System and method for detecting an object using pulsed light

• US 20030036881A1
• Filed: 10/31/2002
• Published: 02/20/2003
• Est. Priority Date: 06/22/2000
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lippa, Allan J., Weber, Willes H., Remillard, Jeffrey Thomas
• Granted Patent: US 7,079,974 B2
• Time in Patent Office: Days
• US Class Current: 702/159
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification
• CPC Class Codes: G02B 5/136 plural reflecting elements forming part of a unitary body G02B5/124 takes precedence
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A system and method for detecting an object is provided. The method includes emitting a light pulse. The method further includes receiving a reflection of the light pulse. The method further includes indicating a presence of the object from the received light pulse. Finally, the method includes adjusting sensitivity of the indicating step based on an elapsed time from the emission.

Claims

1. A method for detecting an object, comprising:

emitting a light pulse;

receiving a reflection of said light pulse;

indicating a presence of the object from said received light pulse; and

,

adjusting sensitivity of said indicating step based on an elapsed time from said emission.

2. The method of claim 1 wherein said adjusting step increasing said sensitivity as said elapsed time from said emission increases.

3. The method of claim 2 wherein said sensitivity is increased by decreasing a signal threshold over said elapsed time, said indicating step including:

comparing a power level of said received light pulse to said signal threshold; and

,

determining said presence of the object when said power level is greater than said signal threshold.

4. The method of claim 2 wherein said sensitivity is increased by increasing a signal gain over said elapsed time, said indicating step including:

multiplying said power level of said received light pulse by said gain to obtain a first value; and

,

determining said presence of the object when said first value is greater than a predetermined threshold.

5. The method of claim 1 wherein sensitivity has a first sensitivity value at a first elapsed time and a second sensitivity value at a second elapsed time after said first elapsed time, said second sensitivity being greater than said first sensitivity.

6. The method of claim 1 wherein said emitting step includes:

transmitting said light pulse to a polymeric light reflector; and

,

reflecting said light pulse outwardly from said light reflector.

7. A method for detecting an object, comprising:

emitting a light pulse;

receiving a reflection of said light pulse;

indicating a presence of the object from said received light pulse; and

,

increasing sensitivity of said indicating step when said received light pulse is received at an elapsed time from said emission that is greater than a predetermined time.

8. The method of claim 7 wherein said emitting step includes:

transmitting said light pulse to a polymeric light reflector; and

,

reflecting said light pulse outwardly from said light reflector.

9. A method for detecting an object, comprising:

emitting a light pulse;

receiving a reflection of said light pulse;

indicating a presence of the object from said received light pulse; and

,

decreasing sensitivity of said indicating step when said received light pulse is received at an elapsed time from said emission that is less than a predetermined time.

10. The method of claim 9 wherein said emitting step includes:

transmitting said light pulse to a polymeric light reflector; and

,

reflecting said light pulse outwardly from said light reflector.

11. A method for detecting an object, comprising:

emitting a plurality of light pulses;

receiving a reflection of said light pulses;

indicating a presence of the object from said received light pulses; and

,

adjusting sensitivity of said indicating step based on a travel time of said pulses.

12. The method of claim 11 wherein said emitting step includes:

transmitting said plurality of light pulses to a polymeric light reflector; and

,

reflecting said light pulses outwardly from said light reflector.

13. A system for detecting an object, comprising:

a light source generating a light pulse, said light pulse being emitted;

a light detector configured to receive a reflection of said pulse; and

,

a controller operably connected to said light source and said detector, said controller configured to indicate a presence of the object from said received light pulse, said controller further configured to adjust sensitivity for detecting the object based on an elapsed time from said emission.

14. The system of claim 13 further comprising a polymeric light reflector receiving said light pulse from said light source and reflecting said light pulse toward the object.

15. The system of claim 13 wherein said light source comprises a near infrared diode laser.

16. The system of claim 13 wherein said light detector comprises a near infrared light detector.

17. The system of claim 13 wherein said sensitivity is adjusted to have a first sensitivity value at a first elapsed time and a second sensitivity value at a second elapsed time after said first elapsed time, said second sensitivity being greater than said first sensitivity.

18. An article of manufacture, comprising:

a computer storage medium having a computer program encoded therein for detecting an object, said computer storage medium comprising;

code for inducing a light transmitter to emit a light pulse;

code for storing values indicative of a reflection of said light pulse; and

,

code for indicating a presence of the object from said stored values; and

,

code for adjusting sensitivity for detecting the object based on elapsed time from said emission.