Road shape recognition apparatus

• US 20070010937A1
• Filed: 06/29/2006
• Published: 01/11/2007
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sakuma, Yasushi
• Granted Patent: US 7,349,771 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 21/3819 Road shape data, e.g. outline of a route
• CPC Class Codes: G01C 21/3837 Data obtained from a single source
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• 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 2013/93271 in the front of the vehicles

Abstract

A front radar recognizes a still object. A process generates a still object map that shows a relative position between the still object and a subject vehicle. The process groups still objects in the still object map. In terms of each individual still object group, the process selects a left or right evaluation map depending on whether the still object group is positioned to the left or right side of a road. The process defines an additive value for the still object group based on the distance between the vehicle and the still object group and based on the vehicle speed. The process adds the still object group'"'"'s additive value to the selected evaluation map. The process subtracts a subtractive value from part of the evaluation map where no values are added. The process recognizes a road shape based on the evaluation map.

Claims

1. A road shape recognition apparatus in a vehicle having radar means for transmitting and receiving a radar wave to detect an object that reflects the radar wave, the apparatus comprising:

still object map generation means for repeatedly generating a still object map indicating a relative position of a still object with respect to the vehicle by extracting the still object based on information indicative of a position and a speed of an object detected by the radar means;

evaluation value setup means for, each time the still object map is generated, providing each unit region, which results from segmentalizing the still object map, with an evaluation value being positive for a unit region containing a still object and being negative for a unit region not containing a still object;

evaluation map creation means for accumulating an evaluation value provided to each unit region in the still object map, which is repeatedly generated, to create an evaluation map such that a unit region indicating high possibility of presence of the still object contains a large evaluation value; and

road shape recognition means for recognizing a road shape based on an evaluation map created by the evaluation map creation means.

2. The road shape recognition apparatus according to claim 1,

wherein the still object map creation means determines whether or not an extracted still object is a roadside object, and generates the still object map using a still object determined to be a roadside object.

3. The road shape recognition apparatus according to claim 2, further comprising:

left-right determination means for determining a still object shown in the still object map belongs to a left end or a right end of a road,

wherein the evaluation map creation means creates two types of independent evaluation maps, which are a left evaluation map for a still object determined to belong to the left end of the road and a right evaluation map for a still object determined to belong to the right end of the road.

4. The road shape recognition apparatus according to claim 3, further comprising:

grouping means for grouping still objects shown in the still object map based on sizes of the still objects and positional relationship between the still objects,

wherein the left-right determination means performs determination for each group of still objects grouped by the grouping means.

5. The road shape recognition apparatus according to claim 1,

wherein the evaluation value setup means varies the evaluation value according to at least one of a speed of the vehicle and a distance to the unit region.

6. The road shape recognition apparatus according to claim 1, further comprising:

probability calculation means for calculating probability of being a roadside object shown in the still object map,

wherein the evaluation value setup means varies an evaluation value for a unit region containing the still object according to probability calculated by the probability calculation means.

7. The road shape recognition apparatus according to claim 1,

wherein the road shape recognition means recognizes a road shape assuming that a roadside object exists in a unit region assigned with an evaluation value greater than or equal to a threshold value for the evaluation map.

8. A method used to recognize a road shape for a vehicle having a radar for transmitting and receiving a radar wave to detect an object that reflects the radar wave, the method comprising:

repeatedly generating a still object map indicating a relative position of a still object with respect to the vehicle by extracting the still object based on information indicative of a position and a speed of an object detected by the radar;

providing each unit region, which results from segmentalizing the still object map, with an evaluation value being positive for a unit region containing a still object and being negative for a unit region not containing a still object, each time the still object map is generated;

accumulating an evaluation value provided to each unit region in the still object map, which is repeatedly generated, to create an evaluation map such that a unit region indicating high possibility of presence of the still object contains a large evaluation value; and

recognizing a road shape based on the created evaluation map.

9. A road shape recognition apparatus in a vehicle having a radar for transmitting and receiving a radar wave to detect an object that reflects the radar wave, the apparatus comprising:

a still object map generation unit that repeatedly generates a still object map indicating a relative position of a still object with respect to the vehicle by extracting the still object based on information indicative of a position and a speed of an object detected by the radar;

an evaluation value setup unit that provides each unit region, which results from segmentalizing the still object map, with an evaluation value being positive for a unit region containing a still object and being negative for a unit region not containing a still object, each time the still object map is generated;

an evaluation map creation unit that accumulates an evaluation value provided to each unit region in the still object map, which is repeatedly generated, to create an evaluation map such that a unit region indicating high possibility of presence of the still object contains a large evaluation value; and

a road shape recognition unit that recognizes a road shape based on an evaluation map created by the evaluation map creation unit.