Three-dimensional triangulation and time-of-flight based tracking systems and methods
View Patent ↗A three-dimension position tracking system is presented. The system includes transmitters and receivers. A transmitter scans continuous or pulsed coherent light beams across a target. The receiver detects the reflected beams. The system recursively determines the location of the target, as a function of time, via triangulation and observation of the time-of-flight of the incoming and outgoing beams. The transmitter includes ultra-fast scanning optics to scan the receiver's field-of-view. The receiver includes arrays of ultra-fast photosensitive pixels. The system determines the angles of the incoming beams based on the line-of-sight of the triggered pixels. By observing the incoming angles and correlating timestamps associated with the outgoing and incoming beams, the system accurately, and in near real-time, determines the location of the target. By combining the geometry of the scattered beams, as well as the beams' time-of-flight, ambiguities inherent to triangulation and ambiguities inherent to time-of-flight location methods are resolved.
1. A system for tracking a target, comprising:
one or more transmitters to transmit one or more outgoing light beams towards the target at one or more outgoing angles, wherein each transmitter includes an epsilon mirror that rotates about a first axis to transmit the one or more light beams towards the target;
two or more receivers to detect one or more incoming light beams at one or more incoming angles, that are reflected by the target, wherein each receiver includes a one dimensional (1D) array of pixels and an anti-epsilon mirror that rotates about a second axis synchronously with the rotating epsilon mirror to correct for an incoming light beam's azimuth angle that is out of plane for an azimuth angle focused on a single row of a corresponding 1D array of pixels, and wherein the rotating mirrors, for the two or more receivers, synchronously redirects and focuses the one or more incoming light beams at each azimuth angle of the single row of their corresponding 1D array of pixels; and
employing a time of flight of the one or more transmitted light beams reflected by the target to lag rotation of the anti-epsilon mirror respective to rotation of the epsilon mirror, wherein the lagged rotation of the anti-epsilon mirror provides active compensation for different distances between the target and the two or more receivers;
a computing device, including:
a memory for storing instructions; and
one or more processors that execute the instructions to perform actions, comprising:
determining a current location of the target based on a combination of an angular lag for the one or more incoming light beams and a time interval of the one or more outgoing light beams at one or more outgoing angles.
2. The system of claim 1 , wherein the one or more processors perform further actions, comprising:
employing one or more non-visible light sources to transmit one or more non-visible outgoing light beams towards the target at the one or more outgoing angles;
employing one or more visible light sources to transmit one or more visible outgoing light beams towards the target if the two or more receivers detect one or more non-visible incoming light beams that are reflected by the target; and
wherein the one or more non-visible light sources disengage transmission of the one or more non-visible outgoing light beams while the one or more visible light sources are transmitting the one or more visible outgoing light beams.
3. The system of claim 1 , wherein the one or more processors perform further actions, comprising:
determining a size of the target relative to a size of a light beam spot from the one or more incoming light beams based on photon intensity detected by the two or more 1D arrays of pixels.
4. The system of claim 1 , wherein the one or more processors perform further actions, comprising:
differentiating between multiple targets having an equivalent azimuth angle based on resolution of ambiguities between the one or more incoming light beams detected by the two or more 1D arrays of pixels.
5. The system of claim 1 , wherein the one or more processors perform further actions, comprising:
determining a proximate location of the target based on a velocity of the target; and
modifying the one or more outgoing angles based on the proximate location of the target.
6. The system of claim 1 , further comprising:
one or more transmitting optical components for the one or more transmitters;
one or more receiving optical components for the one or more receivers; and
providing a phase difference between the one or more receiving optical components and the one or more transmitting optical components that is based on a time interval between the transmitting of the one or more outgoing light beams and detection of the one or more incoming light beams.
7. A method for tracking a target, comprising:
employing one or more transmitters to transmit one or more outgoing light beams towards the target at one or more outgoing angles, wherein each transmitter includes an epsilon mirror that rotates about a first axis to transmit the one or more light beams towards the target;
employing two or more receivers to detect one or more incoming light beams at one or more incoming angles, that are reflected by the target, wherein each receiver includes a one dimensional (1D) array of pixels and an anti-epsilon mirror that rotates about a second axis synchronously with the rotating epsilon mirror to correct for an incoming light beam's azimuth angle that is out of plane for an azimuth angle focused on a single row of a corresponding 1D array of pixels, and wherein the rotating mirrors, for the two or more receivers, synchronously redirects and focuses the one or more incoming light beams at each azimuth angle of the single row of their corresponding 1D array of pixels; and
employing a time of flight of the one or more transmitted light beams reflected by the target to lag rotation of the anti-epsilon mirror respective to rotation of the epsilon mirror, wherein the lagged rotation of the anti-epsilon mirror provides active compensation for different distances between the target and the two or more receivers; and
employing a computing device to determine a current location of the target based on a combination of an angular lag for the one or more incoming light beams and a time interval of the one or more outgoing light beams at one or more outgoing angles.
8. The method of claim 7 , wherein the computing device performs further actions, comprising:
employing one or more non-visible light sources to transmit one or more non-visible outgoing light beams towards the target at the one or more outgoing angles;
employing one or more visible light sources to transmit one or more visible outgoing light beams towards the target if the two or more receivers detect one or more non-visible incoming light beams that are reflected by the target; and
wherein the one or more non-visible light sources disengage transmission of the one or more non-visible outgoing light beams while the one or more visible light sources are transmitting the one or more visible outgoing light beams.
9. The method of claim 7 , wherein the computing device performs further actions, comprising:
determining a size of the target relative to a size of a light beam spot from the one or more incoming light beams based on photon intensity detected by the two or more 1D arrays of pixels.
10. The method of claim 7 , wherein the computing device performs further actions, comprising:
differentiating between multiple targets having an equivalent azimuth angle based on resolution of ambiguities between the one or more incoming light beams detected by the two or more 1D arrays of pixels.
11. The method of claim 7 , wherein the computing device performs further actions, comprising:
determining a proximate location of the target based on a velocity of the target; and
modifying the one or more outgoing angles based on the proximate location of the target.
12. The method of claim 7 , further comprising:
providing one or more transmitting optical components for the one or more transmitters;
providing one or more receiving optical components for the one or more receivers; and
employing the computing device performs further actions, including:
determining a phase difference between the one or more receiving optical components and the one or more transmitting optical components that is based on a time interval between the transmitting of the one or more outgoing light beams and detection of the one or more incoming light beams.
13. An apparatus for tracking a target, comprising:
a computing device, including:
a memory for storing instructions; and
one or more processors that execute the instructions to perform actions, comprising:
enabling one or more transmitters to transmit one or more outgoing light beams towards the target at one or more outgoing angles, wherein each transmitter includes an epsilon mirror that rotates about a first axis to transmit the one or more light beams towards the target;
enabling two or more receivers to detect one or more incoming light beams at one or more incoming angles, that are reflected by the target, wherein each receiver includes a one dimensional (1D) array of pixels and an anti-epsilon mirror that rotates about a second axis synchronously with the rotating epsilon mirror to correct for an incoming light beam's azimuth angle that is out of plane for an azimuth angle focused on a single row of a corresponding 1D array of pixels, and wherein the rotating mirrors, for the two or more receivers, synchronously redirects and focuses the one or more incoming light beams at each azimuth angle of the single row of their corresponding 1D array of pixels;
employing a time of flight of the one or more transmitted light beams reflected by the target to lag rotation of the anti-epsilon mirror respective to rotation of the epsilon mirror, wherein the lagged rotation of the anti-epsilon mirror provides active compensation for different distances between the target and the two or more receivers; and
determining a current location of the target based on a combination of an angular lag for the one or more incoming light beams and a time interval of the one or more outgoing light beams at one or more outgoing angles.
14. The apparatus of claim 13 , wherein the one or more processors perform further actions, comprising:
employing one or more non-visible light sources to transmit one or more non-visible outgoing light beams towards the target at the one or more outgoing angles;
employing one or more visible light sources to transmit one or more visible outgoing light beams towards the target if the two or more receivers detect one or more non-visible incoming light beams that are reflected by the target; and
wherein the one or more non-visible light sources disengage transmission of the one or more non-visible outgoing light beams while the one or more visible light sources are transmitting the one or more visible outgoing light beams.
15. The apparatus of claim 13 , wherein the one or more processors perform further actions, comprising:
determining a size of the target relative to a size of a light beam spot from the one or more incoming light beams based on photon intensity detected by the two or more 1D arrays of pixels.
16. The apparatus of claim 13 , wherein the one or more processors perform further actions, comprising:
differentiating between multiple targets having an equivalent azimuth angle based on resolution of ambiguities between the one or more incoming light beams detected by the two or more 1D arrays of pixels.
17. The apparatus of claim 13 , wherein the one or more processors perform further actions, comprising:
determining a proximate location of the target based on a velocity of the target; and
modifying the one or more outgoing angles based on the proximate location of the target.
18. The apparatus of claim 13 , further comprising:
one or more transmitting optical components for the one or more transmitters;
one or more receiving optical components for the one or more receivers; and
providing a phase difference between the one or more receiving optical components and the one or more transmitting optical components that is based on a time interval between the transmitting of the one or more outgoing light beams and detection of the one or more incoming light beams.
19. A processor readable non-transitory storage media that includes instructions for tracking a target, wherein the execution of the instructions by one or more processors performs actions, comprising:
employing one or more transmitters to transmit one or more outgoing light beams towards the target at one or more outgoing angles, wherein each transmitter includes an epsilon mirror that rotates about a first axis to transmit the one or more light beams towards the target;
employing two or more receivers to detect one or more incoming light beams at one or more incoming angles, that are reflected by the target, wherein each receiver includes a one dimensional (1D) array of pixels and an anti-epsilon mirror that rotates about a second axis synchronously with the rotating epsilon mirror to correct for an incoming light beam's azimuth angle that is out of plane for an azimuth angle focused on a single row of a corresponding 1D array of pixels, and wherein the rotating mirrors, for the two or more receivers, synchronously redirects and focuses the one or more incoming light beams at each azimuth angle of the single row of their corresponding 1D array of pixels; and
employing a time of flight of the one or more transmitted light beams reflected by the target to lag rotation of the anti-epsilon mirror respective to rotation of the epsilon mirror, wherein the lagged rotation of the anti-epsilon mirror provides active compensation for different distances between the target and the two or more receivers; and
employing a computing device to determine a current location of the target based on a combination of an angular lag for the one or more incoming light beams and a time interval of the one or more outgoing light beams at one or more outgoing angles.
20. The processor readable non-transitory storage media of claim 19 , wherein the one or more processors perform further actions, comprising:
employing one or more non-visible light sources to transmit one or more non-visible outgoing light beams towards the target at the one or more outgoing angles;
employing one or more visible light sources to transmit one or more visible outgoing light beams towards the target if the two or more receivers detect one or more non-visible incoming light beams that are reflected by the target; and
wherein the one or more non-visible light sources disengage transmission of the one or more non-visible outgoing light beams while the one or more visible light sources are transmitting the one or more visible outgoing light beams.
21. The processor readable non-transitory storage media of claim 19 , wherein the one or more processors perform further actions, comprising:
determining a size of the target relative to a size of a light beam spot from the one or more incoming light beams based on photon intensity detected by the two or more 1D arrays of pixels.
22. The processor readable non-transitory storage media of claim 19 , wherein the one or more processors perform further actions, comprising:
differentiating between multiple targets having an equivalent azimuth angle based on resolution of ambiguities between the one or more incoming light beams detected by the two or more 1D arrays of pixels.