Halo suppression for multi-channel lidar detection systems

Abstract

A lidar system and method. Each emitter of the emitter array emits a light beam directed toward the FOV through the scanning unit. In one embodiment, an emission light beam guided according to an alternating energy level illumination protocol enables detection under halo, in which a first light beam emitted by a first emitter and having a first energy level illuminates a first FOV region, and a second light beam emitted by a second emitter and having a second energy level illuminates a second FOV region. And a second light beam emitted by the second emitter and having a second energy level irradiates a second FOV region adjacent to the first FOV region, wherein the first energy level is lower than the second energy level. In another embodiment, an emission light beam guided according to an offset illumination protocol enables detection under halo, where a first light beam emitted by a first emitter in a first plurality of scan lines illuminates the FOV portion at a first time and a second light beam emitted by a second emitter in a second plurality of scan lines at a second time. And a second light beam emitted by the second emitter in the second plurality of scan lines illuminates the FOV portion at a second time after the first time. Each detector of the detector array detects a reflection of the emitted light beam.

Description

Technical Field

[0001] This disclosure generally relates to techniques for scanning the surrounding environment, and more specifically, to systems and methods for detecting objects using lidar (LIDAR) scanning and suitable for use in vehicles. Background Technology

[0002] With the advent of driver assistance systems and autonomous vehicles, cars need to be equipped with systems capable of reliably sensing and interpreting their surroundings, including identifying obstacles, hazards, objects, and other physical parameters that may affect vehicle navigation. To this end, many different technologies have been proposed, such as radar and camera-based systems operating individually or redundantly.

[0003] One consideration for driver assistance systems and autonomous vehicles is the ability to determine the surroundings under diverse environmental conditions, including rain, fog, darkness, bright light, and snow. Light detection and ranging (LIDAR) systems are an example of technologies that can function well under varying conditions by measuring the distance to an object by illuminating it with a light source such as a laser and measuring the reflected pulses with sensors. A LiDAR system may include a light deflector for projecting light emitted from the light source into the environment, wherein the light deflector can be controlled to pivot about at least one axis to project the light to a desired location within the field of view. The received reflections can be used to generate a point cloud or depth map representing the spatial location of objects within the field of view. For some applications, the maximum illumination power of a LiDAR system may be limited by eye safety requirements to avoid potential eye damage, such as thermal damage to the retina, that can occur when the light emission is absorbed by the cornea and lens of the eye.

[0004] Driving environments typically contain highly reflective objects, such as traffic signs and road markings, especially those with retroreflectors. Vehicle-based lidar systems are sensitive to high-intensity reflections, which can lead to undesirable phenomena in the generated point cloud map. One such phenomenon is "ghosting," where highly reflective objects produce additional "ghost" points at different locations in the point cloud map, with a size and shape similar to the actual object's point cloud at its proper location. Another phenomenon is "saturation," where high-intensity reflections received by the photodetector exceed its maximum detection capability (i.e., above the high end of the dynamic range), resulting in an incorrect signal output that is lower or "clipping" relative to the true signal value. Saturated detectors typically require time to return to normal operation, rendering the system ineffective during such recovery periods. Another phenomenon, called "halo," occurs when excess photons from high-intensity reflections incident on a single detection element (e.g., detector pixels in a multi-pixel array) spill over to neighboring detector pixels, leading to erroneous readings. This can manifest as visual artifacts in the resulting point cloud based on sensor output, where the point cloud extends beyond the object's outline and into the surrounding area, causing a bright halo around the object, for example. This can lead to misrepresentations of object size or shape, such as incorrectly determining that a detected object is larger than its actual size or has a different shape. Halo effects in the point cloud can also obscure other nearby objects and prevent their detection. More generally, halos can significantly hinder the accurate identification and determination of the characteristics of highly reflective objects and their surrounding areas, as well as the ability to interpret the area around vehicles, such as determining whether these objects pose a potential driving hazard. Halo effects can be induced by a variety of factors, including optical problems (e.g., incident light from highly reflective neighboring sensor pixels; stray light scattered within the optical components) and electronic problems (e.g., leakage of electrons from photodetectors between different channels).

[0005] Therefore, it is necessary to mitigate the adverse effects of halo in lidar detection systems and provide enhanced detection capabilities under conditions that may lead to halo. Summary of the Invention

[0006] According to one aspect of this disclosure, a lidar system for detecting objects in a field of view (FOV) is thus provided. The lidar system includes a laser emitting unit, a scanning unit, a sensing unit, and a processor. The laser emitting unit includes at least one laser emitter array comprising a plurality of laser emitters, each emitter configured to emit a corresponding laser beam. The scanning unit is configured to direct the emitted beam toward the FOV. The sensing unit includes at least one detector array comprising a plurality of detectors, each detector configured to detect a corresponding reflected beam from the FOV. The processor is configured to: enable detection under halo effects, control at least one of the laser emitting unit and the scanning unit to guide the emitted beam toward the field of view (FOV) according to an alternating energy level illumination protocol, such that a first emitted beam emitted by a first emitter having a first energy level illuminates the first FOV region, and a second emitted beam emitted by a second emitter having a second energy level illuminates a second FOV region adjacent to the first FOV region, wherein the first energy level is lower than the second energy level, and wherein a first detector of the detector array receives a first reflected beam of the first emitted beam, and a second detector of the detector array receives a second reflected beam of the second emitted beam. The first emitted beam may include non-emitting emission from the first emitter, and the second emitted beam may include emitting emission from the second emitter. The first and second emitted beams may differ in at least one of the following attributes: radiant intensity; peak power; beam width; emission operation mode; on / off emission scheme; emission modulation; emission timing; number of pulses in a pulse sequence; total luminous flux; emission wavelength; and / or emission frequency. The first and second emitted beams may be emitted simultaneously. The alternating energy level illumination protocol may include: at a first time, a first emitter emitting a first emission beam having a first energy level to illuminate a first field of view (FOV) region, and a second emitter emitting a second emission beam having a second energy level to illuminate a second FOV region adjacent to the first FOV region; and at a second time, a third emission beam having a second energy level emitted by the second emitter to illuminate a third FOV region adjacent to the first FOV region, and a fourth emission beam having a first energy level emitted by the first emitter to illuminate a fourth FOV region adjacent to both the first and third FOV regions, wherein the first energy level is lower than the second energy level. The processor may be configured to determine at least one updated parameter of a target object in the FOV based on the received reflected beam. The processor may be configured to determine a halo around the target object in the FOV based on the received reflected beam. The lidar system may be configured to implement at least one halo correction measure to compensate for the determined halo.The scanning unit can be configured to scan the FOV by guiding an emission beam along a first plurality of scan lines passing through the FOV; shifting the emission beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines; and guiding the emission beam along the second plurality of scan lines. An alternating energy level illumination protocol can include activating at least one emitter group and deactivating at least one emitter group in at least a portion of the frame, wherein for at least one of the plurality of scan lines, the processor can be configured to activate at least one first emitter group to emit at least one beam during a first segment of the scan line, and deactivate at least one second emitter group to not emit a beam during the first segment of the scan line; wherein the processor can also be configured to deactivate the first emitter group during a second segment of the scan line and activate the second emitter group during the second segment of the scan line. The alternating energy level illumination protocol can be applied to each frame portion of the sequence. A first alternating energy level illumination protocol can be applied to illuminate a first region of the frame, and a second alternating energy level illumination protocol can be applied to illuminate a second region of the frame. The processor can be configured to generate a point cloud including the spatial location of objects in the field of view (FOV) based on reflected beams detected by a detector array, and to determine halo artifacts in at least one of a first point cloud and a second point cloud, wherein an alternating energy level illumination protocol is applied in response to the determination. The scanning unit can be configured to scan an FOV by guiding an emission beam along a first plurality of scan lines passing through the FOV; to shift the emission beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines; and to guide the emission beam along a second plurality of scan lines, wherein the scanning unit can be configured to shift the emission beam by sequentially rotating the scanning device about two axes including a scan axis and a tilt axis, and at least one of the first plurality of scan lines and the second plurality of scan lines can include a plurality of scan lines positioned at a common angle along the tilt axis, and the processor can be configured to activate at least one first group of transmitters to emit at least one beam during the first scan lines of the plurality of scan lines, and to deactivate at least one second group of transmitters to not emit a beam during the first scan lines of the plurality of scan lines, and to deactivate the first group of transmitters during the second scan lines of the plurality of scan lines, and to activate the second group of transmitters during the second scan lines of the plurality of scan lines.For each cell in the frame portion, the processor can be configured to classify the cell into a first category comprising a region containing at least one highly reflective object, or into a second category comprising a region not containing at least one highly reflective object. The processor can also be configured to apply an alternating energy level illumination protocol in response to the classification by activating the emitter group of cells classified as the first category and deactivating the emitter group of cells classified as the second category during one of the plurality of scan lines, and by activating the emitter group of cells classified as the second category and deactivating the emitter group of cells classified as the first category during another of the plurality of scan lines. The processor can be configured to apply at least one correction measure to mitigate halo artifacts in the generated point cloud in response to the classification by applying correction measures only at selected pixels of the point cloud classified as the first category.

[0007] According to another aspect of this disclosure, a method for detecting objects in a field of view (FOV) using a lidar is thus provided. The method includes the step of emitting corresponding laser beams from corresponding emitters of a plurality of laser emitters in at least one laser emitter array of a laser emitting unit. The method includes the step of guiding the emitted beams toward the FOV using a scanning unit. The method includes the step of controlling at least one of the laser emitting unit and the scanning unit to guide the emitted beams toward the FOV according to an alternating energy level illumination protocol, such that a first emitted beam having a first energy level emitted by a first emitter illuminates a first FOV region, and a second emitted beam having a second energy level emitted by a second emitter illuminates a second FOV region adjacent to the first FOV region, wherein the first energy level is lower than the second energy level. The method includes the step of detecting a first reflected beam of the first emitted beam at a first detector of a plurality of detectors in at least one detector array of a sensing unit, and detecting a second reflected beam of the second emitted beam at a second detector of the detector array. The first emitted beam may include non-emitting light from the first emitter, and the second emitted beam may include emitting light from the second emitter. The control steps may include controlling at least one attribute of at least one of a first emitted beam and a second emitted beam, wherein the attributes include: radiant intensity; peak power; beam width; emission operation mode; on / off emission scheme; emission modulation; emission timing; number of pulses in a pulse sequence; total luminous flux; emission wavelength; and / or emission frequency. The first and second emitted beams may be emitted simultaneously. An alternating energy level illumination protocol may include: a first emitter emitting a first emitted beam having a first energy level at a first time to illuminate a first field of view (FOV) region; a second emitter emitting a second emitted beam having a second energy level at the first time to illuminate a second FOV region adjacent to the first FOV region; a second emitter emitting a third emitted beam having the second energy level at a second time to illuminate a third FOV region adjacent to the first FOV region; and a first emitter emitting a fourth emitted beam having the first energy level at the second time to illuminate a fourth FOV region adjacent to the first FOV region and the third FOV region, wherein the first energy level is lower than the second energy level. The method may also include the step of determining at least one updated parameter of a target object in the FOV based on the received reflected beam. The method may further include the step of determining the halo of a target object in the field of view (FOV) based on the received reflected beam. The method may also include the step of implementing at least one halo correction measure to compensate for the determined halo.The scanning unit can be configured to scan the field of view (FOV) by guiding an emission beam along a first plurality of scan lines passing through the FOV; shifting the emission beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines; and guiding the emission beam along the second plurality of scan lines. An alternating energy level illumination protocol can include activating at least one emitter group of the emitter and deactivating at least one emitter group of the emitter in at least a portion of the frame, wherein for at least one of the multiple scan lines, at least one first emitter group of the emitter can be activated to emit at least one beam during a first segment of the scan line, and at least one second emitter group of the emitter can be deactivated to not emit a beam during the first segment of the scan line; and the first emitter group can be deactivated during a second segment of the scan line, and the second emitter group can be activated during the second segment of the scan line. The alternating energy level illumination protocol can be applied to each frame portion of the sequence. A first alternating energy level illumination protocol can be applied to illuminate a first region of the frame, and a second alternating energy level illumination protocol can be applied to illuminate a second region of the frame. The method may further include the following steps: generating a point cloud including the spatial location of an object in the field of view (FOV) based on a reflected beam detected by a detector array; and determining a halo artifact in at least one of a first point cloud and a second point cloud, wherein an alternating energy level illumination protocol is applied in response to the determination. The scanning unit can be configured to scan an FOV by guiding an emission beam along a first plurality of scan lines passing through the FOV; to shift the emission beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines; and to guide the emission beam along the second plurality of scan lines. The scanning unit can also be configured to shift the emission beam by sequentially rotating the scanning device about two axes, including a scan axis and a tilt axis. At least one of the first plurality of scan lines and the second plurality of scan lines can include a plurality of scan lines positioned at a common angle along the tilt axis. At least one first group of transmitters can be activated to emit at least one beam during the first scan line of the plurality of scan lines, and at least one second group of transmitters can be deactivated to not emit a beam during the first scan line of the plurality of scan lines. The first group of transmitters can be deactivated during the second scan line of the plurality of scan lines, and the second group of transmitters can be activated during the second scan line of the plurality of scan lines.The method may further include the following steps: for each cell in a frame portion, classifying the cell into a first category comprising a region containing at least one highly reflective object, or into a second category comprising a region not containing at least one highly reflective object; and applying an alternating energy level illumination protocol in response to the classification by activating the emitter group of cells classified as the first category and deactivating the emitter group of cells classified as the second category during one of the plurality of scan lines, and by activating the emitter group of cells classified as the second category and deactivating the emitter group of cells classified as the first category during another of the plurality of scan lines. The method may further include the following step: applying at least one correction measure to mitigate halo artifacts in the point cloud generated in response to the classification by applying correction measures only at selected pixels of the point cloud classified as the first category.

[0008] According to another aspect of this disclosure, a lidar system for detecting objects in a field of view (FOV) is thus provided. The lidar system includes a laser emitting unit, a scanning unit, a sensing unit, and a processor. The laser emitting unit includes at least one laser emitter array comprising a plurality of laser emitters, each emitter configured to emit a corresponding laser beam. The scanning unit is configured to guide the emitted beam toward the FOV and scan the FOV by guiding the emitted beam along multiple scan lines passing through the FOV. The sensing unit includes at least one detector array comprising a plurality of detectors, each detector configured to detect a corresponding reflected beam from the FOV. The processor is configured to: enable detection under halo effects, control a scanning unit according to an offset illumination protocol, guide an emitted beam along a first plurality of scan lines passing through the field of view (FOV), spatially shift the emitted beam from a first set of positions associated with the first plurality of scan lines to a second set of positions associated with a second plurality of scan lines, the displacement of the second plurality of scan lines relative to the first plurality of scan lines defining a tilt increment transverse to the scanning direction along the scan axis, and guide the emitted beam along the second plurality of scan lines such that a first emitted beam emitted by a first transmitter in the transmitter array of the first plurality of scan lines illuminates a portion of the FOV at a first time, and a second emitted beam emitted by a second transmitter in the transmitter array of the second plurality of scan lines illuminates the FOV portion at a second time after the first time, wherein a first detector in the detector array receives a first reflected beam of the first emitted beam, and a second detector in the detector array receives a second reflected beam of the second emitted beam. The first and second emitted beams may be in a common frame portion. The first emitted beam may be in a first frame portion, and the second emitted beam may be in a second frame portion. The processor can be configured to repeatedly spatially shift the emitted beam from a first set of positions to a second set of positions via multiple corresponding spatial displacements of a frame portion sequence, each spatial displacement defining a corresponding tilt increment. The overall spatial displacement, including all tilt increments of the frame portion sequence, may not exceed the angular size of the transmitter array. The FOV may include at least one region of interest (ROI) and at least one region of non-interest (NROI), wherein the NROI is scanned along multiple scan lines defining a first scan resolution, and the ROI is scanned along multiple scan lines defining a second scan resolution higher than the first scan resolution. The NROI may be scanned along multiple scan lines including relative spatial displacements corresponding to the angular size of the transmitter array, and the ROI may be scanned along multiple scan lines including relative spatial displacements corresponding to the angular size between adjacent transmitters of the transmitter array.The processor can be configured to: generate a first point cloud and a second point cloud based on reflected beams from a field of view (FOV) detected by a detector array, each point cloud including the spatial location of an object within the FOV; compare the first point cloud with the second point cloud to detect inconsistencies between them. The FOV may include at least one target object and at least one highly reflective object, and the processor can be configured to determine halo artifacts in at least one of the first and second point clouds. Alternatively, the FOV may include at least one target object and at least one highly reflective object, and the processor can be configured to generate a first point cloud including the spatial location of the first region of the FOV based on reflected beams from a first region of the FOV detected by a detector array; determine halo artifacts in a second point cloud associated with a highly reflective object; generate a second point cloud including the spatial location of the second region of the FOV based on reflected beams from the second region of the FOV detected by the detector array; and detect the target object in the second point cloud.

[0009] According to another aspect of this disclosure, a method for detecting objects in a field of view (FOV) using a lidar is thus provided. The method includes the step of emitting corresponding laser beams from corresponding emitters of a plurality of laser emitters in at least one laser emitter array of a laser emitting unit. The method includes the step of guiding the emitted beams toward the FOV using a scanning unit. The method includes the steps of: controlling the scanning unit to guide the emitted beams toward the FOV according to an offset illumination protocol to enable detection under halo effects, wherein the scanning unit guides the emitted beams along first plurality of scan lines passing through the FOV, spatially shifting the emitted beams from a first set of positions associated with the first plurality of scan lines to a second set of positions associated with second plurality of scan lines, the displacement of the second plurality of scan lines relative to the first plurality of scan lines defining a tilt increment transverse to the scanning direction along the scanning axis, and guiding the emitted beams along the second plurality of scan lines such that a first emitted beam emitted by a first emitter in the emitter array of the first plurality of scan lines illuminates a portion of the FOV at a first time, and a second emitted beam emitted by a second emitter in the emitter array of the second plurality of scan lines illuminates a portion of the FOV at a second time after the first time. The method includes the steps of: detecting a first reflected beam of a first emitted beam at a first detector of a plurality of detectors in at least one detector array of a sensing unit, and detecting a second reflected beam of a second emitted beam at a second detector of the detector array. The first emitted beam and the second emitted beam may be in a common frame portion. The first emitted beam may be in a first frame portion, and the second emitted beam may be in a second frame portion. The method may include repeatedly spatially shifting the emitted beam from a first set of positions to a second set of positions by a plurality of corresponding spatial displacements in a frame portion sequence, each spatial displacement defining a corresponding tilt increment. The overall spatial displacement including all tilt increments in the frame portion sequence may not exceed the angular size of the transmitter array. The FOV may include at least one region of interest (ROI) and at least one region of non-interest (NROI), wherein the NROI is scanned along a plurality of scan lines defining a first scan resolution, and the ROI is scanned along a plurality of scan lines defining a second scan resolution higher than the first scan resolution. The NROI may be scanned along a plurality of scan lines including relative spatial displacements corresponding to the angular size of the transmitter array, and the ROI may be scanned along a plurality of scan lines including relative spatial displacements corresponding to the angular size between adjacent transmitters of the transmitter array. The method may further include the following steps: generating a first point cloud and a second point cloud based on the reflected beams from the FOV detected by the detector array, each point cloud including the spatial location of an object in the FOV; and comparing the first point cloud with the second point cloud to detect inconsistencies between them.The field of view (FOV) may include at least one target object and at least one highly reflective object, and the method may further include the step of determining halo artifacts in at least one of a first point cloud and a second point cloud. The FOV may include at least one target object and at least one highly reflective object, and the method may further include the following steps: generating a first point cloud including the spatial location of the first region of the FOV based on reflected beams from a first region of the FOV detected by a detector array; determining halo artifacts in a second point cloud associated with the highly reflective object; generating a second point cloud including the spatial location of the second region of the FOV based on reflected beams from a second region of the FOV detected by a detector array; and detecting the target object in the second point cloud.

[0010] According to another aspect of this disclosure, a lidar system for detecting objects in a field of view (FOV) is thus provided. The system includes a laser emitting unit, a scanning unit, a sensing unit, and a processor. The laser emitting unit includes at least one laser emitter array comprising a plurality of laser emitters, each configured to emit a corresponding laser beam. The scanning unit is configured to guide the emitted beam toward the FOV and scan the FOV by guiding the emitted beam along multiple scan lines passing through the FOV. The sensing unit includes at least one detector array comprising a plurality of detectors, each configured to detect a corresponding reflected beam from the FOV. The processor is configured to control at least one of the laser emitting unit and the scanning unit to guide the emitted beam toward the FOV according to a modified timing illumination protocol, enabling detection under halo effects. The modified timing illumination protocol includes classifying each cell of a frame portion into a first category comprising a region containing at least one highly reflective object, or into a second category comprising a region not containing at least one highly reflective object, for at least one scan line segment of a frame portion. The modified timing illumination protocol further includes: in response to classification, for each of the first category units classified as a first category, emitting at least one first category pulse beam emission to illuminate the first category unit, and for each of the second category units classified as a second category, emitting a second category pulse beam emission sequence to illuminate the second category unit, wherein the emission timing of each emission in the second category pulse beam emission sequence is time-biased relative to the first category pulse beam emission of the first category unit. A first detector of the detector array receives at least one reflection of the first category pulse beam emission, and a second detector of the detector array receives the reflection of the second category pulse beam emission. The time displacement of the emission of the second set of consecutive second category pulse beam emissions relative to the first set of second category pulse beam emissions may be non-uniform. Multiple first category pulse beam emissions may be emitted to illuminate the first category units, wherein the time displacement between the emission of consecutive second category pulse beam emissions may be non-uniform relative to the emission of consecutive first category pulse beam emissions. The processor may be configured to determine the validity of a response signal based on the accumulation of detector response signals received from the detection of units classified as second category units. The modified timing illumination protocol may be applied to at least one frame of the region of interest (ROI) of the FOV.

[0011] According to another aspect of this disclosure, a method for detecting objects in a field of view (FOV) using a lidar is thus provided. The method includes the step of emitting corresponding laser beams from corresponding emitters of a plurality of laser emitters in at least one laser emitter array of a laser emitting unit. The method includes the step of scanning the FOV using a scanning unit by guiding the emitted beams along multiple scan lines passing through the FOV. The method includes the step of controlling at least one of the laser emitting unit and the scanning unit to guide the emitted beams toward the FOV according to a modified illumination protocol, in order to enable detection under halo effects. The modified timing illumination protocol includes classifying each unit of a frame portion, for at least one scan line segment, into a first category comprising a region containing at least one highly reflective object, or into a second category comprising a region not containing at least one highly reflective object. The modified timing illumination protocol further includes: in response to classification, for each of the first category units classified as a first category, emitting at least one first category pulse beam emission to illuminate the first category unit, and for each of the second category units classified as a second category, emitting a second category pulse beam emission sequence to illuminate the second category unit, wherein the emission timing of each emission in the second category pulse beam emission sequence is time-biased relative to the first category pulse beam emission of the first category unit. The method further includes the steps of: detecting at least one reflection of the first category pulse beam emission at a first detector of the detector array, and detecting a reflection of the second category pulse beam emission at a second detector of the detector array. The time displacement of the emission of the second set of consecutive second category pulse beam emissions relative to the first set of second category pulse beam emissions may be non-uniform. Multiple first category pulse beam emissions may be emitted to illuminate the first category units, wherein the time displacement between the emission of consecutive second category pulse beam emissions may be non-uniform relative to the emission of consecutive first category pulse beam emissions. The method may include the step of: determining the validity of a response signal based on the accumulation of detector response signals received from the detection of units classified as second category units. The modified timing illumination protocol may be applied to at least one frame of the region of interest (ROI) of the field of view (FOV). Attached Figure Description

[0012] This disclosure will be more fully understood and appreciated through the following detailed embodiments, taken in conjunction with the accompanying drawings, in which:

[0013] Figure 1A This is a schematic diagram of a lidar system constructed and operated according to embodiments of the present disclosure;

[0014] Figure 1B It is from the embodiments of this disclosure Figure 1A A diagram showing an exemplary output of a single scan cycle of a lidar system;

[0015] Figure 2A This is a schematic diagram of an exemplary multi-channel lidar system constructed and operated according to embodiments of the present disclosure;

[0016] Figure 2B This is a schematic diagram of another exemplary multi-channel lidar system constructed and operated according to another embodiment of the present disclosure;

[0017] Figure 3A This is an illustration of an exemplary scanning pattern of a field of view obtained using a scanning device according to embodiments of the present disclosure;

[0018] Figure 3B This is an illustration of another exemplary scanning mode of a field of view obtained using a scanning device according to another embodiment of the present disclosure;

[0019] Figure 4A This is an illustration of a first exemplary detector array constructed and operated according to embodiments of the present disclosure;

[0020] Figure 4B This is an illustration of a second exemplary detector array constructed and operated according to another embodiment of the present disclosure;

[0021] Figure 4C This is an illustration of a third exemplary detector array constructed and operated according to another embodiment of the present disclosure;

[0022] Figure 5A This is a schematic diagram of an exemplary illumination protocol with a uniform energy level and an emitted beam that is completely incident on an object.

[0023] Figure 5B This is a schematic diagram of another exemplary illumination protocol with a uniform energy level and an emitted beam partially incident on an object;

[0024] Figure 6A This is a schematic diagram of an exemplary illumination protocol for an emitted light beam having alternating energy levels and being fully incident on an object, operating according to another embodiment of this disclosure;

[0025] Figure 6B This is a schematic diagram of another exemplary illumination protocol, which operates according to another embodiment of the present disclosure, and has an emitted light beam having alternating energy levels and is partially incident on an object;

[0026] Figure 6C This is a schematic diagram of another exemplary illumination protocol, which operates according to another embodiment of the present disclosure, and has an emitted light beam having alternating energy levels and being partially incident on an object over an extended duration.

[0027] Figure 7AThis is an illustration of an exemplary illumination protocol operating according to embodiments of the present disclosure, wherein a region of interest in the scene is partially occluded;

[0028] Figure 7B This is an illustration of another exemplary illumination protocol with vertical offset illumination operating according to embodiments of the present disclosure;

[0029] Figure 7C illustrates the use of an embodiment according to this disclosure. Figure 7B An image frame sequence of an exemplary point cloud map obtained using an illumination protocol;

[0030] Figure 8A This is an exemplary front view schematic diagram of mutual illumination between a target object and a highly reflective object positioned at the same distance but at different heights, operated according to embodiments of the present disclosure.

[0031] Figure 8B This is an exemplary side view of a target object and a highly reflective object positioned at the same distance but at different heights, operating according to embodiments of the present disclosure, illuminating each other.

[0032] Figure 8C This is an exemplary front view schematic diagram of mutual illumination between target objects positioned at different distances and different heights and operated according to embodiments of the present disclosure;

[0033] Figure 8D This is an exemplary side view of a target object and a highly reflective object positioned at different distances and heights, operating according to embodiments of the present disclosure, illuminating each other.

[0034] Figure 8E This is an exemplary front view schematic diagram of mutual illumination between target objects positioned at different distances and at overlapping heights, operated according to embodiments of the present disclosure;

[0035] Figure 8F This is an exemplary side view schematic illustration of mutual illumination between target objects positioned at different distances and at overlapping heights, operated according to embodiments of the present disclosure.

[0036] Figure 8G This is an exemplary front view schematic diagram of the separation illumination of a target object and a highly reflective object located at the same distance but at different heights, operated according to embodiments of the present disclosure.

[0037] Figure 8H This is an exemplary side view schematic diagram of the separate illumination of a target object and a highly reflective object positioned at the same distance but at different heights, operated according to embodiments of the present disclosure.

[0038] Figure 8IThis is an exemplary front view schematic diagram of the separation illumination of a target object and a highly reflective object positioned at different distances and different heights according to embodiments of the present disclosure;

[0039] Figure 8J This is an exemplary side view schematic diagram of the separation illumination of a target object and a highly reflective object positioned at different distances and different heights according to embodiments of the present disclosure;

[0040] Figure 9 This is the use of the embodiments of this disclosure. Figure 7B A sequence of frames of exemplary point cloud maps obtained using a vertical offset illumination protocol;

[0041] Figure 10A This is an illustration of an exemplary default scanning mode with variable resolution for different sub-regions of the field of view;

[0042] Figure 10B This is an illustration of an exemplary vertical tilt scanning mode with variable resolution for different sub-regions of the field of view, operating according to embodiments of the present disclosure;

[0043] Figure 11 This is an illustration of a sequence of exemplary vertical tilt scan cycles with variable resolution, operated according to embodiments of the present disclosure;

[0044] Figure 12 This is a schematic diagram of an exemplary frame divided into sub-regions, operating according to embodiments of the present disclosure;

[0045] Figure 13 This is an illustration of an exemplary default illumination protocol for a multi-channel transmitter array used in the frame portion;

[0046] Figure 14A This is an illustration of an exemplary alternating illumination protocol for selectively activated emission on a frame portion sequence applied to a selected frame sub-region, operating according to embodiments of the present disclosure;

[0047] Figure 14B This is an illustration of another exemplary alternating illumination protocol for selectively activated emission applied to selected frame sub-regions, operating according to embodiments of the present disclosure.

[0048] Figure 14C It operates according to embodiments of this disclosure and Figure 13 A diagram illustrating the timing of the emission related to the default illumination protocol;

[0049] Figure 14D It operates according to embodiments of this disclosure and Figure 14A A diagram illustrating the timing of the emission related to the alternating illumination protocol;

[0050] Figure 15A This is the use of the embodiments of this disclosure. Figure 14A An illustration of a general reflection pattern obtained by an alternating illumination protocol, wherein the retroreflector is in a first exemplary position within the field of view (FOV);

[0051] Figure 15B This is the use of the embodiments of this disclosure. Figure 14A An illustration of a general reflection pattern obtained by an alternating illumination protocol, wherein the retroreflector is in a second exemplary position within the field of view (FOV);

[0052] Figure 16 This is an illustration of another exemplary alternating illumination protocol for selectively activated emission over a frame sequence, operating according to embodiments of the present disclosure, applied to selected frame sub-regions;

[0053] Figure 17A This is an illustration of exemplary illumination performed by a multi-channel emitter array in a scene having a retroreflector close to a target object, according to embodiments of the present disclosure;

[0054] Figure 17B The operation corresponding to the embodiments of this disclosure Figure 17A A diagram illustrating the detector macropixel response distribution under exemplary illumination;

[0055] Figure 18 This is a schematic illustration of an exemplary frame portion having a classification of macropixels between highly reflective and non-highly reflective objects, operating according to embodiments of the present disclosure;

[0056] Figure 19A This is a diagram illustrating an exemplary default timing protocol for transmissions of different categories of transmitter groups;

[0057] Figure 19B This is an illustration of a modified timing protocol operating according to embodiments of the present disclosure for transmission by transmitter groups of different classifications having relative time offsets therebetween; and

[0058] Figure 20 This is an illustration of multiple timing diagrams demonstrating operation according to embodiments of the present disclosure to identify invalid detections from a halo effect. Detailed Implementation

[0059] This disclosure overcomes the shortcomings of the prior art by providing methods and systems for mitigating halo effects in lidar detection systems. Specifically, the disclosed methods and systems relate to maintaining the object detection capability of a lidar detection system even when subjected to halo effects.

[0060] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms such as those defined in common dictionaries shall be interpreted as having the same meaning as they have in the context of the specification and claims, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein. For the sake of brevity and / or clarity, well-known functions or constructions may not be described in detail.

[0061] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. Rather, these terms are used only to distinguish one element, component, region, layer, and / or part from another.

[0062] It should be understood that when a component is referred to as being "on," "attached" to, "operably coupled" to, "operably linked" to, "operably engaged" with, "connected" to, "coupled" to, "contacted" with, or "added" to another component, it can be directly on, attached to, connected to, operably coupled to, operably engaged with, coupled to, added to, and / or in contact with the other component, or there may be intermediate components. Conversely, when a component is referred to as "directly contacting" or "directly adding" to another component, there are no intermediate components and / or steps.

[0063] Whenever the terms “about” or “approximately” are used, they are intended to refer to a measurable value, such as a quantity, duration of time, etc., and are intended to cover variations from specified values ​​(e.g., ±20%, ±10%, ±5%, ±1%, ±0.1%), as such variations are appropriate for performing the disclosed methods.

[0064] For clarity, certain features of this disclosure described in the context of individual embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, various features of this disclosure described in the context of a single embodiment may also be provided individually or in any suitable sub-combination, or applicable to any other described embodiment of this disclosure. Certain features described in the context of various embodiments are not considered essential features of those embodiments unless the embodiment does not function without those elements.

[0065] Throughout this application, various embodiments may be presented in a range format. It should be understood that the range format description is merely for convenience and brevity and should not be construed as a rigid limitation on the range of embodiments. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and individual numerical values ​​within that range, regardless of the width of the range. For example, a description of a range such as from 1 to 6 should be considered as having specifically disclosed subranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within that range, such as 1, 2, 3, 4, 5, and 6. Whenever a range of numerical values ​​is indicated herein, it means any referenced number (fraction or integer) included within the indicated range. For example, the phrases “range between the first and second indicator numbers” and “range from the first indicator number to the second indicator number” are used interchangeably herein and are intended to include the first and second indicator numbers and all fractions and integers between them.

[0066] Whenever the term "plurality" or "a plurality" is used, it is intended to include, for example, "multiple" or "two or more". The term "plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, etc. When used herein, the set of terms may include one or more items. Unless explicitly stated otherwise, the method embodiments described herein are not limited to a particular order or sequence. Furthermore, some of the described method embodiments or elements thereof may occur or be performed simultaneously, at the same point in time, or concurrently.

[0067] As used herein, the term “repetitively” should be interpreted broadly to include any one or more of the following: “continuously,” “periodicly repetitive,” and “non-periodicly repetitive,” wherein periodic repetition is characterized by a constant length interval between repetitions, and non-periodic repetition is characterized by a variable length interval between repetitions.

[0068] The term "highly reflective object" is used herein to refer to an object or entity that reflects and / or emits a considerably high level of radiation intensity, such that reflections received from such an object may cause undesirable electro-optical phenomena, such as a halo effect. Examples of highly reflective objects may include, but are not limited to, traffic signs and road markings with retroreflective elements (e.g., retroreflective stickers on the rear bumper of a vehicle), and high-radiation light emitting sources, such as lidar systems from oncoming vehicles.

[0069] The terms “user” and “operator” are used interchangeably herein to refer to any individual or group of individuals who use or operate the methods, apparatus or systems according to the disclosed embodiments.

[0070] This document describes disclosed embodiments for illustrative purposes within the context of an automotive LiDAR system for driver assistance applications, but it can be further adapted to other contexts and uses. The term "vehicle" should be interpreted broadly to mean any type of vehicle or transport equipment operating in any environment (e.g., air, land, or sea), including but not limited to: automobiles, cars, vans, trucks, motorcycles; aircraft or sea vessels; unmanned aerial vehicles (drones); electric or hybrid vehicles; electric bicycles (e-bikes); electric scooters, etc.

[0071] Now for reference Figure 1A , Figure 1A This is a schematic diagram of a lidar system (generally designated 100) constructed and operated according to the disclosed embodiments. The lidar system 100 includes a projection unit 102, a scanning unit 104, a sensing unit 106, and a processing unit 108. The projection unit 102 includes at least one light source 112. The scanning unit 104 includes at least one light deflector 114. The sensing unit 106 includes at least one sensor 116. The processing unit 108 includes at least one processor 118. The lidar system 100 can be mounted on a vehicle 110. The projection unit 102 projects light into the environment of the lidar system 100, such as the environment surrounding the vehicle 110. The scanning unit 104 directs the projected light into the environment to scan the field of view (FOV) 120 around the vehicle 110, and the scanning unit 104 directs reflected light from the environment towards the sensing unit 106. The sensing unit 106 receives reflections from the environment around the vehicle 110 and sends reflection signals indicating light reflected from objects in the FOV 120 to the processing unit 108. The lidar system 100 optionally includes at least one optical window 124 for directing projected light toward the field of view (FOV) 120 and / or for receiving reflected light from objects within the FOV 120. The optical window 124 may include or be associated with an optical component for manipulating one or more properties of the projected or reflected light, such as collimation of the projected light or focusing of the reflected light. The optical window 124 may be implemented, for example, by an opening, a flat window, a lens, or another type of optical element.

[0072] At least a portion of the lidar system 100 may be mounted to or integrated into a part of the vehicle 110, such as: a bumper, fender, side panel, spoiler, roof, headlight assembly, taillight assembly, rearview mirror assembly, hood, trunk, or any other suitable part of the vehicle 110 capable of accommodating at least a portion of the lidar system 100. In some embodiments, the lidar system 100 may capture a complete surround view of the environment of the vehicle 110, for example, characterized by a 360-degree horizontal field of view. In one example, the lidar system 100 may include a single scanning unit 104 mounted on the roof of the vehicle 110. In another example, the lidar system 100 may include multiple scanning units 104, each having a corresponding field of view (e.g., 80° to 120°), such that the overall horizontal field of view is covered by a 360-degree scan around the vehicle 110. Alternatively, a 360-degree horizontal field of view can be achieved by mounting multiple lidar systems 100 on the vehicle 110, each lidar system 100 having a single scanning unit 104. It should be noted that one or more lidar systems 100 need not provide a complete 360° field of view, and in some cases, a narrower field of view may be useful. For example, the vehicle 110 may employ a first lidar system 100 having a first FOV (e.g., approximately 75°) pointing in the forward direction of the vehicle, and a second lidar system 100 optionally having a second FOV (e.g., approximately 75°) pointing in the rearward direction (e.g., optionally having a lower detection range). It should also be noted that the one or more lidar systems 100 may be characterized by different vertical field of view angles.

[0073] The term "field of view (FOV) of a lidar system" can broadly encompass the range of the observable environment in which an object can be detected by the lidar system. Similarly, the term "instantaneous field of view (FOV)" can broadly encompass the range of the observable environment in which an object can be detected by the lidar system at any given moment. For example, for a scanning lidar system, the instantaneous FOV is narrower than the entire FOV of the lidar system and can be moved within the FOV of the lidar system to enable detection in other parts of the FOV.

[0074] The light source 112 of the projection unit 102 is configured to emit light, such as a series of light pulses, into the environment. The light source 112 can be a laser, such as a solid-state laser, a semiconductor laser, or a laser diode, or an alternative light source, such as a light-emitting diode (LED). For example, the light source 112 may include multiple laser diodes coupled together. For example, the light source 112 can be implemented by a vertical-cavity surface-emitting laser (VCSEL), or alternatively by an external-cavity diode laser (ECDL). In some examples, the light source 112 can emit light with wavelengths between about 650 nm and about 1150 nm, such as between about 800 nm and about 1000 nm, such as between about 850 nm and about 950 nm. In other examples, the light source 112 can emit light with wavelengths between about 1300 nm and about 1600 nm. In some examples, the light emitted by light source 112 may have an average power between about 50 mW and about 500 mW, a peak power between about 50 W and about 200 W, and a pulse width between about 2 ns and about 100 ns. Light source 112 may emit light in different formats, such as light pulses, frequency modulation, continuous wave (CW), quasi-CW, or any other form corresponding to the specific light source employed. The projection format and other parameters may be periodically changed by light source 112 based on selected factors, such as the scanned FOV and / or environmental conditions, such as instructions from processing unit 108.

[0075] The light deflector 114 of the scanning unit 104 guides emitted light from the light source 112 toward at least a portion of the field of view (FOV) 120 and guides reflected light from at least a portion of the FOV 120 toward the sensor 116. For example, the scanning unit 104 may include a first (outgoing) light deflector 114 for guiding light in the outgoing direction (also referred to as the transmission direction or "Tx") from the light source 112 to the FOV 120, and a second (incoming) light deflector 114 for guiding light reflected from the FOV 120 in the incoming direction (also referred to as the receiving direction or "Rx") toward the sensor 116. The light deflectors 114 may pivot (i.e., rotate about at least one axis of rotation while substantially keeping the center of rotation fixed) to scan the field of view. The light deflector 114 may include at least one component or mechanism configured to deflect light off its original path, such as: a mirror, prism, controllable lens, mechanical mirror, mechanically scanned polygon, active diffraction (e.g., controllable LCD), Risley prism, non-mechanical electro-optic beam steering, polarization grating, optical phased array (OPA), etc. The light deflector 114 may include multiple optical elements, such as at least one reflective element (e.g., mirror) and at least one refractive element (e.g., prism, lens). The light deflector 114 may be movable, such as to cause different degrees (e.g., discrete degrees, or over a continuous span of degrees) of light deflection. The light deflector 114 may be controllable in different ways, such as by deflecting the selected degree (e.g., ), change the amount of the deflection angle (e.g., The optical deflector 114 can be moved by a certain amount (e.g., M millimeters) and / or the rate of change of the deflection angle can be changed. The optical deflector 114 can be operable to change a single plane (e.g., The deflection angle within the coordinate system, or the change between two non-parallel planes (e.g., and The deflection angle within the coordinate system. Alternatively or additionally, the optical deflector 114 may be operable to change the deflection angle between predetermined settings (e.g., along a predefined scan path).

[0076] Scanning unit 104 can receive reflections from at least a portion 122 of the FOV 120 corresponding to the instantaneous positioning of the light deflector 114, which broadly refers to the position or spatial location of at least one controlled component of the light deflector 114 at an instantaneous point in time or a short time span. The instantaneous positioning of the light deflector 114 can be determined relative to a reference frame, such as at least one fixed point in the scene. The instantaneous positioning of the light deflector 114 can include movement of at least one component of the light deflector 114, such as a limited degree of movement relative to the maximum degree of change during scanning of the FOV 120. For example, scanning the entire FOV 120 can include changing the deflection of light within a first angular range, and the instantaneous positioning of the light deflector 114 can include an angular shift of the light deflector within a second (narrower) angular range. The instantaneous positioning of the optical deflector 114 can correspond to at least one spatial positioning of the optical deflector 114 during the acquisition of reflected light, which is processed to provide data for a single point of a point cloud generated by the lidar system 100. In some examples, the instantaneous positioning of the optical deflector 114 can correspond to a fixed positioning or orientation, or an angular region scanned through by the optical deflector 114 during illumination (pixel time) of a specific sub-region of the FOV 120. In some examples, the instantaneous positioning of the optical deflector 114 can correspond to a positioning or orientation range traversed along the scan positioning or orientation range as part of a repeated scan of the FOV 120. The optical deflector 114 can be moved such that the optical deflector 114 is located in multiple different instantaneous positions during a scan cycle of the FOV 120. In other words, during the period in which the scan cycle occurs, the optical deflector 114 can move through a series of different instantaneous positions and orientations, and the optical deflector 114 can arrive at each different instantaneous position and orientation at different times during the scan cycle.

[0077] Sensor 116 of sensing unit 106 detects reflections from one or more objects in FOV 120. Sensor 116 can be any type of sensing device or element capable of measuring the properties of electromagnetic radiation (e.g., power, frequency, phase, pulse timing, pulse duration) and generating an output (such as an electronic signal) related to the measured properties for subsequent processing and / or transmission. Sensor 116 may include multiple sensors that may be the same or different in at least one sensor characteristic (e.g., sensitivity, resolution, size). For example, sensor 116 may include a combination of sensor types for achieving at least one selected objective, such as: improving detection over a distance span or at a selected distance (e.g., close range); improving dynamic range; improving time response; and improving detection in changing environmental conditions (e.g., heat, cold, rain, snow, fog, low visibility, etc.). For example, sensor 116 can be implemented by a silicon photomultiplier tube (SiPM) sensor, a solid-state single-photon sensitive device that may include an array of avalanche photodiodes (APDs) or single-photon avalanche diodes (SPADs) serving as detection elements on a common silicon substrate. In one example, the typical distance between SPADs may be between about 10 μm and about 50 μm, with each SPAD having a recovery time between about 20 ns and about 100 ns. Sensor 116 may also include similar photomultipliers from other (e.g., non-silicon) materials. Although SiPM devices operate in a digital / switching mode, SiPMs can be considered analog devices because all microcells can be read in parallel, allowing the generation of signals ranging from single photons to hundreds and thousands of photons detected by different SPADs within a dynamic range. Sensor 116 can generate a single output from a combination of multiple sensor types for subsequent processing. The terms “sensor” and “detector” are used interchangeably herein.

[0078] Processor 118 receives information from the elements of lidar system 100 and performs necessary data processing. For example, processor 118 receives a signal indicating reflected light detected by sensor 116 and determines information about one or more objects in FOV 120 (e.g., distance to the objects), such as based on generating a point cloud map. Specifically, processor 118 can process the detection results of the sensors, which create time information indicating the time period between the emission of the light signal (i.e., the emitted beam) and its detection by the sensor, where this time period can be referred to as the "time of flight" of the light signal. Processor 118 can also receive and provide instructions and can selectively control the operation of system elements. For example, processor 118 can be configured to coordinate the operation of light source 112 with the movement of light deflector 114 to scan FOV 120, such that each instantaneous positioning of light deflector 114 during a scanning cycle can be associated with a specific portion 122 (i.e., a "scan segment") of FOV 120.

[0079] Processor 118 can constitute any physical device or group of devices having circuitry that performs logical operations on one or more inputs. For example, processor 118 may include one or more integrated circuits (ICs), including application-specific integrated circuits (ASICs), microchips, microcontrollers, microprocessors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), servers, virtual servers, or all or part of other circuitry suitable for executing instructions or performing logical operations. Instructions executed by the processor may, for example, be preloaded into memory integrated with or embedded in the controller, or may be stored in a separate memory. Memory may include: random access memory (RAM), read-only memory (ROM), hard disk, optical disk, magnetic media, flash memory, other permanent fixed or volatile memory, or any other mechanism capable of storing instructions. Processor 118 may include multiple processors. Each processor may have a similar configuration, or processors may have different configurations that are electrically connected or disconnected from each other. For example, processors may be separate circuits or integrated into a single circuit. When more than one processor is used, the processors may be configured to operate independently or cooperatively, and may be located in a common location or remotely from each other. Processors can be coupled electrically, magnetically, optically, acoustically, mechanically, or by other means that allow them to interact.

[0080] The components of the lidar system 100 can be based on hardware, software, or a combination thereof. It should be understood that the functionality associated with each component of the lidar system 100 can be distributed among multiple devices or components, which can reside in a single location or multiple locations. For example, the functionality associated with processor 118 can be distributed among a single processing unit or multiple processing units. Processor 118 can be part of a server or remote computer system accessible via a communication medium or network, such as a cloud computing platform.

[0081] The lidar system 100 may optionally include Figure 1A Additional components not shown and / or related to Figure 1A Additional components, not shown, are associated to enable the implementation of the disclosed subject matter. For example, the lidar system 100 may include a user interface (not shown) for allowing a user to control various parameters or settings of the components of the lidar system 100, and / or a display device (not shown) for visually displaying information related to the operation of the lidar system 100.

[0082] refer to Figure 1B , Figure 1B This is an exemplary output image from a single scan cycle of a lidar system 100 according to a disclosed embodiment. In this example, scanning unit 104 is integrated into the right front headlight assembly of vehicle 110. Each gray dot in the image corresponds to a specific location in the environment surrounding vehicle 110 determined from reflections detected by sensing unit 106. In addition to location, each gray dot may also be associated with other types of information, such as intensity (e.g., the amount of light received from the corresponding location), reflectivity, proximity to other points, etc. Lidar system 100 can generate multiple point cloud data entries from detected reflections over multiple scan cycles of the FOV, enabling, for example, the determination of a point cloud model of the environment surrounding vehicle 110. By processing the generated point cloud data entries of the environment surrounding vehicle 110, a surround view image can be generated from the point cloud model. The point cloud model can be provided to a feature extraction module, which processes the point cloud information to identify multiple features. Each feature may include data about different aspects of the point cloud and / or objects in the environment surrounding vehicle 110 (e.g., other vehicles, trees, people, roads). Features can have the same resolution as the point cloud model (i.e., the same number of data points, optionally arranged in a 2D array of similar size), or they can have different resolutions. The representation of vehicle 110 is indicated by boundary lines or bounding boxes separating regions or objects in the image (e.g., as shown in the image). Figure 1B (As depicted in the text).

[0083] The point cloud model represents a depth map of an exemplary type, wherein other forms of 3D scene models or depth images may alternatively be generated according to the disclosed embodiments. The LiDAR system 100 can generate a time series of depth maps of the scene, wherein different depth maps may be generated at different times. Each depth map in the sequence associated with a scan cycle is also referred to herein as a “frame,” wherein each frame is generated at a selected frame rate. The LiDAR system 100 may employ a fixed frame rate (e.g., 10Hz, 25Hz, 50Hz) or a dynamic frame rate, and the frame rate of different frames in the sequence may be variable.

[0084] According to one aspect of this disclosure, the lidar system can operate in a multi-beam scanning or multi-channel configuration. Specifically, the lidar system 100 can be configured with multiple light sources 112 to enable scanning of different portions of the field of view (FOV) or to differentially scan the FOV using pulses with different light emission properties (e.g., intensity, wavelength, frequency, power, pulse width, modulation, duty cycle). For example, the light sources 112 can include multiple individual light sources that can be characterized by common or different light emission types or properties and can operate in a coordinated manner. For example, the light sources 112 can be implemented by a multi-channel laser emitter array configured to emit multiple beams, wherein each of the multiple channels (e.g., multiple emitters) emits a corresponding beam with corresponding light emission properties toward a corresponding portion of the FOV 120.

[0085] refer to Figure 2AThis is a schematic diagram of an exemplary multi-channel lidar system 100 constructed and operated according to another embodiment of the present disclosure. The lidar system 100 includes a multi-channel laser emitter array 150, a beam splitter 140, an optional collimator 141, a plurality of optical deflectors 171 and 173, at least one lens 175, and a multi-channel detector array 130. The laser emitter array 150 includes a plurality of laser emitters configured to selectively emit corresponding beams. The laser emitter array 150 may include a plurality of active regions and a plurality of inactive regions, wherein each active region is configured to emit laser light (i.e., corresponding to a laser emitter), and each inactive region does not emit laser light. The active regions of the laser array can be separated from each other by one or more inactive regions. Therefore, the laser array 150 includes a plurality of laser-emitting active regions 156 and a plurality of non-laser-emitting inactive regions 158, wherein each active region 156 corresponds to a channel. For example, laser array 150 may be a quaternary array comprising four active regions 156 or channels, such as four laser sources configured to emit four laser beams 142, 144, 146, and 148, respectively. Multiple beams can also be generated by a single emitted laser beam split into multiple beams, such as splitting a single beam emitted by a single emitter. Laser array 150 may typically include any number of active regions or channels or laser sources, such as 8, 16, 32, or 64. Each pair of active regions 156 in laser array 150 is separated by at least one inactive region 158. The sizes of active regions 156 and inactive regions 158 may be equal or unequal. For example, laser array 150 may include alternating and repeating sequences of active regions 156 or emitters and adjacent inactive regions 158 of equal size. Laser array 150 may be a monolithic array of laser sources that can be fabricated on a single (e.g., monolithic) silicon wafer. The laser array 150 may include one or more types of emitters or laser sources, which may be arranged in a one-dimensional (1D) array or a two-dimensional (2D) array. The laser sources may be arranged in any type of pattern, such as a square or rectangular pattern, or a hexagonal stacked arrangement.

[0086] Light emitted from a laser source can travel through various optical components associated with the optical path, such as one or more lenses, collimators, and deflectors. Specifically, laser array 150 emits multiple laser beams 142, 144, 146, 148, which are optionally collimated by at least one collimator 141 before incident on beam splitter 140. At least some of the emitted beams 142, 144, 146, 148 can be emitted divergently, such that the respective emitted beams 142, 144, 146, 148 diverge from each other upon exiting laser array 150, wherein the amount or angle or divergence of the different beams can be variable. The multiple emitted beams 142, 144, 146, 148 pass through beam splitter 140 and are guided towards FOV 120 by optical deflectors 171, 173. Multiple reflected beams 162, 164, 166, 168, reflected from one or more objects in FOV 120, are received at beam splitter 140 and then focused onto detector array 130 by lens 175. The reflected beams 162, 164, 166, 168 may optionally be guided toward beam splitter 140 by at least one deflector 171, 173.

[0087] Detector array 130 may include a plurality of detectors configured to selectively detect corresponding reflected light beams 162, 164, 166, 168 reflected from FOV 120, and to generate electrical signals in response to the received reflected light beams to detect one or more objects in FOV. The detector array may include a plurality of active regions and a plurality of inactive regions, wherein each active region is configured to detect laser light (i.e., a photosensitive region corresponding to a detector), and each inactive region does not detect light (i.e., is not photosensitive). The active regions of the detector array may be separated from each other by one or more inactive regions. Thus, detector array 130 includes a plurality of photosensitive active regions 132 and a plurality of inactive regions 134, wherein each active region 132 corresponds to a channel. For example, detector array 130 may be a quaternion array comprising four active regions 132 or channels, such as four detectors configured to detect the four reflected light beams 162, 164, 166, 168 respectively. Detector array 130 may typically include any number of active regions or channels or detectors, such as 8, 16, 32, or 64. Each pair of active regions 132 in detector array 130 is separated by at least one inactive region 134. The active regions 132 and inactive regions 134 may be of equal or unequal size. For example, detector array 130 may include alternating and repeating sequences of active regions 132 and adjacent inactive regions 134 of equal size. Detector array 130 may be a monolithic array of detectors that can be fabricated on a single (e.g., monolithic) silicon wafer. Active regions 132 may include one or more types of detectors that may be arranged as a one-dimensional (1D) array or a two-dimensional (2D) array. For example, detector array 130 may be implemented by a multi-channel SiPM sensor array, a SPAD array, or an APD array.

[0088] In alternative embodiments, the beam splitter can redirect multiple emitted beams and pass through multiple reflected beams, rather than passing through multiple emitted beams and redirecting multiple reflected beams (e.g.) Figure 2A (As depicted in the text). Reference Figure 2B This is a schematic diagram of another exemplary multi-channel lidar system 100 constructed and operated according to another embodiment of the present disclosure. Figure 2B The lidar system 100 is typically similar to Figure 2AThe lidar system 100, in addition to multiple emitted beams 142, 144, 146, 148 emitted by laser array 150 being reflected or redirected by beam splitter 140 to optical deflectors 171, 173, which in turn guide the emitted beams 142, 144, 146, 148 toward FOV 120. The emitted beams 142, 144, 146, 148 may optionally be collimated by at least one collimator 141 before incident on beam splitter 140. Multiple reflected beams 162, 164, 166, 168 are reflected from one or more objects in FOV 120 and redirected by optical deflectors 171, 173 toward beam splitter 140, which allows the reflected beams 162, 164, 166, 168 to pass through lens 175 to detector array 130. The reflected beams 162, 164, 166, and 168 may optionally reach the beam splitter 140 without being guided by at least one deflector 171 or 173.

[0089] Referring back to Figure 1, the scanning unit 104 of the lidar system 100 can be configured to project multiple laser beams emitted by a multi-channel laser array onto the field of view (FOV) 120 of the lidar system 100 to simultaneously scan the FOV along multiple scan lines. The scanning unit 104 may include one or more optical components (e.g., described as a light deflector 114 in Figure 1) configured to receive and guide the multiple laser beams to scan the FOV. For example, the scanning unit 104 may include at least one of the following: a transparent scanning prism, a diffraction scanner, a liquid crystal on silicon (LCoS) scanner, a single dual-axis scanning mirror, a pair of single-axis scanning mirrors, a rotating polygon, a liquid crystal deflector, a MEMS mirror, etc. (Reference) Figure 2A and Figure 2B Multiple emitted beams 142, 144, 146, 148, emitted by laser array 150 and redirected or passed through by beam splitter 140, can be incident on a scanning device (not shown), such as a mechanically actuated dual-axis scanning mirror or polygon scanner. It should be understood that this configuration can provide multiple beams spaced apart and having intensities below the eye safety threshold at different distances. Furthermore, multiple beams projected from a single scanning mirror can be arranged perpendicularly or horizontally relative to each other, which can result in an extended vertical FOV compared to a single beam incident on a mirror or a multi-beam configuration lacking vertical point orientation within the FOV.

[0090] Scanning unit 104 may include one or more scanning mirrors that can rotate about at least one axis (e.g., two substantially orthogonal axes). For example, a first axis of rotation, referred to as the "tilt axis," allows scanning unit 104 to tilt to guide multiple laser beams in a vertical (i.e., up / down) direction of the FOV, while a second axis of rotation, referred to as the "scan axis," allows scanning unit 104 to scan to guide multiple laser beams in a horizontal (i.e., left / right) direction of the FOV. The dual-axis scanning mirrors can be actuated using suitable actuation mechanisms (e.g., motor-driven actuation, magneto-actuation, etc.). Rotation of the dual-axis scanning mirrors about the scan axis can guide multiple laser beams along multiple scan lines passing through the FOV.

[0091] refer to Figure 3A , Figure 3AThis is an illustration of an exemplary scanning pattern of a field of view obtained using a scanning device according to embodiments of the present disclosure. A 2D scanning device, such as a mechanically actuated biaxial scanning mirror, guides multiple laser beams emitted from a laser emitter array through the scanning pattern shown, labeled 180. The y-axis represents the “slow axis amplitude” of scanning pattern 180 (e.g., the tilt axis), and the x-axis represents the “fast axis amplitude” of scanning pattern 180 (e.g., the scan axis), where the values ​​on the axes are normalized to the maximum amplitude of the scan, such that the maximum amplitude is 1. For example, sequentially rotating the scanning device along the scan axis can guide the laser beams along multiple points in a horizontal direction (e.g., from left to right), as shown by scan line 181. Further sequentially rotating the scanning device along the tilt axis can guide the laser beams along multiple points in a vertical direction (e.g., from top to bottom). In this illustration, a “raster” type scan is presented. However, alternative scan lines can be used, such as a unidirectional horizontal scan (e.g., from right to left), which can be implemented using a rotating polygon (rotated in a single rotational direction). The aforementioned combination of 2D movements of the scanning unit can generate a scanning pattern 180, including horizontal scan lines 181, 183, and 185. Note that the horizontal scan lines 181, 183, and 185 can be non-uniformly spaced. For example, to scan certain areas of the FOV, such as areas above and below the center area, a vertical tilt increment of the scanning device greater than the minimum available tilt increment can be selected. A vertical tilt increment different from that of the scan center can be used to scan the areas above and below the scan center, which can point towards the horizon. For example, the areas above and below the scan center can be scanned using a vertical tilt increment of approximately 0.6°, which can correspond to the angular size of the entire laser array, thus producing a coarse sampling resolution equal to the laser spacing in the laser array. Laser spacing refers to the center-to-center distance between the active (light-emitting) regions of the laser array. For a selected scanning area, such as the area including the scan center, a minimum vertical tilt angle can be used to provide more closely spaced scan lines in that area, and thus provide a higher sampling rate or point cloud resolution in the selected scanning area. For example, the central region of the field of view (FOV), such as the region of interest, can be associated with an area near the horizon and typically includes more distant or higher-density objects of interest, thus allowing for scanning at a higher resolution. In contrast, the top or bottom regions of the FOV can be associated with an area farther from the horizon and typically contain more nearby or fewer objects of interest, thus allowing for scanning at a lower resolution. Vertical point cloud resolution can depend on the scan line spacing, while horizontal point cloud resolution can depend on the frequency at which the laser emitter pulses as the scanning device scans along each horizontal scan line, with higher pulse frequencies corresponding to a higher potential horizontal resolution of the generated point cloud.

[0092] When the scanning device receives multiple laser beams emitted by a laser array (e.g., laser array 150) and optionally guided by a beam splitter (e.g., beam splitter 140), a first rotation of the scanning device about a scanning axis can generate multiple horizontal scan lines passing through a first set of positions, and a second rotation of the scanning device about a tilt axis can vertically offset the horizontal scan lines, thereby generating a second set of scan lines passing through a second set of positions perpendicularly spaced from the first set of positions. The rotation rate of the scanning device about the scanning axis can be faster than the rotation rate about the tilt axis.

[0093] refer to Figure 3B , Figure 3B This is an illustration of another exemplary scanning pattern of the field of view obtained using a scanning device according to another embodiment of the present disclosure. The scanning device guides multiple laser beams through a scanning pattern generally labeled 190. The y-axis represents the vertical scanning angle of scanning pattern 190 (described in 5-degree increments), and the x-axis represents the horizontal scanning angle of scanning pattern 190 (described in 10-degree increments). A first rotation of the scanning device about a scanning axis guides the emitted laser beams along multiple horizontal scanning lines 191, 193, 195. A second rotation of the scanning device about a tilt axis causes vertical displacement of the horizontal scanning lines 191, 193, 195. .

[0094] Scanning devices may be capable of rotating about multiple axes of rotation, or alternatively may include one or more optical components (e.g., mirrors or deflectors), each of which can rotate about only a single axis of rotation. For example, a scanning device may include a first single-axis scanning mirror and a second single-axis scanning mirror, such that the first single-axis scanning mirror receives multiple laser beams from a laser emitter array and directs the laser beams toward the second single-axis scanning mirror, which in turn directs the laser beams toward the field of view (FOV). For example, the first single-axis scanning mirror rotates about a first axis of rotation (e.g., a scanning axis) to move the laser beams along first multiple scan lines passing through the FOV, and the second single-axis scanning mirror rotates about a second axis of rotation (e.g., a tilt axis) to shift the laser beams from a first set of locations associated with the first multiple scan lines to a second set of locations associated with the second multiple scan lines to generate scanning patterns, such as patterns 180 and 190. (See reference for example.) Figure 2A , Figure 2B The first single-axis scanning mirror can be implemented by a first optical deflector 171, and the second single-axis scanning mirror can be implemented by a second optical deflector 173. The first deflector 171 can rotate in the left-right direction around a first axis (such as a horizontal axis or a scanning axis), causing multiple beams 142, 144, 146, and 148 to generate horizontal scanning lines, such as scanning lines 191, 193, and 195. Figure 3BThe second deflector 173 can rotate in the vertical direction about a second axis (such as a vertical axis or a tilt axis) perpendicular to the first axis, causing the horizontal scan lines 191, 193, and 195 to shift vertically. .

[0095] The scanning device can rotate around a scanning axis and / or a tilt axis to project a laser beam onto a desired field of view (FOV). The reflected beam from the FOV can be received at a detector to detect the presence of one or more objects within the FOV. The FOV of the lidar system 100 can have a vertical angular dimension between 6 and 90 degrees, and a horizontal angular dimension between 20 and 140 degrees. The range of the FOV can depend on several factors, such as the maximum rotational span of the scanning device around the respective scanning and tilt axes, the divergence angle of the laser beam, and the angles between multiple laser beams projected from the scanning device.

[0096] The field of view (FOV) can be scanned repeatedly at a given frame scan rate to continuously detect changes in the location of objects within the FOV. For example, the FOV of a lidar system 100 can be scanned at a frame scan rate between 5 Hz and 40 Hz, such as 20 Hz (i.e., 20 times per second). The scan rate can be adjusted according to application requirements. The frame scan rate can define at least one angular dimension of the laser beam point corresponding to the projected laser beam. For example, multiple laser beams projected from the scanning device onto the FOV can cause corresponding reflected beams, each reflecting beam forming a beam point with an angular dimension such as 0.07 degrees × 0.11 degrees. The vertical arrangement of the beam points can depend on the configuration of the emitters of the laser emitter array, where the distance between adjacent emitters can correspond to the interval between reflected beam points. For example, the laser beam point can have a vertical angular dimension of 0.1 degrees and can be spaced approximately 0.2 degrees apart from adjacent beam points (i.e., corresponding to a 2:1 ratio of inactive to active regions of the laser emitter array). If the laser array comprises 16 channels, the overall vertical pattern of the projected beam (also referred to herein as a "comb") can occupy an angular height of approximately 4.6 degrees. This comb can be manipulated horizontally across the width of the field of view (FOV) by a scanning device, where the horizontal resolution can be determined by the scanning speed and the laser pulse rate. When the horizontal limit is reached, the scanning device can vertically increment (e.g., rotate about a tilt axis) to continue horizontal scanning of the FOV along a new set of horizontal scan lines. It should be understood that the vertical comb pattern of horizontal scanning over the FOV represents an exemplary scanning configuration, and other embodiments may include a horizontal comb of vertical scanning over the FOV, such as using a horizontally oriented laser array.

[0097] The scanning device can be controlled to rotate around at least one axis to provide variable resolution scanning. For example, in scanning mode 190, for regions 192 and 194 at the top and bottom of the scan, respectively, the scanning device can rotate around the vertical tilt axis in angular increments at least as large as the angular dimension of the laser array. However, in region 196 at the scan center, which may include a horizon (e.g., between + / - 5 degrees), the scanning device can rotate around the vertical tilt axis in angular increments smaller than the angular dimension of the laser array. For example, a laser array with eight channels, where each emitted laser beam has an angular width of 0.1° and the angular width of the interval between adjacent emitted laser beams is 0.2°, defines a total angular dimension of 2.4°. For such a laser array, the vertical rotation of the scanning device in the top scan region 192 and the bottom scan region 194 can be in angular increments greater than 2.4°, while the vertical rotation in the central scan region 196 can be in angular increments less than 2.4° to provide higher scanning resolution in the central scan region 196.

[0098] The multi-channel lidar system 100 may include multiple detectors configured to emit electrical signals in response to multiple reflected beams received from the field of view (FOV). For example, detector array 130 ( Figure 2A , Figure 2B The array comprises multiple detectors, each operable to detect selected reflected beams 162, 164, 166, and 168 received from the FOV 120. Each detector corresponds to an active region, which can also be considered a separate “pixel,” separated from adjacent active regions by one or more inactive regions of variable spacing. The terms “detector,” “active region,” and “pixel” are used interchangeably herein to refer to discrete units of an array of detectors configured to generate a discrete electrical signal response to incident reflection. References Figure 4A , Figure 4B , Figure 4C . Figure 4A This is an illustration of a first exemplary detector array 200 constructed and operated according to embodiments of the present disclosure. Figure 4B This is an illustration of a second exemplary detector array 210 constructed and operated according to embodiments of the present disclosure, and Figure 4C This is an illustration of a third exemplary detector array 220 constructed and operated according to embodiments of the present disclosure. Each of the detector arrays 200, 210, and 220 is a monolithic 1D array comprising arrays labeled "n" (n1 to n...). N N active regions and labeled "m" (m1 to m) N-1The detector array 200 comprises N-1 inactive regions, where N can be any desired number (e.g., 4, 8, 16, 32, 64). Each pair of active regions is separated by a corresponding inactive region of a selected width. The detector array 200 includes alternating and repeating sequences of active regions 202, each active region 202 being spaced apart by an inactive region 204 of equal size to each active region 202, thus defining a 1:1 size ratio of active to inactive regions. The detector array 210 includes alternating and repeating sequences of active regions 212 spaced apart by corresponding inactive regions 214, each inactive region 214 having twice the width of the active regions 212, such that the size ratio of active to inactive regions is 1:2. The detector array 220 includes alternating and repeating sequences of active regions 222 spaced apart by corresponding inactive regions 224, each inactive region 224 having five times the width of the active regions 212, such that the size ratio of active to inactive regions is 1:5. Typically, the spacing between the active regions (or the relative width of the inactive regions) of the detector array in the multi-channel lidar system of this disclosure can be any desired number.

[0099] When multiple reflected beams are received from the FOV, each reflected beam can form a corresponding beam point on one or more active regions of the detector array. For example, reference Figure 4A The detector array 200 includes exemplary beam points 205 incident on a plurality of active regions 202 (e.g., active regions n2, n3) of the detector array 200. Thus, the plurality of active regions 202 can generate corresponding signals corresponding to a detected object, from which a plurality of received beams associated with the beam points 205 are reflected. The plurality of detection signals can provide increased resolution to the region of the detected object, wherein each active region 202 of the detector array 200 represents a different pixel in a sub-region within the region of the detected object.

[0100] The ratio of the distance between the active regions of the detectors to the distance between the beam points incident on the detectors can be a predetermined value. For example, the distance between beam points formed by laser beams emitted from the laser array (e.g., laser array 150) of the lidar system 100 (i.e., the distance between beam points incident on the detector array of the lidar system 100) can be a predetermined multiple of the distance or spacing between the active regions of the detector array (e.g., active region 202 of detector array 200), such as a multiple of 0.5, 1.0, or 1.5. The angular dimension (e.g., angular width or height) of each beam point (formed by the emitted laser beam and / or the reflected laser beam incident on the detector array) can also be a predetermined multiple of the angular dimension of the active regions of the detector array, such as a multiple of 0.5, 1.0, or 1.5.

[0101] According to one aspect of this disclosure, light is directed to the FOV 120 of the lidar system 100 using a selected illumination and / or scanning protocol, such as a light emission protocol with an emission beam having alternating energy levels. This illumination protocol can be used to maintain object detection capability regardless of halo effects, for example, to enable the differentiation between active pixels generated by halos and active pixels generated by reflections from real objects. Haloes can occur when high-intensity reflections are received from one or more highly reflective and / or nearby objects (such as retroreflectors). High-intensity reflections can overload the detectors, causing excessive photons to spill into neighboring detectors in the detector array, resulting in erroneous readings. Haloes can manifest as visual artifacts in the generated point cloud model, where the point cloud representation of an object extends beyond the contours of the object's actual shape and size, allowing bright halos to appear around the object and potentially obscuring other adjacent objects. Haloes can significantly impair the ability to detect and determine the characteristics of highly reflective objects and surrounding areas, such as the ability to interpret the environment around the vehicle 110. The halo effect can be caused by several factors, including optical phenomena such as diffraction caused by the finite aperture of optical components (e.g., deflectors or mirrors of scanning devices) or stray light scattered inside the optical components (e.g., generated by strong reflections and reflected from the inner surface inside the LIDAR housing), and electronic phenomena such as leakage or overflow of photodetector electrons between different channels or active regions of the detector array (i.e., electrical crosstalk).

[0102] refer to Figure 5A and Figure 5B . Figure 5A This is a schematic diagram of an exemplary optical emission protocol with a uniform energy level and an emitted beam that is completely incident on an object. Figure 5B This is a schematic diagram of another exemplary optical emission protocol with a uniform energy level and a beam of light partially incident on an object. In the scenario shown, it is typically labeled 240 (…). Figure 5A ) and 245 ( Figure 5BMultiple beams are simultaneously emitted from corresponding emitters of a multi-channel laser array (not shown) at multiple time points, each beam having an individually controlled energy level. Referring to scenario 240, at a first time t1, the laser array simultaneously emits a first set of emitted beams, including a first beam 241A and a second beam 241B, both beams 241A and 241B having high energy levels. At a second time t2, the laser array simultaneously emits a second set of emitted beams, including a first beam 242A and a second beam 242B, both beams 242A and 242B having high energy levels. Each of the first set of emitted beams 241A and 241B and the second set of emitted beams 242A and 242B is incident on a highly reflective object 235 and receives a corresponding reflection at a multi-channel detector array 250. A first beam point 261A corresponding to the reflection of a first emitted beam 241A emitted at time t1 is received at a first detector 252 of the detector array 250, and a second beam point 261B corresponding to the reflection of a second emitted beam 241B emitted at time t1 is received at a second detector 254 of the detector array 250. A detector response signal 271A represents the response signal of detector 252 relative to beam point 261A, and a detector response signal 271B represents the response signal of detector 254 relative to beam point 261B. A first beam point 262A corresponding to the reflection of a first emitted beam 242A emitted at time t2 is received at a first detector 252, and a second beam point 262B corresponding to the reflection of a second emitted beam 242B emitted at time t2 is received at a second detector 254. A detector response signal 272A represents the response signal of detector 252 relative to beam point 262A, and a detector response signal 272B represents the response signal of detector 254 relative to beam point 262B. Since all emitted beams 241A, 241B and 242A, 242B are incident on object 235, all corresponding beam points 261A, 261B and 262A, 262B represent effective reflections from object 235, even though a portion of beam points 261A, 261B and 262A, 262B (or the residual energy of each reflection) may leak into adjacent detectors due to oversaturation caused by the high energy levels of emitted beams 241A, 241B and 242A, 242B.

[0103] Referring to scenario 245, at a first time t1, the laser array simultaneously emits a first set of emission beams, including a first beam 246A from a first emitter and a second beam 246B from a second emitter, both beams 246A and 246B having high energy levels. The first emission beam 246A is not incident on object 235, while the second emission beam 246B is incident on object 235, such that the region between the first beam 246A and the second beam 246B defines the edge of object 235. At a second time t2, the laser array simultaneously emits a second set of emission beams, including a first beam 247A and a second beam 247B, both beams 247A and 247B having high energy levels. The first emission beam 247A is not incident on object 235, while the second emission beam 247B is incident on object 235, such that the region between the first beam 247A and the second beam 247B defines the edge of object 235. A multi-channel detector array 250 receives reflections from object 235. Specifically, the first emitted beam 246A emitted at time t1 does not strike the object 235, therefore no corresponding reflection is received at detector 252 of detector array 250. However, the second emitted beam 246B emitted at time t1 strikes the object 235, therefore a beam point 266B corresponding to the reflection of the second emitted beam 246B is received at the second detector 254 of detector array 250. Detector response signal 276A is the response signal of detector 252 at time t1, and detector response signal 276B is the response signal of detector 254 at time t1. Detector response signal 276B is generated by the reflection of the emitted beam 246B from the object 235, corresponding to beam point 266B. However, detector response signal 276A is generated by oversaturation of detector 254, where a portion of the reflection of the second emitted beam 246B leaks or overflows into detector 252 due to the high energy level of emitted beam 246B, causing detector response signal 276A to not represent a valid reflection from object 235 (i.e., because emitted beam 246A is not incident on object 235). Similarly, the first emitted beam 247A emitted at time t2 is not incident on object 235, and therefore no corresponding reflection is received at detector 252, while the second emitted beam 247B emitted at time t2 is incident on object 235, and therefore a beam point 267B corresponding to the reflection of the second emitted beam 247B is received at the second detector 254. Detector response signal 277B is generated by the reflection of the second emitted beam 247B from object 235, while detector response signal 277A is generated by oversaturation in detectors 254 to 252 due to the high energy level of emitted beam 247B. Since only the emitted beams 246B and 247B are incident on the object 235, only the response signals 276B and 277B (corresponding to the corresponding beam points 266B and 267B) indicate effective reflection from the object 235.However, response signals 276A and 277A represent overflow of reflections associated with emitted beams 246B and 247B from neighboring detectors 254, where received reflections (beam points 266B and 267B) leak or overflow into detector 252 (due to the high energy levels of the corresponding emitted beams 246B and 247B) and do not represent effective reflections from object 235. As a result, when employing a light emission protocol with uniform energy levels as in scene 245, it may hinder the determination of the edges of object 235 in the generated point cloud. Note that this oversaturation of detectors 254 to 252 from high-energy emitted beams 246B and 247B (and the subsequent invalid response signals 276A and 277A) is caused by the high reflectivity of object 235, while alternative objects with low reflectivity do not cause overflow of reflections into neighboring detectors even for high-energy emitted beams, and therefore do not result in the corresponding invalid response signals.

[0104] By implementing an illumination protocol with alternating energy levels, invalid response signals caused by leakage from high-intensity reflections from neighboring detectors can be avoided. The alternating energy levels of the emitted beam pulses can be implemented in various ways. For example, a low-energy beam can have a low radiant intensity or low radiant power or luminous flux level, while a high-energy beam can have a high radiant intensity or high radiant power or luminous flux level. Alternatively or additionally, a low-energy beam can have a low peak power, while a high-energy beam can have a high peak power. Further alternatively, a low-energy beam can represent negative emission or no-pulse emission, while a high-energy beam can represent positive emission (i.e., corresponding to an "on / off" or "1 / 0" scheme). Generally, differential beam energy (e.g., low or high energy levels) can be provided by modifying one or more properties of the emitted beam, including but not limited to: intensity, peak power, beam duration, emission operation mode (e.g., on / off), emission modulation, timing, wavelength, frequency, number of pulses in the pulse sequence, etc. The on / off scheme can have the disadvantage of reducing the pixel rate (i.e., frames per second multiplied by pixels per frame) of a lidar system because the energy beam in the off state will not produce any measurements. When evaluating the response signal of each detector in a detector array, the differences in emitted energy during the analysis of reflected signals can potentially increase complexity due to the varying energy emitted by different differential beams (e.g., low energy versus high energy). For example, the analysis of reflected signals could be based on varying criteria, such as different thresholds used to distinguish between positive and negative detection, depending on the intensity or energy level of the corresponding emission. Signal analysis could include evaluating properties of the object causing the reflection, such as reflectivity or grazing angle.

[0105] In some embodiments, a lidar system may include a pulsed laser diode driver configured to drive laser emission from a laser array to generate an emitted beam with alternating energy levels. For example, the disclosed pulsed laser diode may include one or more electronic components or circuits that allow the laser diode to generate multiple laser pulses. This circuitry may constitute a pulsed laser diode driver configured to activate the laser diode to generate multiple laser pulses. It is contemplated that the pulsed laser diode driver may be a resonant laser driver based on a boost DC / DC topology, which may not require a dedicated high-voltage power supply. Alternatively, instead of a high-voltage power supply, the disclosed laser driver may include an inductor that can be periodically energized or de-energized to provide the necessary high voltage for generating multiple laser pulses. The pulsed laser diode driver may include at least one switching circuit connected to at least one laser diode configured to generate at least one optical pulse. For example, the disclosed laser diode driver may include electronic circuitry, such as a switching circuit, connected to a voltage power supply. The switching circuit may be connected to at least one laser diode and may be configured to deliver a high-voltage pulse to the laser diode to generate at least one laser pulse.

[0106] refer to Figure 6A , Figure 6B and Figure 6C . Figure 6A This is a schematic diagram of an exemplary illumination protocol for an emitted beam having alternating energy levels and being fully incident on an object, operating according to another embodiment of this disclosure. Figure 6B This is a schematic diagram of another exemplary illumination protocol, which operates according to another embodiment of the present disclosure, and has an emitted light beam having alternating energy levels and is partially incident on an object. Figure 6C This is a schematic diagram of another exemplary illumination protocol, operating according to another embodiment of the present disclosure, of an emitted beam having alternating energy levels and partially incident on an object over an extended duration. In the scenario shown, it is typically labeled 280 (…). Figure 6A ), 285 Figure 6B ) and 310 ( Figure 6CMultiple beams are simultaneously emitted from corresponding emitters of a multi-channel laser array (not shown) at multiple time points, each beam having an individually controlled energy level. Referring to scenario 280, at a first time t1, the laser array simultaneously emits a first set of beams, including a first beam 281A with a low energy level and a second beam 281B with a high energy level. At a second time t2, the laser array simultaneously emits a second set of beams, including a first beam 282A with a high energy level and a second beam 282B with a low energy level. Both sets of beams 281A, 281B and 282A, 282B are incident on a highly reflective object 235 and receive corresponding reflections at a multi-channel detector array 250. The first detector 252 of the detector array 250 receives the reflection of the first emitted beam 281A, which forms the first beam point 291A, emitted at time t1, and generates a corresponding response signal 301A reflecting positive detection (i.e., a high signal value). The second detector 254 of the detector array 250 receives the reflection of the second emitted beam 281B, which forms the second beam point 291B, emitted at time t1, and generates a corresponding response signal 301B reflecting positive detection (i.e., a high signal value). It should be noted that due to the higher energy level of the second emitted beam 281B relative to the first emitted beam 281A, the second beam point 291B may have a higher energy (depicted as larger for illustrative purposes) than the first beam point 291A (described as smaller for illustrative purposes). However, the generated response signals 301A and 301B can be substantially similar because both reflections are sufficient to trigger positive detection (i.e., having an intensity above a minimum detection threshold) in the corresponding detectors 252 and 254. Similarly, the first detector 252 receives the reflection of the first emitted beam 282A, which forms the first beam point 292A, emitted at time t2 and generates a corresponding response signal 302A, and the second detector 254 receives the reflection of the second emitted beam 282B, which forms the second beam point 292B, emitted at time t2 and generates a corresponding response signal 302B, wherein the generated response signals 302A and 302B can be substantially similar, even though the first beam point 292A may have a higher energy level than the second beam point 292B due to the higher energy level of the first emitted beam 282A relative to the second emitted beam 282B. Since all emitted beams 281A, 281B and 282A, 282B are incident on object 235, all corresponding beam points 291A, 291B and 292A, 292B represent effective reflections from object 235, even though some high-energy reflections (i.e., corresponding portions of beam points 291B and 292A) may leak or overflow into neighboring detectors due to the high energy levels of the corresponding emitted beams (i.e., beams 281B and 282A).Compared to the uniform energy level illumination protocol of scenario 240, in which virtually all received reflections could lead to detector oversaturation (because all emitted beams have high energy levels), in the alternating energy level illumination protocol of scenario 280, only some (e.g., half) of the received reflections could lead to detector oversaturation due to the low energy levels of some emitted beams 281A, 282B.

[0107] Referring to scenario 285, at a first time t1, the first emitter of the laser array emits a first beam 286A with a low energy level, while the second emitter of the laser array simultaneously emits a second beam 286B with a high energy level. At a second time t2, the first emitter emits a first beam 287A with a high energy level, while the second emitter emits a second beam 287B with a low energy level. Neither the first emitted beams 286A nor 287A are incident on the object 235, while both the second emitted beams 286B and 287B are incident on the object 235, such that the region between the first beams 286A and 287A and the second beams 286B and 287B defines the edge of the object 235. More generally, the first emitted beam 286A is incident on a first field of view (FOV) region, while the second emitted beam 286B is incident on a second field of view region adjacent to or adjacent to the first FOV region. Accordingly, the first emitted beam 287A is incident on a third FOV region adjacent to the first FOV region, and the second emitted beam 287B is incident on a fourth FOV region adjacent to both the first and third FOV regions. In this context, the term "adjacent" can be defined based on the angular distance between adjacent regions or the absence of additional regions between them (e.g., such that there is substantially no gap between adjacent regions, or such that there is no illuminated area between adjacent regions). For example, adjacent FOV regions can be defined such that the generated point cloud does not include points (pixels) between points in adjacent regions. In another example, adjacent FOV regions can be defined such that adjacent regions can be illuminated sequentially, with no area illuminated between the illumination of the first and second adjacent regions. The multi-channel detector array 250 receives reflections from the object 235. Specifically, no reflection is received at the first detector 252 because the first emitted beams 286A and 287A are not incident on the object 235. The second detector 254 receives reflections of the second emitted beams 286B and 287B incident on the object 235. These reflections form corresponding beam points 296B and 297B at corresponding times t1 and t2. The second detector 254 generates corresponding response signals 306B and 307B corresponding to the beam points 296B and 297B formed by the reflections of the corresponding emitted beams 286B and 287B from the object 235. It should be noted that beam point 296B is characterized by a higher energy level than beam point 297B, because the emitted beam 286B at time t1 has a higher energy level than the emitted beam 287B at time t2. However, the generated response signals 306B and 307B can be substantially similar because both reflections are sufficient to trigger positive detection in detector 254.The first detector 252 generates a first response signal 306A at time t1, which reflects a positive detection (i.e., a high signal value) caused by the reflection saturation of the high-energy emitted beam 286B leaking into the first detector 252, such that the response signal 306A does not represent a valid reflection from the object 235. Therefore, the invalid response signal 306A may hinder the determination of the edge of the object 235 in the point cloud generated at time t1. However, the first detector 252 generates a second response signal 307A at time t2, which reflects a negative detection (i.e., a low signal value) because the low-energy reflection of the emitted beam 287B at time t2 is unsaturated or overflows into the first detector 252. Therefore, the detector response signal 307A represents a valid negative detection that can be used to determine the edge of the object 235 (i.e., between the scene regions corresponding to detectors 252 and 254). Therefore, the alternating sequence generates signal patterns that indicate some response signals are invalid (e.g., 306A) while other response signals are valid (e.g., 307A), making it possible to determine valid and invalid response signals (compared to the uniform energy level illumination protocol of scene 245).

[0108] By sequentially applying an alternating energy level illumination protocol to an extended sequence, effective detection can be achieved for at least a portion of the emission / reflection sequence, allowing the determination of object edges on that sequence. Referring to scenario 310, a laser array emits multiple emission beams in an alternating energy level mode over an extended duration. A first emitter emits a low-energy beam 311A ​​at time t1, followed by a high-energy beam 312A at time t2, then a low-energy beam 313A at time t3, then a high-energy beam 314A at time t4, and so on in a cyclical pattern. A second emitter emits a high-energy beam 311B at time t1, followed by a low-energy beam 312B at time t2, then a high-energy beam 313B at time t3, then a low-energy beam 314B at time t4, and so on in a cyclical pattern. A first beam sequence (311A...316A) emitted by a first emitter does not incident on object 235, while a second beam sequence (311b...316b) emitted by a second emitter does incident on object 235, such that the region between them defines the edge of object 235. A first detector 252 of the multi-channel detector array 250 generates a series of response signals corresponding to the reflections of the first emitted beam sequence (311A...316A), reflecting alternating invalid positive detections (caused by leakage or overflow from adjacent high-intensity reflections) and valid negative detections (where no leakage or overflow occurs from adjacent low-intensity reflections), such that the selected valid detection ensures correct edge determination. Specifically, the first detector 252 generates a first response signal 331A at time t1, which reflects an invalid positive detection (i.e., a high signal value) caused by reflection saturation of the high-energy emitted beam 311B leaking into the first detector 254, and does not represent a valid reflection from object 235. Similar invalid response signals 333A and 335A are generated at times t3 and t5, respectively, caused by the saturation of corresponding reflections from the high-energy emission beams 313B and 315B. The first detector 252 generates an additional sequence of valid response signals, including response signal 332A at time t2, response signal 334A at time t4, and response signal 336A at time t6, each reflecting a negative detection (i.e., a low signal value) because the corresponding low-intensity reflections from the low-energy emission beams 312B, 314B, and 316B are not saturated into the first detector 252. Therefore, response signals 332A, 334A, 336A, and the sequence of valid response signals 331B…316B generated by the second detector 254 can be used to determine the edges of object 235 in the generated point cloud. Following the prior determination of object parameters based on invalid response signals, valid response signals can also be used to determine updated object parameters of object 235 (e.g., object size, height, shape, type).

[0109] While the above scenario illustrates a vertically oriented laser array scanning horizontally across the FOV, other embodiments may employ alternative scanning configurations, such as a horizontally oriented laser array scanning vertically across the FOV.

[0110] Consistent with this disclosure, a lidar system can be configured to detect objects by scanning the environment of the lidar system. The term "scanning the environment of the lidar system" broadly includes the field of view or a portion of the field of view illuminating the lidar system. In one example, scanning the environment of the lidar system can be achieved by moving or pivoting a light deflector to deflect light in different directions toward different portions of the field of view. In another example, scanning the environment of the lidar system can be achieved by changing the positioning (i.e., position and / or orientation) of a sensor relative to the field of view. In yet another example, scanning the environment of the lidar system can be achieved by changing the positioning (i.e., position and / or orientation) of a light source relative to the field of view. In yet another example, scanning the environment of the lidar system can be achieved by changing the positioning of at least one light source and at least one sensor to move rigidly relative to the field of view (i.e., the relative distance and orientation of the sensor and the light source remain unchanged).

[0111] Consistent with the disclosed embodiments, a lidar system may include at least one scanning unit having at least one light deflector configured to deflect light from a light source in order to scan a field of view. The term "light deflector" includes any mechanism or module configured to deflect light off its original path; for example, a mirror, prism, controllable lens, mechanical mirror, mechanically scanned polygon, active diffraction (e.g., controllable LCD), Risley prism, non-mechanical electric beam steering, polarization grating, optical phased array (OPA), etc. In one embodiment, a light deflector may include multiple optical components, such as at least one reflective element (e.g., a mirror), at least one refractive element (e.g., a prism, a lens), etc. In one example, the light deflector may be movable to deflect light to different degrees (e.g., discrete degrees, or over a continuous span of degrees). The light deflector may optionally be controllable in different ways (e.g., deflected to an angle). Change the deflection angle The components of the optical deflector can be moved by M millimeters, and the rate at which the deflection angle changes can be altered. Furthermore, the optical deflector can optionally be operable to change a single plane (e.g., The deflection angle within the coordinate system. The optical deflector can optionally be operated to change the angle between two non-parallel planes (e.g., coordinates). and The deflection angle within the coordinate system. Alternatively or additionally, the optical deflector may be optionally operable to vary the deflection angle between predetermined settings (e.g., along a predefined scan path) or otherwise. Regarding the use of optical deflectors in lidar systems, it should be noted that optical deflectors can be used in the outgoing direction (also known as the transmission direction or TX) to deflect light from the light source to at least a portion of the field of view. However, optical deflectors can also be used in the incoming direction (also known as the receiving direction or RX) to deflect light from at least a portion of the field of view to one or more optical sensors.

[0112] According to another aspect of this disclosure, an offset illumination protocol is used to guide the light towards the FOV 120 of the lidar system 100, such that the emitted and reflected beams are offset or spatially shifted in at least one scan cycle (i.e., frame), such as by applying a modified scan pattern. For example, a second set(s) of scan lines may be shifted relative to a first set(s) of scan lines, the spatial shift being transverse to the scan direction (e.g., in the vertical direction for a vertical comb pattern scanning horizontally over the FOV), such that a portion of the FOV is illuminated by a first emitted beam from the first set of scan lines, and the same portion of the FOV is illuminated by a second emitted beam from the second set of scan lines. The scan lines may be spatially shifted between consecutive frames in a frame sequence, such that at least one frame in the sequence defines a shift in the scan direction relative to at least another frame in the sequence. The offset illumination protocol may include at least one variable resolution scan cycle for capturing a frame sequence at a reduced frame rate. Such an illumination protocol can be used to maintain object detection capability even under halo effects, for example, to distinguish between active pixels caused by halos and active pixels caused by reflections from real objects, thereby distinguishing between valid and invalid detector response signals.

[0113] refer to Figure 7A , Figure 7AThis is an illustration of an exemplary illumination protocol operating according to embodiments of the present disclosure, wherein a region of interest in a scene is partially occluded. In the illustrated scene 347, a target object 342 is located near a highly reflective object 345 (referred to as a “reflector”) in a field of view (FOV) 340. The FOV 340 is scanned using a first scan mode, wherein at least a portion of the target object 342 is mutually illuminated with the reflector 345 in a common frame 352. Mutual illumination refers to an object illuminated by a set of light emitted simultaneously from a multichannel laser array. Specifically, during a portion of the scan cycle, the target object 342 and the reflector 345 are illuminated by a set of mutually simultaneous light emissions from one or more emitters (or active emission regions) of a vertically oriented multichannel laser array. One or more detectors (or active areas) of the detector array receiving reflections from object portion 343 of target object 342 experience a halo effect from one or more neighboring detectors receiving reflections from retroreflector 345, resulting in a halo artifact 351 of object portion 343 in the point cloud map of occluded frame 352. If FOV 340 is scanned with the same scan mode and frame alignment (which includes blurred frame 352), then target object 342 can be partially occluded in detected frames, regardless of the number of captured frames.

[0114] It should be noted that mutual illumination between the target object 342 and the retroreflector 345 in a common frame can occur when the object 342 and the retroreflector 345 are in various spatial positions and alignments relative to each other. For example, in the first scene 361, the target object 342 is located at approximately the same distance or depth as the retroreflector 345 (e.g., in a common vertical plane) but at a different and non-overlapping position or spatial location (e.g., at a different height), and is illuminated by mutual light emission 358 in the common frame, such as... Figure 8A (Front view) and Figure 8B As shown in the side view. In another scene 362, the target object 342 is located at a different distance from the retroreflector 345 (e.g., the retroreflector 345 is positioned further away from the lidar system than the object 342) and at different non-overlapping locations (e.g., at different heights), and is illuminated by mutual light emission 358 in a common frame, as shown. Figure 8C (Front view) and Figure 8D (Side view) As shown. In the third scene 363, the target object 342 is located at a different distance from the retroreflector 345 and is in an overlapping position or spatially positioned (e.g., such that a portion of the object 342 is at approximately the same height as a portion of the retroreflector 345) and is illuminated by mutual light emission 358 in the common frame, as... Figure 8E (Front view) and Figure 8F As shown in the (side view).

[0115] refer to Figure 7B , Figure 7B It is operated according to embodiments of this disclosure and has relative to Figure 7A Illustration of another exemplary illumination protocol with vertical offset illumination. In the illustrated scenario 348, illumination is used with a method including illumination relative to... Figure 7A The second scan mode scan of the haloed frame 352, vertically offset or shifted, includes a field of view 340 (FOV) 340 of the target object 342 close to the retroreflector 345, such that the object portion 343 is no longer mutually illuminated by the retroreflector 345 in the common frame of the shifted frame. In the first vertically offset frame 354 (e.g., shifted upward relative to frame 352), the retroreflector 345 is illuminated by the emitter array, but the target object 342 is not illuminated, such that the resulting offset frame 354 includes a halo artifact 351 produced by the retroreflector 345. In the second vertically offset frame 356 following the first vertically offset frame 354 (e.g., shifted upward relative to a subsequent frame of the haloed frame 352), the target object 342 is illuminated by the emitter array, but the retroreflector 345 is not illuminated. Therefore, the detector receiving the reflection of object portion 343 in frame 356 is not affected by the halo effect from retroreflector 345 (the reflection from retroreflector 345 is not received by the neighboring detector in the same frame 356), so object portion 343 appears visible in the corresponding point cloud map of frame 356.

[0116] Target object 342 and retroreflector 345 can be spatially positioned and aligned relative to each other and individually illuminated in different frames using a vertical offset illumination protocol. For example, in a scene 364, target object 342 is located at approximately the same distance as retroreflector 345 (e.g., in a common vertical plane) but at different and non-overlapping locations (e.g., at different heights), and retroreflector 345 is illuminated by a first light emission 359 in a first frame excluding target object 342, as... Figure 8G (Front view) and Figure 8H As shown in the side view. In another scene 365, the target object 342 is located at a different distance from the retroreflector 345 (e.g., in a different vertical plane) and at a different and non-overlapping location (e.g., at a different height). The retroreflector 345 is illuminated by the first light emission 359 in the first frame excluding the target object 342, as shown. Figure 8I (Front view) and Figure 8J As shown in the (side view).

[0117] Therefore, information obtained in other frames with relative offsets (such as frame 356) can be used, for example, during subsequent image processing stages, to supplement image pixels (i.e., points in the point cloud) that are occluded in some frames (such as object portion 343 in frame 352). Reference Figure 9 , Figure 9 This is the use of the embodiments of this disclosure. Figure 7B The following is a sequence of frames of an exemplary point cloud obtained using a vertical offset illumination protocol. In the first frame 371, the object 375 (i.e., the person) and the retroreflector are mutually illuminated such that the illuminated area ends substantially near the bottom edge of the retroreflector. As a result, halo artifacts extend along the upper portion of the object 375, which is partially occluded in frame 371, while the lower portion of the object 375 (e.g., including the legs of the imaged person) appears visible. In the second frame 372, which is vertically offset relative to the first frame 371, the retroreflector and the object 375 are mutually illuminated such that the illuminated area extends substantially beyond the boundary of the retroreflector. As a result, halo artifacts extend along the upper and lower portions of the object, such that the object 375 is substantially completely occluded in frame 372. In the third frame 373, which is vertically offset relative to the second frame 372, the retroreflector and the object 375 are mutually illuminated such that the illuminated area ends substantially near the top edge of the retroreflector. As a result, object 375 in frame 373 appears to be partially occluded; however, the upper part of object 375 (e.g., including the head of the person being imaged) appears visible. It should be noted that certain parts of an imaged object may be visible in some frames but occluded in others. Therefore, information relating to object parts that are not visible in one frame can be extracted from other frames, where those same object parts appear visible in other frames due to offset illumination.

[0118] According to one aspect of this disclosure, the processor can determine that at least one received frame is subject to halo artifacts based on received reflections. This determination may take into account relevant factors such as the sensitivity level of detector 116 and the reflectivity of objects in the FOV. If it is determined that a region in a frame is subject to halo artifacts, then it can be determined that the same region in different frames in the frame sequence is not subject to halo artifacts. The image can be supplemented by using visible objects from these regions by replacing the halo-subjected regions with the same un-halo-subjected regions from different frames. Thus, a combination of regions from at least two frames in the frame sequence can be used to generate an improved single frame or multiple frames with more visible object portions. As described above, various scanning techniques and optical components (e.g., mirrors or deflectors) can be used to obtain offset (i.e., vertically shifted) frames. For example, a first scanning mirror configured to rotate along a tilt axis (i.e., guide the emitted beam in the vertical direction of the FOV) can have a rotation angle spanning between a minimum angle and a maximum angle, where the minimum to maximum angle can be an amount of offset selection (e.g., positive or negative) to align the vertical scan with the amount of offset selection (e.g., in the upward or downward direction).

[0119] At least some information in the offset frame can be obtained at a reduced frame rate. For example, a first portion of the target object 342 can be obtained in the first frame at a first (e.g., higher) frame rate, while a second portion of the target object 342 can be obtained in the second frame at a second (e.g., lower) frame rate. The amount of reduction can depend on the size of the vertical offset between frames, where an increased vertical offset can correspond to a reduction in the frame rate. Specifically, a larger offset size (vertical offset) between frames can extend the previously obscured visible portion of the target object (i.e., by increasing the displacement or alignment offset between the target object and the retroreflector or other objects in the scene that could cause a halo), but the frame rate will also need to be reduced proportionally.

[0120] refer to Figure 10A and Figure 10B . Figure 10A This is an illustration of an exemplary default scan mode 380 with variable resolution for different sub-regions of the field of view. Figure 10B This is an illustration of an exemplary vertical tilt scan mode 410 with variable resolution for different sub-regions of the field of view, operating according to embodiments of the present disclosure. In the default scan mode 380 ( Figure 10A ) and vertical tilt scan mode 410 ( Figure 10BIn this system, a scanning unit guides multiple beams emitted from a multi-channel laser array along a series of scan lines on the field of view (FOV). Specifically, the beams emitted from a vertically oriented laser array are horizontally scanned on the FOV by sequentially rotating at least one scanning device (e.g., a mirror or deflector) on a scanning axis (i.e., in the horizontal direction to generate horizontal scan lines) and on a tilt axis (i.e., in the vertical direction to vertically shift scan lines). Each scan cycle is divided into separate scan regions, where the central region of the FOV defines the region of interest (ROI), such as a region near the horizon, which may include more objects of interest, and where the top and bottom regions of the FOV define the regions of non-interest (NROI), such as regions far from the horizon, which may include fewer objects of interest. Each FOV region is scanned in the vertical direction at a selected resolution, for example by modifying the tilt increment of the scanning device to generate scan lines with variable vertical spacing on the selected region of the FOV. For example, a larger vertical tilt increment can be used to scan the NROI region (top and bottom regions) to provide greater spacing between scan lines, resulting in a lower sampling rate and lower point cloud resolution in the NROI region. Conversely, a smaller vertical tilt increment can be used to scan the ROI region (center region) to provide more closely spaced scan lines, resulting in a higher sampling rate and higher point cloud resolution. For instance, the NROI region can be scanned with a tilt increment corresponding to the angular size of the laser array, providing a coarse sampling resolution matching the laser spacing of the laser array. The ROI region can be scanned with the minimum available tilt increment of the scanning device to provide the maximum sampling resolution in the ROI region. The terms "vertical offset" and "vertical tilt increment" are used interchangeably herein and refer to the vertical displacement between scan lines along the vertical axis (e.g., the tilt axis) of the scanning pattern. It should also be noted that the term "tilt increment" is generally used herein to refer to "vertical tilt increment," which represents an exemplary scanning configuration in the context of horizontal scan lines scanned vertically on the FOV, where other embodiments may include "horizontal tilt increments" associated with vertical scan lines scanned horizontally on the FOV.

[0121] In the default scan mode 380 ( Figure 10AIn this model, each frame is divided into a top scan region 382 of the NROI, a center scan region 383 of the ROI, and a bottom scan region 384 of the NROI, where each scan region 382, ​​383, 384 (representing the scanned portion of the FOV) has a vertical scan angle of 10 degrees. Each frame is scanned at an exemplary scan rate of 20 frames per second (fps). Frame 380 is scanned at the first scan line 385, followed by a second scan line 387 with a vertical tilt increment of 5°, and then another scan line 389 with a vertical tilt increment of 5°, such that the top scan region 382 is surrounded by scan lines 385, 387. Another scan line 390 is applied at the same angular location as the previous scan line 389, followed by a minimum vertical tilt increment of 0.2° and another pair of scan lines 393, 394. Frame 380 is further scanned at a pair of scan lines 395 and 396 after a tilt increment of 4.8°, and then further scanned at another pair of scan lines 397 and 398 after a minimum tilt increment of 0.2°, such that the central scan region 383 is surrounded by scan lines 389, 390, 393, 394, 395, 396, 397, and 398. Another scan line 401 is applied after a tilt increment of 4.8°, followed by another scan line 403 after a tilt increment of 5°, such that the bottom scan region 384 is surrounded by scan lines 401 and 403. Therefore, NROI regions 382 and 384 are scanned at a lower resolution with scan lines spaced at 5° (corresponding to half the vertical angle of the corresponding region size), while ROI region 383 is scanned at a higher resolution, including a greater number of scan lines with closer spacing.

[0122] In vertical tilt scan mode 410 ( Figure 10BIn this model, each frame is divided into a top scan region 412 for the NROI, a center scan region 413 for the ROI, and a bottom scan region 414 for the NROI, with the frame rate reduced to an exemplary scan rate of 16 fps. The top scan region 412 has a vertical scan angle of 5°, the center scan region 413 has a vertical scan angle of 15°, and the bottom scan region 414 has a vertical scan angle of 10°. The vertical tilt scan mode 410 includes additional scan lines relative to the default scan mode 380. Specifically, frame 410 is scanned at a first scan line 415, which surrounds the top scan region 412. After a 5° vertical tilt increment, frame 410 is further scanned by a pair of scan lines 417, 418, followed by a minimum tilt increment of 0.2° and another pair of scan lines 421, 422, followed by a further tilt increment of 4.8° and another pair of scan lines 423, 424. The remainder of scan mode 410 corresponds to the default scan mode 380. Specifically, after a 0.2° tilt increment, another pair of scan lines 427 and 478 (corresponding to scan lines 393 and 394 in the default scan mode 380) are applied; followed by scan lines 429 and 430 (corresponding to scan lines 395 and 396 in the default scan mode 380) after a 4.8° tilt increment; followed by scan lines 433 and 434 (corresponding to scan lines 397 and 398 in the default scan mode 380) after a 0.2° tilt increment, such that the central scan region 413 is surrounded by scan lines 417, 418, 421, 422, 423, 424, 427, 428, 429, 430, 433, and 434. Scan mode 410 includes another scan line 435 (corresponding to scan line 401) after a tilt increment of 4.8°, and another scan line 436 (corresponding to scan line 403) after a tilt increment of 5°, such that the bottom scan region 414 is surrounded by scan lines 435 and 436. Therefore, additional scan lines (418, 421, 422) are included in the vertically offset scan mode 410 relative to the default scan mode 380, thereby increasing the angular size of the ROI region 413 to 15°, wherein the ROI region 413 is scanned at a higher resolution than the NROI regions 412 and 414, including a larger number of scan lines with closer spacing. It should be understood that, for illustrative purposes, scan modes 380 and 410 are described as having a “top-down” scan direction (i.e., where the first scan line is at the top of the FOV and subsequent scans are offset downwards), but a “bottom-up” scan direction (i.e., where the first scan line is at the bottom of the FOV and subsequent scans are offset upwards) may alternatively be implemented. In another example, the FOV can be scanned in a raster mode, which can be overlapping or non-overlapping, where the scan resolution of the selected FOV region can be increased in different ways (e.g., by applying a higher pulse rate).

[0123] When applying a vertical offset illumination protocol, consecutive frames are selected by the vertical tilt increment of the vertical offset, while maintaining the desired (e.g., maximum) resolution of the selected area of ​​field of view (FOV) (e.g., ROI). Reference Figure 11 This is an illustration of an exemplary vertical tilt scan cycle sequence with variable resolution operating according to embodiments of the present disclosure. Each frame is divided into a top scan region of the NROI with a vertical scan angle of 5 degrees, a center scan region of the ROI with a vertical scan angle of 15 degrees, and a bottom scan region of the NROI with a vertical scan angle of 10 degrees, corresponding to vertical offset scan mode 410. A first frame 441 is obtained at a first positioning relative to the FOV (i.e., default frame alignment). A second frame 442 is obtained with a vertical offset of -1.2° relative to the first frame 441 (e.g., a downward angular increment of 1.2°). A third frame 443 is obtained with a vertical offset of -2.4° relative to the second frame 442 (e.g., a downward angular increment of 2.4°), and therefore the third frame 443 has a vertical offset of -3.6° relative to the first frame 441. A fourth frame 444 is obtained with a vertical offset of +1.2° relative to the third frame 442 (e.g., an upward angular increment of 1.2°), and therefore the fourth frame 444 has a vertical offset of -2.4° relative to the first frame 441. In the exemplary vertical offset frame sequence shown, the maximum vertical offset between any two consecutive frames is 2.4°. While the top 3.6° of the NROI in the top scan region may not always be fully visible (due to possible halo effects), the entire ROI in the center scan region is always fully visible at the (higher) ROI scan resolution because the vertical offset of the successive scan cycles ensures that all object portions of the detected object are visible in at least one of the vertically offset frames 441, 442, 443, and 444, even if some object portions may be occluded in at least another of frames 441, 442, 443, and 444. A set of scan lines, defined by an angle of 10°, scans the Region of Interest (ROI) at a higher ROI resolution, vertically offset along the ROI in frame sequences 441, 442, 443, and 444 (as shown in the figure). Note that the angle of the ROI region remains constant across the frame sequence, and only the vertical offset (vertical tilt increment) changes in each frame 441, 442, 443, and 444. For a given sequence, the maximum displacement or vertical offset across the entire sequence should not exceed the angle or spacing of the entire transmitter array. For example, in frame sequences 441, 442, 443, and 444, the total vertical offset of 3.6° should be less than the angle of the transmitter array.

[0124] Information obtained from other frames in a vertically tilted frame sequence, such as the most recently matched valid pixels of the object portion (e.g., within the first 3 frames), can be used to replace or supplement any occluded object pixels (i.e., pixels halos). "Extra" pixels in the ROI (outside 9.6°) can be reduced to the default (lower) NROI scan resolution.

[0125] Vertical offset scanning modes enable the exposure of additional data in the field of view (FOV) that might otherwise be hidden (e.g., due to halo effects); however, this additional exposure can be achieved at a reduced frame rate. Larger offsets between frames (larger tilt increments) allow for the exposure of a larger amount of previously hidden data, but will correspondingly require a larger frame rate reduction. It should be understood that vertical offset illumination protocols can be used to control scan resolution, allowing desired scan resolution to be obtained for one or more selected FOV regions. Vertical offset illumination protocols are not limited by the physical constraints of the detector array (e.g., length or angle) and can establish the desired offset for each frame.

[0126] According to another aspect of this disclosure, an alternating illumination protocol is used to guide light toward the field of view (FOV) 120 of the lidar system 100, such that emitted beams from a multi-channel emitter array are selectively applied over a period of time. Specifically, selected emitter groups of the emitter array are activated in a predetermined mode within a corresponding frame and in a frame sequence, while other emitter groups can be deactivated. As a result, objects in the FOV can appear fully visible in at least one frame of the sequence, regardless of possible halo effects that may occur in other frames of the sequence. Different alternating illumination protocols can be applied to different sub-regions of the FOV, thereby providing a higher resolution scan cycle for at least one region of interest (ROI) of the FOV. This alternating illumination protocol can be used to maintain object detection capability when subjected to halo effects, such as enabling the differentiation between effective detection pixels (generated by object reflection) and ineffective detection pixels (generated by halo effects).

[0127] refer to Figure 12 , Figure 12 This is a schematic diagram of an exemplary frame 501 of a field of view (FOV) divided into sub-regions, operating according to embodiments of the present disclosure. Frame 501 is divided into sub-regions including a top scan region 502 of the non-restricted area of ​​interest (NROI), a center scan region 503 of the ROI, and a bottom scan region 504 of the NROI, each sub-region having a vertical angular span of 10 degrees. The center scan region 503 is further divided into a first (e.g., left-side) center scan region 505, a second (e.g., middle) center scan region 506, and a third (e.g., right-side) center scan region 507. Each of the scan regions 502, 504, 505, 506, and 507 can be scanned using a corresponding scan mode and illumination protocol, as will be discussed further below.

[0128] refer to Figure 13 This is an illustration of an exemplary default illumination protocol 510 for a multi-channel transmitter array used for frame portion 511 (such as projected onto a surface of a portion of the FOV). Figure 13 In the example, frame portion 511 is a 4 × 4 cell matrix, where each column (also referred to herein as a “macropixel”) represents a set of simultaneous light emissions from a vertically oriented multichannel laser array during a portion of a scan cycle, and each cell in the column (also referred to herein as a “pixel”) represents a group of emitters from the laser array. For example, if the laser array comprises 16 channels or emitters, a single cell of frame portion 511 could represent a group of four emitters, with each pair of emitters separated by at least one inactive region. An exemplary angular length of the laser array (i.e., the dimension along the vertical direction of frame portion 511) is 4.8°, such that the angular size of each individual cell is 1.2° (i.e., the size representing four active regions and staggered inactive regions). An exemplary angular width of each channel or emitter (i.e., the dimension along the horizontal direction of frame portion 511) is 0.1°, such that the angular size of the four columns (representing four groups of emitters) is 0.4°.

[0129] In the default illumination protocol 510, a first series of emitted beams is emitted simultaneously from all emitter groups at a first time t1, followed by a delay corresponding to a duration of 0.2° angular width until a later time t3, at which point a second series of beams is emitted simultaneously from all emitter groups. Note that the delay time (0.2° angular width) can depend on various factors, such as the emission characteristics of the emitted light (e.g., power, wavelength, pulse length, pulse rate, etc.), to ensure eye safety requirements are met. The delay time can represent the elapsed time between the movement of the deflector from a first angle to a second angle (e.g., rotation of the scanning mirror) during the execution of a scan. Each time slot of frame portion 511 represents a separate scan line segment across multiple scan lines of the FOV. Therefore, the term "scan line segment" is used herein to refer to an instantaneous portion of a single scan line, such as the instantaneous horizontal positioning of a scan line in a vertical comb pattern scanning horizontally across the FOV, where the scan line segment can correspond to the instantaneous field of view detected by the lidar system.

[0130] A multi-channel detector array receives reflections from the field of view (FOV) corresponding to each emission series, such that each detector pixel (the corresponding pixel of a cell in frame portion 511) represents a reflection from the emission from the corresponding emitter group. For example, four groups of detectors receive a first series of reflections from a first series of beams emitted at time t1, where each detector group (e.g., four detectors) corresponds to a corresponding emitter group (e.g., four emitters) and a corresponding detector pixel (the corresponding frame portion cell), such that all four groups form a first detector macropixel (the corresponding frame portion column) based on the reflections received from the first emission series at time t1. Accordingly, four detector groups receive a second series of reflections from a second emission series at time t3 to form a second detector macropixel. If, for a given detection series (i.e., a frame portion column) of frame portion 511, a retroreflector is present anywhere along the detector macropixel, the entire macropixel may experience a halo effect.

[0131] Although in this example each detector group corresponding to a frame unit may have 4 detectors, it should be understood that a single detector and / or a single emission corresponding to each frame unit in a macropixel may exist.

[0132] refer to Figure 14A , Figure 14AThis is an illustration of an exemplary alternating illumination protocol (generally designated 520) operating according to embodiments of the present disclosure, wherein emission is selectively activated on a sequence of frame portions to be applied to selected frame sub-regions. The alternating illumination protocol 520 includes a sequence of frame portions, including a first frame portion 521 (“Frame Portion N”), a second frame portion 522 (“Frame Portion N+1”), and a third frame portion 523 (“Frame Portion N+2”). The configuration and dimensions of frame portions 521, 522, and 523 are similar to those of frame portion 511, wherein each cell represents a group of transmitters, and wherein each cell has an angular length of 1.2° (e.g., representing four active regions and staggered inactive regions), and an angular width of 0.1° (e.g., representing a single transmitter). “1” is used to depict the illumination protocol to indicate a single emission of a corresponding transmitter group or cell, and a dash is used to indicate non-emission. Each time slot of frame portions 521, 522, and 523 represents a scan line segment across multiple scan lines of the field of view (FOV). In the first frame portion 521 (“Frame Portion N”), during the first scan segment at time t1, the first and third emitter groups of the laser array are activated (i.e., emit beams), while the second and fourth emitter groups of the laser array are deactivated (i.e., do not emit beams). During the second scan segment at time t2 of Frame Portion 521, the second and fourth emitter groups are activated, while the first and third emitter groups are deactivated. During the third scan segment at time t3 of Frame Portion 521, the first and third emitter groups are activated, while the second and fourth emitter groups are deactivated (i.e., similar to the emission mode at time t1). It should be understood that an emitter group may include at least one emitter.

[0133] In the second frame portion 522, during the first scan segment (t1) and the third scan segment (t3), the first and second transmitter groups are activated, while the third and fourth transmitter groups are deactivated. During the second scan segment (t2) of the second frame portion 522, the third and fourth transmitter groups are activated, while the first and second transmitter groups are deactivated. In the third frame portion 523, during the first scan segment (t1) and the third scan segment (t3), the first and fourth transmitter groups are activated, while the second and third transmitter groups are deactivated. During the second scan segment (t2) of the third frame portion 523, the second and third transmitter groups are activated, while the first and fourth transmitter groups are deactivated.

[0134] Note that for each of frame segments 521, 522, 523, each emitter group is activated at least once (i.e., during at least one scan segment) and deactivated at least once (i.e., during at least one scan segment). It should also be noted that for each frame segment 521, 522, 523 in the frame segment sequence, the emission patterns of the activated and deactivated emitter groups are different. However, during a horizontal scan spanning an angular width of 0.2°, a similar total emission count is provided compared to the default illumination protocol 510. As will be explained below, the alternating illumination protocol 520 ensures that at least a portion of at least one frame segment in the sequence is free from halo effects. Each emission pattern (selectively activated and deactivated emitter groups) can be repeated in a cyclical pattern on subsequent scan segments within the frame segment (e.g., such that the fourth scan segment t4 equals the first scan segment t1; the fifth scan segment t5 equals the second scan segment t2; the sixth scan segment t6 equals the third scan segment t3, etc.). Similarly, the transmission pattern can be repeated consecutively on subsequent frame portions of the sequence in any order or combination (e.g., such that: frame portion N+3 = frame portion N; frame portion N+4 = frame portion N+1; frame portion N+5 = frame portion N+2; and so on in a cyclic pattern). More generally, the transmission pattern of a single frame portion can be repeated consecutively on multiple frame portions of the sequence (e.g., such that frame portion N+1 is repeated sequentially and consecutively for several frame portions defining the sequence, or one or more alternative embodiments). The transmission pattern of frame portions can be repeated and alternated between frames of the FOV.

[0135] It should be understood that the alternating illumination protocol 520 describes a series of exemplary emission modes, while other emission modes are also operable to avoid halo effects in at least one frame portion or at least a portion of a frame in a sequence. The alternating illumination protocol of the disclosed embodiments may include any number of frame portions or frames having any number of scan lines. Reference Figure 14B , Figure 14B This is an illustration of another exemplary alternating illumination protocol 530 for selectively activated emission applied to selected frame sub-regions according to embodiments of the present disclosure. The alternating illumination protocol 530 includes a sequence of four frame portions 531, 532, 532, 533, each frame portion having four scan lines, wherein at least one emitter group is deactivated once during a given scan period.

[0136] For the default illumination protocol 510, where the duration between consecutive emissions corresponds to an angular width of 0.2° (i.e., the delay between individual activations of all transmitter groups in an instantaneous positioning of two consecutive scan segments or along a scan line), the emitted beams can have a default time of flight (TOF), such as 300 meters (m), where the TOF value can be selected based on various system requirements or limitations. However, for the alternating illumination protocol 520, the duration between consecutive emissions corresponds to an angular width of 0.1° because at least one transmitter group is activated for each scan segment of the frame portion, and there is no "deactivation period" in a given scan positioning (as in scan segment t2 of frame portion 511 in protocol 510). Therefore, the default TOF can lead to interference between multiple beams emitted in consecutive scan segments of the frame portion. Reference Figure 14C and Figure 14D . Figure 14C It operates according to embodiments of this disclosure and Figure 13 A diagram of the timing of the emission related to the default illumination protocol 510 (labeled 515). Figure 14D It operates according to embodiments of this disclosure and Figure 14A A timing diagram (labeled 525) illustrating the emission associated with the alternating illumination protocol 520. Referring to timing diagram 515, during the first scan segment (t1) of frame portion 511 of the default illumination protocol 510, the first beam 516 is emitted by the activated emitter group at time t1, wherein the first beam 516 is characterized by a default (maximum) TOF of 300 m. TOF During the second scan segment (t2) of frame portion 511 at time t2, all transmitter groups are deactivated and therefore no emission occurs. During the third scan segment (t3) of frame portion 511, the second beam 517 is emitted by the activated transmitter group at time t3, wherein the second beam 517 is also characterized by a default TOF of 300m. TOF Due to the time delay between time t3 and time t3, even when the maximum TOF value is applied, the timing of the reflections associated with the emitted beams 516 and 517 does not overlap.

[0137] Referring to timing diagram 525, during the first scan segment (t1) of frame portions 521, 522, and 523 of alternating illumination protocol 520, a default maximum TOF of 300 m is achieved. 526 TOF The first beam 526 is emitted by the activated emitter group at time t1. If, during the second scan segment (t2) of the frame portion, the second beam 527 is emitted by the activated emitter group at time t2 with the same default TOF of 300 m. TOFIf the second emitted beam 527 reflects the light, the reflection may interfere with the first activated detector configured to receive the reflection from the first emitted beam 526. Specifically, because the second emitted beam 527 is at the TOF 526 of the first emitted beam 526... TOF The second emitted beam 527 is emitted at time t2 prior to completion, therefore at least a portion of the second emitted beam 527 is at time t2 of the first emitted beam 526. TOF Overlap can cause interfering reflections from pixels of the active detector during this period (e.g., reflections from the second beam might be received by incorrect detector pixels). Therefore, the TOF for each transmission pulse can be reduced, for example, to half the default amount, to avoid this interference. For example, in an alternative scenario, a TOF 528 with a range of 150 meters is transmitted at time t1. TOF The first emitted beam 528 of the reduced TOF (depicted with dashed lines) is emitted at time t2, and the TOF 529 with a range of 150 meters is emitted at time t2. TOF The second emission beam 529 with reduced TOF. Therefore, the second emission beam 529 with reduced TOF will be at the TOF of the first emission beam 528. TOF It starts after the end, thus eliminating interference from the received reflections at the active detector.

[0138] The emission mode of the alternating illumination protocol 520 is operable to eliminate possible halo effects in at least one detector macropixel of at least one frame portion of at least one frame. (Reference) Figure 15A , Figure 15A This is the use of the embodiments of this disclosure. Figure 13 An illustration of the general reflection pattern obtained by the alternating illumination protocol 520 of A, wherein the retroreflector is positioned at a first exemplary location within the FOV. A multi-channel detector array receives reflections from the FOV according to the emission pattern of the alternating illumination protocol 520, such that each detector group (corresponding to detector pixels and frame portion units) receives reflections of emissions from its corresponding transmitter group. The retroreflector 535 is positioned within the FOV such that it extends across the respective detection windows of the first and second detector groups. In other words, for each scan line of a scan cycle, the retroreflector 535 covers at least a portion of the individual or momentary FOV of each detector in the first and second detector groups of the detector array.

[0139] At the first scan line segment (t1) of frame portion 521, the first transmitter group (in frame portion unit 521) lA The emission from the first detector group (at point 521) is incident on the retroreflector 535. The corresponding high reflectivity reflection received at the first detector group causes oversaturation and leakage into the third detector group, which receives reflections from the activated third emitter group, thus causing oversaturation at the third detector pixel (in frame portion unit 521).1C A halo is generated at the location (in the first scan segment). Therefore, the first detector macropixel (in the first scan segment) experiences an invalid detector response signal from the halo. Note that the fourth detector group does not receive reflections from the deactivated fourth emitter group during the first scan segment, so it can be determined that the received reflections are caused by the halo (although the detectors of the deactivated emitter group may still experience oversaturated high reflectivity reflections from neighboring detectors). At the second scan segment (t2) of frame portion 521, the second emitter group (in frame portion unit 521) generates a halo. 2B The emission from the second detector group (at point 521) is incident on the retroreflector 535, such that the corresponding high reflectivity reflection received at the second detector group results in the fourth detector pixel (in frame portion unit 521) receiving the reflection from the activated fourth emitter group. 2D The halo at (t3) in frame portion 521. At the third scan line segment (t3) of frame portion 521, the first emitter group (in frame portion unit 521) 3A The emission from the first detector group (at point 535) is incident on the retroreflector 535, such that the corresponding high reflectivity reflection received at the first detector group results in the third detector pixel (in frame portion unit 521) receiving the reflection from the activated third emitter group. 3C The halo effect occurs at the location (e.g., at point 521). Therefore, all three detector macropixels in all scan segments of the first frame portion 521 experience invalid detector response signals due to the halo effect. However, this would also be the case if the default illumination protocol 510 were implemented, where all emitter groups are activated for each emission series.

[0140] Considering the second frame portion 522, at its first scan segment (t1) and third scan segment (t3), the first and second transmitter groups (in frame portion unit 521) lA and 521 lB The emissions from the first and second detector groups (at the second frame portion 522) are incident on the retroreflector 535, and the corresponding first and second detector groups receive the corresponding high reflectivity reflections. However, the other emitter groups of the macropixel are not activated, and therefore the corresponding third and fourth detector groups are unaffected. However, at the second scan segment (t2) of the second frame portion 522, no emissions are incident on the retroreflector 535 because the first and second emitter groups are deactivated during this scan period, and therefore the corresponding activated detector groups (the third and fourth groups) are not subjected to halos. Therefore, the second detector macropixel of the second frame portion 522 is operable to include only valid detections and is less susceptible to invalid response signals from halos. Therefore, in this scenario, at least one frame portion of the frame portion sequence 521, 522, 523 includes a fully valid detector macropixel.

[0141] Further reference Figure 15B , Figure 15B This is the use of the embodiments of this disclosure. Figure 13An illustration of the general reflection pattern obtained by alternating illumination protocol 520 of A, wherein the retroreflector is positioned at a second exemplary location within the FOV. A multi-channel detector array receives reflections from the FOV according to the emission pattern of alternating illumination protocol 520, such that each detector group receives reflections of emissions from a corresponding transmitter group. Retroreflector 535 is positioned within the FOV such that it extends across the respective detection windows of the second and third detector groups of the detector array (i.e., for each scan segment, retroreflector 535 covers at least a portion of the individual or momentary FOV of each detector in the second and third detector groups).

[0142] At each of the first scan segment (t1) and the third scan segment (t3) in frame portion 521, the third transmitter group (in frame portion unit 521) 1C The emission from the first emitter group is incident on the retroreflector 535, such that the corresponding high reflectivity reflection received at the first detector group results in the first detector pixel (in the corresponding frame portion unit 521) receiving the reflection from the first emitter group. lA and 521 3A The halo at (t2) in frame portion 521. At the second scan segment (t2) of frame portion 521, the second emitter group (in frame portion unit 521) 2 B The emission from the fourth emitter group (at point 535) is incident on the retroreflector 535, such that the corresponding high reflectivity reflection received at the second detector group results in the fourth detector pixel (in frame portion unit 521) receiving the reflection from the fourth emitter group. 2D The halo effect occurs at the location of the first detector pixel (e.g., at the first and third scan segments). Similarly, for the second frame portion 522, high reflectivity reflections received at the second detector group at the first and third scan segments result in a halo effect at the second detector pixel, while high reflectivity reflections received at the third detector group at the second scan segment result in a halo effect at the fourth detector pixel. Therefore, all three detector macropixels in all scan segments of the first frame portion 521 and the second frame portion 522 experience invalid detector response signals from the halo effect. However, this would also be the case if the default illumination protocol 510 were to be implemented, in which all emitter groups are activated for each emission series.

[0143] For the third frame segment 523, at each of the first scan segment (t1) and the third scan segment (t3), no emission is incident on the retroreflector 535 because the second and third emission groups are deactivated, and therefore the detector groups (first and fourth groups) receiving reflections from the active emission do not experience halos during these scan segments. During the second scan segment (t2), the second and third emission groups (in frame segment unit 521) 2B and 521 2CThe emissions from the first and fourth emitter groups are all incident on the retroreflector 535; however, the first and fourth emitter groups are deactivated, so the corresponding first and fourth detector groups are not subjected to halos. Therefore, all three detector macropixels in the third frame 523 will only include valid detections and are less susceptible to invalid response signals from the halo effect. Thus, in this scenario, at least one frame portion of the frame portion sequence 521, 522, 523 includes three fully valid detector macropixels.

[0144] According to one aspect of this disclosure, an alternating illumination protocol (such as) for selectively activated emitter groups in a sequential firing mode is provided. Figure 14A The alternating illumination protocol 520 is applied to non-ROI frame sub-regions, such as the top scan region 502 and bottom scan region 504 of frame 501. Figure 12 Different illumination protocols can be applied to ROI frame sub-regions, such as the center scan region 503 of frame 501. The default illumination protocol's frame portion (such as frame portion 511) Figure 13 Subjected to the default scan mode 380, as referenced above. Figure 10A The discussion focuses on the following: Specifically, the top scan region 382 of the NROI is scanned at a lower resolution, where the scan lines have large relative intervals (e.g., 5° between scan lines 385 and 387). Similarly, the bottom scan region 384 of the NROI is scanned at a lower resolution, where the scan lines have large relative intervals (e.g., 5° between scan lines 401 and 403). In contrast, the central scan region 383 of the ROI is scanned at a higher resolution, comprising a larger number of scan lines with closer relative intervals (e.g., 0.2° between scan lines 389 and 393). Furthermore, the central scan region 383 includes replicated scan lines for a specific vertical positioning (also referred to herein as “superscan”). For example, the central scan region 383 includes a first set of replicated scan lines 389, 390; a second set of replicated scan lines 393, 394 (after a 0.2° vertical tilt); a third set of replicated scan lines 395, 396 (after a 4.8° vertical tilt); and a fourth set of replicated scan lines 397, 398 (after a 0.2° vertical tilt). Therefore, the central scan region 383 is characterized by additional scan lines that are not available in the top and bottom scan regions 382, ​​384.

[0145] According to one aspect of this disclosure, a first scan line of a duplicated scan line pair can be used to learn the position of the retroreflector in the FOV, while a second scan line of the duplicated scan line pair can subsequently be used to obtain effective detection from the FOV (as will be discussed further below). The emitter group of macropixels is divided into two subgroups, each subgroup being positioned at the same horizontal scan location (scan line segment) but emitting at different times (i.e., in individual scan lines of the scan line pair). Reference Figure 16 , Figure 16 This is an illustration of another exemplary alternating illumination protocol (generally designated 540) operating according to embodiments of the present disclosure, which has selectively activated emission over a frame sequence for application to selected frame sub-regions. Alternating illumination protocol 540 includes a sequence of frame portions, including a first frame portion 541 (“Frame Portion N”), a second frame portion 542 (“Frame Portion N+1”), and a third frame portion 542 (“Frame Portion N+2”). The configuration and dimensions of frame portions 541, 542, and 543 are similar to those of frame portion 511 and frame portion sequences 521, 522, and 523, wherein each unit represents a group of transmitters, and wherein each unit has an angular length of 1.2° (e.g., representing four active regions and staggered inactive regions), and wherein each unit has an angular width of 0.1° (e.g., representing a single transmitter). Each time slot of frame portions 541, 542, and 543 represents a scan line segment across multiple scan lines of the field of view (FOV). Alternating illumination protocol 540 is operable for application to ROI sub-regions of a frame, such as side scan regions 505, 507 of frame 501, which include duplicate scan lines (i.e., overscans). In illumination protocol 540, "1" indicates emission of a corresponding emitter group or unit during a first scan line paired with duplicate scan lines, and "2" indicates emission of a corresponding emitter group or unit during a second scan line paired with duplicate scan lines, while a dashed line (-) indicates no emission of a corresponding emitter group or unit.

[0146] In the first frame segment 541, during the first scan segment (t1), the first transmitter group is activated during the first scan line of the superscan pair (e.g., scan line 389 for superscan pair 389, 390 of scan mode 380) and deactivated during the second scan line of the superscan pair (e.g., scan line 390 for superscan pair 389, 390). Furthermore, during the first scan segment of frame segment 541, the second transmitter group is activated only for the second scan line of the superscan pair and deactivated for the first scan line of that pair; the third transmitter group is activated only for the first scan line of the superscan pair and deactivated for the second scan line of that pair; and the fourth transmitter group is activated only for the second scan line of the superscan pair and deactivated for the first scan line of that pair. During the second scan segment (t2) of frame segment 541, all four transmitter groups are completely deactivated. During the third scan line segment (t3) of frame portion 541, the first and third transmitter groups are activated only for the first scan line of the superscan pair and deactivated for the second scan line of the pair, while the second and fourth transmitter groups are activated only for the second scan line of the superscan pair and deactivated for the first scan line of the pair (i.e., similar to the transmission mode at time t1).

[0147] In the second frame segment 542, during the first scan segment (t1) and the third scan segment (t3), the first and second transmitter groups are activated for the first scan line of the superscan pair and deactivated for the second scan line of the pair. During these scan segments, the third and fourth transmitter groups are activated for the second scan line of the superscan pair and deactivated for the first scan line of the pair. During the second scan segment (t2) of the second frame segment 542, all four transmitter groups are completely deactivated. In the third frame segment 543, during the first scan segment (t1) and the third scan segment (t3), the first and fourth transmitter groups are activated for the first scan line of the superscan pair and deactivated for the second scan line of the pair. During these scan segments, the second and third transmitter groups are activated for the second scan line of the superscan pair and deactivated for the first scan line of the pair. During the second scan segment (t2) of the third frame segment 543, all four transmitter groups are completely deactivated.

[0148] It should be noted that the reduction in the Time of Flight (TOF) of the emitted beam required by the alternating illumination protocol 520 (as described above) due to the deactivation period in each frame segment is unnecessary for the illumination protocol 540. In the alternating protocol 520, where at least one emitter group is activated for each scan segment of the frame, such that the duration between consecutive emission corresponds to an angular width of 0.1°, a reduced TOF of the emitted beam (e.g., from 300m to 150m) is required to avoid interference between corresponding reflections received by the active detector (e.g., ...). Figure 14D (As shown). In contrast, illumination protocol 540 includes at least one scan segment without emission in each frame, such that the duration between consecutive emission corresponds to an angular width of 0.2°. As in frame portion 511 of the default protocol 510, no emitter group is activated between time t2 and time t3 in frames 541, 542, and 543, therefore even when the two beam groups are characterized by a default maximum TOF of 300m (as shown). Figure 14C As shown), the timing of the reflections from the beam emitted during the first active scanning period (at time t1) and the continuous beam emitted during the next active scanning period (at time t3) do not overlap.

[0149] As in alternation protocol 520, for each frame segment 541, 542, 543 in alternation protocol 540, the emission modes of the activated and deactivated transmitter groups are different. Each transmitter group is activated for one scan line and deactivated for a second scan line paired with a duplicate scan line in a given scan line segment (e.g., horizontal positioning). However, during scanning across an angular width of 0.2° (e.g., horizontal), a similar total number of emissions as in default protocol 510 and alternation protocol 520 is provided. Alternation protocol 540 can ensure that halo effects are avoided for at least one frame segment or at least a portion of a frame in the sequence. It should be understood that alternation protocol 540 depicts an exemplary emission mode, and other emission modes may also be operable to avoid halo effects in at least one frame segment or at least a portion of a frame in the sequence.

[0150] According to one aspect of this disclosure, processing unit 108 can determine that at least one received frame has experienced halo artifacts based on received reflections. This determination may take into account relevant factors such as the sensitivity level of detector 116 and the reflectivity of objects in the field of view (FOV). Processing unit 108 may implement one or more correction measures to counteract or compensate for (e.g., mitigate) the determined halo artifacts. Such halo correction measures may include: applying an adaptive illumination scheme (i.e., illuminating the target object less than the rest of the FOV), and / or applying an adaptive sensing scheme (i.e., reducing the detector sensitivity in response to the target object).

[0151] According to one aspect of this disclosure, processing unit 108 may apply a halo detection process to scan regions within the field of view (FOV) and determine the locations of highly reflective and non-highly reflective objects within the FOV. Based on this determination, processing unit 108 may apply an adaptive illumination scheme. For example, during at least a portion of at least one scanning cycle, projection unit 102 may be guided to simultaneously illuminate only regions within the FOV containing highly reflective objects without illuminating other FOV regions, and subsequently illuminate other regions (e.g., regions containing non-highly reflective objects) without illuminating the FOV regions containing highly reflective objects. Processing unit 108 may then apply a halo removal process to selectively remove halo artifacts only in FOV regions associated with highly reflective objects, while avoiding applying such halo removal in FOV regions associated with non-highly reflective objects.

[0152] refer to Figure 17A , Figure 17AThis is an illustration of exemplary illumination performed by a multi-channel emitter array in a scenario with a retroreflector close to a target object, according to embodiments of the present disclosure. In the illustrated scenario, the target object 554 is located near a highly reflective object 552 (referred to as the "reflector") in a field of view (FOV) 550. The FOV 550 is scanned by a vertically oriented multi-channel laser array, where macropixels 551 represent a collection of simultaneous light emissions from the laser array during a portion of a scan cycle, and each unit (i.e., pixel) of the macropixels 551 represents a set of emission channels or active emitters of the laser array. The retroreflector 552 is fully illuminated by multiple units of the macropixels 551 (e.g., the three uppermost pixels), while a portion of the retroreflector 552 is mutually illuminated with a portion of the target object 554 in subsequent units of the macropixels 551 (e.g., the lowermost pixel).

[0153] A multi-channel detector array receives reflections from the FOV 550 corresponding to the illumination of macropixel 551, such that each detector pixel (a set of active detectors or detection channels) receives reflections emitted from its corresponding emitter group. Referring to the bottommost pixel of macropixel 551, when an area containing a highly reflective object, retroreflector 551, and another target object 554 is illuminated, the received reflections partially include reflections from retroreflector 552 and partially include reflections from a non-highly reflective object. In this scenario, the target object 554 may be partially occluded by reflections from retroreflector 552. Further reference... Figure 17B , Figure 17B The operation corresponding to the embodiments of this disclosure Figure 17AIllustration of the detector macro-pixel response distribution (labeled 556) for an exemplary illumination. The detector response distribution 556 depicts the intensity level (y-axis) of the detector response signal as a function of the positioning (x-axis) of the detector group or detection channel along the detector array. For an initial group of detection channels (e.g., positioning = 0, 1, 2, …, m < n, calculated from the upper end of the macro-pixel 551), the detection signal intensity is at a high level, indicating a highly reflective object, corresponding to the received reflection from the retroreflector 552. For the next group of detection channels (e.g., positioning = m,......, n), the detection signal intensity decreases or attenuates, corresponding to the received reflection from the FOV region that undergoes a halo effect due to the mutual illumination of the retroreflector 552 and the target object 554 in the common pixel. Based on the detector response distribution 556, the processing unit 108 can identify the positioning of one or more retroreflectors 552 in the FOV 550 and can apply one or more measures to remove or compensate for the halo artifacts generated by the retroreflector 552. For example, if an attenuation is detected in the response signal associated with the detection of a retroreflector on multiple channels in a multi-channel array, the response signal can be used to determine the positioning of the retroreflector within the simultaneously illuminated detector group. The resolution of the halo detection can be less than the simultaneously illuminated FOV region (e.g., a group of 4 emitters in an exemplary macro-pixel unit).

[0154] A mapping process can be applied to map the retroreflector to an angular positioning in the FOV , such as by analyzing the detector response distribution as described above. Such a mapping process can involve classifying pixels or cells as containing a highly reflective object or containing a "conventional" or non-highly reflective object. Specifically, the emitter / detector groups of the macro-pixel are divided into two categories, where the first category represents the reflection of a highly reflective object (denoted as "R"), and the second category represents the reflection of a conventional or non-highly reflective object (denoted as "N"). For example, the first scan line of the replicated scan line pairing (super-scan) of the FOV region can be used for this classification.

[0155] Referring to Figure 18 , Figure 18 is a schematic diagram of an exemplary frame portion (labeled 591) having a classification of macro-pixels between highly reflective and non-highly reflective object reflections, operating in accordance with an embodiment of the present disclosure. The frame portion 591 is similar to the frame portion 511 ( Figure 13The array is depicted as a 4×4 cell matrix, where each column (i.e., macropixel) represents a set of simultaneous light emitted by a vertically oriented multichannel laser array during a portion of the scan cycle, and each cell (i.e., pixel) in the column represents a set of emitters in the array. For one or more scan segments of a frame portion, each cell can be classified as containing at least one highly reflective object (“R”) or containing only non-highly reflective objects (“N”) (i.e., containing no highly reflective objects), for example, depending on whether the corresponding detection of the cell exceeds a predefined signal strength threshold. Figure 18 In the example, the reflection from retroreflector 595 falls on the upper half of the second macropixel (t2) and the third macropixel (t3). Therefore, frame portion unit 591 2A 591 2B 591 3A and 591 3B Units in frame portion 591 are classified as high reflectivity reflective (“R”), while all other units are classified as low reflectivity reflective (“N”). It should be noted that even if a macropixel experiences a halo, high reflectivity reflective (“R”) units within a single unit can be distinguished from low reflectivity reflective (“N”) units. For example, one technique for this distinction could include applying different signal strength thresholds based on the relative positioning of units within the macropixel (such as relative to other previously classified “R” or “N” units). In another example, each scan line can utilize information learned in previous scan lines, such that the classification of a second scan line can be based on the previous classification of units in the first scan line, where the first scan line classification can utilize the previous classification of first scan lines in a previous frame portion. In yet another example, the classification of units in one frame portion can be based on the classification of units in another frame portion (e.g., a previous frame portion).

[0156] Adaptive illumination schemes can be applied based on the classification of macro-pixel units. For example, refer to illumination protocol 540 ( Figure 16 During the first scan line of the duplicate scan line pairing, the emitter group of macropixel units classified as high reflectivity (“R”) is activated (“1”), while the emitter group of macropixel units classified as low reflectivity (“N”) is deactivated (“-”). However, during the second scan line of the duplicate scan line pairing, the emitter group of macropixel units classified as “N” is activated (“1”), while the emitter group of macropixel units classified as “R” is deactivated (“-”). The alternating illumination protocol 540 can be applied to ROI sub-regions of a frame, such as the side scan regions 505, 507 of frame 501, which include duplicate scan lines (i.e., overscans).

[0157] Therefore, the processing unit 108 can apply a mapping process to map the highly reflective object (reflector) to the angular positioning within the field of view (FOV). Furthermore, an adaptive illumination scheme can be applied in response to this mapping. For example, a multi-channel emitter array can be guided to selectively illuminate only the retroreflector region (“R” cell) of the FOV (field of view) during at least a portion of the scan cycle, while ignoring the non-reflector region (“N” cell) of the FOV, and to avoid igniting the retroreflector region (“R” cell) while ignoring the non-reflector region (“N” cell) during at least another portion of the scan cycle. The processing unit 108 can then apply at least one correction measure or halo removal process to selectively remove halo artifacts only in the detection of FOV regions associated with high-reflectivity objects (e.g., retroreflectors), such as regions adjacent to high-reflectivity objects identified as subject to halo artifacts. In this case, it can be determined that different frame portions or the same region within a frame are not subject to halo artifacts. The halo-affected regions can be replaced with the same regions from different frame portions or non-halo-affected frames, supplementing the image with visible objects from these regions, making it possible to generate an enhanced image using a combination of regions from multiple frame portions or frames in the sequence. By avoiding the application of halo correction measures in areas not subject to halo artifacts, processing time can be reduced and efficiency and error rates can be improved.

[0158] According to one aspect of this disclosure, using a series of beam emissions emitted within a single pixel time (i.e., the time for measuring a single FOV region up to a given distance range) can increase the confidence and ability to identify invalid reflections due to halo effects. Simultaneous illumination of all cells, compared to other illumination protocols that illuminate only a portion of the cells in a frame and avoid illuminating adjacent cells, enables data measurement at higher resolution (i.e., FOV regions or cells are not "skipped" to prevent halo).

[0159] Typically, lidar systems determine the location of objects in the field of view by detecting light reflected from these objects. However, reflected light can be a small fraction of emitted light, and environmental interference is significant relative to reflected light. To obtain confidence that the light detected by the lidar system is associated with reflections from "real" objects (as opposed to environmental interference such as ambient light, crosstalk from other devices, or reflections from dust or fog) rather than noise, a lidar system can use a sequence of light pulses when illuminating a portion of the field of view. If the reflected light comprises a series of pulses associated with the emitted light pulse sequence, the confidence that the reflected light is associated with a "real" object can be increased. When the confidence level of the reflected light exceeds a threshold, a conventional lidar system can consider the object to be "real" (i.e., not noise) and generate a single point cloud data point. For example, light source 112 can generate light pulses with pulse widths less than a few nanoseconds, such as up to one-tenth of a nanosecond, between 0.1 nanoseconds (ns) and 10 ns. The time interval between emitted light pulses can have a duration between 5 ns and 100 ns.

[0160] According to one aspect of this disclosure, the first scan line paired with the replicated scan line of the ROI region can be used to classify pixels or cells as belonging to highly reflective objects or "normal" or non-highly reflective objects. Specifically, the emitter / detector group of macropixels is divided into two categories, where the first category represents the reflection of highly reflective objects (denoted as "R"), and the second category represents the reflection of normal or non-highly reflective objects (denoted as "N"), such as reference frame portion 591 above ( Figure 18 As described in the first scan line of the frame section, each cell is classified as containing at least one highly reflective object (“R”) or containing only non-highly reflective objects (“N”) (i.e., containing no highly reflective objects), such as depending on whether the corresponding detection of the cell exceeds a predefined signal strength threshold.

[0161] The classification of macropixel units can be applied to the initial scan lines paired with scan lines in selected areas of the field of view (FOV), such as the region of interest (ROI). For example, refer to... Figure 10AThe first scan line 389 of the scan line pairs 389, 390 defining the ROI region 383 is used for macropixel classification. In other words, after the scan of scan line 389, each cell corresponding to each macropixel of the ROI region 383 is assigned "N" or "R" depending on whether the corresponding detection exceeds a signal strength threshold. This classification can then be utilized in the second scan line 390 of the scan line pairs 389, 390 and in subsequent scan lines of the ROI region. Specifically, during subsequent scan lines, a relative time offset can be applied between different categories of emitter groups for a given macropixel to enable the identification of objects that may be obscured by a halo effect at a given time point, as will be discussed further below. The previous macropixel classification can be dynamically updated during subsequent scan lines of the FOV region, such as by modifying the classification applied in the initial first scan line (e.g., scan line 393 of the scan line pairs 393, 394) during subsequent first scan lines (e.g., scan line 395 of subsequent scan line pairs 395, 396).

[0162] refer to Figure 19A , Figure 19A This is an illustration of an exemplary default timing protocol for emission from different classes of emitter groups. An exemplary macropixel (i.e., representing a set of simultaneous light emission by a multi-channel array during a portion of a scan period) includes at least one emitter group classified as “high reflectivity” (“R”), and at least one emitter group classified as “non-high reflectivity”, such as the second macropixel of frame portion 591 acquired at time t2. Figure 18 Timing diagram 600 shows the emission sequence of the "Category R emitter group" of macropixels, where the first beam 601 is emitted at time t1, the second beam 602 is emitted at time t3, and the third beam 603 is emitted at time t5. Timing diagram 610 shows the emission sequence of the "Category N emitter group" of macropixels, where the first beam 611 is emitted at time t1, the second beam 612 is emitted at time t3, and the third beam 613 is emitted at time t5. Therefore, in the default protocol with three repetitive pulse beams emitted, the emission time of the Category R emitter group matches the emission time of the Category N emitter group.

[0163] refer to Figure 19B , Figure 19BThis is an illustration of a modified timing protocol for the emission of transmitter groups of different categories having relative time offsets, operating according to embodiments of the present disclosure. For an exemplary macropixel including at least one category R (high reflectivity) transmitter group and at least one category N (non-high reflectivity) transmitter group, timing diagram 620 represents a pulse beam emission sequence for the category R transmitter group, and timing diagram 630 represents a pulse beam emission sequence for the category N transmitter group. Timing diagram 620 includes a first beam 621 emitted at time t1, a second beam 622 emitted at time t3, and a third beam 623 emitted at time t5, which is similar to the timing of the emission of the category R transmitter group in the default protocol. Figure 20 Timing diagram 600 of A). However, timing diagram 630 includes a first beam 631 emitted at time t2, which is time-shifted from time t1 (e.g., after time t1). Timing diagram 630 also includes a second beam 632 emitted at time t4, which is time-shifted from time t3 (e.g., after time t3), and a third beam 633 emitted at time t6, which is time-shifted from time t5 (e.g., after time t5). Thus, the timing of the emission is time-shifted or biased relative to the class R emitter group. Such a time shift prevents the accumulation of halo reflections (from highly reflective objects) at the common time of multiple receiving windows across a given macropixel, thereby enabling the detection of one or more target (e.g., non-highly reflective) objects that might otherwise suffer from halo effects.

[0164] refer to Figure 20 , Figure 20 This is an illustration of multiple timing diagrams demonstrating operation according to embodiments of the present disclosure to identify invalid detections from a halo effect. Timing diagram 640 represents a pulse beam emission sequence of an exemplary macropixel class R emitter group, and timing diagram 650 represents a pulse beam emission sequence of the same macropixel class N emitter group. Timing diagram 640 includes a first beam 641 emitted at time t1, a second beam 642 emitted at time t3, and a third beam 643 emitted at time t5 (similar to...). Figure 18 Timing diagram 620 of B). Timing diagram 650 includes a first beam 651 emitted at time t2, a second beam 652 emitted at time t4, and a third beam 653 emitted at time t6, such that the emission of the class N transmitter group (641, 642, 643) is time-biased relative to the emission of the class R transmitter group (651, 652, 653).

[0165] Timing diagram 660 represents the sum or accumulation of the individual detector response signals associated with the emission sequence of the Category N transmitter group (i.e., the accumulation of the individual detection receiving windows for each emitted beam 651, 652, 653). The target object is located at a distance of 100 meters within the FOV. A highly reflective object or retroreflector is also located at a distance of 100 meters. The sum timing diagram 660 includes multiple response signals 667, 668, 669, 671, 673, 673 corresponding to invalid detection due to halo effects, and a peak response 670 corresponding to valid target detection. For example, the response signal 669 at 90 meters reflects the invalid halo response signal of the detector associated with the Category N transmitter group due to reflection from the Category R emitted beam 641 emitted at time t1. Specifically, the reflection of beam 641 is incident on the retroreflector located at 100 meters from time t1, which is 10 meters before time t2 when the category N emission beam 651 begins. The response signal 669 is equal to the difference between time t5 (the retroreflector's position) and time t2 (the emission time of beam 651), resulting in detection at 90 meters. Similarly, due to the reflection of category R emission beam 642, the response signal 668 at 80 meters reflects the invalid halo response signal of the detector associated with the category N emitter group. Specifically, the reflection of beam 642 is incident on the retroreflector located at 100 meters from time t3, which is 20 meters before time t4 when the category N emission beam 652 begins. The peak response 670 at 100 meters reflects the cumulative effective detection of the target object produced by emission beams 651, 652, and 653. Specifically, the detection of target objects accumulates across multiple receiving windows at the same timing position, resulting in a peak (i.e., higher energy level) detection response 670 in the sum timing diagram 660 due to the sum of all target object detections. In contrast, invalid detections caused by the halo effect occur at different timing positions and therefore do not accumulate consistently across multiple receiving windows, resulting in multiple reduced (i.e., lower energy level) detection responses 667, 668, 669, 671, 673, and 673 in the sum timing diagram 660.

[0166] Therefore, invalid and valid detections can be identified by calculating the ratio between the maximum signal value and the cumulative signal value at a given detection time point. For example, if the ratio is approximately equal to the fraction 1 / n, where the denominator "n" corresponds to the number of receiving windows or response signals, the corresponding detection is associated with a valid target object. Conversely, if the ratio is approximately equal to 1, the corresponding detection is associated with an invalid detection (e.g., an invalid detection due to a halo effect).

[0167] It is important to note that the staggered timing positions of invalid halo detections in the total response signal are a function of the time offset between the emission of category R emitter group and the emission of category N emitter group. For example, the 10m time displacement between invalid detection 669 and peak detection 670 is determined by the time offset between the emission of category R first beam 641 (at time t1) and the emission of category N first beam 651 (at time t2). Similarly, the 20m time displacement between invalid detection 668 and peak detection 670 is determined by the time offset between the emission of category R second beam 642 (at time t3) and the emission of category N second beam 652 (at time t4). If the default timing protocol is used, the detection of the target object will suffer from the halo effect of invalid detections at the same timing position (100m). However, by applying a modified timing protocol with time offset between the transmissions from the category R transmitter group (of highly reflective objects) and the transmissions from the category N transmitter group (of non-highly reflective objects), invalid detection occurs at different timing positions on multiple receiving windows and can therefore be identified and extracted from the summed response signal.

[0168] According to one aspect of this disclosure, a method for detecting objects in a field of view (FOV) using a lidar is provided. The method may include the step of emitting corresponding laser beams from respective emitters of a plurality of laser emitters in at least one laser emitter array of a laser emitting unit. The method may include the step of guiding the emitted beams toward the FOV using a scanning unit. The method may include the steps of: controlling at least one of the laser emitting unit and the scanning unit to guide the emitted beams toward the FOV according to an alternating energy level illumination protocol so as to enable detection under halo effects, such that a first emitted beam having a first energy level emitted by a first emitter illuminates a first FOV region, and a second emitted beam having a second energy level emitted by a second emitter illuminates a second FOV region adjacent to the first FOV region, wherein the first energy level is lower than the second energy level. The method may include the steps of: detecting a first reflected beam of the first emitted beam at a first detector of a plurality of detectors in at least one detector array of a sensing unit, and detecting a second reflected beam of the second emitted beam at a second detector of the detector array.

[0169] According to another aspect of this disclosure, a method for detecting objects in a field of view (FOV) using a lidar is provided. The method may include the step of emitting corresponding laser beams from corresponding emitters of a plurality of laser emitters in at least one laser emitter array of a laser emitting unit. The method may also include the step of guiding the emitted beams toward the FOV using a scanning unit. The method may include the following steps: to enable detection under halo effects, controlling the scanning unit to guide the emitted beams toward the FOV according to an offset illumination protocol, wherein the scanning unit guides the emitted beams along first plurality of scan lines passing through the FOV, shifting the emitted beams from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with second plurality of scan lines, the second plurality of scan lines being shifted from the first plurality of scan lines by a displacement amount defined as a tilt increment transverse to the scanning direction along the scanning axis, and guiding the emitted beams along the second plurality of scan lines such that a first emitted beam emitted by a first emitter in the emitter array of the first plurality of scan lines illuminates a portion of the FOV at a first time, and a second emitted beam emitted by a second emitter in the emitter array of the second plurality of scan lines illuminates a portion of the FOV at a second time after the first time. The method may include the following steps: detecting a first reflected beam of a first emitted beam at a first detector of a plurality of detectors in at least one detector array of a sensing unit, and detecting a second reflected beam of a second emitted beam at a second detector of a detector array.

[0170] While certain embodiments of the disclosed subject matter have been described to enable those skilled in the art to practice these embodiments, the foregoing description is intended to be exemplary only. It should not be used to limit the scope of the disclosed subject matter, which should be determined by reference to the appended claims.

Claims

1. A lidar system for detecting objects in a field of view (FOV), the system comprising: A laser emitting unit, the laser emitting unit comprising at least one laser emitting array, the laser emitting array comprising a plurality of laser emitting units, each emitting unit being configured to emit a corresponding laser beam; A scanning unit configured to direct an emitted beam toward the FOV; A sensing unit, the sensing unit including at least one detector array, the at least one detector array including a plurality of detectors, each detector being configured to detect a corresponding reflected beam from the FOV; as well as A processor configured to: control at least one of the laser emitting unit and the scanning unit to guide the emitted beam toward the FOV according to an alternating energy level illumination protocol, such that a first emitted beam having a first energy level emitted by a first emitter illuminates a first FOV region, and a second emitted beam having a second energy level emitted by a second emitter illuminates a second FOV region adjacent to the first FOV region, wherein the first energy level is lower than the second energy level, and wherein a first detector of the detector array receives a first reflected beam of the first emitted beam, and a second detector of the detector array receives a second reflected beam of the second emitted beam.

2. The lidar system according to claim 1, wherein, The first emitted beam includes light emitted by the first emitter, and the second emitted beam includes light emitted by the second emitter.

3. The lidar system according to claim 1, wherein, The first emitted beam and the second emitted beam differ in at least one property selected from the group consisting of: Radiation intensity Peak power Beam width, Launch operation mode, On / off launch scheme, Emission modulation, Launch timing, The number of pulses in a pulse sequence Total luminous flux Emission wavelength, and Transmission frequency.

4. The lidar system according to claim 1, wherein, The first emission beam and the second emission beam are emitted simultaneously.

5. The lidar system according to claim 1, wherein, The alternating energy level irradiation protocol includes: At a first moment, a first emitter emits a first emission beam with a first energy level to illuminate a first field of view (FOV) region, and a second emitter emits a second emission beam with a second energy level to illuminate a second FOV region adjacent to the first FOV region. At a second time, the second transmitter emits a third emission beam having the second energy level to illuminate a third FOV region adjacent to the first FOV region, and the first transmitter emits a fourth emission beam having the first energy level to illuminate a fourth FOV region adjacent to the first FOV region and the third FOV region, wherein the first energy level is lower than the second energy level.

6. The lidar system according to claim 1, wherein, The processor is configured to determine at least one updated parameter of the target object in the FOV based on the received reflected beam.

7. The lidar system according to claim 1, wherein, The processor is configured to determine the halo of a target object in the FOV based on the received reflected beam of light.

8. The lidar system according to claim 7 is further configured to implement at least one halo correction measure to compensate for the determined halo.

9. The lidar system according to claim 1, wherein, The scanning unit is configured to scan the FOV by: guiding an emission beam along a first plurality of scan lines passing through the FOV; shifting the emission beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines; and guiding the emission beam along the second plurality of scan lines. The alternating energy level illumination protocol includes activating at least one transmitter group of transmitters and deactivating at least one transmitter group of transmitters in at least a portion of a frame. Wherein, for at least one of a plurality of scan lines, the processor is configured to activate at least one first emitter group of the emitter to emit at least one beam during a first segment of the scan line, and to deactivate at least one second emitter group of the emitter to not emit a beam during the first segment of the scan line; and wherein the processor is further configured to deactivate the first emitter group during a second segment of the scan line, and to activate the second emitter group during the second segment of the scan line.

10. The lidar system according to claim 9, wherein, The alternating energy level illumination protocol is applied to each frame portion of the sequence.

11. The lidar system according to claim 9, wherein, A first alternating energy level illumination protocol is applied to illuminate a first region of the frame, and a second alternating energy level illumination protocol is applied to illuminate a second region of the frame.

12. The lidar system according to claim 9, wherein, The processor is configured to: generate a point cloud including the spatial location of objects in the FOV based on the reflected beams detected by the detector array, and determine halo artifacts in at least one of the first point cloud and the second point cloud, wherein an alternating energy level illumination protocol is applied in response to the determination.

13. The lidar system according to claim 1, wherein, The scanning unit is configured to scan the FOV by guiding an emission beam along a first plurality of scan lines passing through the FOV, shifting the emission beam from a first set of positions associated with the first plurality of scan lines to a second set of positions associated with a second plurality of scan lines, and guiding the emission beam along the second plurality of scan lines. The scanning unit is configured to shift the emission beam by sequentially rotating the scanning device about two axes including a scan axis and a tilt axis. At least one of the first plurality of scan lines and the second plurality of scan lines includes several scan lines positioned at a common angle along the tilt axis. The processor is configured to activate at least one first emitter group among the emitters to emit at least one light beam during a first scan line of the plurality of scan lines, and to deactivate at least one second emitter group among the emitters during the first scan line of the plurality of scan lines to not emit a light beam, and wherein the processor is configured to deactivate the first emitter group during a second scan line of the plurality of scan lines, and to activate the second emitter group during the second scan line of the plurality of scan lines.

14. The lidar system according to claim 13, wherein, For each unit in the frame portion, the processor is configured to classify the unit into a first category or a second category, the first category including a region containing at least one highly reflective object, and the second category including a region not containing at least one highly reflective object. The processor is configured to apply an alternating energy level irradiation protocol in response to the classification by activating the emitter group of units classified as the first category and deactivating the emitter group of units classified as the second category during one of the plurality of scan lines, and by activating the emitter group of units classified as the second category and deactivating the emitter group of units classified as the first category during another of the plurality of scan lines.

15. The lidar system according to claim 14, wherein, The processor is configured to apply the correction measures in response to the classification by applying at least one correction measure only at selected pixels of the point cloud classified as the first category to mitigate halo artifacts in the generated point cloud.

16. A method for detecting objects in a field of view (FOV) using a lidar system, the method comprising the steps of: A corresponding laser beam is emitted from the respective emitter of a plurality of laser emitters in at least one laser emitter array of the laser emitting unit; The scanning unit is used to guide the emitted beam toward the FOV; To enable detection under halo effects, at least one of the laser emitting unit and the scanning unit is controlled to guide the emitted beam toward the FOV according to an alternating energy level illumination protocol, such that a first emitted beam emitted by a first emitter having a first energy level illuminates a first FOV region, and a second emitted beam emitted by a second emitter having a second energy level illuminates a second FOV region adjacent to the first FOV region, wherein the first energy level is lower than the second energy level; as well as A first reflected beam of a first emitted beam is detected at a first detector of a plurality of detectors in at least one detector array of the sensing unit, and a second reflected beam of a second emitted beam is detected at a second detector of the detector array.

17. The method according to claim 16, wherein, The first emitted beam includes light emitted by the first emitter, and the second emitted beam includes light emitted by the second emitter.

18. The method according to claim 16, wherein, The control steps include controlling at least one property of at least one of the first emitted beam and the second emitted beam, the property being selected from the group consisting of: Radiation intensity Peak power Beam width, Launch operation mode, On / off launch scheme, Emission modulation, Launch timing, The number of pulses in a pulse sequence Total luminous flux Emission wavelength, and Transmission frequency.

19. The method of claim 16, wherein, The first emission beam and the second emission beam are emitted simultaneously.

20. The method of claim 16, wherein, The alternating energy level irradiation protocol includes: A first emitter emits a first beam of light with a first energy level to illuminate the first field of view (FOV) region at a first moment. A second emitter emits a second beam of light with a second energy level at the first time to illuminate a second field of view (FOV) region adjacent to the first FOV region. A third emission beam with a second energy level is emitted by a second transmitter at a second time to illuminate a third FOV region adjacent to the first FOV region; and A fourth emission beam having the first energy level is emitted by the first transmitter at the second time to illuminate a fourth FOV region adjacent to the first FOV region and the third FOV region. The first energy level is lower than the second energy level.

21. The method of claim 16, further comprising the step of: Based on the received reflected beam, at least one updated parameter of the target object in the FOV is determined.

22. The method of claim 16, further comprising the step of: The halo of the target object in the FOV is determined based on the received reflected beam.

23. The method of claim 21, further comprising the step of implementing at least one halo correction measure to compensate for the determined halo.

24. The method of claim 16, wherein, The scanning unit is configured to scan the FOV by guiding the emitted beam along a first plurality of scan lines passing through the FOV, shifting the emitted beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines, and guiding the emitted beam along the second plurality of scan lines, wherein the alternating energy level illumination protocol includes activating at least one group of emitters and deactivating at least one group of emitters in at least a portion of a frame. Wherein, for at least one of the plurality of scan lines, at least one first emitter group of emitters is activated to emit at least one light beam during a first segment of the scan line, and at least one second emitter group of emitters is deactivated to not emit a light beam during the first segment of the scan line; and wherein the first emitter group is deactivated during a second segment of the scan line, and the second emitter group is activated during the second segment of the scan line.

25. The method according to claim 24, wherein, The alternating energy level illumination protocol is applied to each frame portion of the sequence.

26. The method according to claim 24, wherein, A first alternating energy level illumination protocol is applied to illuminate a first region of the frame, and a second alternating energy level illumination protocol is applied to illuminate a second region of the frame.

27. The method of claim 24, further comprising the step of: Based on the reflected beams detected by the detector array, a point cloud including the spatial positions of objects in the FOV is generated; as well as Identify halo artifacts in at least one of a first point cloud and a second point cloud, wherein an alternating energy level illumination protocol is applied in response to the identification.

28. The method according to claim 16, wherein, The scanning unit is configured to scan the FOV by guiding an emission beam along a first plurality of scan lines passing through the FOV, shifting the emission beam from a first set of positions associated with the first plurality of scan lines to a second set of positions associated with a second plurality of scan lines, and guiding the emission beam along the second plurality of scan lines. The scanning unit is configured to shift the emission beam by sequentially rotating the scanning device about two axes including a scan axis and a tilt axis. At least one of the first plurality of scan lines and the second plurality of scan lines includes several scan lines positioned at a common angle along the tilt axis. In this configuration, at least one first emitter group of the transmitter is activated to emit at least one light beam during a first scan line of the plurality of scan lines, and at least one second emitter group of the transmitter is deactivated to not emit a light beam during the first scan line of the plurality of scan lines, and wherein the first emitter group is deactivated during a second scan line of the plurality of scan lines, and the second emitter group is activated during the second scan line of the plurality of scan lines.

29. The method of claim 24, further comprising the step of: For each unit in the frame portion, the unit is classified into a first category or a second category, the first category including regions containing at least one highly reflective object, and the second category including regions that do not contain at least one highly reflective object. as well as In response to the classification, an alternating energy level irradiation protocol is applied by activating the emitter group of units classified as the first category and deactivating the emitter group of units classified as the second category during one of the plurality of scan lines, and by activating the emitter group of units classified as the second category and deactivating the emitter group of units classified as the first category during another of the plurality of scan lines.

30. The method of claim 29, further comprising the step of: The correction measures are applied in response to the classification to mitigate halo artifacts in the generated point cloud by applying at least one correction measure only at selected pixels of the point cloud classified as the first category.

31. A lidar system for detecting objects in a field of view (FOV), the system comprising: A laser emitting unit, the laser emitting unit comprising at least one laser emitting array, the laser emitting array comprising a plurality of laser emitting units, each emitting unit being configured to emit a corresponding laser beam; A scanning unit configured to guide an emitted beam toward the FOV and to scan the FOV by guiding the emitted beam along multiple scan lines passing through the FOV; A sensing unit, the sensing unit including at least one detector array, the at least one detector array including a plurality of detectors, each detector being configured to detect a corresponding reflected beam from the FOV; as well as A processor configured to: enable detection under halo effects, control a scanning unit according to an offset illumination protocol to guide an emitted beam along a first plurality of scan lines passing through the field of view (FOV), shift the emitted beam from a first set of locations associated with the first plurality of scan lines to a second set of locations associated with a second plurality of scan lines, the shift of the second plurality of scan lines from the first plurality of scan lines defining a displacement amount of tilt increment transverse to the scanning direction along the scan axis, and guide the emitted beam along the second plurality of scan lines. Such that a first emission beam emitted by a first transmitter in the first transmitter array of the first plurality of scan lines illuminates a portion of the field of view (FOV) at a first time, and a second emission beam emitted by a second transmitter in the second transmitter array of the second plurality of scan lines illuminates the FOV portion at a second time after the first time. Wherein, the first detector of the detector array receives the first reflected beam of the first emitted beam, and the second detector of the detector array receives the second reflected beam of the second emitted beam.

32. The lidar system according to claim 31, wherein, The first emitted beam and the second emitted beam are in a common frame portion.

33. The lidar system according to claim 31, wherein, The first emitted beam is in the first frame portion, and the second emitted beam is in the second frame portion.

34. The lidar system according to claim 31, wherein, The processor is configured to repeatedly spatially shift the emitted beam from a first set of positions to a second set of positions via multiple corresponding spatial displacements in a frame partial sequence, each spatial displacement defining a corresponding tilt increment.

35. The lidar system according to claim 34, wherein, The overall spatial displacement of all tilt increments in the frame portion sequence does not exceed the angular size of the transmitter array.

36. The lidar system according to claim 35, wherein, The FOV includes at least one region of interest (ROI) and at least one region of non-interest (NROI), wherein the NROI is scanned along multiple scan lines defining a first scan resolution, and the ROI is scanned along multiple scan lines defining a second scan resolution higher than the first scan resolution.

37. The lidar system according to claim 36, wherein, The NROI is scanned along multiple scan lines that include relative spatial displacements corresponding to the angular magnitudes of the transmitter array, and wherein the ROI is scanned along multiple scan lines that include relative spatial displacements corresponding to the angular magnitudes between adjacent transmitters of the transmitter array.

38. The lidar system according to claim 31, wherein, The processor is configured to generate a first point cloud and a second point cloud based on reflected beams from the FOV detected by the detector array, each point cloud including the spatial location of an object in the FOV, and to compare the first point cloud with the second point cloud to detect inconsistencies between them.

39. The lidar system according to claim 38, wherein, The FOV includes at least one target object and at least one highly reflective object, wherein the processor is configured to determine halo artifacts in at least one of a first point cloud and a second point cloud.

40. The lidar system according to claim 31, wherein, The field of view (FOV) includes at least one target object and at least one highly reflective object, wherein the processor is configured to: generate a first point cloud including the spatial location of the first region of the FOV based on a reflected beam from a first region of the FOV detected by a detector array; determine halo artifacts in a second point cloud associated with the highly reflective object; generate a second point cloud including the spatial location of the second region of the FOV based on a reflected beam from a second region of the FOV detected by the detector array; and detect the target object in the second point cloud.

41. A method for detecting objects in a field of view (FOV) using a lidar system, the method comprising the steps of: A corresponding laser beam is emitted from the respective emitter of a plurality of laser emitters in at least one laser emitter array of the laser emitting unit; The scanning unit is used to guide the emitted beam toward the FOV; To enable detection under halo effects, the control scanning unit guides the emitted beam toward the field of view (FOV) according to an offset illumination protocol. The scanning unit guides the emitted beam along a first set of scan lines passing through the FOV, shifting the emitted beam from a first set of positions associated with the first set of scan lines to a second set of positions associated with a second set of scan lines. This shift of the second set of scan lines from the first set of scan lines defines a displacement along the scan axis transverse to the scan direction, and the emitted beam is guided along the second set of scan lines. The first emission beam emitted by the first transmitter in the transmitter array of the first plurality of scan lines illuminates the FOV portion of the FOV at a first time, and the second emission beam emitted by the second transmitter in the transmitter array of the second plurality of scan lines illuminates the FOV portion at a second time after the first time. as well as A first reflected beam of a first emitted beam is detected at a first detector of a plurality of detectors in at least one detector array of the sensing unit, and a second reflected beam of a second emitted beam is detected at a second detector of the detector array.

42. The method according to claim 41, wherein, The first emitted beam and the second emitted beam are in a common frame portion.

43. The method according to claim 41, wherein, The first emitted beam is in the first frame portion, and the second emitted beam is in the second frame portion.

44. The method of claim 41, comprising repeatedly spatially shifting the emitted beam from a first set of positions to a second set of positions by a plurality of corresponding spatial displacements of a sequence of frame portions, each spatial displacement defining a corresponding tilt increment.

45. The method according to claim 44, wherein, The overall spatial displacement of all tilt increments in the frame portion sequence does not exceed the angular size of the transmitter array.

46. ​​The method according to claim 41, wherein, The FOV includes at least one region of interest (ROI) and at least one region of non-interest (NROI), wherein the NROI is scanned along multiple scan lines defining a first scan resolution, and the ROI is scanned along multiple scan lines defining a second scan resolution higher than the first scan resolution.

47. The method of claim 44, wherein, The NROI is scanned along multiple scan lines that include relative spatial displacements corresponding to the angular magnitudes of the transmitter array, and wherein the ROI is scanned along multiple scan lines that include relative spatial displacements corresponding to the angular magnitudes between adjacent transmitters of the transmitter array.

48. The method of claim 41, further comprising the step of: A first point cloud and a second point cloud are generated based on the reflected beams from the field of view (FOV) detected by the detector array. Each point cloud includes the spatial location of the object within the FOV, and... The first point cloud is compared with the second point cloud to detect inconsistencies between them.

49. The method according to claim 46, wherein, The FOV includes at least one target object and at least one highly reflective object, and the method further includes the step of determining halo artifacts in at least one of a first point cloud and a second point cloud.

50. The method according to claim 41, wherein, The field of view (FOV) includes at least one target object and at least one highly reflective object, and the method further includes the following steps: A first point cloud, including the spatial location of the first region of the FOV, is generated based on the reflected beams from the first region of the FOV detected by the detector array. Identify the halo artifact in the second point cloud associated with the highly reflective object, and A second point cloud, including the spatial location of the second region of the FOV, is generated based on the reflected beam from the second region of the FOV detected by the detector array. Detect the target object in the second point cloud.

51. A lidar system for detecting objects in a field of view (FOV), the system comprising: A laser emitting unit, the laser emitting unit comprising at least one laser emitting array, the laser emitting array comprising a plurality of laser emitting units, each emitting unit being configured to emit a corresponding laser beam; A scanning unit configured to guide an emitted beam toward the FOV and to scan the FOV by guiding the emitted beam along multiple scan lines passing through the FOV; A sensing unit, the sensing unit including at least one detector array, the at least one detector array including a plurality of detectors, each detector being configured to detect a corresponding reflected beam from the FOV; as well as A processor configured to: control at least one of a laser emitting unit and a scanning unit to guide an emitted beam toward the FOV according to a modified timing illumination protocol, in order to enable detection under halo effects, the modified timing illumination protocol including: For at least one scan line segment of a frame portion, each unit of the frame portion is classified into a first category or a second category, the first category including regions containing at least one highly reflective object, and the second category including regions not containing at least one highly reflective object; and In response to classification, for each of the first category units classified as a first category, at least one first category pulse beam emission is emitted to illuminate the first category unit, and for each of the second category units classified as a second category, a second category pulse beam emission sequence is emitted to illuminate the second category unit, wherein the emission timing of each emission in the second category pulse beam emission sequence is time-offset relative to the first category pulse beam emission of the first category unit. The first detector of the detector array receives at least one reflection from a pulse beam emitted in the first category, and the second detector of the detector array receives a reflection from a pulse beam emitted in the second category.

52. The lidar system according to claim 51, wherein, The time displacement of the second group of continuous second-category pulse beams is non-uniform relative to the first group of second-category pulse beams.

53. The lidar system according to claim 51, wherein, Multiple first-category pulse beams are emitted to illuminate the first-category unit, wherein the time displacement between consecutive second-category pulse beams is non-uniform relative to the consecutive first-category pulse beams.

54. The lidar system according to claim 51, wherein, The processor is configured to determine the validity of the response signal based on the accumulation of detector response signals for the detection of units classified as the second category.

55. The lidar system according to claim 51, wherein, The modified timing illumination protocol is applied to at least one frame of the region of interest (ROI) of the FOV.

56. A method for detecting objects in a field of view (FOV) using a lidar system, the method comprising the following steps: A corresponding laser beam is emitted from the respective emitter of a plurality of laser emitters in at least one laser emitter array of the laser emitting unit; The FOV is scanned by using a scanning unit to guide the emitted beam along multiple scan lines passing through the FOV; To enable detection under halo effects, at least one of the laser emitting unit and the scanning unit is controlled to guide the emitted beam toward the FOV according to a modified timing illumination protocol, which includes: For at least one scan line segment of a frame portion, each unit of the frame portion is classified into a first category or a second category, the first category including a region containing at least one highly reflective object, and the second category including a region not containing at least one highly reflective object; as well as In response to classification, for each of the first category units classified as a first category, at least one first category pulse beam emission is emitted to illuminate the first category unit, and for each of the second category units classified as a second category, a second category pulse beam emission sequence is emitted to illuminate the second category unit, wherein the emission timing of each emission in the second category pulse beam emission sequence is time-biased relative to the first category pulse beam emission of the first category unit, and At least one reflection of a first category pulse beam emission is detected at a first detector of a plurality of detectors in at least one detector array of the sensing unit, and a reflection of a second category pulse beam emission is detected at a second detector of the detector array.

57. The method according to claim 56, wherein, The time displacement of the second group of continuous second-category pulse beams is non-uniform relative to the first group of second-category pulse beams.

58. The method according to claim 56, wherein, Multiple first-category pulse beams are emitted to illuminate the first-category unit, wherein the time displacement between consecutive second-category pulse beams is non-uniform relative to the consecutive first-category pulse beams.

59. The method of claim 56, further comprising the step of: The validity of the response signal is determined based on the accumulation of detector response signals for the received detection of units classified as the second category.

60. The method of claim 56, wherein, The modified timing illumination protocol is applied to at least one frame of the region of interest (ROI) of the FOV.

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