INTERLACING SCAN PATTERNS TO ENHANCE REGIONS OF INTEREST
Apparatus and method for enhancing resolution in a light detection and ranging (LiDAR) system. In some embodiments, an emitter is configured to emit a first beam of light pulses over a baseline, first field of view (FoV). Responsive to an activation signal, a controller circuit directs the emitter to concurrently interleave a second beam of light pulses over a second FoV within the first FoV. The first and second beams may be provided at different resolutions and frame rates, and may have pulses with different waveform characteristics to enable decoding using separate detection channels. The interlaced beams provide variable scanning of particular areas of interest within the baseline FoV. The second beam may be activated based on range information obtained from the first beam, or from an external sensor. Separate light sources operative at different wavelengths can be used to generate the first and second beams.
1 . An apparatus comprising:
an emitter of a LiDAR system configured to emit a first beam comprising light pulses at a first resolution to rasterize a baseline, first field of view (FoV); and
a controller circuit configured to, responsive to an activation signal, direct the emitter to concurrently emit a second beam comprising light pulses at a different, second resolution to rasterize a second FoV within the first FoV, the second beam interleaved with the first beam within the second FoV.
2 . The apparatus of claim 1 , wherein the emitter comprises a first beam source configured to generate the first beam and a second beam source configured to generate the second beam.
3 . The apparatus of claim 2 , wherein the second beam source is normally in a deactivated state and the controller circuit operates, responsive to the activation signal, to transition the second beam source from the deactivated state to an activated state to generate the second beam.
4 . The apparatus of claim 2 , wherein prior to the activation signal the second beam is directed to rasterize a first portion of the first FoV outside the second FoV and wherein responsive to the activation signal the second beam is moved so as to only rasterize the second FoV.
5 . The apparatus of claim 1 , wherein the activation signal is generated responsive to range information obtained using the first beam from the first FoV.
6 . The apparatus of claim 1 , wherein the activation signal is generated using an external sensor.
7 . The apparatus of claim 1 , wherein the light pulses in the first beam are provided with a first wavelength and the light pulses in the second beam are provided with a different, second wavelength.
8 . The apparatus of claim 1 , wherein each of the first and second beams are rasterized over the respective first and second FoVs in different orthogonal directions.
9 . The apparatus of claim 1 , further comprising an actuator that mechanically moves an optical element to direct the second beam to the second FoV.
10 . The apparatus of claim 1 , wherein each of the first and second beams are respectively directed using at least a selected one of a micromirror device, a solid-state array device, a galvanometer or a rotatable polygon.
11 . The apparatus of claim 1 , wherein a first portion of the light pulses of the first beam are directed to the second FoV and a remaining second portion of the light pulses of the first beam are directed to the first FoV outside the second FoV at a reduced density.
12 . The apparatus of claim 1 , wherein the light pulses are rasterized along orthogonal x-y axes in rows and columns in both the first FoV and the second FoV.
13 . The apparatus of claim 1 , wherein a size and location of the second FoV are selected based on range information obtained using a detector that detects reflected pulses from the first FoV.
14 . The apparatus of claim 1 , wherein the pulses in the first beam have a first set of waveform characteristics and are processed by a first detection channel of a detector at a first frame rate, and the pulses in the second beam have a different, second set of waveform characteristics that are processed by a different, second detection channel at a different second frame rate.
15 . A method, comprising:
using an emitter of a LiDAR system to emit a first beam comprising light pulses at a first resolution and a first frame rate over a baseline, first field of view (FoV);
receiving an activation signal; and
interleaving the first beam with a second beam comprising light pulses at a higher, second resolution and a higher, second frame rate over a smaller second FoV within the first FoV responsive to the activation signal.
16 . The method of claim 15 , wherein the first beam is rasterized along a first axial direction and the second beam is rasterized along a second axial direction orthogonal to the first axial direction.
17 . The method of claim 15 , further comprising providing the respective pulses in the first and second beams with different waveform characteristics and using the different waveform characteristics to process reflected pulses from the first beam in a first detection channel and reflected pulses from the second beam in a different, second detection channel.
18 . The method of claim 15 , further comprising decoding range information from a target in the first FoV and generating the activation signal responsive to the decoded range information.
19 . The method of claim 15 , further comprising using at least a selected one of a rotatable mirrored polygon, a solid state array integrated circuit device, or a DLP micromirror device to direct each of the respective first and second beams through at least one optical element.
20 . The method of claim 13 , wherein the first beam is generated by a first laser source at a first nominal wavelength and the second beam is generated by a different, second laser source at a different, second nominal wavelength.