Obstacle detection device, driving assistance system, and obstacle detection method

• US 10,789,850 B2
• Filed: 03/23/2017
• Issued: 09/29/2020
• Est. Priority Date: 05/10/2016
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Watanabe, Shintaro, Shimizu, Shoichi, Hori, Junji, Tsujita, Wataru
• Primary Examiner(s): Woldemariam, Aklilu K
• Application Number:
  US16/097,434
• Publication Number:
  US 20200265718A1
• Time in Patent Office: 1,286 Days
• Field of Search: 348 84, 348148, 382103, 382104, 382106, 382154, 382199
• CPC Class Codes: B60Q 9/00 Arrangement or adaptation of signal devices not provided for in one of main groups B60Q1/00 - B60Q7/00 , e.g. haptic signalling
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B60R 21/00 Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks safety belts or body harnesses in vehicles B60R22/00; devices, apparatus or methods for life-saving in general A62B; safety devices for propulsion unit control specially adapted for, or arranged in, vehicles B60K28/00; seats constructed to protect the occupant from the effect of abnormal g-forces, e.g. crash or safety seats, B60N2/42; energy-absorbing arrangements for hand wheels for steering vehicles B62D1/11; energy-absorbing arrangements for vehicle steering columns B62D1/19; harnessing in aircraft B64D25/00
• CPC Class Codes: B60T 2201/022 Collision avoidance systems
• CPC Class Codes: B60T 2210/32 Vehicle surroundings
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01C 3/06 Use of electric means to obtain final indication
• CPC Class Codes: G01S 17/93 for anti-collision purposes
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 10/60 relating to illumination properties, e.g. using a reflectance or lighting model
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• CPC Class Codes: G06V 20/64 Three-dimensional objects
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes
• CPC Class Codes: H04N 23/56 : provided with illuminating means
• CPC Class Codes: H04N 7/18 : Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A first light projector projects first slit light that spreads in the width direction of a vehicle in a direction other than a direction parallel to a contact ground surface. A second light projector projects second slit light that spreads in the width direction of the vehicle in a direction parallel to the contact ground surface. An obstacle detection unit detects an obstacle using a captured image of an area surrounding the vehicle where the first slit light and the second slit light are projected.

Claims

1. An obstacle detection device comprising:

a first light projecting unit for projecting first slit light toward an area surrounding a vehicle;

a second light projecting unit for projecting second slit light that spreads in a width direction or a front-rear direction of the vehicle toward the area surrounding the vehicle in a direction parallel to a contact ground surface on the vehicle;

an imaging unit for capturing an image of the area surrounding the vehicle from a position not included on either a plane including a direction in which the first slit light spreads and a direction in which the first slit light is projected or a plane including the direction in which the second slit light spreads and the direction in which the second slit light is projected;

a first reconstruction unit for reconstructing a shape of a part hit by the first slit light using the image captured by the imaging unit;

a second reconstruction unit for reconstructing a shape of a part hit by the second slit light using the image captured by the imaging unit;

a travel amount calculating unit for calculating a travel amount of the vehicle; and

a moving object detecting unit for detecting a moving object in the area surrounding the vehicle using the shape reconstructed by the second reconstruction unit and the travel amount of the vehicle calculated by the travel amount calculating unit,

wherein an obstacle is detected using the shape reconstructed by the first reconstruction unit, the shape reconstructed by the second reconstruction unit, and the travel amount of the vehicle calculated by the travel amount calculating unit.

2. The obstacle detection device according to claim 1, further comprising:

an integration unit for reconstructing a three-dimensional shape of the area surrounding the vehicle by integrating shapes reconstructed by the first reconstruction unit using the travel amount of the vehicle calculated by the travel amount calculating unit and information of the moving object detected by the moving object detecting unit; and

an obstacle detection unit for detecting an obstacle using the three-dimensional shape reconstructed by the integration unit.

3. The obstacle detection device according to claim 1, wherein the second light projecting unit for projecting the second slit light is installed at a position different from that of the first light projecting unit for projecting the first slit light.

4. The obstacle detection device according to claim 1, wherein when the second light projecting unit projects the second slit light that spreads in the width direction of the vehicle, the first slit light spreads in the width direction of the vehicle and is projected in a direction other than the direction parallel to the contact ground surface on the vehicle.

5. The obstacle detection device according to claim 4, wherein the first light projecting unit for projecting the first slit light is installed on at least one of a rear surface and a front surface of the vehicle.

6. The obstacle detection device according to claim 4, wherein the second slit light spreads in the width direction of the vehicle and is projected in at least one of a backward direction and a forward direction of the vehicle.

7. The obstacle detection device according to claim 6, wherein the second light projecting unit for projecting the second slit light is installed on at least one of a rear surface and a front surface of the vehicle.

8. The obstacle detection device according to claim 1, wherein when the second light projecting unit projects the second slit light that spreads in the front-rear direction of the vehicle, the first slit light spreads in a vertical direction and is projected from a side surface of the vehicle in at least one of a right direction, a diagonally forward right direction, a diagonally backward right direction, a left direction, a diagonally forward left direction, and a diagonally backward left direction.

9. The obstacle detection device according to claim 8, wherein the first light projecting unit for projecting the first slit light is installed on at least one of a left side surface and a right side surface of the vehicle.

10. The obstacle detection device according to claim 8, wherein the second slit light spreads in the front-rear direction of the vehicle and is projected in at least one of a left direction and a right direction of the vehicle.

11. The obstacle detection device according to claim 10, wherein the second light projecting unit for projecting the second slit light is installed on at least one of a left side surface and a right side surface of the vehicle.

12. The obstacle detection device according to claim 2,

wherein the first reconstruction unit and the second reconstruction unit, by using a plurality of images captured in time series by the imaging unit, reconstruct, for each of the plurality of images, a shape of a part hit by the first slit light and a shape of a part hit by the second slit light, respectively,

the moving object detecting unit detects the moving object in the area surrounding the vehicle using the shapes reconstructed by the second reconstruction unit using the respective plurality of images and the travel amount of the vehicle calculated by the travel amount calculating unit, and

the integration unit integrates the shapes reconstructed by the first reconstruction unit using the respective plurality of images by using the travel amount of the vehicle calculated by the travel amount calculating unit and information of the moving object detected by the moving object detecting unit.

13. The obstacle detection device according to claim 1, wherein at least one of the first reconstruction unit and the second reconstruction unit calculates a three-dimensional position from coordinate values of a position of the corresponding slit light captured in the image on a basis of a principle of triangulation, by using a position of at least corresponding one of the first light projecting unit and the second light projecting unit, a projection direction of the corresponding slit light, and a position, an imaging direction, and an angle of view of the imaging unit, and thereby reconstructs the corresponding shape.

14. The obstacle detection device according to claim 1, wherein the moving object detecting unit translates a position of a shape before travel of the vehicle reconstructed by the second reconstruction unit by the travel amount of the vehicle on a basis of the shape reconstructed by the second reconstruction unit and the travel amount of the vehicle calculated by the travel amount calculating unit, determines whether the translated shape before the travel and a shape after the travel reconstructed by the second reconstruction unit coincide with each other, and determines that the shapes are those of the moving object in a case where the shapes do not coincide.

15. The obstacle detection device according to claim 2, wherein the moving object detecting unit translates a position of a shape before travel of the vehicle reconstructed by the second reconstruction unit by the travel amount of the vehicle on a basis of the shape reconstructed by the second reconstruction unit and the travel amount of the vehicle calculated by the travel amount calculating unit, detects an amount of shift between the translated shape before the travel and a shape after the travel reconstructed by the second reconstruction unit, and detects the amount of shift as a travel amount of the moving object.

16. The obstacle detection device according to claim 15, wherein the integration unit translates a shape before the travel reconstructed by the first reconstruction unit by the travel amount of the vehicle and the travel amount of the moving object on a basis of the shape reconstructed by the first reconstruction unit, the travel amount of the vehicle calculated by the travel amount calculating unit, and the travel amount of the moving object detected by the moving object detecting unit, integrates the translated shape before the travel and a shape after the travel reconstructed by the first reconstruction unit, and thereby reconstructs the three-dimensional shape of the area surrounding the vehicle.

17. A driving assistance system, comprising:

an obstacle detection device according to claim 1;

a collision determination unit for performing collision determination between the vehicle and an obstacle using an obstacle detection result of the obstacle detection device; and

an alarm unit for issuing an alarm on a basis of the determination result of the collision determination unit.

18. The driving assistance system according to claim 17, further comprising a brake control unit for controlling a brake of the vehicle on a basis of the determination result of the collision determination unit.

19. An obstacle detection method, comprising:

a step of projecting first slit light toward an area surrounding a vehicle;

a step of projecting second slit light that spreads in a width direction or a front-rear direction of the vehicle toward the area surrounding the vehicle in a direction parallel to a contact ground surface on the vehicle;

a step of capturing an image of the area surrounding the vehicle from a position not included on either a plane including a direction in which the first slit light spreads and a direction in which the first slit light is projected or a plane including the direction in which the second slit light spreads and the direction in which the second slit light is projected;

a step of reconstructing a shape of a part hit by the first slit light using the captured image of the area surrounding the vehicle;

a step of reconstructing a shape of a part hit by the second slit light using the captured image of the area surrounding the vehicle;

a step of calculating a travel amount of the vehicle; and

a step of detecting a moving object in the area surrounding the vehicle using the shape of the part hit by the second slit light and the travel amount of the vehicle; and

a step of detecting an obstacle using the shape of the part hit by the first slit light, the shape of the part hit by the second slit light, and the travel amount of the vehicle.