JP7114865B2 - VEHICLE POSITION DETECTION METHOD AND VEHICLE POSITION DETECTION DEVICE - Google Patents

Description

The present invention relates to a vehicle position detection method and a vehicle position detection device.

Conventionally, as an indication of the position of a vehicle at a roundabout, the angle of rotation (angle of rotation) between the position of the road on which the vehicle traveled before entering the roundabout and the position of the vehicle at the roundabout is There is a technique to calculate The rotation angle is obtained by integrating rotation angular velocities detected by a gyro or the like (see Patent Document 1).

JP-A-11-248479

As described above, when the rotation angle is obtained by integrating the rotation angular velocity, there is a problem that errors in the rotation angular velocity are accumulated and the accuracy of the rotation angle cannot be improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a vehicle position detection method and a vehicle position detection device capable of accurately detecting a rotation angle indicating the position of a vehicle on a roundabout. .

A vehicle position detection method according to one aspect of the present invention is a vehicle position detection method for a vehicle position detection device including a GPS radio wave receiver, a map database, a sensor, and a vehicle position detection circuit. The vehicle position detection circuit determines whether or not the vehicle is in the roundabout based on the vehicle position acquired by the GPS radio wave receiver and the map information accumulated in the map database. If the vehicle position detection circuit determines that the vehicle is inside the roundabout, the position of the vehicle in the roundabout is determined based on the absolute angle of the direction of the vehicle inside the roundabout obtained by the sensor. Determine the angle of rotation between the reference position and the position of the vehicle. The vehicle position detection circuit obtains the relative positions of the vehicle and feature points around the vehicle based on the surrounding object information about the objects around the vehicle acquired by the sensor, and detects the feature points from the candidate feature points based on the rotation angle. and determine the position of the vehicle based on the positions and relative positions of the selected feature points.

ADVANTAGE OF THE INVENTION According to this invention, the rotation angle which shows the position of the vehicle in a roundabout can be accurately detected.

FIG. 1A is a functional block diagram showing part of a vehicle equipped with a vehicle position detection device according to an embodiment of the invention. FIG. 1B is a functional block diagram showing a configuration example of an automatic driving controller. FIG. 2 is a flow chart for explaining the vehicle position detection method according to the embodiment of the present invention. FIG. 3 is a diagram for explaining calculation of the rotation angle. FIG. 4 is a diagram for explaining correction of the position of the own vehicle. FIG. 5 is a diagram for explaining calculation of the relative position. FIG. 6 is a diagram for explaining acquisition of the positions of feature points.

Embodiments will be described with reference to the drawings. In the description of the drawings, the same parts are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 1A, the vehicle includes an automatic driving controller 1, an input device 2, an external sensor unit 3, an internal sensor unit 4, a GPS (Global Positioning System) radio wave receiving unit 5, a map database 6, and an HMI (human machine interface). It comprises a controller 7 , an actuator section 8 and a display device 9 . In order not to confuse this vehicle with other vehicles, it is referred to as the "own vehicle".

The automatic driving controller 1 corresponds to a vehicle position detection circuit, and can be realized using a microcomputer having a CPU (Central Processing Unit), a memory, and an input/output unit. A computer program for causing the microcomputer to function as the automatic driving controller 1 is installed in the microcomputer and executed. Thereby, the microcomputer functions as the automatic driving controller 1 . Here, an example of realizing the automatic operation controller 1 by software is shown, but of course, the automatic operation controller 1 can be configured by preparing dedicated hardware for executing each information processing shown below. It is possible.

The input device 2 is a device for the vehicle occupant to input various information, and can be used as the input device 2 such as a switch shared with the navigation system mounted on the vehicle or a switch provided on the steering wheel. .

The external sensor unit 3 includes a radar device such as a laser radar or a millimeter wave radar, or a camera such as a monocular or compound eye stereo camera (both not shown). , lane markings and road edges) (referred to as surrounding object information) is output to the automatic driving controller 1 .

The internal sensor unit 4 detects the yaw angle, roll angle, and pitch angle of the body of the host vehicle and outputs them to the automatic driving controller. The internal sensor unit 4 also detects the operation amounts of the accelerator pedal and the brake pedal of the host vehicle and the steering angle of the steering wheel, and outputs them to the automatic driving controller 1 . The yaw angle, roll angle, and pitch angle of the vehicle body can be calculated by integrating the angular velocities of the yaw angle, roll angle, and pitch angle detected using a gyro sensor. Also, the internal sensor unit 4 detects the vehicle speed and outputs it to the automatic driving controller 1 . The internal sensor unit 4 also detects an absolute angle indicating the direction of the vehicle and outputs it to the automatic driving controller 1 .

An absolute angle is, for example, a clockwise angle relative to north. For example, if the vehicle is facing east, the absolute angle is 90 degrees. The internal sensor unit 4 includes a sensor such as an electronic compass, for example, and calculates an absolute angle using the electronic compass or the like. Note that the absolute angle reference may be other than north. Also, the absolute angle may be an angle in the counterclockwise direction.

The GPS radio wave receiving unit 5 obtains the position of the own vehicle by receiving radio waves from three or more GPS satellites, and outputs the position to the automatic driving controller 1 .

The map database 6 accumulates detailed map information of the area where the vehicle travels, and the automatic driving controller 1 refers to the detailed map information. The detailed map information includes information such as the positions of roads and intersections. The intersections include cross intersections, T-shaped intersections, and circular intersections called roundabouts.

A roundabout is an intersection where three or more roads connect to a ring road (called a ring road). Here, a roundabout means a ring road.

The detailed map information also includes information about objects around the road. This information includes, for example, positional information on lane markings and roadsides, and information on feature points (b11, b12, b13, b14, see FIG. 4) extracted from the image around the roundabout (positions and features amount).

The display device 9 is, for example, a navigation system mounted on the vehicle, and the HMI controller 7 outputs audio and video for route guidance to the display device 9 . The display device 9 reproduces route guidance audio and displays images.

The automatic driving controller 1 detects the position of the own vehicle, obtains a target route starting from the position of the own vehicle, and instructs the actuator unit 8 to drive the own vehicle along the target route. Outputs control information for controlling steering. In addition, the automatic driving controller 1 outputs control information for controlling the vehicle interior environment and the vehicle exterior environment, and control information for controlling the input device 2 to perform driving assistance and autonomous driving.

The automatic driving controller 1 includes, as functional components realized by executing a computer program, a first vehicle position calculation unit 11 (first vehicle position calculation circuit), a second vehicle position calculation unit 12 (second vehicle position calculation circuit), a third vehicle position calculation unit 13 (third vehicle position calculation circuit), a vehicle position correction unit 14 (vehicle position correction circuit), a target route calculation unit 15 (target route calculation circuit), and a vehicle travel control unit 16 (vehicle running control circuit).

The first vehicle position calculator 11 calculates the position of the vehicle based on the vehicle speed and yaw angle of the vehicle. The second vehicle position calculator 12 calculates the position of the vehicle on the roundabout based on the absolute angle indicating the direction of the vehicle. The third vehicle position calculator 13 calculates the relative positions of the vehicle and feature points of objects around the vehicle, and calculates the position of the vehicle based on the relative positions and the positions of the feature points.

The vehicle position correction unit 14 corrects the position of the vehicle calculated by the first vehicle position calculation unit 11 and the position of the vehicle calculated by the second vehicle position calculation unit 12 based on the shape of the roundabout and the like.

The target route calculation unit 15 calculates a target route along which the vehicle should travel, starting from the position of the vehicle. The vehicle travel control unit 16 outputs vehicle speed and steering control information to the actuator unit 8 so that the host vehicle travels along the target route.

The actuator unit 8 controls the amount of operation of the accelerator pedal (driving force), the amount of operation of the brake pedal (braking force), and the steering angle (steering amount) of the steering wheel of the own vehicle based on the vehicle speed and steering control information, The own vehicle is automatically driven along the target route.

Further, the actuator unit 8 controls the environment inside the vehicle and the environment outside the vehicle based on control information for the environment inside the vehicle and the environment outside the vehicle. The actuator unit 8 also controls the input device 2 based on control information for driving assistance and autonomous driving.

Next, with reference to FIG. 2, an example of the vehicle position detection method in the own vehicle of FIG. 1 will be described. The own vehicle repeats the processing of FIG.

Step S<b>1 : The automatic driving controller 1 acquires the position of the own vehicle from the GPS radio wave receiving section 5 .
Step S3: Next, the automatic driving controller 1 refers to the detailed map information and determines whether or not the own vehicle is present in the roundabout based on the position of the roundabout and the position of the own vehicle.

If the own vehicle exists within the roundabout (S3: YES), the position of the own vehicle is detected based on the vehicle speed and yaw angle, and the position of the own vehicle is detected based on the absolute angle.

(Position detection of own vehicle based on vehicle speed and yaw angle)
Step S5: In detecting the position of the host vehicle based on the vehicle speed and the yaw angle, the first vehicle position calculator 11 of the automatic driving controller 1 first acquires the vehicle speed and the yaw angle from the internal sensor unit 4 .
Step S7: Next, the first vehicle position calculator 11 calculates the relative position of the current position of the vehicle with respect to the past position of the vehicle on the map based on the vehicle speed and the yaw angle. Based on the position and the relative position, the current position of the own vehicle on the map is calculated. The obtained position of the own vehicle is used as the "past position of the own vehicle" in the next step S7. Hereinafter, the position obtained in step S7 will be referred to as the first vehicle position.

(Position detection of self-vehicle based on absolute angle)
Step S<b>9 : In detecting the position of the own vehicle based on the absolute angle, the second vehicle position calculator 12 of the automatic driving controller 1 first acquires the absolute angle from the internal sensor unit 4 .
Step S11: Next, the second vehicle position calculator 12 calculates the rotation angle between the reference position on the roundabout and the position of the host vehicle, with the center of the roundabout as the axis, based on the absolute angle.

Here, the calculation of the rotation angle in step S11 will be described with reference to FIG.
A plurality of roads R are connected to the roundabout RA. In FIG. 3, the top is north. In the roundabout RA, the position in the north direction from the center C of the roundabout RA is defined as the reference position P of the roundabout RA.

On the other hand, the absolute angle of the own vehicle is the angle in the clockwise direction with north as the reference. The absolute angle θ at the position 100 of the host vehicle is the angle between the tangent line 101 of the circle passing through the position 100 and the direction N to the north. A tangent line 101 indicates the traveling direction of the host vehicle at the position 100 .

A clockwise rotation angle α between the reference position P and the vehicle position 100 about the center C can be obtained by the following equation.
[Number 1]
α=(3π/2)+θ

That is, in step S13, the second vehicle position calculator 12 substitutes the absolute angle θ into this equation, for example, to obtain the rotation angle α. If the reference position P is changed, the coefficient (3/2) applied to π should be changed.
Note that the absolute angle reference may be other than north. Also, the absolute angle may be an angle in the counterclockwise direction.

Returning to FIG. 2, the description is continued.
Step S13: The second vehicle position calculator 12 calculates the current position of the host vehicle on the map based on the rotation angle obtained in step S11. For example, the position of the own vehicle on the map is obtained based on the reference position on the map and the size (eg, diameter) and rotation angle of the roundabout. Hereinafter, the position obtained in step S13 will be referred to as the second vehicle position.

Step S15: After performing the processing of steps S7 and S11, the vehicle position correction unit 14 of the automatic driving controller 1 corrects the position of the own vehicle when the first vehicle position and the second vehicle position are different from each other, Proceed to step S17. If the first vehicle position and the second vehicle position are the same, they are treated as the position of the own vehicle after correction in step 17 and thereafter.

Correction of the position of the host vehicle in step S15 will be described with reference to FIG.
The roundabout RA in FIG. 4 is not a perfect circle, but has sections a1 and a2 (collectively referred to as straight sections for convenience) that are straight lines or have large curvature radii. Assuming that the absolute angle is an angle in the clockwise direction with respect to the reference position P, the absolute angle is approximately 90 degrees anywhere in the section a1. In section a2, the absolute angle is approximately 270 degrees everywhere. Therefore, when the rotation angle obtained in step S11 belongs to the range of 90 degrees ± error, or belongs to the range of 270 degrees ± error, that is, in the section where the radius of curvature of the roundabout is large, the second vehicle A position closer to the first vehicle position than the position is obtained as the position of the own vehicle after correction. That is, the second vehicle position is weighted low and the first vehicle position is weighted high.

On the other hand, for example, when the roundabout is a perfect circle, or in a section other than a straight section, that is, in a section where the radius of curvature of the roundabout is small, the corrected vehicle position is closer to the second vehicle position than the first vehicle position. It is obtained as the position of the vehicle. That is, the weighting of the second vehicle position is increased and the weighting of the first vehicle position is decreased. Note that the position of the straight section is stored in the detailed map information and referred to during correction.

Returning to FIG. 2, the description is continued.
Step S<b>17 : The third vehicle position calculation unit 13 of the automatic driving controller 1 acquires detailed map information from the map database 6 and acquires surrounding object information from the external sensor unit 3 .
Step S19: Next, the third vehicle position calculation unit 13 calculates the relative position between the feature point of the object around the own vehicle and the own vehicle based on the surrounding object information, and proceeds to step S21.

Calculation of the relative position in step S19 will be described with reference to FIG.
As shown in FIG. 5, while the host vehicle is running, the external sensor unit 3 sequentially acquires, for example, an image (surrounding object information) of a forward range b. The automatic driving controller 1, for example, extracts a feature point b1 (for example, a point where the roadsides are connected) from the image, and based on the position change of the feature point b1 in each image, the relative position G of the feature point b1 and the own vehicle. find the position. Known methods such as SIFT (Scale Invariant Feature Transform) feature amount and SURF (Speed-Up Robust Feature) feature amount can be used as a method for extracting feature points and describing feature points.

Returning to FIG. 2, the description is continued.
Step S21: The third vehicle position calculator 13 searches the map database 6 to find one or more feature points having the same feature (SIFT feature amount, SURF feature amount) as the feature point whose relative position is calculated. solicit candidates. Then, a feature point is selected from the feature point candidates based on the rotation angle obtained in step S11, the position of the feature point is acquired, and the process proceeds to step S23.

Acquisition of the position of the feature point in step S21 will be described with reference to FIG.
Assume that the position of the own vehicle obtained in step S15 is position G in the roundabout RA of FIG. The position G is obtained in step S15 based on the rotation angle obtained in step S11. On the other hand, the feature point whose relative position was obtained in step S19 is the feature point b11, and there are other feature points b12, b13, and b14 as feature points having the same features as the feature point b11. The third vehicle position calculation unit 13 selects the feature point candidate b11 (feature point b11) closest to the position G from the feature points b11 to b14 as feature point candidates, and calculates the position of the feature point b11 from the detailed map information. to get

Returning to FIG. 2, the description is continued.
Step S23: The third vehicle position calculator 13 calculates the position of the own vehicle based on the relative position obtained in step S19 and the position of the feature point (b11) selected in step S21, and proceeds to step S41. Here, the relative position obtained in step S19 based on the position of the characteristic point obtained in step S21 is used as the position of the own vehicle.

Now, if it is determined in step S3 that the own vehicle does not exist within the roundabout (S3: NO), the process proceeds to step S31.
Step S31: The first vehicle position calculation unit 11 of the automatic driving controller 1 acquires the vehicle speed and the yaw angle from the internal sensor unit 4 as in step S5.
Step S33: Next, the first vehicle position calculator 11 calculates the current position of the host vehicle, as in step S7.

Step S35: Next, the third vehicle position calculation unit 13 of the automatic driving controller 1 acquires detailed map information from the map database 6 and acquires surrounding object information from the external sensor unit 3, as in step S17.

Step S37: Next, the third vehicle position calculation unit 13 calculates the relative positions of the feature points and the host vehicle, acquires the positions of the feature points, and calculates the relative positions and the positions of the feature points, similarly to S19 to S23. Based on this, the position of the own vehicle is calculated, and the process proceeds to step S41.

Step S41: The target route calculation unit 15 of the automatic driving controller 1 calculates the position of the vehicle based on the position of the vehicle obtained in step S23 or step S37 and the information on the road where the vehicle exits the roundabout. A target route that the host vehicle should travel as a starting point is calculated.

The information on the exit road from the roundabout can be obtained, for example, from the information on the planned travel route set in advance in the navigation system of the vehicle.

Step S43: Next, the vehicle travel control unit 16 of the automatic driving controller 1 outputs vehicle speed and steering control information to the actuator unit 8 so that the host vehicle travels along the target route obtained in step S41. and finish the process.

The actuator unit 8 controls the amount of operation of the accelerator pedal (driving force), the amount of operation of the brake pedal (braking force), and the steering angle (steering amount) of the steering wheel of the own vehicle based on the vehicle speed and steering control information, The own vehicle is automatically driven along the target route. This allows the vehicle to automatically exit from a roundabout, for example.

In the embodiment, the position of the own vehicle is obtained from the absolute angle, the own vehicle is caused to travel along the target route with the position of the own vehicle as the starting point, and the own vehicle is automatically exited from, for example, a roundabout. The vehicle is not limited to this, and may be manually operated by the driver. In this case, before the exit road from the roundabout, the display device 9 informs the occupants (such as the driver) of the own vehicle by voice, display (image or video display), sound, etc. that the exit road is before the exit road. You may notify us.

In addition, in the embodiment, the vehicle position detection device is mounted on the target vehicle for position detection. However, by installing a vehicle position detection device in a server device that can communicate with the target vehicle or in another vehicle that is not the target vehicle, and transmitting and receiving necessary information and instructions by communication between the server device or the other vehicle and the target vehicle, the same (1) may be performed remotely. Communication between the server device and the target vehicle can be performed by wireless communication or road-to-vehicle communication. Communication between the other vehicle and the target vehicle can be performed by so-called inter-vehicle communication.

As described above, according to the embodiment, the absolute angle indicating the direction of the vehicle in the roundabout is detected (S9), and based on the absolute angle, the center of the roundabout is used as an axis, and the reference position in the roundabout and the vehicle position are detected. A rotation angle between vehicle positions is obtained (S13). Therefore, compared to the method of obtaining the rotation angle by integrating the rotation angular velocity, there is no accumulation of errors in the rotation angular velocity, so the rotation angle indicating the position of the vehicle on the roundabout can be accurately detected.

Surrounding object information about objects around the vehicle is acquired (S17), and relative positions between feature points of objects around the own vehicle and the own vehicle are obtained based on the surrounding object information (S19). Then, a feature point (b11) is selected from the feature point candidates (FIG. 6: b11 to b14) based on the rotation angle, and the position of the host vehicle is obtained based on the position and relative position of the selected feature point (S23). . Therefore, for example, a plurality of feature point candidates can be narrowed down, and the position of the host vehicle can be obtained with high accuracy.

In addition, as surrounding object information about objects around the own vehicle, an image around the own vehicle is acquired using a radar device or a camera mounted on the own vehicle (S17), and feature points around the own vehicle are obtained from the image. Then, the relative position between the extracted feature points and the host vehicle is obtained (S19). Then, by searching the map database 6 that accumulates information on the feature points, one or more feature point candidates (FIG. 6: b11 ˜b14) is obtained (S21). Therefore, feature point candidates can be obtained, and by narrowing them down, the position of the own vehicle can be obtained with high accuracy.

A first vehicle position is obtained as the position of the own vehicle based on the vehicle speed and the yaw angle of the own vehicle (S7), and a second vehicle position is obtained as the position of the own vehicle based on the rotation angle (S13). Then, in sections with a large radius of curvature in the roundabout (for example, sections a1 and a2 in FIG. 4), a position closer to the first vehicle position than the second vehicle position is determined as the position of the host vehicle (S15). On the other hand, in sections with a small radius of curvature in the roundabout (for example, other than sections a1 and a2 in FIG. 4), a position closer to the second vehicle position than the first vehicle position is determined as the position of the host vehicle (S15). Therefore, the position of the own vehicle can be obtained regardless of the radius of curvature of the roundabout, and the position of the own vehicle can be obtained with high accuracy.

Although embodiments of the present invention have been described above, the statements and drawings forming part of this disclosure should not be construed as limiting the present invention. Various alternative embodiments, implementations and operational techniques will become apparent to those skilled in the art from this disclosure.

Each function shown in each of the above embodiments may be implemented by one or more processing circuits. Processing circuitry includes programmed processing devices, such as processing devices that include electrical circuitry. Processing devices also include devices such as application specific integrated circuits (ASICs) and conventional circuit components arranged to perform the functions described in the embodiments.

1 Automatic driving controller 2 Input device 3 External sensor unit 4 Internal sensor unit 5 GPS (Global Positioning System) radio wave receiving unit 6 Map database 7 HMI (human machine interface) controller 8 Actuator unit 9 Display device 11 First vehicle position calculation unit 12 Second vehicle position calculator 13 Third vehicle position calculator 14 Vehicle position corrector 15 Target route calculator 16 Vehicle travel controller RA Roundabout R Road C Center of roundabout θ Absolute angle P Reference position α Rotation angle N North direction b1 feature points b11, b12, b13, b14 feature point candidates G position of own vehicle a1, a2 section

Claims (3)

A vehicle position detection method for a vehicle position detection device comprising a GPS radio wave receiver, a map database, a sensor, and a vehicle position detection circuit,
The vehicle position detection circuit includes:
determining whether or not the vehicle is in the roundabout based on the position of the vehicle acquired by the GPS radio wave receiving unit and the map information accumulated in the map database;
When it is determined that the vehicle is present in the roundabout, based on the absolute angle indicating the direction of the vehicle in the roundabout acquired by the sensor, the center of the roundabout is used as the axis, and the reference in the roundabout determining the angle of rotation between the position and the position of the vehicle;
obtaining relative positions between feature points around the vehicle and the vehicle based on surrounding object information about objects around the vehicle acquired by the sensor ;
Selecting a feature point from candidate feature points based on the rotation angle;
A vehicle position detection method, comprising determining the position of the vehicle based on the positions of the selected feature points and the relative positions. The vehicle position detection circuit includes:
obtaining an image of the surroundings of the vehicle using a radar device or a camera mounted on the vehicle as the surrounding object information;
extracting feature points around the vehicle from the image, obtaining the relative position between the extracted feature points and the vehicle;
2. The method according to claim 1 , wherein one or more candidate feature points having features similar to those of the feature point for which the relative position is determined are obtained by searching a map database storing information about the feature points. vehicle position detection method. a GPS radio wave receiving unit that acquires the position of the vehicle;
a map database that accumulates map information;
sensors for obtaining absolute angles indicating the orientation of the vehicle and surrounding object information about objects surrounding the vehicle ;
a vehicle position detection circuit;
The vehicle position detection circuit includes:
determining whether the vehicle is in the roundabout based on the position of the vehicle and the map information;
when it is determined that the vehicle is in the roundabout, based on the absolute angle of the vehicle in the roundabout, between a reference position in the roundabout and the position of the vehicle with the center of the roundabout as an axis; Find the rotation angle of
Obtaining relative positions between feature points around the vehicle and the vehicle based on the surrounding object information;
A feature point is selected from the candidate feature points based on the rotation angle, and the position of the vehicle is obtained based on the position of the selected feature point and the relative position.
A vehicle position detection device characterized by :

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