Method and apparatus for recognizing shape of road

• US 6,553,283 B2
• Filed: 02/27/2001
• Issued: 04/22/2003
• Est. Priority Date: 03/09/2000
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Morikawa, Katsuhiro, Shirai, Noriaki
• Primary Examiner(s): Nguyen, Thu
• Application Number:
  US09/793,498
• Publication Number:
  US 20010025211A1
• Time in Patent Office: 784 Days
• Field of Search: 701/1, 701/117, 701/23-28, 701/58-59, 701/65, 701/91-94, 701/96-99, 342/5, 342/42, 342/46-47, 342/52-54, 342/56, 342/70-71, 342/104-105, 342/107, 342/109, 342/113-114, 342/146, 342/149, 342/357.08, 342/371-372, 342/454-458, 342/461, 340/435-437, 180/167, 180/169
• US Class Current: 701/1
• CPC Class Codes: B60R 16/0231 Circuits relating to the driving or the functioning of the vehicle monitoring tyres B60C23/00; indicating overspeed B60K31/00; for dash boards B60K37/00, B60Q3/10; for indicating emergencies B60Q1/52; brake control systems B60T; registering or indicating the working of vehicles G07C5/00; measuring distance G01C, e.g. combinations of speed and distance G01C23/00; engine indicators G01L; measuring speed or acceleration G01P
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/9329 cooperating with reflectors or transponders

Abstract

A transmission wave is applied to a predetermined angular range in a width-wise direction of a vehicle. Object-unit data pieces containing at least data pieces representing distances to objects in correspondence with vehicle-width-wise direction angles are generated on the basis of a reflected wave. A determination is made as to whether each object is moving or stationary on the basis of a speed of the vehicle and a relative speed of the object. From the object-unit data pieces, ones are extracted which are effective for road shape recognition on the basis of a result of determining whether each object is moving or stationary. Ones of the extracted object-unit data pieces which represent monotonically increasing distances as viewed along one of clockwise and counterclockwise angle directions are grouped to generate data representing a road-side-object group. A road edge is recognized on the basis of the data representing the road-side-object group.

Claims

1. An apparatus for recognizing a road shape, comprising:

radar means for applying a transmission wave to a predetermining angular range in a width-wise direction of a vehicle and for detecting each object based upon a reflected wave which results from reflection of the transmission wave; and

recognizing means for recognizing a shape of a road extending ahead of the vehicle based upon a result of detection by the radar means;

wherein the recognizing means comprises;

1) object-unit data generating means for generating object-unit data pieces containing at least data pieces representing distances to objects in correspondence with vehicle-width-wise direction angles based upon the result of the detection by the radar means;

2) object recognizing means for determining whether each object is moving or stationary based upon a speed of the vehicle and a relative speed of the object which is derived from the reflected wave;

3) effective data extracting means for extracting objects from the object-unit data pieces which are effective for road shape recognition based upon a result of the determination by the object recognizing means;

4) road-side-object group data generating means for grouping objects of the extracted effective object-unit data pieces which represent monotonically increasing distances as viewed along a clockwise angle direction to generate data representative of a first road-side-object group, for grouping ones of the extracted effective object-unit data pieces which represent monotonically increasing distances as viewed along a counterclockwise angle direction to generate data representative of a second road-side-object group, for determining whether or not a farthest object in the first road-side-object group is on a same road side as other objects in the first road-side-object group based upon a positional relationship among the farthest object and the other objects, for keeping the farthest object in the first road-side-object group only when the farthest object is on the same road side as the other objects, for determining whether or not a farthest object in the second road-side-object group is on a same road side as other objects in the second road-side-object group based upon a positional relationship among the farthest object and the other objects, and for keeping the farthest object in the second road-side-object group only when the farthest object is on the same road side as the other objects; and

5) road edge recognizing means for recognizing a road edge based upon the data representative of the first and second road-side-object groups generated by the road-side-object group data generating means.

2. The apparatus of claim 1, wherein the road-side-object group data generating means is further for unconditionally removing a farthest object from the first and second road-side-object groups and using a resultant first and second road-side-object groups as a final first and second road-side-object groups.

3. The apparatus of claim 1, wherein the recognizing means comprises a computer.

4. An apparatus for recognizing a road shape, comprising:

radar means for applying a transmission wave to a predetermined angular range in a width-wise direction of a vehicle and for detecting each object based upon a reflected wave which results from reflection of the transmission wave; and

recognizing means for recognizing a shape of a road extending ahead of the vehicle based upon a result of detection by the radar means;

wherein the recognizing means comprises;

1) object-unit data generating means for generating object-unit data pieces containing at least data pieces representing distances to objects in correspondence with vehicle-width-wise direction angles based upon the result of the detection by the radar means;

2) object recognizing means for determining whether each object is moving or stationary based upon a speed of the vehicle and a relative speed of the object which is derived from the reflected wave;

3) effective data extracting means for extracting objects from the object-unit data pieces which are effective for road shape recognition based upon a result of the determination by the object recognizing means;

4) road-side-object group data generating means for grouping objects of the extracted effective object-unit data pieces which represent monotonically increasing distances as viewed along a clockwise angle direction to generate data representative of a first road-side-object group, for grouping ones of the extracted effective object-unit data pieces which represent monotonically increasing distances as viewed along a counterclockwise angle direction to generate data representative of a second road-side-object group, for determining whether or not a farthest object in the first road-side-object group and a farthest object in the second road-side-object group are the same, for, when the farthest objects are the same, removing the farthest object from the first and second road-side-object groups and changing the first and second road-side-object groups into third and fourth road-side-object groups respectively, and for generating data representative of the third road-side-object group and data representative of the fourth road-side-object group; and

5) road edge recognizing means for recognizing a first road edge based upon the data representative of the third road-size-object group and for recognizing a second road edge based upon the data representative of the fourth road-side-object group.

5. An apparatus for recognizing a road shape, comprising:

radar means for applying a transmission wave to a predetermining angular range in a width-wise direction of a vehicle and for detecting each object based upon a reflected wave which results from reflection of the transmission wave; and

recognizing means for recognizing a shape of a road extending ahead of the vehicle based upon a result of detection by the radar means;

wherein the recognizing means comprises;

1) object-unit data generating means for generating object-unit data pieces containing at least data pieces representing distances to objects in correspondence with vehicle-width-wise direction angles based upon the result of the detection by the radar means;

2) object recognizing means for determining whether each object is moving or stationary based upon a speed of the vehicle and a relative speed of the object which is derived from the reflected wave;

3) effective data extracting means for extracting objects from the object-unit data pieces which are effective for road shape recognition based upon a result of the determination by the object recognizing means;

4) road-side object group data generating means for grouping objects of the extracted effective object-unit data pieces which represent monotonically increasing distances as viewed along a clockwise angle direction to generate data representative of a first road-side-object group, for grouping ones of the extracted effective object-unit data pieces which represent monotonically increasing distances as viewed along a counterclockwise angle direction to generate data representative of a second road-side-object group, for determining whether or not a farthest object in the first road-side-object group and a farthest object in the second road-side-object group are the same, for, when the farthest object in the first and second road-side-object group is the same, determining which of the first and second road-side-object groups has a higher possibility of actually containing the farthest object based upon positional relationships among the farthest object and other objects in the first and second road-side-object groups, for keeping the farthest object in one of the first and second road-side-object groups which corresponds to the higher possibility and removing the farthest object from the other of the first and second road-side-object groups to generate a third and a fourth road-side-object groups from the first and second road-side-object groups respectively, and for generating data representative of the third road-side-object group and data representative of the fourth road-side-object group; and

5) road edge recognizing means for recognizing a first road edge based upon the data representative of the third road-side-object group and for recognizing a second road edge based upon the data representative of the fourth road-side-object group.

6. A method for recognizing a road shape, comprising:

applying a transmission wave to a predetermining angular range in a width-wise direction of a vehicle;

detecting each object based upon a reflected wave which results from reflection of the transmission wave; and

recognizing a shape of a road extending ahead of the vehicle based upon the detecting of each object based upon a reflected wave which results from reflection of the transmission wave;

wherein the method of recognizing a shape of a road extending ahead of the vehicle based upon the detecting further comprises;

(1) generating object-unit data containing at least data representing distances to objects in correspondence with vehicle-width-wise direction angles based upon results of the detecting of each object based upon a reflected wave which results from reflection of the transmission wave;

(2) determining whether each object is moving or stationary based upon a speed of the vehicle and a relative speed of the object as derived from the reflected wave;

(3) extracting objects from the object-unit data which are effective for road shape recognition based upon results of the determining whether each object is moving or stationary based upon a speed of the vehicle and a relative speed of the object which is derived from the reflected wave;

(4) grouping objects of the extracted effective object-unit data which represent monotonically increasing distances as viewed along one of clockwise and counterclockwise angular directions to generate data representative of a road-side-object group;

(5) determining a farthest object in the data representative of the road-side-object group;

(6) determining if the road-side-object group actually contains the farthest object based upon a higher possibility of containing the farthest object on the basis of positional relationships among the farthest object and other objects in the road-side-object group; and

(7) removing the farthest object from the road-side-object group if it is determined that the road-side-object group does not contain the farthest object based upon the higher possibility of positional relationships among the farthest object and other objects in the road-side-object group.