Method and apparatus for detecting objects with modifying gain and sensor means

• US 5,311,012 A
• Filed: 03/15/1993
• Issued: 05/10/1994
• Est. Priority Date: 04/10/1990
• Status: Expired due to Fees

• Current Assignee: Autosense LLC
• Original Assignee: Auto-Sense. Limited
• Inventors: Mathews, Paul, Juds, Scott
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): Davenport, Teresa
• Application Number:
  US08/032,736
• Time in Patent Office: 421 Days
• Field of Search: 250/222.1, 250/221, 250/214 AG, 356/28.5, 356/28, 340/567, 340/933, 340/941, 340/942
• US Class Current: 250/222.1
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4918 Controlling received signal intensity, gain or exposure of sensor

Abstract

A method and apparatus are disclosed which allow for the detection of an object (14) by the generation of a radiated beam (18) and a subsequent reflection by the object (14) of a portion (20) thereof. The detection of particulate object material (16) due to a reflection of a portion (22) of the generated beam (18) is minimized.

Claims

1. An object detector for detecting the presence of an object being remotely located at a distance from said object detector and reflecting a beam of radiation therefrom, said object detector comprising:

(a) sensor means having a modifiable gain defined by said distance of said object from said object detector, for receiving said reflected beam of radiation from said object for producing a signal in response to said received reflected beam of radiation and for amplifying said produced signal according to said modifiable gain thereby producing an amplified signal therefrom;

(b) gain means coupled to said sensor means for increasing said modifiable gain for a placement of said object at a first distance from said object detection, for decreasing said modifiable gain for a placement of said object at a second distance from said object detector, said second distance being greater than said first distance, and for increasing said modifiable gain for a placement of said object at a third distance from said object detector, said third distance being greater than said second distance.

2. The object detector of claim 1 further comprising acquisition means coupled to said sensor means and to said gain means for acquiring said beam of radiation of said object.

3. The object detector of claim 1 further comprising generating means coupled to said detecting means for generating a beam of radiation therefrom and for detecting said beam of radiation to said object.

4. The object detector of claim 1 wherein said sensor means comprises photosensor means for defining said detecting signal as having a positive polarity.

5. The object detector of claim 1 wherein said gain means comprises:

second photosensor means for generating a correcting signal; and

threshold means coupled to said photosensor means and to said second photosensor means, for producing a third signal only if said detecting signal is larger than said correcting signal.

6. The object detector of claim 3, wherein said generating means comprises a light emitting diode.

7. The object detector of claim 2, wherein said acquisition means comprises a lens.

8. The object detector of claim 1 wherein said object comprises a motor vehicle.

9. The object detector of claim 6 wherein said generated beam of radiation has a height associated therewith, said generating means further comprising means for reducing said height of said beam.

10. The object detector of claim 5 wherein said gain means further comprises means coupled to said second photosensor means, for forcing said correcting signal to have a negative polarity associated therewith.

11. An object detector having a defined threshold detection distance associated therewith, for use on a motor vehicle for detecting the presence of an object being remotely located at a distance from said object detector, said object detector comprising;

(a) generation means for generating a beam of radiation therefrom and for directing said beam of radiation to said object so as to be reflected thereby;

(b) acquisition means optically coupled to said reflected beam of radiation for acquiring the same;

(c) first detector means coupled to said acquisition means for receiving said reflected beam of radiation and for producing a first signal having a positive polarity in response to said received reflected beam;

(d) second detector means coupled to said acquisition means for receiving said reflected beam of radiation and for producing a second signal having a negative polarity in response to said received reflected beam and for cooperating with said first detector means to define a modifiable gain defined by said distance of said object from said object detector for increasing said modifiable gain for placement of said object at a first distance from said object detection, for decreasing said modifiable gain for a placement of said object at a second distance from said object detection, said second distance being greater than said first distance, and for increasing said modifiable gain for a placement of said object at a third distance from said object detector, said third distance being greater than said second distance;

(e) thresholding means coupled to said first and to said second detector means for receiving said first and second signals and for adding the same and for generating a detection signal in response to said addition and for suppressing said detection signal if said object is located within a predetermined distance from said object detector, said predetermined distance being less than said defined threshold detection distance.

12. The object of claim 11, wherein said generating means comprises a light emitting diode.

13. The object detector of claim 12, wherein said acquisition means comprises a lens.

14. The object detector of claim 12, wherein said generated beam has a height associated therewith, said generating means further comprising means for reducing said height of said generating beam.