map matching is performed on a position (upper circle position) on the display that is considerably shifted (triangle position on the road in the figure). As described above, the vehicle position is erroneously displayed on the map, thereby causing various problems to the user. It goes without saying that such a problem can occur even when traveling on a general road.

  The present invention has been proposed to solve the above-described problems of the prior art, and its purpose is to correct a vehicle speed error by a vehicle speed sensor based on information obtained by a camera attached to the vehicle body. Accordingly, it is an object of the present invention to provide a highly useful navigation technology, that is, a navigation device, a method, and a program, which can calculate and display the position of the vehicle by highly accurate autonomous navigation (dead reckoning).

In order to achieve the above object, a navigation device according to claim 1 is a navigation device having at least a dead reckoning positioning function using a vehicle speed pulse and a satellite positioning function using GPS, and is equipped with the navigation device. In a navigation device that displays a current position of a moving object based on road map data prepared in advance using a computer or an electronic circuit,
A photographing means is attached to the moving body at a predetermined position, and a vehicle speed detection unit that detects a vehicle speed of the moving body calculates a vehicle speed of the moving body from data obtained from a predetermined vehicle speed sensor. A detection unit; an image data processing unit that processes image data of a subject for travel distance confirmation obtained from the photographing unit; and a vehicle speed calculation that calculates a vehicle speed of the moving body from the data obtained by the image data processing unit A second vehicle speed detection unit, and a vehicle speed correction unit that corrects the vehicle speed obtained by the first vehicle speed detection unit to the vehicle speed obtained by the second vehicle speed detection unit. Features.

The navigation method according to claim 4 captures the invention according to claim 1 from the viewpoint of the method, and uses at least a dead reckoning positioning function using vehicle speed pulses and a satellite positioning function using GPS. In the navigation method of displaying the current position of the moving body with the photographing means attached at a predetermined position based on road map data prepared in advance using a computer or an electronic circuit,
The vehicle speed detecting step for detecting the vehicle speed of the moving body includes a first vehicle speed detecting step for calculating the vehicle speed of the moving body from data obtained from a predetermined vehicle speed sensor, and a travel distance confirmation subject obtained from the photographing means. Obtained in the second vehicle speed detecting step and the first vehicle speed detecting step including a step of calculating the vehicle data of the moving body from the data obtained by the image data processing. And correcting the vehicle speed to the vehicle speed obtained in the second vehicle speed detection step.

  A navigation program according to a seventh aspect captures the invention according to the first and fourth aspects from the viewpoint of a computer program, and the current position of a moving body having a photographing means attached at a predetermined position, In a navigation program to be displayed based on road map data prepared in advance by controlling a computer, the computer calculates a first vehicle speed for the moving object from data obtained from a predetermined vehicle speed sensor, and the imaging Image data of a subject for travel distance confirmation obtained from the means is processed, a second vehicle speed for the moving body is calculated from the data obtained by the image data processing, and the first vehicle speed is calculated using the first vehicle speed. The vehicle speed is corrected to 2.

  According to the invention described in claims 1, 4, and 7 as described above, when an error occurs in the vehicle speed calculated based on the detection value of the vehicle speed sensor or the like by the first vehicle speed detection unit. However, since the vehicle speed is appropriately corrected based on the higher-accuracy vehicle speed obtained by the second vehicle speed detector, it is possible to reduce the error in the vehicle position due to dead reckoning.

  According to a second aspect of the present invention, in the navigation device according to the first aspect, the subject for confirming the travel distance is a white line portion / no white line portion provided on a road, and processing in the image data processing unit However, both ends of the white line portion are extracted, and the length of the white line portion and the time for which the moving body passes through both ends of the white line portion are measured.

  The invention according to claim 5 captures the invention according to claim 2 from the viewpoint of the method, and in the navigation method according to claim 4, the subject for checking the travel distance is provided on a road. The processing of the image data extracts both ends of the white line portion, and measures the length of the white line portion and the time for the moving body to pass through both ends of the white line portion. It is characterized by being.

  The invention according to claim 8 is the one in which the invention according to claim 2 and claim 5 is captured from the viewpoint of a computer program. In the navigation program according to claim 7, the subject for checking the travel distance is The white line portion / no white line portion provided on the road, and the image data processing extracts both ends of the white line portion, and the moving body passes through the length of the white line portion and both ends of the white line portion. It is characterized by measuring the time to perform.

  In the inventions according to claims 2, 5 and 8 described above, the vehicle speed with higher accuracy can be obtained by using the white line portion / no white line portion provided on the road as the object for confirming the travel distance. Can be detected.

  According to a third aspect of the present invention, in the navigation device according to the first aspect, the subject for travel distance confirmation is a distance confirmation member provided in the vicinity of a road, and the processing in the image data processing unit includes: It is characterized in that it measures the travel distance from the first distance confirmation member to the last distance confirmation member and the time required to travel between them.

  The invention described in claim 6 is obtained by capturing the invention described in claim 3 from the viewpoint of the method, and in the navigation method according to claim 4, the subject for checking the travel distance is provided in the vicinity of the road. A distance confirmation member, and the processing of the image data includes the distance traveled from the first distance confirmation member to the last distance confirmation member, and the time required to travel between them. It is a thing to measure.

  The invention described in claim 9 is obtained by capturing the invention described in claims 3 and 6 from the viewpoint of a computer program. In the navigation program according to claim 7, the subject for checking the travel distance is A distance confirmation member provided in the vicinity of the road, in which the processing of the image data travels between and the distance traveled from the first distance confirmation member to the last distance confirmation member as the measurement target It is characterized in that it measures the time required for.

  In the inventions according to claims 3, 6, and 9 as described above, a more accurate vehicle speed is detected by using a distance confirmation member provided in the vicinity of the road as a subject for confirming the travel distance. can do.

  According to the present invention as described above, based on the information obtained by the camera attached to the vehicle body, the vehicle speed error by the vehicle speed sensor is corrected, the vehicle position is calculated by highly accurate autonomous navigation (dead reckoning), and It is possible to provide a navigation technique, a navigation device, a method, and a program that enable display and is highly useful.

  Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be specifically described with reference to the drawings. In addition, although this embodiment is realizable by controlling the computer provided with the peripheral device by the program, the implementation | achievement aspect of the hardware and program in this case can be variously changed. In addition to the navigation apparatus and method, the present invention can be grasped as a program as described above and a computer-readable storage medium storing such a program. Therefore, in the following description, virtual circuit blocks that implement the functions of the present invention and this embodiment are used.

[1. Constitution〕
The present invention is an improvement of the configuration of the vehicle speed detection unit in the conventional navigation apparatus shown in FIG. 4, and is configured as shown in FIG. The other configuration is the same as that of the conventional type shown in FIG.

  That is, the vehicle speed detection unit 30 is obtained from the first vehicle speed detection unit 31 that calculates the speed of the host vehicle by processing the vehicle speed pulse obtained from the automobile body, and the camera C attached to a predetermined position of the host vehicle. Image data processing unit 321 for processing the image data to be processed, and data obtained by this image data processing unit 321, for example, the time when the vehicle passes through both ends of the white line part, or the average value and the length of the white line part The vehicle speed calculated by the second vehicle speed detection unit 32 including the vehicle speed calculation unit 322 for calculating the vehicle speed and the first vehicle speed detection unit 31 is corrected to the vehicle speed calculated by the second vehicle speed detection unit 32. Vehicle speed correction unit 33.

  In the present embodiment, a white line portion provided on the road or a travel distance confirmation signboard or the like is used as a travel distance confirmation subject, and these are photographed by the camera C installed in front of the vehicle. The vehicle speed can be obtained by measuring the time passing through the vehicle. Note that the installation location of the camera is not particularly limited as long as it is a position where the subject for confirming the travel distance can be captured.

  That is, as shown in FIG. 2, when there are two or more lanes on one side of an expressway or toll road, a center line indicating the boundary between the center of the road or between adjacent lanes is installed. ing. Usually, such a center line is provided with white line portions and white line portions having a predetermined length alternately. The lengths of the white line portion and the white line portion are determined based on the standard. For example, on a toll road, the length of the white line portion is 12 meters and the length of the white line portion is 8 meters. .

  When traveling on a road where such a center line is installed, when the white line portion of the center line is detected from the image entering the field of view by the camera C installed in front of the vehicle, the second line An image data processing unit 321 provided in the vehicle speed detection unit 32 acquires the image data, detects both ends of the white line portion, and measures a time Ta during which the vehicle passes through both ends. Since the calculation accuracy is low with only one white line, a predetermined number (n times) is measured, and the average time, Ta ave = (Ta1 + Ta2 + Ta3 +... + Tan) / n is calculated. Subsequently, the vehicle speed calculation unit 322 calculates the vehicle speed from the calculated average time and the length of the white line portion.

  Note that when the vehicle travels a short distance, the vehicle speed error caused by the first vehicle speed detection unit 31 that measures the vehicle speed in the same manner as the conventional method has a significant effect on displaying the current position of the vehicle on a map. Since the correction process that is frequently performed also leads to a decrease in performance of other processes (for example, map drawing on the screen, etc.), the process of correcting the vehicle speed obtained from the first vehicle speed detection unit 31 is as follows: It is configured to be performed every time a predetermined distance set arbitrarily is traveled.

  In addition, if a sudden change in vehicle speed occurs during measurement, the data is invalid. As a result, even when an error occurs in the vehicle speed calculated based on the detection value of the vehicle speed sensor or the like, the correction of the vehicle speed is performed as appropriate, so that it is possible to reduce the error in the vehicle position due to dead reckoning. Become.

  Further, as described above, not only the white line portion can be used as a subject for travel distance confirmation, but also a distance confirmation signboard provided near the road can be used. For example, the above-mentioned means cannot be employed in a place where the center line is not a white line / no white line, such as a one-lane road. Accordingly, in that case, a distance confirmation sign provided on the side of the road or the like may be captured by the camera.

  In this case, unlike the white line of the center line, the distance confirmation sign is installed only at a certain distance, so that when the vehicle speed by this sign is detected, the correction process is immediately executed. It is configured as follows.

[2. Action)
Details of the processing of the vehicle speed detection unit 30 in the navigation device of the present embodiment having the above-described configuration will be described with reference to the flowchart of FIG.
First, when the vehicle is traveling on the center line composed of the white line portion / no white line portion as described above or a road on which a sign for distance confirmation is installed, the field of view is obtained by the camera C installed in front of the vehicle. When either the white line part of the center line or the distance confirmation sign is detected from the video entering inside, the image data processing unit 321 provided in the second vehicle speed detection unit 32 acquires the image data ( Step 301). In step 302, it is determined whether the detected line is a white line or a distance check sign. If a white line is detected, the process proceeds to step 303, and if a distance check sign is detected. Proceeds to step 310.

  Subsequently, it is determined whether the detected white line portion or no white line portion (step 303). When the detected white line portion is detected, both ends of the white line portion are detected, the time Ta during which the vehicle passes through both ends is measured (step 304), and the measurement result is stored (step 305).

  Next, it is determined whether or not the predetermined number of times has been measured (step 306). If the predetermined number of times has not yet been reached, the process returns to step 303 and the processes of steps 303 to 306 are repeated. On the other hand, if the predetermined number of times (n times) is measured, the process proceeds to step 307, and the average time is calculated from the stored data for n times. That is, Ta ave = (Ta1 + Ta2 + Ta3 +... + Tan) / n is calculated. Then, the vehicle speed is calculated from the average time and the length of the white line portion (step 308), and the vehicle speed obtained from the first vehicle speed detector 31 is corrected (step 309).

  If the detected sign is the sign for distance confirmation in step 302, the character drawn on the sign for distance confirmation is recognized and stored, and the first sign for distance confirmation to be measured is obtained. The travel distance from the first to the last sign for confirming the distance and the time required to travel between them are measured (step 310), the measurement result is stored (step 311), and then the process returns to step 308. The process of 309 is performed.

[3. effect〕
According to the present embodiment as described above, even when an error occurs in the vehicle speed calculated by the first vehicle speed detection unit 31 based on the detection value of the vehicle speed sensor or the like, the second vehicle speed detection unit 32 obtains the error. Since the vehicle speed is appropriately corrected based on the higher-accuracy vehicle speed, it is possible to reduce the error in the vehicle position due to dead reckoning.

[4. Other embodiments]
Note that the present invention is not limited to the above-described embodiment, and the distance (length) is fixedly apparent as a travel distance confirmation subject to be subjected to vehicle speed calculation in the second vehicle speed detection unit 32. If there is a proper installation, it may be captured as a target.

  Further, the present invention can be applied to a so-called off-board type navigation system in which the latest data is provided via a wireless communication network instead of the so-called on-board type in which navigation data is placed in the vehicle. It is. In this case, a server outside the vehicle connected via the communication network can perform all or part of the above processing, and the processing result is reduced by the in-vehicle computer to acquire the processing result. be able to. In addition, this invention is not limited to vehicle-mounted use, It is applicable also to another moving means and portable navigation.

The functional block diagram which shows the structure of the navigation apparatus which concerns on this invention. The figure which shows the imaging state by the camera attached to the vehicle body. The flowchart which shows the procedure of the process in the navigation apparatus which concerns on this invention. The functional block diagram which shows the structure of the conventional navigation apparatus. The figure which shows the condition where "deviation" arose with the actual own vehicle position and the own vehicle position on a display in the conventional navigation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Absolute position and direction detection part 2 ... Relative direction detection part 3 ... Vehicle speed detection part 4 ... Main CPU and its peripheral circuit 5 ... ROM
6 ... DRAM
7 ... SRAM
8 ... VRAM
DESCRIPTION OF SYMBOLS 9 ... User interface part 10 ... Display part 11 ... Input part 12 ... HDD control part 13 ... FM multiplex reception and processing part 14 ... Light / radio wave beacon reception and processing part 30 ... Vehicle speed detection part 31 ... First vehicle speed detection part 32 ... second vehicle speed detection unit 321 ... image data processing unit 322 ... vehicle speed calculation unit 33 ... vehicle speed correction unit 40 ... current position detection unit 41 ... destination designation unit 42 ... route setting unit 43 ... map display unit 44 ... guidance control unit M ... Memory group

Claims (9)

A navigation device having at least a dead reckoning positioning function using a vehicle speed pulse and a satellite positioning function using GPS,
In a navigation device that displays the current position of a mobile unit equipped with the navigation device based on road map data prepared in advance using a computer or an electronic circuit,
The moving body is attached with a photographing means at a predetermined position,
A vehicle speed detection unit that detects the vehicle speed of the moving body,
A first vehicle speed detector that calculates the vehicle speed of the moving body from data obtained from a predetermined vehicle speed sensor;
An image data processing unit that processes image data of a subject for travel distance confirmation obtained from the photographing unit, and a vehicle speed calculation unit that calculates the vehicle speed of the moving body from the data obtained by the image data processing unit. A second vehicle speed detector;
A vehicle speed correction unit that corrects the vehicle speed obtained by the first vehicle speed detection unit to the vehicle speed obtained by the second vehicle speed detection unit;
A navigation device comprising: The subject for checking the travel distance is a white line portion / no white line portion provided on the road,
The processing in the image data processing unit extracts both ends of the white line portion, and measures the length of the white line portion and the time for which the moving body passes through both ends of the white line portion. Item 4. The navigation device according to Item 1. The object for confirming the travel distance is a distance confirmation member provided near the road,
The processing in the image data processing unit is to measure the travel distance from the first distance confirmation member to the last distance confirmation member, and the time required to travel between them. The navigation device according to claim 1, wherein A navigation method using at least a dead reckoning positioning function using a vehicle speed pulse and a satellite positioning function using GPS,
In a navigation method for displaying the current position of a moving object having a photographing means attached at a predetermined position based on road map data prepared in advance using a computer or an electronic circuit,
A vehicle speed detecting step for detecting the vehicle speed of the moving body is as follows:
A first vehicle speed detection step of calculating a vehicle speed of the moving body from data obtained from a predetermined vehicle speed sensor;
A second vehicle speed detecting step including a step of processing image data of a subject for traveling distance confirmation obtained from the photographing means, and a step of calculating a vehicle speed of the moving body from the data obtained by the image data processing; When,
Correcting the vehicle speed determined in the first vehicle speed detecting step to the vehicle speed determined in the second vehicle speed detecting step;
A navigation method comprising: The subject for checking the travel distance is a white line portion / no white line portion provided on the road,
5. The processing of the image data includes extracting both ends of the white line portion and measuring a length of the white line portion and a time required for the moving body to pass through both ends of the white line portion. The navigation method described in 1. The object for confirming the travel distance is a distance confirmation member provided near the road,
The processing of the image data is to measure a travel distance from a first distance confirmation member to a last distance confirmation member that is a measurement target, and a time required to travel between them. The navigation method according to claim 4. In a navigation program for displaying the current position of a moving body with a photographing means attached at a predetermined position based on road map data prepared in advance by controlling a computer,
In the computer,
Calculating a first vehicle speed for the moving body from data obtained from a predetermined vehicle speed sensor;
Processing the image data of the subject for travel distance confirmation obtained from the photographing means, and calculating the second vehicle speed for the moving body from the data obtained by the image data processing;
A navigation program for correcting the first vehicle speed to the second vehicle speed. The subject for checking the travel distance is a white line portion / no white line portion provided on the road,
8. The processing of the image data includes extracting both ends of the white line portion and measuring a length of the white line portion and a time required for the moving body to pass through both ends of the white line portion. The navigation program described in. The object for confirming the travel distance is a distance confirmation member provided near the road,
The processing of the image data is to measure a travel distance from a first distance confirmation member to a last distance confirmation member that is a measurement target, and a time required to travel between them. The navigation program according to claim 7.

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