Target detection system using radar and image processing

• US 7,376,247 B2
• Filed: 07/21/2005
• Issued: 05/20/2008
• Est. Priority Date: 04/14/2000
• Status: Expired due to Fees

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Ohta, Akihiro, Oka, Kenji
• Primary Examiner(s): Werner; Brian
• Assistant Examiner(s): Goradia; Shefali
• Application Number:
  US11/188,160
• Publication Number:
  US 20050271253A1
• Time in Patent Office: 1,034 Days
• Field of Search: 342/52, 342/55, 342/70, 342/27, 342/66, 342/90, 342 95- 97, 342/26.R, 342 26 A- 26 D, 342/28, 342/46, 372118-146, 382/100, 382/103, 382/107
• US Class Current: 382/103
• CPC Class Codes: G01C 11/06 by comparison of two or more pictures of the same area
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/41 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G06T 7/97 Determining parameters from multiple pictures depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85
• CPC Class Codes: G06V 10/25 Determination of region of interest [ROI] or a volume of interest [VOI]

Abstract

A target detection system using an EHF radar and the image processing is disclosed, in which the processing time is shortened by mutually complementing the disadvantages of the EHF radar and the image processing thereby to improve the reliability. The system comprises a radar, an image acquisition unit and an image processing ECU. The microcomputer of the ECU specifies an image recognition area based on the power output from the radar, and carries out the image processing only within the specified recognition area for the image obtained from the image acquisition unit. By performing the image processing only for the area where a target is detected by the radar, the time required for image processing is shortened on the one hand and the erroneous detection of letters on the road surface or the like is eliminated.

Claims

1. A target detection system comprising:

a radar for scanning an interior of a specified area by radiating a radio wave, for outputting target data responsive to a target being detected in the specified area based on receipt of a reflected wave, for outputting a flag in a first state in response to the target being detected in a first distance range, for outputting the flag in a second state in response to the target being detected in a second distance range, and for outputting no flag in response to the target being detected in a third distance range;

an image acquisition unit for acquiring an image of the specified area and outputting corresponding image data;

an image recognition unit for outputting edge data by processing the image data output from said image acquisition unit; and

a processing unit for selecting the edge data associated with a distance in the first distance range in response to the flag being output in the first state, for selecting the edge data associated with a distance in the second distance range in response to the flag being output in the second state, and for selecting the edge data associated with a distance in the third distance range in response to no flag being output, and for detecting the target based on the selected edge data and the target data output from said radar.

2. The target detection system according to claim 1, wherein:

said image acquisition unit is equipped with two cameras;

said image recognition unit extracts the edges of input images from said two cameras and generates distance information by calculating a distance to each edge from a parallax between two of the edges.

3. The target detection system according to claim 1, wherein:

said first distance range is 0 to 5 m, said second distance range is 5 to 10m, and said third distance range is more than 10 m.

4. The target detection system according to claim 1, wherein:

said processing unit is configured to remove the edge data associated with a distance in the second distance range and the edge data associated with a distance in the third distance range in response to the flag being output in the first state, is configured to remove the edge data associated with a distance in the first distance range and the edge data associated with a distance in the third distance range in response to the flag being output in the second state, and is configured to remove the edge data associated with a distance in the first distance range and the edge data associated with a distance in the second distance range in response to the flag being output in the third state, and is configured to detect the target based on remaining edge data and the target data output from said radar.

5. The target detection system of claim 1, wherein the first state is a substantially stable state.

6. The target detection system of claim 5, wherein the flag output in the first state is output continuously for a temporary period of time.

7. The target detection system of claim 6, wherein the flag output in the second state is output intermittently.

8. The target detection system of claim 1, wherein the second state is a substantially unstable state.

9. The target detection system of claim 1, wherein the processing unit is configured to only select the edge data associated with a distance in the first distance range in response to the flag being output in the first state, configured to only select the edge data associated with a distance in the second distance range in response to the flag being output in the second state, and configured to only select the edge data associated with a distance in the third distance range in response to no flag being output.