OPTICAL DETECTION SYSTEM

• US 20180081032A1
• Filed: 10/01/2015
• Published: 03/22/2018
• Est. Priority Date: 10/02/2014
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Torruellas, William E., Fry, Robert L., Bankman, Isaac N., Brown, David M., Tadmor, Gil, Clark, JR., Thomas Raphael
• Granted Patent: US 10,295,658 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/484 Transmitters

Abstract

An active optical detection system includes an optical transmitter configured to transmit light in a signal pattern and an optical receiver configured to receive light and determine a correlation between the received light and the signal pattern. The correlation of the received light and the signal pattern is indicative of range to an object.

Claims

1. An active optical detection system comprising:

an optical transmitter configured to transmit light in a signal pattern; and

an optical receiver configured to receive light and determine a correlation between the received light and the signal pattern,

wherein a correlation of the received light and the signal pattern is indicative of range to an object.

2. The active optical detection system of claim 1, wherein the optical receiver comprises:

a photo detector configured to detect the received light; and

processing circuitry configured for the determination of the correlation between the received light and the signal pattern.

3. The active optical detection system of claim 2, wherein the processing circuitry is further configured to determine a transmission angle of the transmitted light.

4. The active optical detection system of claim 3, wherein the processing circuitry is further configured to determine a direction of the object based on the transmission angle of the transmitted light.

5. The active optical detection system of claim 2, wherein the processing circuitry is further configured determine a direction of the object based on a segment of the photo detector or a photo detector of a plurality of photo detectors which received the received light correlated to the signal pattern, wherein the segment of the photo detector or the photo detector of a plurality of photo detectors which received the received light correlated to the signal pattern is indicative of a reception angle.

6. The active optical detection system of claim 2, wherein the processing circuitry is further configured to determine a plurality of correlations between the received light and the signal pattern and determine a velocity of the object based on at least two correlations.

7. The active optical detection system of claim 2, wherein the processing circuitry further comprises detection logic configured to compare the correlation of the received light and the signal pattern to a predetermined correlation threshold, wherein the processing circuitry determination of the range of the object is based on a correlation which satisfies the correlation threshold.

8. The active optical detection system of claim 1, wherein the signal pattern is a pseudo-random bit pattern.

9. The active optical detection system of claim 1, wherein the optical transmitter comprises:

a signal generator configured to generate the signal pattern; and

a light source operably coupled to the signal generator to transmit the light in the signal pattern.

10. The active optical detection system of claim 9, wherein

the light source comprises a plurality of light sources, and

the signal generator is further configured to generate a unique signal pattern for each light source of the plurality of light sources.

11. The active optical detection system of claim 9, wherein the light source comprises at least one laser.

12. The active optical detection system of claim 11, wherein the at least one laser comprises a plurality of lasers and the respective lasers of the plurality of lasers transmit light at different wavelengths.

13. The active optical detection source of claim 9, wherein the light source comprises at least one light emitting diode.

14. The active optical detection system of claim 1, wherein the optical transmitter further comprises an optical amplifier to amplify the transmitted light from the light source prior to transmitting the transmitted light.

15. The active optical detection system of claim 14, wherein the light source comprises a plurality of light sources,

wherein the optical transmitter further comprises:

a multiplexor operably coupled between the plurality of light sources and the optical amplifier to transmit the modulated light signals from the plurality of light sources to the optical amplifier in a single light signal; and

a demultiplexor operably coupled to the optical amplifier to separate the amplified light signals before emitting the light.

16. The active optical detection system of claim 1, wherein the optical receiver further comprises:

an optical filter to inhibit light of wavelengths different than the light source from being received by the photo detector.

17. A method comprising:

transmitting light in a signal pattern;

receiving light at an active optical detection system;

determining a correlation between the received light and the signal pattern; and

determining, by the active optical detection system, a range to an object based on the correlation between the received light and the signal pattern.

18. The method of claim 17 further comprising:

determining a transmission angle of the light or a reception angle of the received light correlated to the signal pattern; and

determining a direction of the object based on transmission angle or reception angle.

19. The method of claim 18 further comprising:

comparing the correlation between the received light and the signal pattern to a predetermined correlation threshold,

wherein the determination of the range or the direction of the object is based on correlations which satisfy the correlation threshold

20. The method of claim 17, wherein

the determining a correlation between the received light and the signal pattern comprises determining a plurality of correlations between the received light and the signal pattern, and

the method further comprises determining a velocity of the object based on at least two correlations.