CMOS camera with integral laser ranging and velocity measurement

• US 20040118624A1
• Filed: 12/20/2002
• Published: 06/24/2004
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: Continental Autonomous Mobility US LLC (Continental AG)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Beuhler, Allyson, Polak, Anthony, Castro, Francisco
• Granted Patent: US 6,860,350 B2
• Time in Patent Office: Days
• US Class Current: 180/167
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/931 of land vehicles

Abstract

The invention provides a method and system for adjusting vehicle speed, beginning with a modulated laser pulse being emitted. A reference portion of the emitted modulated laser pulse is extracted, a reflected portion of the emitted modulated laser pulse is received, and the reflected portion is combined with the reference portion on a portion of an imaging array. A determination of a relative velocity is based on the combined reflected portion and reference portion.

Claims

1. A method of adjusting vehicle speed, comprising:

emitting a modulated laser pulse;

extracting a reference portion of the emitted modulated laser pulse;

receiving a reflected portion of the emitted modulated laser pulse;

combining the reflected portion with the reference portion on a portion of an imaging array; and

determining a relative velocity based on the combined reflected portion and reference portion.

2. The method of claim 1 wherein the modulated laser pulse is emitted at a wavelength between 350 nanometers and 1100 nanometers.

3. The method of claim 1 wherein the modulated laser pulse is amplitude modulated at a frequency between 10 MHz and 1000 MHz.

4. The method of claim 1 wherein the reference portion of the emitted modulated laser pulse is extracted with an extractive optical element selected from the group consisting of a partially reflective mirror, an optical fiber, an optical waveguide, and an optical grating.

5. The method of claim 1 wherein the reflected portion of the emitted modulated laser pulse is received at a first mobile vehicle from a reflective surface of a second mobile vehicle.

6. The method of claim 1 wherein the imaging array comprises a CMOS photodetector array.

7. The method of claim 6 wherein the CMOS photodetector array is addressable.

8. The method of claim 6 wherein an integration time of the CMOS photodetector array is controllable.

9. The method of claim 6 wherein a frame rate of the CMOS photodetector array is adjustable.

10. The method of claim 1 further comprising:

comparing the combined reflected portion and reference portion to a threshold level; and

determining the time between a first threshold crossing and a second threshold crossing.

11. The method of claim 1 further comprising:

determining a distance based on the combined reflected portion and reference portion.

12. The method of claim 11 further comprising:

adjusting the vehicle speed based on the distance determination.

13. The method of claim 1 further comprising:

adjusting the vehicle speed based on the relative velocity determination.

14. The method of claim 1 further comprising:

generating an image with the imaging array.

15. A system for adjusting vehicle speed, the system comprising:

means for emitting a modulated laser pulse;

means for extracting a reference portion of the emitted modulated laser pulse;

means for receiving a reflected portion of the emitted modulated laser pulse;

means for combining the reflected portion with the reference portion on a portion of an imaging array; and

means for determining a relative velocity based on the combined reflected portion and reference portion.

16. The system of claim 15 further comprising:

means for comparing the combined reflected portion and reference portion to a threshold level; and

means for determining the time between a first threshold crossing and a second threshold crossing.

17. The system of claim 15 further comprising:

means for determining a distance based on the combined reflected portion and reference portion.

18. The system of claim 17 further comprising:

means for adjusting the vehicle speed based on the distance determination.

19. The system of claim 15 further comprising:

means for adjusting the vehicle speed based on the relative velocity determination.

20. The system of claim 15 further comprising:

means for generating an image with the imaging array.

21. A CMOS camera with integral laser ranging, comprising:

a semiconductor laser;

an extractive optical element operably positioned to extract a portion of a modulated laser pulse emitted from the semiconductor laser;

a CMOS imaging array operably positioned to receive the extracted portion and a reflected portion of the modulated laser pulse; and

a controller operably coupled to the laser and the CMOS imaging array, wherein a relative velocity is determined based on the extracted portion and the reflected portion of the modulated laser pulse.

22. The CMOS camera of claim 21, wherein the extractive optical element is selected from the group consisting of a partially reflective mirror, an optical fiber, an optical waveguide, and an optical grating.

23. The CMOS camera of claim 21, wherein a distance is determined based on the extracted portion and the reflected portion of the modulated laser pulse.

24. An adaptive cruise control for a vehicle, comprising:

a semiconductor laser;

an extractive optical element operably positioned to extract a portion of a modulated laser pulse emitted from the semiconductor laser;

a CMOS imaging array operably positioned to receive the extracted portion and a reflected portion of the modulated laser pulse;

a controller operably coupled to the laser and the CMOS imaging array; and

a cruise control module operably communicating with the controller, wherein a relative velocity is determined based on the extracted portion and a reflected portion of the modulated laser pulse, and a relative velocity signal is sent from the controller to the cruise control module to adjust the vehicle speed.

25. The adaptive cruise control of claim 24, wherein the extractive optical element is selected from the group consisting of a partially reflective mirror, an optical fiber, an optical waveguide, and an optical grating.

26. The adaptive cruise control of claim 24, wherein a distance is determined based on the extracted portion and the reflected portion of the modulated laser pulse.