LiDAR systems and methods for focusing on ranges of interest
Embodiments discussed herein refer to LiDAR systems to focus on one or more regions of interests within a field of view.
1. A light detection and ranging (LiDAR) system, comprising:
a beam steering system comprising:
a polygon structure; and
a mirror coupled to a mirror controller that controls movement speed and direction of the mirror;
a laser system configured to emit light pulses that are steered by the beam steering system in accordance with a field of view (FOV); and
a region of interest (ROI) controller coupled to the beam steering system and the laser system, the ROI controller configured to:
adjust light pulse intervals such that the LiDAR system has a different horizontal angle scan resolution within a region of interest from an area outside of the region of interest, and
adjust the movement speed of the mirror such that the LiDAR system has a different vertical angle scan resolution within the region of interest from the area outside of the region of interest.
2. The LiDAR system of claim 1 , wherein the ROI controller is configured to:
for light pulses steered towards the at least one ROI, control the movement speed of the mirror such that it is slower compared to the movement speed of the mirror when the light pulses are steered towards a non-ROI.
3. The LiDAR system of claim 1 , wherein the ROI controller is configured to:
adjust the movement speed of the mirror based on a beam steering angle within the FOV.
4. The LiDAR system of claim 1 , wherein the ROI controller is configured to:
adjust a repetition rate of the light pulses based on the beam steering angle.
5. The LiDAR system of claim 1 , wherein the ROI controller is configured to:
when the beam steering system is directed to an ROI:
set the movement speed to a ROI movement speed; and
set the repetition rate to a ROI repetition rate; and
when the beam steering system is directed to a non-ROI:
set the movement speed to a non-ROI movement speed; and
set the repetition rate to a non-ROI repetition rate, wherein the ROI movement speed is slower than the non-ROI movement speed, and wherein the ROI repetition rate is faster than the non-ROI repetition rate.
6. The LiDAR system of claim 5 , wherein the beam steering angle is a vertical beam steering angle.
7. The LiDAR system of claim 5 , wherein the beam steering angle is a horizontal beam steering angle.
8. The LiDAR system of claim 1 , wherein the laser system comprises a plurality of light emission paths each directed towards the beam steering system, wherein the light emission paths are aligned such that a fixed angle exists between any two immediately adjacent light emission paths.
9. The LiDAR system of claim 8 , wherein the ROI controller is configured to control the mirror movement speed based on the fixed angle, a frame rate in which the beam steering system scans the FOV, and the at least one ROI.
10. The LiDAR system of claim 9 , wherein the ROI controller is configured to control the mirror movement speed based on a desired angular resolution.
11. The LiDAR system of claim 8 , wherein the laser system comprises a plurality of fiber tips that are associated with a common laser source, wherein each fiber tip is associated with a respective one the of the plurality of light emission paths.
12. The LiDAR system of claim 8 , wherein the laser system comprises:
a collimator associated with a laser source; and
a plurality of partially reflective mirrors that redirect light energy being emitted from the collimator along respective ones of the plurality of light emission paths.
13. The LiDAR system of claim 1 , wherein the laser system comprises a plurality of light emission paths each directed towards the beam steering system, wherein each light emission path is associated with a collimator coupled to its own laser source.
14. The LiDAR system of claim 13 , wherein an orientation of each collimator is adjustable to control an angle between adjacent collimators.
15. The LiDAR system of claim 1 , further comprising:
a receiver system comprising a focusing lens and at least one detector, wherein a scan region exist between the focusing lens and the mirror;
wherein the mirror comprises a prism; and
wherein the laser system comprises at least one light emission path source positioned outside of the scan region and is directed towards the prism.
16. The LiDAR system of claim 15 , the receiver system comprising a plurality of detectors, wherein a scan region exist between the at least one detector and the mirror;
wherein the mirror comprises a planar portion flanked by a first curved mirror portion and a second curved mirror portion; and
wherein the laser system comprises a plurality of light emission path sources positioned outside of the scan region and are directed towards the mirror.
17. The LiDAR system of claim 16 , wherein the first and second curved mirror portions are used to non-ROI regions, and wherein the planar portion is used for the at least one ROI region.
18. The LiDAR system of claim 1 , wherein the polygon comprises a trapezoidal cross-section in which a first facet is not parallel to a second facet.
19. The LiDAR system of claim 1 , wherein the trapezoidal cross-section produces a scanned pattern having vertical overlap but no curve in a vertical direction.
20. The LiDAR system of claim 1 , wherein the light pulses form a plurality of light beams, and wherein in the area outside of the region of interest, the mirror is configured such that a plurality of immediately adjacent vertical scan lines of the FOV are from different light beams of the plurality of light beams.
21. The LiDAR system of claim 1 , wherein the ROI controller is further configured to adjust the light pulses such that a pulse size of the light pulses inside the region of interest is smaller than a pulse size of the light pulses outside of the region of interest.