2D scanning high precision LiDAR using combination of rotating concave mirror and beam steering devices
The present disclosure describes a system and method for coaxial LiDAR scanning. The system includes a first light source configured to provide first light pulses. The system also includes one or more beam steering apparatuses optically coupled to the first light source. Each beam steering apparatus comprises a rotatable concave reflector and a light beam steering device disposed at least partially within the rotatable concave reflector. The combination of the light beam steering device and the rotatable concave reflector, when moving with respect to each other, steers the one or more first light pulses both vertically and horizontally to illuminate an object within a field-of-view; obtain one or more first returning light pulses, the one or more first returning light pulses being generated based on the steered first light pulses illuminating an object within the field-of-view, and redirects the one or more first returning light pulses.
1. A light detection and ranging (LiDAR) scanning system, comprising:
one or more light sources configured to provide one or more light pulses; and
a beam steering apparatus optically coupled to the one or more light sources to receive the one or more light pulses;
the beam steering apparatus comprising a light beam steering device and a reflector having a plurality of reflective surfaces,
wherein the light beam steering device is configured to direct the one or more light pulses to the reflector,
wherein the reflector is configured to redirect, upon receiving the one or more light pulses from the light beam steering device, the one or more light pulses to a field-of-view, and
wherein a combination of the reflector and the light beam steering device, when moving with respect to each other, is configured to:
scan the one or more light pulses both vertically and horizontally to illuminate an object within the field-of-view, and
receive return light formed based on the illumination of the object within the field-of-view, and
direct the return light to a detector,
and wherein the light beam steering device is configured to oscillate between two end vertical positions to obtain multiple scanlines in-between.
2. The LiDAR scanning system of claim 1 , wherein the light beam steering device is an oscillation mirror.
3. The LiDAR scanning system of claim 2 , wherein the oscillation mirror is operative to oscillate about a first axis and the reflector is operative to rotate about a second axis, wherein the combination of the oscillation mirror and the reflector, when moving based on their respective axes, coaxially illuminates the object using the one or more light pulses and receives the return light.
4. The LiDAR scanning system of claim 2 , wherein the oscillation mirror is a one-facet mirror.
5. The LiDAR scanning system of claim 2 , wherein the oscillation mirror is a multiple-facet mirror.
6. The LiDAR scanning system of claim 1 , further comprising one or more optics disposed between the one or more light sources and the light beam steering device, the one or more optics facilitating directing the one or more light pulses to the light beam steering device.
7. The LiDAR scanning system of claim 1 , wherein an angle between any two adjacent reflective surfaces of the plurality of reflective surfaces is other than a 90-degree angle.
8. The LiDAR scanning system of claim 1 , wherein the reflector is a polygonal-shaped structure.
9. The LiDAR scanning system of claim 1 , wherein the one or more light pulses form two beams of light pulses comprising a first light beam and a second light beam, and wherein the beam steering apparatus scans the first light beam in a first range within the field-of-view and scans the second light beam in a second range within the field-of-view, the first range and the second range overlap.
10. The LiDAR scanning system of claim 1 ,
wherein the reflector is further configured to direct the return light to the light beam steering device, and
wherein the light beam steering device is further configured to direct, upon receiving the return light from the reflector, the return light to a detector.
11. A light detection and ranging (LiDAR) system, comprising:
one or more light sources configured to generate one or more light beams;
a beam scanner configured to scan a field-of-view of the LiDAR system using the one or more light beams, the beam scanner comprising a planar mirror and a polygon mirror comprising a plurality of reflective surfaces,
wherein the planar mirror is pivotable along a first axis to direct the one or more light beams to the polygon mirror,
wherein the polygon mirror is rotatable about a second axis orthogonal to the first axis to redirect the one or more light beams to a field-of-view, and
wherein the beam scanner is optically coupled to the one or more light sources and is positioned to:
scan the one or more light beams both vertically and horizontally to illuminate an object within the field-of-view of the LiDAR system,
receive return light formed based on the illumination of the object within the field-of-view, and
direct the return light to a detector,
and wherein the planar mirror is configured to oscillate between two end vertical positions to obtain multiple scanlines in-between.
12. The LiDAR system of claim 11 , wherein the plurality of reflective surfaces comprises four or more reflective surfaces.
13. The LiDAR system of claim 11 , wherein the polygon mirror is operative to rotate about a polygon mirror axle, the polygon mirror axle extending into a block of the polygon mirror through two opposing non-reflective surfaces of the block.
14. The LiDAR system of claim 11 , wherein:
the one or more light beams comprise a first light beam and a second light beam,
the first light beam and the second light beam are scanned by the beam scanner to define a first field-of-view and a second field-of-view, respectively,
the first field-of-view and the second field-of-view, in combination, define the field-of-view of the LiDAR system, and
the first field-of-view and the second field-of-view partially overlap to define an overlap region within the field-of-view of the LiDAR system.
15. The LiDAR system of claim 11 , wherein:
the one or more light beams comprise a first light beam and a second light beam, and
each of the first light beam and second light beam is scanned by the beam scanner to define a respective partial field-of-view of approximately 60 degrees wide in one direction.
16. The LiDAR system of claim 11 , wherein the polygon mirror is further configured to direct the return light to the planar mirror, and
wherein the planar mirror is further configured to direct the return light to the detector.
17. A light detection and ranging (LiDAR) system, comprising:
one or more light sources configured to generate one or more light beams;
a beam scanner configured to scan a field-of-view of the LiDAR system using the one or more light beams, the beam scanner comprising a polygon mirror and a second mirror,
wherein the polygon mirror comprises a plurality of reflective surfaces and is rotatable about a polygon mirror axle to direct the one or more light beams to the second mirror,
wherein the second mirror is pivotable along an axis orthogonal to the polygon mirror axle to direct the one or more light beams to a field-of-view, and
wherein the beam scanner is optically coupled to the one or more light sources and is positioned to:
scan the one or more light beams both vertically and horizontally to illuminate an object within the field-of-view of the LiDAR system,
receive return light formed based on the illumination of the object within the field-of-view, and
direct the return light to a detector,
and wherein the second mirror is configured to oscillate between two end vertical positions to obtain multiple scanlines in-between.
18. The LiDAR system of claim 17 , wherein the plurality of reflective surfaces comprises four or more reflective surfaces.
19. The LiDAR system of claim 17 , wherein:
the one or more light beams comprise a first light beam and a second light beam,
the first light beam and the second light beam are scanned by the beam scanner to define a first field-of-view and a second field-of-view, respectively,
the first field-of-view and the second field-of-view, in combination, define the field-of-view of the LiDAR system, and
the first field-of-view and the second field-of-view partially overlap to define an overlap region within the field-of-view of the LiDAR system.
20. The LiDAR system of claim 17 , wherein the second mirror is further configured to direct the return light to the polygon mirror, and
wherein the polygon mirror is further configured to direct the return light to the detector.
21. A method for performing LiDAR scanning using a LiDAR system, comprising:
directing one or more light pulses from one or more light sources to a beam steering apparatus optically coupled to the one or more light sources, the beam steering apparatus comprising a light beam steering device and a reflector having a plurality of reflective surfaces;
directing, by the light beam steering device of the beam steering apparatus, the one or more light pulses toward the reflector,
upon receiving the one or more light pulses from the light beam steering device, directing, by the reflector, the one or more light pulses to a field-of-view, wherein the one or more light pulses are steered by a combination of the light beam steering device and the reflector both vertically and horizontally to illuminate an object within the field-of-view,
receiving return light formed based on the illumination of the object within the field-of-view, and
directing the return light to a detector,
wherein the light beam steering device is configured to oscillate between two end vertical positions to obtain multiple scanlines in-between.
22. The method of claim 21 , wherein the one or more light pulses form two beams of light pulses comprising a first light beam and a second light beam, wherein the one or more light pulses are steered by scanning the first light beam in a first range within the field-of-view and scanning the second light beam in a second range within the field-of-view, the first range and the second range overlap.
23. The LiDAR system of claim 21 , wherein directing the return light to the detector comprises:
directing, by the reflector, the return light to the light beam steering device, and
directing, upon the light beam steering device receiving the return light from the reflector, the return light to a detector.