JP2007256007A - Navigation system, and control method therefor, and control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation system, its control method, and control program that allows improvement in the accuracy of the position of own vehicle, by increasing the frequency of unit distance calculation. <P>SOLUTION: An image detecting section 41 detects road-surface characteristic objects in an image photographed by a camera 4. On the basis of this detection, an intersection decision section 52 decides whether the vehicle has entered an intersection, and stores the decision to a buffer memory. When it is decided that the vehicle has entered the intersection, a flag indicating the entry into the intersection is set. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a navigation device that can increase the frequency of calculation of a unit distance and improve the vehicle position accuracy, a control method thereof, and a control program.

  In recent years, with the development of information processing technology, navigation devices for mobile objects such as vehicles have become widespread. The navigation device uses road map data prepared in advance, for example, based on the other navigation method in which the position of the vehicle is measured by a GPS receiver and detection values of various sensors such as a gyroscope, a geomagnetic sensor, an acceleration sensor, and a vehicle speed pulse. In combination with autonomous navigation that calculates the position of the vehicle, it detects the behavior of the vehicle such as the current position, direction, and speed and displays it on the surrounding map, or calculates the route to the specified destination The information is displayed on the display device or by a synthesized voice.

Among the positioning techniques in such a navigation device, the vehicle speed pulse is mainly used for detecting the moving distance of the vehicle. That is, based on the distance per pulse (referred to as “unit distance”), the travel distance is estimated from the number of vehicle speed pulses. This unit distance is calculated by obtaining the position information of the previous intersection right / left turn point and the current intersection right / left turn point from the map information at the time of right / left turn at the intersection, calculating this section distance, the total number of vehicle speed pulses in the section Obtained from the section distance.
Japanese Utility Model Publication No. 61-50209

  In the vehicle speed sensor, since the vehicle speed pulse output varies depending on the road surface condition and the tire condition, the distance characteristic accuracy with respect to the vehicle speed is constantly reduced. That is, the unit distance per pulse changes depending on the tire replacement, the summer tire, the winter tire, the wear of the tire itself, and the like. Therefore, the unit distance re-acquisition process is always required. As described above, this re-acquisition process requires a left / right turn at an intersection, but the unit distance cannot be obtained during a long straight run, resulting in an incorrect estimated travel distance. .

  The present invention solves the problems as described above, and an object thereof is to provide a navigation device, a control method thereof, and a control program capable of increasing the frequency of unit distance calculation and improving the vehicle position accuracy. It is in.

  The present invention achieves the above object as follows. In the method and control program, “means” and “processing means” are appropriately read as “processing”.

  First, according to one aspect of the present invention (Claims 1, 4, and 7), road map data, a positioning system including vehicle speed detecting means for detecting a travel distance of a moving object, an imaging unit that images the periphery of the vehicle, and information A navigation device (a control method or a control program thereof) including a storage unit that stores road surface features in advance, and an image from the imaging unit stored in the storage unit An image detection means for detecting road surface features by collating with surface features, an intersection determination means for determining whether or not a mobile object has entered an intersection based on the detected road surface features, and this intersection determination means Means for calculating from the vehicle speed detection means the distance between the two intersections determined by the above as the first distance between the intersections, and the coordinate point stored in the road map data as the distance between the two intersections 1 in the vehicle speed detecting means based on the comparison result by the means for calculating the distance between the second intersections, the comparing means for comparing the distance between the first intersections and the distance between the second intersections. Correction means for correcting a unit distance per pulse.

  According to another aspect of the present invention (Claims 2 and 5), in the above aspect, the storage unit classifies and stores road surface features according to roadside belts, side grooves, or curbs, and the image detection. The means classifies and detects the road surface features according to their types, and the intersection determination means determines whether or not a moving body has entered the intersection for each type of road surface features. It is characterized by that.

  In this way, the side gutter, curbstone, and roadside belt are independently detected, and the vehicle approach to the intersection can be detected from each of a plurality of judgment materials, so the calculation of the unit distance using more accurate vehicle speed pulses Processing is possible, and the vehicle position accuracy can be improved.

  In addition, by detecting road surface features such as roadside belts, side grooves, curbs, etc. with a camera, the unit distance calculation process using vehicle speed pulses that could only be calculated at the time of a right or left turn at an intersection so far is straight ahead at the intersection. The calculation is possible even when passing, and the accuracy of the vehicle position can be improved by increasing the frequency of unit distance calculation. In addition, since the camera (front view / back view / side view etc.) used in the safety support apparatus can be used as the imaging means, the introduction is inexpensive and easy.

  According to another aspect of the present invention (Claims 3 and 6), in each of the above aspects, the intersection determination means determines whether or not the mobile object has entered the intersection for each type of road surface feature, and then stores it in the buffer memory. It is memorized and a flag indicating whether or not an intersection has been entered is set. Thus, the vehicle position accuracy can be improved by setting the flag based on the type of road surface feature.

  As described above, according to the present invention, by detecting road surface features such as roadside belts, gutters, and curbs with a camera, if the vehicle is traveling on the road, not only right and left turns at the intersection but also the intersection It is possible to calculate the unit distance by the vehicle speed pulse even when the vehicle travels straight ahead, and the accuracy of the vehicle position determination in navigation can be improved.

  Next, a navigation device according to the present invention (hereinafter referred to as “the present device”), a control method and a control program for the corresponding navigation device will be described with reference to the drawings.

[1. Constitution〕
The present embodiment relates to a vehicle position determination device (hereinafter also referred to as “this device”) realized integrally with a navigation device, and can be grasped as a control method and a control program thereof. As shown in the configuration diagram of FIG. 1, the present apparatus includes, as a positioning system, a GPS receiver 1 that is a current position information reception unit, a vehicle speed detector 2 that is a travel distance detection unit that uses vehicle speed pulses, and an orientation detection unit. The gyro sensor 3 is provided. The apparatus typically includes CCD cameras 4 such as front, rear, and side surfaces mounted on the vehicle as imaging means for imaging the periphery of the vehicle.

  Here, each camera 4 shoots a road surface. For example, (1) a camera that is attached to a front nose and is used for confirming an approach to an intersection with poor visibility, and (2) when the vehicle is moved back. And (3) a camera mounted on a vehicle used for a system that detects a white line on the road, detects a lane departure, and warns the driver.

  Further, the image detection unit 41 performs conversion processing of the analog input signal from the camera 4 into digital image data and detection processing of roadside features, road grooves, curbs (boundary blocks), and the like, which will be described later. The detection processing portion may be configured to cause the control unit 5 to perform processing as the image detection unit 51 as indicated by a broken line in FIG.

  In addition, this apparatus includes a control unit 5 that performs information processing such as control of each unit, a VICS receiver 6 that is a broadcast reception unit for VICS information from FM multiplex broadcasting, and an information display unit 7 (for example, a monitor on a liquid crystal panel). Etc.), an operation unit 8 such as a switch for receiving input of information and instructions, a user interface 9 for controlling the relationship between the display unit 7 and the operation unit 8 and the control unit 5, a memory 10 which is a storage unit, And map data 11 read from a map data reproducing unit (for example, a storage device such as HDD, DVD-ROM, CD-ROM).

  Moreover, as a processing means corresponding to the following effects, the control part 5 implement | achieves each part (52, 53 ...) shown in FIG. 1 with a predetermined program. It should be noted that conventional navigation devices and elements in the range corresponding to the information processing (for example, destination designation reception, route search, guidance guidance output, etc.) are not specific to the present invention and are omitted.

[2. Effect)
[2-1. (Overview)
In the present embodiment configured as described above, the image detection unit 41 (image detection means) detects road surface features (roadside belts, gutters, curbs) from the video taken by the camera 4 (image detection processing). . At this time, in the memory 10 (storage unit), road surface features are classified and stored in advance as roadside bands, side grooves, or curbs, and the image detection unit 41 refers to them.

  Based on the road surface feature detected in this way, the intersection determination unit 52 (intersection determination means) determines whether the vehicle has entered the intersection and records it in the buffer memory. That is, the road surface features detected by the image detection unit 41 are classified into roadside belts, side grooves, and curbs, and stored in a predetermined buffer memory. If the vehicle determines that an intersection is approaching, a flag indicating the intersection approach is set. More specifically, for example, as shown in FIGS. 2 to 4, a situation in which the roadside belt is interrupted from the vertical line shape on the right side of the screen and disappears downward as the vehicle enters the intersection from the image detection unit 41. It is calculated based on the detection output and detects that the vehicle enters the intersection.

  The first calculation unit 53, the second calculation unit 54, and the comparison unit 55 use the entry flag (entrance side groove flag / entrance curb flag / entrance road side zone flag) set as described above to unit distance. Execute unit distance acquisition processing to calculate. That is, the first calculation unit 53 calculates the distance from the total number of vehicle speed pulses of the vehicle speed pulse in this section, with the first intersection distance being the intersection between the previous intersection and the current intersection. On the other hand, the second calculation unit 54 acquires position information between the previous intersection point and the current intersection point from the map data 11 as a coordinate point, and calculates a second intersection distance from the information on the coordinate point. Then, the comparison unit 55 compares the first intersection distance with the second intersection distance to obtain a difference between the first intersection distances with respect to the second intersection distance. The distance per pulse, which is a unit distance, is corrected.

  At this time, if the above approach flag (one or more or two or more under the condition of multiple detection) is set while driving on the road, it indicates that the vehicle has entered the intersection directly. In the acquisition process, the unit distance is calculated on the assumption that the vehicle has reached the intersection of the map road. Further, a gutter, a curbstone and the like are calculated based on the detection output from the image detection unit 41 in the same procedure, and the intersection determination unit 52 detects that the vehicle enters the intersection. In addition, it is possible to detect all inflows and inflows at the intersection of the vehicle in the same procedure.

[2-2. Example of image)
Next, as a specific example, FIG. 2 is a schematic diagram when a vehicle traveling on a road enters an intersection. When the vehicle moves as shown in FIGS. 2 (a) → (b) → (c), for example, in a camera attached to the front nose of this vehicle, FIGS. 3 (a) → (b) → (c) You can shoot images like In this example, the vehicle position in FIG. 2 and the camera image in FIG. The image detection unit 41 uses video (FIG. 3) from such a camera as input information, for example, detects a roadside band by extracting a white line, and appropriately calculates the shading of the side grooves and curbs based on the 3D structure. It is detected using techniques such as pattern recognition. The output result from such an image detection unit 41 is important information for detecting the approach of the vehicle to the intersection in the control unit 5.

  In the control unit 5, for example, as shown in FIGS. 3 (a) → (b) → (c), the white line on the roadside belt changes from the vertical line shape on the right side of the screen (FIG. 3 (a)) to the intersection approach of the vehicle. The situation in which the vehicle is interrupted (FIG. 3 (b)) and disappears downward (FIG. 3 (c)) is calculated and determined based on the detection output from the image detection unit 41, and the vehicle enters the intersection. Can be detected. Further, a side groove, a curbstone, and the like can be determined based on the output from the image detection unit 41 in the same procedure, and it can be detected that the vehicle has entered the intersection.

[2-3. (Example of flowchart)
Next, FIG. 4 illustrates a specific flowchart of the above processing. In this example, first, extracted information, which is a detection output from the image detection unit 41, is taken into the control unit 5 (Step 401), and the extracted information is classified (Step 402). Depending on the type of feature, the extracted information is saved for a side ditch (step 403), for a curbstone (step 406), and for a roadside zone (step 409).

  For example, taking the case where the type is a side groove as a specific example, the intersection determination unit 52 stores the classified extracted information in a predetermined buffer memory for the side groove (step 403), searches the buffer memory, and Has entered the intersection (step 404), that is, whether or not the extract showing the vicinity of the intersection as shown in FIG. 3 disappears downward. If it is determined that the vehicle has entered the intersection (YES), data indicating that the vehicle has entered the intersection, for example, an approach side groove flag is set in the extracted information or other predetermined data area (step 405). .

  Note that this side groove buffer memory prepares a storage capacity necessary and sufficient for detecting the approach of an intersection in consideration of, for example, the processing speed of the image detection unit 41, the speed when entering the vehicle, and the like. For example, if the detection criterion of the image detection unit 41 is a fixed time interval (interval), the time required for entering the intersection may be assumed. If the detection criterion of the image detection unit is the amount of change in the detection target, it can be determined from the minimum update time and the vehicle speed at the time of entry.

  Of course, the curb and the roadside belt are the same as those shown in FIG. In the example of FIG. 4, detection processing is independently performed for the side grooves, curbstones, and roadside belts, and the plurality of judgment materials can be used for comprehensive judgment such as composite conditions while detecting the approach of the intersection of the vehicle. Therefore, excellent determination accuracy can be obtained.

[2-4. (Use in unit distance acquisition processing)

  Now, the approach flag (entrance side groove flag, approach curb flag, approach road side belt flag) set as described above is used in the unit distance acquisition (re-acquisition) process in the control unit 5. For example, if an approach flag (one or more or two or more under the condition of multiple detection) is set while driving on the road, it indicates that the vehicle has entered straight into the intersection. The unit distance is calculated assuming that the vehicle has reached the intersection of the map road.

  Further, the entry flag is reset within the vehicle position determination process. The unit distance recalculation process can be performed by a procedure such as obtaining the travel distance per pulse from the travel distance on the map between the previous passing intersection and the current intersection and the total number of vehicle speed pulses in the same section. In addition, although the above-mentioned description was described on the assumption that the vehicle would go straight to the intersection, a left / right turn and an inflow / outflow at the intersection can be similarly processed.

[3. effect〕
As described above, in the present embodiment, vehicle speed pulses that can be calculated only at the time of a right or left turn at an intersection so far are used by detecting road surface features such as roadside belts, gutters, and curbs with a camera. The unit distance calculation process can be calculated even when the vehicle passes straight through an intersection, and the vehicle position accuracy can be improved by increasing the frequency of unit distance calculation. In addition, since the camera (front view / back view / side view etc.) used in the safety support apparatus can be used as the imaging means, the introduction is inexpensive and easy.

  In this embodiment, the flag set based on the type of road surface feature facilitates the storage and use of information on whether or not the vehicle is on the road. Further, in the present embodiment, smooth and comfortable driving by highly accurate vehicle position determination is realized by utilizing a plurality of types of positioning principles and information such as VICS.

The functional block diagram which shows the structure of embodiment of this invention. The schematic diagram which illustrates the vehicle intersection approach in embodiment of this invention. The figure which illustrates the camera image at the time of the vehicle intersection approach in embodiment of this invention. The flowchart which shows an example of the process sequence regarding a road surface characteristic object in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Receiver 2 ... Vehicle speed detector 3 ... Gyro sensor 4 ... Camera 41 ... Image detection part 5 ... Control part 51 ... Image detection part 52 ... Intersection determination part 53 ... 1st calculation part 54 ... 2nd calculation part 55 ... Comparison unit 56 ... Correction unit 6 ... VICS receiver 7 ... Display unit 8 ... Operation unit 9 ... User interface 10 ... Memory 11 ... Map data

Claims (7)

In a navigation device comprising road map data, a positioning system including a vehicle speed detecting means for detecting a travel distance of a moving body, an imaging unit that images the periphery of the vehicle, and a control unit that performs information processing,
It has a storage unit that prestores road surface features,
Image detection means for detecting a road surface feature by comparing an image from the imaging unit with a road surface feature stored in the storage unit;
An intersection judging means for judging and recording the presence or absence of an intersection approach of a moving object based on the detected road surface feature;
Means for calculating from the vehicle speed detection means a distance between two intersections determined by the intersection determination means as a first inter-intersection distance;
Means for calculating the distance between the two intersections from the coordinate points stored in the road map data as a second intersection distance;
A comparison means for comparing the distance between the first intersections and the distance between the second intersections;
A navigation device comprising: a correction unit that corrects a unit distance per pulse in the vehicle speed detection unit from a comparison result by the comparison unit. The storage unit classifies road surface features into roadside belts, side grooves, curbs, and stores them.
The image detection means is to detect the road surface features classified by type.
2. The navigation apparatus according to claim 1, wherein the intersection determination means determines whether or not a moving body has entered the intersection for each type of road surface feature.   The intersection determination means determines whether or not the moving object has entered the intersection for each type of road surface feature, stores it in the buffer memory, and sets a flag indicating whether or not the vehicle has entered the intersection. The navigation device according to claim 1 or 2, wherein In a control method for a navigation device comprising road map data, a positioning system including vehicle speed detection means for detecting a travel distance of a moving body, an imaging unit that images the periphery of the vehicle, and a control unit that performs information processing,
The navigation device includes a storage unit that prestores road surface features,
An image detection step of detecting a road surface feature by comparing an image from the imaging unit with a road surface feature stored in the storage unit;
An intersection determination step for determining and recording the presence or absence of an intersection approach of a moving object based on the detected road surface feature;
Calculating a distance between the determined two intersections from the vehicle speed detection means as a first distance between the intersections;
Calculating a distance between the two intersections from a coordinate point stored in the road map data as a second intersection distance;
Comparing the distance between the first intersection and the distance between the second intersection;
And a correction step of correcting a unit distance per pulse in the vehicle speed detection means from the comparison result. In the storage unit, road surface features are classified and stored as roadside belts, gutters or curbs,
The image detection step includes a process of classifying and detecting the road surface features for each type,
5. The method of controlling a navigation device according to claim 4, wherein the intersection determination step includes a process of determining whether or not a moving body has entered the intersection for each type of road surface feature.   The intersection determination step includes a process of determining whether or not a moving body has entered the intersection for each type of road surface feature, storing the information in a buffer memory, and setting a flag indicating whether or not the vehicle has entered the intersection. The method for controlling a navigation device according to claim 4, wherein: In a control program for a navigation device comprising road map data, a positioning system including vehicle speed detection means for detecting a travel distance of a moving body, an imaging unit for imaging the periphery of the vehicle, and a control unit for performing information processing,
The navigation device includes a storage unit that prestores road surface features,
Checking the image from the imaging unit with the road surface feature stored in the storage unit to detect the road surface feature,
Based on the detected road surface features, the presence or absence of the intersection of the moving body is determined and recorded,
A distance between the determined two intersections is calculated from the vehicle speed detection means as a first distance between the intersections;
The distance between the two intersections is calculated as a second intersection distance from the coordinate points stored in the road map data;
Comparing the distance between the first intersection and the distance between the second intersection;
A navigation apparatus control program for correcting a unit distance per pulse in the vehicle speed detecting means from a comparison result.