Laser radar based on two-dimensional emitter array

Abstract

A LiDAR (lidar) system with a two-dimensional array of emitters is provided. A LiDAR system includes an optical scanner and a plurality of emitter groups optically coupleable to the optical scanner. Each transmitter group of the plurality of transmitter groups includes a plurality of transmitters. At least two emitter groups of the plurality of emitter groups are disposed at different positions with respect to the optical scanner such that scanning areas corresponding to the at least two emitter groups are different. The LiDAR further includes a control device configured to selectively control one or more of the plurality of emitter groups to emit the transmitted light beam toward the light scanner. The light scanner is configured to vertically and horizontally divert the transmitted beam to a field of view (FOV), and receive return light formed based on the diverted transmitted beam.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to U.S. Patent Application No. 18 / 380,911, filed on October 17, 2023, entitled "Two - Dimensional Transmitter Array - Based LiDAR", which claims priority to U.S. Provisional Patent Application No. 63 / 418,405, filed on October 21, 2022, entitled "Two - Dimensional Transmitter Array - Based LiDAR". For all purposes, the contents of these applications are hereby incorporated by reference in their entireties. Technical Field

[0003] The present disclosure generally relates to optical scanning and, more particularly, to a light detection and ranging (LiDAR) system having a two - dimensional transmitter array. Background Art

[0004] Light detection and ranging (LiDAR) systems use light pulses to create an image or a point cloud of the external environment. LiDAR systems can be scanning or non - scanning systems. Some typical scanning LiDAR systems include a light source, a light transmitter, an optical steering system, and a light detector. The light source generates a light beam that, when emitted from the LiDAR system, is directed by the optical steering system in a specific direction. When the emitted light beam is scattered or reflected by an object, a portion of the scattered or reflected light returns to the LiDAR system to form a return light pulse. The light detector detects the return light pulse. Using the difference between the time when the return light pulse is detected and the time when the corresponding light pulse in the light beam is emitted, the LiDAR system can determine the distance to the object based on the speed of light. This technique for determining distance is known as the time - of - flight (ToF) technique. The optical steering system can direct the light beam along different paths to allow the LiDAR system to scan the surrounding environment and generate an image or a point cloud. A typical non - scanning LiDAR system illuminates the entire field of view (FOV) instead of scanning the entire FOV. An example of a non - scanning LiDAR system is flash LiDAR, which can also use the ToF technique to measure the distance to an object. LiDAR systems can also use techniques other than time - of - flight and scanning to measure the surrounding environment. Summary of the Invention

[0005] The embodiments provided in this disclosure use a two-dimensional emitter array in a LiDAR system to achieve an ultra-wide FOV and a customizable scan pattern for complex sensing requirements. In one embodiment, the LiDAR system includes an optical scanner and a plurality of emitter groups that can be optically coupled to the optical scanner. Each emitter group of the plurality of emitter groups includes a plurality of emitters. At least two emitter groups of the plurality of emitter groups are disposed at different positions relative to the optical scanner such that the scan regions corresponding to the at least two emitter groups are different. The LiDAR further includes a control device configured to selectively control one or more of the plurality of emitter groups to emit a transmitted beam toward the optical scanner. The optical scanner is configured to steer the transmitted beam vertically and horizontally into a field of view (FOV) and receive the return light formed based on the steered transmitted beam.

[0006] In one embodiment, a vehicle is provided that includes a light detection and ranging (LiDAR) system. The LiDAR system includes an optical scanner and a plurality of emitter groups that can be optically coupled to the optical scanner. Each emitter group of the plurality of emitter groups includes a plurality of emitters. At least two emitter groups of the plurality of emitter groups are disposed at different positions relative to the optical scanner such that the scan regions corresponding to the at least two emitter groups are different. The LiDAR further includes a control device configured to selectively control one or more of the plurality of emitter groups to emit a transmitted beam toward the optical scanner. The optical scanner is configured to steer the transmitted beam vertically and horizontally into a field of view (FOV) and receive the return light formed based on the steered transmitted beam.

[0007] In one embodiment, a method for controlling a light ranging and detection (LiDAR) system is provided. The LiDAR system includes an optical scanner and a plurality of emitter groups that can be optically coupled to the optical scanner. The method includes selectively controlling one or more of the plurality of emitter groups to emit a transmitted beam toward the light.

[0008] At least two emitter groups of the plurality of emitter groups are disposed at different positions relative to the optical scanner such that the scan regions corresponding to the at least two emitter groups are different. The method further includes steering the transmitted beam vertically and horizontally into a field of view (FOV) and receiving the return light formed based on the steered transmitted beam. Description of the Drawings

[0009] The present application can be best understood by reference to the embodiments described below in conjunction with the drawings, in which like parts may be denoted by like reference numerals.

[0010] Figure 1 One or more exemplary LiDAR systems disposed or included in a motor vehicle are illustrated.

[0011] Figure 2 It is a block diagram illustrating the interaction between an exemplary LiDAR system and multiple other systems including a vehicle perception and planning system.

[0012] Figure 3 It is a block diagram illustrating an exemplary LiDAR system.

[0013] Figure 4 It is a block diagram illustrating an exemplary fiber - based laser source.

[0014] Figures 5A to 5C It illustrates an exemplary LiDAR system that uses a pulsed signal to measure the distance to an object set in the field of view (FOV).

[0015] Figure 6 It is a block diagram illustrating an exemplary device for implementing systems, devices, and methods in various embodiments.

[0016] Figure 7 It is a diagram illustrating an exemplary LiDAR system including multiple transmitter groups according to some embodiments.

[0017] Figures 8A to 8E It is a diagram illustrating an example of a transmitter group according to some embodiments.

[0018] Figure 9 It is a diagram illustrating an example of a transmitter group optically coupled to a collimating lens for guiding a transmitted beam according to some embodiments.

[0019] Figures 10A to 10B It is a diagram illustrating an example of the components of multiple transmitter groups for optically coupling to multiple collimating lenses and collecting lenses according to some embodiments.

[0020] Figures 11A to 11C It is a diagram illustrating an example of multiple transmitter groups optically coupled to an optical scanner according to some embodiments.

[0021] Figures 12A to 12C It is a diagram illustrating an example of a scan pattern generated by multiple transmitter groups according to some embodiments.

[0022] Figure 13 It shows an illustrative method for controlling a LiDAR system according to some embodiments. Detailed Description

[0023] To more thoroughly understand the various embodiments of the present invention, the following description sets forth many specific details, such as specific configurations, parameters, examples, etc. However, it should be recognized that this description is not intended to limit the scope of the present invention, but rather to provide a better description of the exemplary embodiments.

[0024] Throughout the specification and claims, unless the context clearly indicates otherwise, the following terms have the meanings explicitly associated herein:

[0025] As used herein, the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it may be. Thus, as described below, various embodiments of the present invention can be readily combined without departing from the scope or spirit of the disclosure.

[0026] As used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or", unless the context clearly indicates otherwise.

[0027] The term "based on" is not exclusive and allows for additional factors not described, unless the context clearly indicates otherwise.

[0028] As used herein and unless the context otherwise provides, the term "coupled to" is intended to include both direct coupling (where two elements coupled to each other are in contact with each other) and indirect coupling (where at least one additional element is located between the two elements).

[0029] Accordingly, the terms "coupled to" and "coupled with" are used synonymously. In the context of a networking environment where two or more components or devices can exchange data, the terms "coupled to" and "coupled with" are also used to mean "communicatively coupled with... via one or more intermediate devices". The components or devices can be optical, mechanical, and / or electrical devices.

[0030] Although the following description uses the terms "first", "second", "third", etc. to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first transmitter group can be referred to as a second transmitter group or a third transmitter group, and similarly, without departing from the scope of the various described examples, a second transmitter group can be referred to as a first transmitter group or a third transmitter group, and a third transmitter group can be referred to as a first transmitter group or a second transmitter group. The first transmitter group, the second transmitter group, and the third transmitter group can all be transmitter groups, and in some cases, can be separate and distinct transmitter groups.

[0031] Additionally, throughout the specification, the meanings of "a", "an", and "the" include the plural, and the meaning of "in" can include "in" and "on".

[0032] Although some of the various embodiments presented herein constitute a single combination of inventive elements, it should be understood that the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment includes elements A, B, and C, and another embodiment includes elements B and D, the inventive subject matter is also considered to include the other remaining combinations of A, B, C, or D, even if not explicitly discussed herein. Additionally, the transitional term "comprising" means having the components or elements, or those components or elements. As used herein, the transitional term "comprising" is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.

[0033] As used throughout the description herein and in the claims that follow, when a system, engine, server, device, module, or other computing element is described as being configured to perform or execute a function on data in a memory, the meaning of "configured to" or "programmed to" is defined as one or more processors or cores of the computing element being programmed by a set of software instructions stored in the memory of the computing element to perform the set of functions on target data or data objects stored in the memory.

[0034] It should be noted that any language for a computer should be understood to include any suitable combination of computing devices or network platforms (including servers, interfaces, systems, databases, agents, peers, engines, controllers, modules, or other types of computing devices that operate individually or jointly). It should be understood that a computing device includes a processor that is configured to execute software instructions stored on a tangible, non-transitory computer-readable storage medium (e.g., hard disk drive, FPGA, PLA, solid-state drive, RAM, flash memory, ROM, or any other volatile or non-volatile storage device). The software instructions configure or program the computing device to provide roles, responsibilities, or other functions as discussed below with respect to the disclosed apparatus. Additionally, the disclosed technology may be embodied as a computer program product that includes a non-transitory computer-readable medium storing software instructions that cause a processor to perform the disclosed steps associated with the implementation of computer-based algorithms, processes, methods, or other instructions. In some embodiments, various servers, systems, databases, or interfaces exchange data using standardized protocols or algorithms, possibly based on HTTP, HTTPS, AES, public-private key exchange, web service APIs, known financial transaction protocols, or other electronic information exchange methods. Data exchange between devices may occur via: packet-switched networks, the Internet, LANs, WANs, VPNs, or other types of packet-switched networks; circuit-switched networks; cell-switched networks; or other types of networks.

[0035] A LiDAR system may have one or more emitters for emitting laser beams. The scanning ability of the LiDAR system can be improved by using multiple emitters. For example, by using multiple emitters, a wide FOV and high scanning resolution can be obtained. On the other hand, multiple emitters may make the LiDAR system bulky. For example, if each emitter has its own optical and / or electrical components, the size of the emitter may increase significantly. Existing LiDAR systems typically have a limited FOV even when they are installed in small spaces of a vehicle (e.g., rearview mirror assembly, lamp housing, bumper, roof, etc.) because the small space limits the scanning ability of the LiDAR. Therefore, there is a need for a compact LiDAR system that can fit into small spaces and perform scans with a wide FOV.

[0036] In addition, multiple emitters that are always operating in a LiDAR system may result in a large amount of energy consumption. Consequently, the total cost of the LiDAR system also increases. It is desirable to customize the scan pattern configuration and specify areas with a high-density point cloud as needed. Therefore, there is a need for an energy-saving and cost-effective mechanism to control multiple emitters and meet complex sensing requirements.

[0037] The embodiments discussed herein improve the scanning ability and energy efficiency of a LiDAR system by using multiple emitter groups and a control device configured to selectively control one or more of the multiple emitter groups. Each emitter group of the multiple emitter groups includes multiple emitters. Benefiting from the multiple emitter groups, the LiDAR system can provide an ultra-wide FOV (e.g., more than 120 degrees). The control device can selectively switch the on / off state of one or more emitter groups to save energy and meet complex sensing requirements. The control device can selectively adjust the transmission orientation to achieve a configurable scan pattern and create a customized high-density point cloud area. The wavelength can also be customized by using different types of laser sources for the multiple emitter groups.

[0038] Embodiments of the present invention are described below. In various embodiments of the present invention, a LiDAR system having a two-dimensional emitter array is provided. The LiDAR system includes an optical scanner and multiple emitter groups that can be optically coupled to the optical scanner. Each emitter group of the multiple emitter groups includes multiple emitters. At least two of the multiple emitter groups are disposed at different positions relative to the optical scanner such that the scanning areas corresponding to the at least two emitter groups are different. The LiDAR further includes a control device configured to selectively control one or more of the multiple emitter groups to emit transmission beams toward the optical scanner. The optical scanner is configured to turn the transmission beams vertically and horizontally (FOV) and receive the return light formed based on the turned transmission beams.

[0039] Figure 1 Illustrated are one or more exemplary LiDAR systems 110 and 120A - 120I disposed or included in a motor vehicle 100. The vehicle 100 can be an automobile, a sport utility vehicle (SUV), a truck, a train, a van, a bicycle, a motorcycle, a tricycle, a bus, a motor scooter, a tram, a ship, a boat, an underwater vehicle, an airplane, a helicopter, an unmanned aerial vehicle (UAV), a spacecraft, etc. The motor vehicle 100 can be a vehicle with any level of automation. For example, the motor vehicle 100 can be a partially automated vehicle, a highly automated vehicle, a fully automated vehicle, or a driverless vehicle. A partially automated vehicle can perform some driving functions without human driver intervention. For example, a partially automated vehicle can perform blind spot monitoring, lane keeping and / or lane change operations, automatic emergency braking, intelligent cruise and / or traffic following, etc. Certain operations of a partially automated vehicle may be limited to specific applications or driving scenarios (e.g., limited to highway driving). A highly automated vehicle can generally perform all operations of a partially automated vehicle with fewer restrictions. A highly automated vehicle can also detect its own limits when operating the vehicle and, when necessary, request the driver to take over control of the vehicle. A fully automated vehicle can perform all vehicle operations without driver intervention, but can also detect its own limits and, when necessary, request the driver to take over. A driverless vehicle can operate on its own without any driver intervention.

[0040] In a typical configuration, the motor vehicle 100 includes one or more LiDAR systems 110 and 120A - 120I. Each of the LiDAR systems 110 and 120A - 120I can be a scanning - based LiDAR system and / or a non - scanning LiDAR system (e.g., flash LiDAR). A scanning - based LiDAR system scans one or more light beams in one or more directions (e.g., horizontal and vertical directions) to detect objects in the field of view (FOV). A non - scanning LiDAR system emits laser light without scanning to illuminate the FOV. For example, flash LiDAR is a type of non - scanning LiDAR system. Flash LiDAR can emit laser light and use a single light pulse or light shot to simultaneously illuminate the FOV.

[0041] LiDAR systems are common sensors for at least partially automated vehicles. In one embodiment, as Figure 1As shown, the motor vehicle 100 may include a single LiDAR system 110 (e.g., without LiDAR systems 120A - 120I) disposed at the highest position of the vehicle (e.g., on top of the vehicle). Disposing the LiDAR system 110 on top of the vehicle facilitates 360 - degree scanning around the vehicle 100. In some other embodiments, the motor vehicle 100 may include multiple LiDAR systems, including two or more of systems 110 and / or 120A - 120I. As Figure 1 shown, in one embodiment, multiple LiDAR systems 110 and / or 120A - 120I are attached to the vehicle 100 at different positions of the vehicle. For example, LiDAR system 120A is attached to the vehicle 100 at the right front corner; LiDAR system 120B is attached to the vehicle 100 at the front center position; LiDAR system 120C is attached to the vehicle 100 at the left front corner; LiDAR system 120D is attached to the vehicle 100 at the right side rearview mirror; LiDAR system 120E is attached to the vehicle 100 at the left side rearview mirror; LiDAR system 120F is attached to the vehicle 100 at the rear center position; LiDAR system 120G is attached to the vehicle 100 at the right rear corner; LiDAR system 120H is attached to the vehicle 100 at the left rear corner; and / or LiDAR system 120I is attached to the vehicle 100 at the center facing the rear end (e.g., the rear end of the top of the vehicle). It should be understood that one or more LiDAR systems may be distributed and attached to the vehicle in any desired manner, and Figure 1 only one embodiment is illustrated. As another example, LiDAR systems 120D and 120E may be attached to the B - pillar of the vehicle 100 instead of the rearview mirrors. As another example, LiDAR system 120B may be attached to the windshield of the vehicle 100 instead of the front bumper.

[0042] In some embodiments, LiDAR systems 110 and 120A - 120I are independent LiDAR systems, having their respective laser sources, control electronics, transmitters, receivers, and / or steering mechanisms. In other embodiments, some of LiDAR systems 110 and 120A - 120I may share one or more components to form a distributed sensor system. In one example, optical fibers are used to deliver laser light from a centralized laser source to all LiDAR systems. For example, system 110 (or another system located at the center or any location of vehicle 100) includes a light source, a transmitter, and a photodetector, but no steering mechanism. System 110 can distribute the transmitted light to each of systems 120A - 120I. The transmitted light can be distributed via optical fibers. Optical connectors can be used to couple the optical fibers to each of systems 110 and 120A - 120I. In some examples, one or more of systems 120A - 120I include a steering mechanism, but no light source, transmitter, or photodetector. The steering mechanism can include one or more movable mirrors, such as one or more polygonal mirrors, one or more single flat mirrors, one or more multi - flat mirrors, etc. Embodiments of the light source, transmitter, steering mechanism, and photodetector will be described in more detail below. Via the steering mechanism, one or more of systems 120A - 120I scan light into one or more corresponding FOVs and receive the corresponding returned light. The returned light is formed by scattering or reflecting the transmitted light by one or more objects in the FOV. Systems 120A - 120I may also include collection lenses and / or other optics to focus and / or direct the returned light into an optical fiber, which delivers the received returned light to system 110. System 110 includes one or more photodetectors for detecting the received returned light. In some examples, system 110 is disposed inside the vehicle such that it is in a temperature - controlled environment, while one or more of systems 120A - 120I may be at least partially exposed to the external environment.

[0043] Figure 2 FIG. 200 is a block diagram illustrating the interaction between an in - vehicle LiDAR system 210 and a plurality of other systems including a vehicle perception and planning system 220. The LiDAR system 210 can be mounted on or integrated into a vehicle. The LiDAR system 210 includes sensors that scan laser light into the surrounding environment to measure the distance, angle, and / or velocity of objects. Based on the scattered light returned to the LiDAR system 210, it can generate sensor data (e.g., image data or 3D point cloud data) representing the perceived external environment.

[0044] The LiDAR system 210 may include one or more of a short-range LiDAR sensor, a mid-range LiDAR sensor, and a long-range LiDAR sensor. The short-range LiDAR sensor measures objects up to approximately 20 - 50 meters from the LiDAR sensor. The short-range LiDAR sensor can be used, for example, to monitor nearby moving objects (e.g., pedestrians crossing the road in a school zone), parking assistance applications, etc. The mid-range LiDAR sensor measures objects up to approximately 70 - 200 meters from the LiDAR sensor. The mid-range LiDAR sensor can be used, for example, to monitor road intersections, assist in merging onto or off of a highway, and so on. The long-range LiDAR sensor measures objects located 200 meters and above. The long-range LiDAR sensor is typically used when the vehicle is traveling at high speeds (e.g., on a highway), such that the vehicle's control system may have only a few seconds (e.g., 6 - 8 seconds) to respond to any situation detected by the LiDAR sensor. As Figure 2 shown, in one embodiment, LiDAR sensor data can be provided to the vehicle perception and planning system 220 via the communication path 213 for further processing and control of vehicle operations. The communication path 213 can be any wired or wireless communication link capable of transmitting data.

[0045] Still referring to Figure 2 , in some embodiments, other vehicle sensors 230 are configured to provide additional sensor data either individually or in conjunction with the LiDAR system 210. The other vehicle sensors 230 can include, for example, one or more cameras 232, one or more radars 234, one or more ultrasonic sensors 236, and / or other sensors 238.

[0046] The camera 232 can capture images and / or videos of the vehicle's external environment. The camera 232 can capture, for example, high-definition (HD) video with millions of pixels per frame. The camera includes an image sensor that facilitates the generation of monochromatic or color images and videos. Color information may be important in interpreting data in certain situations (e.g., interpreting an image of a traffic light). Color information may not be obtainable from other sensors such as LiDAR or radar sensors. The camera 232 can include one or more of a narrow focal length camera, a wider focal length camera, a side camera, an infrared camera, a fisheye camera, etc. The image and / or video data generated by the camera 232 can also be provided to the vehicle perception and planning system 220 via the communication path 233 for further processing and control of vehicle operations. The communication path 233 can be any wired or wireless communication link capable of transmitting data. The camera 232 can be mounted or integrated onto the vehicle at any location (e.g., rearview mirror, pillar, front grille, and / or rear bumper, etc.).

[0047] Other vehicle-mounted sensors 230 may further include a radar sensor 234. The radar sensor 234 uses radio waves to determine the distance, angle, and speed of an object. The radar sensor 234 generates electromagnetic waves in the radio or microwave spectrum. The electromagnetic waves are reflected by the object, and some of the reflected waves return to the radar sensor, thereby providing information about the object's position and speed. The radar sensor 234 may include one or more of short-range radar, mid-range radar, and long-range radar. The short-range radar measures objects at a distance of about 0.1 - 30 meters from the radar. The short-range radar is useful for detecting objects near a vehicle (such as other vehicles, buildings, walls, pedestrians, cyclists, etc.). The short-range radar can be used for detecting blind spots, assisting lane changes, providing rear-end collision warnings, assisting parking, providing emergency braking, etc. The mid-range radar measures objects at a distance of about 30 - 80 meters from the radar. The long-range radar measures objects located at about 80 - 200 meters. The mid-range and / or long-range radar can be used for, for example, traffic tracking, adaptive cruise control, and / or highway automatic braking. The sensor data generated by the radar sensor 234 can also be provided to the vehicle perception and planning system 220 via the communication path 233 for further processing and controlling vehicle operations. The radar sensor 234 can be installed or integrated into the vehicle at any location (such as the rearview mirror, pillar, front grille, and / or rear bumper, etc.).

[0048] Other vehicle-mounted sensors 230 may further include an ultrasonic sensor 236. The ultrasonic sensor 236 uses sound waves or pulses to measure an object located outside the vehicle. The sound waves generated by the ultrasonic sensor 236 are emitted into the surrounding environment. At least some of the emitted waves are reflected by the object and return to the ultrasonic sensor 236. Based on the returned signal, the distance to the object can be calculated. The ultrasonic sensor 236 can be used for, for example, checking blind spots, identifying parking spaces, providing lane change assistance in traffic, etc. The sensor data generated by the ultrasonic sensor 236 can also be provided to the vehicle perception and planning system 220 via the communication path 233 for further processing and controlling vehicle operations.

[0049] The ultrasonic sensor 236 can be installed or integrated into the vehicle at any location (such as the rearview mirror, pillar, front grille, and / or rear bumper, etc.).

[0050] In some embodiments, one or more other sensors 238 may be attached in the vehicle, and may also generate sensor data. The other sensors 238 may include, for example, a Global Positioning System (GPS), an Inertial Measurement Unit (IMU), etc. The sensor data generated by the other sensors 238 may also be provided to the vehicle perception and planning system 220 via the communication path 233 for further processing and controlling vehicle operations. It should be understood that the communication path 233 may include one or more communication links to transmit data between the various sensors 230 and the vehicle perception and planning system 220.

[0051] In some embodiments, as Figure 2 shown, the sensor data from other on-vehicle sensors 230 may be provided to the on-vehicle LiDAR system 210 via the communication path 231. The LiDAR system 210 may process the sensor data from other on-vehicle sensors 230. For example, the sensor data from a camera 232, a radar sensor 234, an ultrasonic sensor 236, and / or other sensors 238 may be correlated or fused with the sensor data of the LiDAR system 210, thereby at least partially offloading the sensor fusion process performed by the vehicle perception and planning system 220. It should be understood that other configurations may also be implemented to transmit and process the sensor data from various sensors (e.g., the data may be transmitted to a cloud or an edge computing service provider for processing, and then the processing results may be transmitted back to the vehicle perception and planning system 220 and / or the LiDAR system 210).

[0052] Still referring to Figure 2 , in some embodiments, the sensors on other vehicles 250 are used to provide additional sensor data alone or together with the LiDAR system 210. For example, two or more nearby vehicles may have their respective LiDAR sensors, cameras, radar sensors, ultrasonic sensors, etc. The nearby vehicles may communicate with each other and share sensor data. The communication between vehicles is also referred to as V2V (vehicle-to-vehicle) communication. For example, as Figure 2 shown, the sensor data generated by other vehicles 250 may be transmitted to the vehicle perception and planning system 220 and / or the on-vehicle LiDAR system 210 via the communication path 253 and / or the communication path 251, respectively. The communication paths 253 and 251 may be any wired or wireless communication links capable of transmitting data.

[0053] Sharing sensor data facilitates better perception of the environment outside the vehicle. For example, a first vehicle may not sense a pedestrian who is behind a second vehicle but approaching the first vehicle. The second vehicle can share sensor data related to the pedestrian with the first vehicle, so that the first vehicle can have additional reaction time to avoid colliding with the pedestrian. In some embodiments, similar to the data generated by sensor 230, the data generated by sensors on other vehicles 250 can be correlated or fused with the sensor data generated by LiDAR system 210 (or other LiDAR systems located in other vehicles), thereby at least partially offloading the sensor fusion process performed by the vehicle perception and planning system 220.

[0054] In some embodiments, the intelligent infrastructure system 240 is used to provide sensor data alone or together with LiDAR system 210. Certain infrastructure can be configured to communicate with vehicles to transfer information, and vice versa.

[0055] The communication between the vehicle and the infrastructure is generally referred to as V2I (vehicle-to-infrastructure) communication. For example, the intelligent infrastructure system 240 can include intelligent traffic lights, which can convey their status to approaching vehicles in a message such as "turn yellow in 5 seconds". The intelligent infrastructure system 240 can also include its own LiDAR system installed near the intersection, so that it can transfer traffic monitoring information to the vehicle. For example, a vehicle turning left at an intersection may not have sufficient sensing capabilities because some of its own sensors may be blocked by oncoming traffic. In this case, the sensors of the intelligent infrastructure system 240 can provide useful data to the vehicle turning left. Such data can include, for example, traffic conditions, object information in the vehicle's turning direction, traffic light status, and predictions. These sensor data generated by the intelligent infrastructure system 240 can be provided to the vehicle perception and planning system 220 and / or the on-vehicle LiDAR system 210 via communication paths 243 and / or 241 respectively. The communication paths 243 and / or 241 can include any wired or wireless communication link capable of transmitting data. For example, the sensor data from the intelligent infrastructure system 240 can be transmitted to the LiDAR system 210 and correlated or fused with the sensor data generated by the LiDAR system 210, thereby at least partially offloading the sensor fusion process performed by the vehicle perception and planning system 220. The above V2V and V2I communications are examples of vehicle-to-X (V2X) communications, where "X" represents any other device, system, sensor, infrastructure, etc. that can share data with the vehicle.

[0056] Still referring to Figure 2, via various communication paths, the vehicle perception and planning system 220 receives sensor data from one or more of the LiDAR system 210, other on-vehicle sensors 230, other vehicles 250, and / or the intelligent infrastructure system 240. In some embodiments, different types of sensor data are correlated and / or fused by the sensor fusion subsystem 222. For example, the sensor fusion subsystem 222 may use multiple images or videos captured by multiple cameras disposed at different positions of the vehicle to generate a 360-degree model. The sensor fusion subsystem 222 obtains sensor data from different types of sensors and uses the combined data to more accurately perceive the environment. For example, the on-vehicle camera 232 may not be able to capture clear images because it faces the sun or a light source directly (e.g., the headlights of another vehicle at night). The LiDAR system 210 may not be affected much, and thus the sensor fusion subsystem 222 can combine the sensor data provided by the camera 232 and the LiDAR system 210 and use the sensor data provided by the LiDAR system 210 to compensate for the unclear images captured by the camera 232. As another example, in rainy or foggy weather, the radar sensor 234 may work better than the camera 232 or the LiDAR system 210. Accordingly, the sensor fusion subsystem 222 can use the sensor data provided by the radar sensor 234 to compensate for the sensor data provided by the camera 232 or the LiDAR system 210.

[0057] In other examples, the sensor data generated by other on-vehicle sensors 230 may have a lower resolution (e.g., radar sensor data), and thus may need to be correlated and confirmed by the LiDAR system 210, which typically has a higher resolution. For example, the radar sensor 234 may detect a manhole cover (also known as an inspection hole cover) as an object that the vehicle is approaching. Due to the low-resolution characteristic of the radar sensor 234, the vehicle perception and planning system 220 may not be able to determine whether the object is an obstacle that the vehicle needs to avoid. Therefore, the high-resolution sensor data generated by the LiDAR system 210 can be used to correlate and confirm that the object is a manhole cover and will not cause damage to the vehicle.

[0058] The vehicle perception and planning system 220 further includes an object classifier 223. Using the raw sensor data and / or the correlated / fused data provided by the sensor fusion subsystem 222, the object classifier 223 can use any computer vision technique to detect and classify objects and estimate the positions of the objects. In some embodiments, the object classifier 223 can use machine learning-based techniques to detect and classify objects. Examples of machine learning-based techniques include algorithms such as Region-based Convolutional Neural Network (R-CNN), Fast R-CNN, Faster R-CNN, Histogram of Oriented Gradients (HOG), Region-based Fully Convolutional Network (R-FCN), Single Shot Detector (SSD), Spatial Pyramid Pooling (SPP-net), and / or You Only Look Once (Yolo).

[0059] The vehicle perception and planning system 220 further includes a road detection subsystem 224. The road detection subsystem 224 locates the road and identifies objects and / or markings on the road. For example, based on the raw or fused sensor data provided by the radar sensor 234, the camera 232, and / or the LiDAR system 210, the road detection subsystem 224 can build a 3D model of the road based on machine learning techniques (e.g., pattern recognition algorithms for identifying lanes). Using the 3D model of the road, the road detection subsystem 224 can identify objects (e.g., obstacles or debris on the road) and / or markings (e.g., lane lines, turn signs, crosswalk signs, etc.) on the road.

[0060] The vehicle perception and planning system 220 further includes a localization and vehicle pose subsystem 225. Based on the raw or fused sensor data, the localization and vehicle pose subsystem 225 can determine the position and the pose of the vehicle. For example, using the sensor data from the LiDAR system 210, the camera 232, and / or the GPS data, the localization and vehicle pose subsystem 225 can determine the precise position of the vehicle on the road and the six degrees of freedom of the vehicle (e.g., whether the vehicle is moving forward or backward, up or down, left or right). In some embodiments, a High-Definition (HD) map is used for vehicle localization. The HD map can provide a very detailed three-dimensional computer map for precisely locating the position of the vehicle. For example, using the HD map, the localization and vehicle pose subsystem 225 can precisely determine the current position of the vehicle (e.g., which lane of the road the vehicle is currently in and how close it is to the roadside or the sidewalk) and predict the future position of the vehicle.

[0061] The vehicle perception and planning system 220 further includes an obstacle predictor 226. The objects identified by the object classifier 223 can be stationary (e.g., light poles, road signs) or dynamic (e.g., moving pedestrians, bicycles, another vehicle). For moving objects, predicting their movement paths or future positions is important for avoiding collisions. The obstacle predictor 226 can predict obstacle trajectories and / or warn the driver or the vehicle planning subsystem 228 of potential collisions. For example, if there is a high likelihood that the trajectory of an obstacle will intersect the current movement path of the vehicle, the obstacle predictor 226 can generate such a warning. The obstacle predictor 226 can use various techniques to make such predictions. These techniques include, for example, constant speed or acceleration models, constant turn rate and speed / acceleration models, models based on Kalman filters and extended Kalman filters, models based on recurrent neural networks (RNNs), models based on long short-term memory (LSTM) neural networks, encoder-decoder RNN models, etc.

[0062] Still referring to Figure 2 , in some embodiments, the vehicle perception and planning system 220 further includes a vehicle planning subsystem 228. The vehicle planning subsystem 228 can include one or more planners, such as a route planner, a driving behavior planner, and a motion planner. The route planner can plan the route of the vehicle based on the vehicle's current location data, target location data, traffic information, etc. The driving behavior planner uses the obstacle prediction results provided by the obstacle predictor 226 to adjust the timing and planned movement based on how other objects might move. The motion planner determines the specific actions that the vehicle needs to follow. The planning results are then transmitted to the vehicle control system 280 via the vehicle interface 270. The communication can be performed through communication paths 227 and 271, which include any wired or wireless communication links that can transmit data.

[0063] The vehicle control system 280 controls the steering mechanism, throttle, brakes, etc. of the vehicle to operate the vehicle according to the planned route and movement. In some examples, the vehicle perception and planning system 220 may further include a user interface 260 that provides access to the vehicle control system 280 to the user (e.g., the driver) to override or take over control of the vehicle when necessary, for example. The user interface 260 may also be separate from the vehicle perception and planning system 220. The user interface 260 may communicate with the vehicle perception and planning system 220, for example, to obtain and display raw or fused sensor data, identified objects, the position / attitude of the vehicle, etc. The displayed data may help the user better operate the vehicle. The user interface 260 may communicate with the vehicle perception and planning system 220 and / or the vehicle control system 280 via communication paths 221 and 261, respectively, which communication paths include any wired or wireless communication links capable of transmitting data. It should be understood that Figure 2 the various systems, sensors, communication links, and interfaces can be configured in any desired manner and are not limited to Figure 2 the configuration shown.

[0064] Figure 3 is a block diagram illustrating an exemplary LiDAR system 300. The LiDAR system 300 can be used to implement Figure 1 and Figure 2 the LiDAR systems 110, 120A - 120I, and / or 210 shown in. In one embodiment, the LiDAR system 300 includes a light source 310, a transmitter 320, an optical receiver and a photodetector 330, a steering system 340, and a control circuit 350. These components are coupled together using communication paths 312, 314, 322, 332, 342, 352, and 362. These communication paths include communication links (wired or wireless, bidirectional or unidirectional) between the various LiDAR system components, but do not have to be physical components themselves. Although the communication paths can be implemented by one or more wires, buses, or optical fibers, the communication paths can also be wireless channels or free - space optical paths, so there is no physical communication medium. For example, in one embodiment of the LiDAR system 300, the communication path 314 between the light source 310 and the transmitter 320 can be implemented using one or more optical fibers. The communication paths 332 and 352 can represent optical paths implemented using free - space optical components and / or optical fibers. And the communication paths 312, 322, 342, and 362 can be implemented using one or more wires carrying electrical signals. The communication paths can also include one or more of the above - mentioned types of communication media (e.g., they can include optical fibers and free - space optical components, or include one or more optical fibers and one or more wires).

[0065] In some embodiments, the LiDAR system 300 can be a coherent LiDAR system. Frequency-modulated continuous wave (FMCW) LiDAR is an example. Coherent LiDAR detects objects by mixing the returned light from the objects and the light from a coherent laser transmitter.

[0066] Thus, as Figure 3 shown, if the LiDAR system 300 is a coherent LiDAR, it can include a path 372,

[0067] which provides a portion of the transmitted light from the transmitter 320 to the optical receiver and photodetector 330. The path 372 can include one or more optical devices (e.g., optical fibers, lenses, mirrors, etc.) for providing the light from the transmitter 320 to the optical receiver and photodetector 330. The transmitted light provided by the transmitter 320 can be modulated light and can be split into two parts. One part is emitted into the FOV, while the second part is sent to the optical receiver and photodetector of the LiDAR system. The second part is also referred to as the light kept local (LO) in the LiDAR system. The transmitted light is scattered or reflected by various objects in the FOV, and at least a portion of it forms the returned light. The returned light is then detected and interfered and recombined with the second part of the transmitted light kept local. Coherent LiDAR provides a mechanism for optically sensing the range of an object and its relative velocity along the line of sight (LOS).

[0068] The LiDAR system 300 can also include Figure 3 other components not shown, such as a power bus, a power supply, an LED indicator, a switch, etc. Additionally, there can be other communication connections between components, such as a direct connection between the light source 310 and the optical receiver and photodetector 330 to provide a reference signal so that the time from the emission of the light pulse to the detection until the returned light pulse can be accurately measured.

[0069] The light source 310 outputs a laser beam for irradiating an object in the field of view (FOV). The laser can be infrared light with a wavelength in the range of 700 nm to 1 mm. The light source 310 can be, for example, a semiconductor-based laser (e.g., a diode laser) and / or a fiber-based laser. The semiconductor-based laser can be, for example, an edge-emitting laser (EEL), a vertical-cavity surface-emitting laser (VCSEL), an external-cavity diode laser, a vertical-cavity surface-emitting laser, a distributed feedback (DFB) laser, a distributed Bragg reflector (DBR) laser, an interband cascade laser, a quantum cascade laser, a quantum well laser, a double heterostructure laser, etc. The fiber-based laser is a laser in which the active gain medium is a fiber doped with rare earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium, and / or holmium. In some embodiments, the fiber laser is based on a double-clad fiber, where the gain medium forms the core of the fiber surrounded by two layers of cladding. The double-clad fiber allows the core to be pumped with a high-power beam, enabling the laser source to be a high-power fiber laser source.

[0070] In some embodiments, the light source 310 includes a master oscillator (also referred to as a seed laser) and a power amplifier (MOPA). The power amplifier amplifies the output power of the seed laser. The power amplifier can be a fiber amplifier, a bulk amplifier, or a semiconductor optical amplifier. The seed laser can be a diode laser (e.g., a Fabry-Perot cavity laser, a distributed feedback laser), a solid-state bulk laser, or an external-cavity tunable diode laser. In some embodiments, the light source 310 can be an optically pumped microchip laser. A microchip laser is an alignment-free monolithic solid-state laser in which the laser crystal is directly in contact with the end mirrors of the laser resonator. Microchip lasers are typically pumped by laser diodes (directly or using fibers) to obtain the desired output power. The microchip laser can be based on a neodymium-doped yttrium aluminum garnet (Y3Al5O12) laser crystal (i.e., Nd:YAG), or a neodymium-doped vanadate (i.e., ND:YVO4) laser crystal. In some examples, the light source 310 can have multiple amplification stages to achieve high power gain, such that the laser output can have high power, enabling the LiDAR system to have a long scan range. In some examples, the power amplifier of the light source 310 can be controlled such that the power gain can be changed to achieve any desired laser output power.

[0071] Figure 4 is a block diagram illustrating an exemplary fiber-based laser source 400 having a seed laser and one or more pumps (e.g., laser diodes) for pumping the desired output power. The fiber-based laser source 400 is Figure 3An example of the light source 310 shown. In some embodiments, the fiber-based laser source 400 includes a seed laser 402 to generate an initial optical pulse of one or more wavelengths (e.g., an infrared wavelength such as 1550 nm), and the initial optical pulse is provided to a wavelength division multiplexer (WDM) 404 via a fiber 403. The fiber-based laser source 400 further includes a pump 406 for providing laser power (e.g., a different wavelength such as 980 nm) to the WDM 404 via a fiber 405. The WDM 404 multiplexes the optical pulse provided by the seed laser 402 and the laser power provided by the pump 406 onto a single fiber 407. Then, the output of the WDM 404 can be provided to one or more preamplifiers 408 via the fiber 407. The preamplifier 408 can be an optical amplifier that amplifies the optical signal (e.g., having a gain of about 10 - 30 dB). In some embodiments, the preamplifier 408 is a low-noise amplifier. The preamplifier 408 outputs to an optical combiner 410 via a fiber 409. The combiner 410 combines the output laser of the preamplifier 408 with the laser power provided by a pump 412 via a fiber 411. The combiner 410 can combine optical signals having the same wavelength or different wavelengths. An example of the combiner is a WDM.

[0072] The combiner 410 provides the combined optical signal to a booster amplifier 414, which generates an output optical pulse via a fiber 415. The booster amplifier 414 provides further amplification of the optical signal (e.g., another 20 - 40 dB). The output optical pulse can then be emitted to the transmitter 320 and / or the steering mechanism 340 (as Figure 3 shown). It should be understood that Figure 4 illustrates an exemplary configuration of the fiber-based laser source 400. The laser source 400 can have many other configurations using different combinations of one or more of the components shown in Figure 4 and / or other components not shown in Figure 4 (e.g., other components such as power supplies, lenses, filters, beam splitters, combiners, etc.).

[0073] In some variations, the fiber-based laser source 400 can be controlled (e.g., by a control circuit 350) to generate pulses of different amplitudes based on the fiber gain profile of the fiber used in the fiber-based laser source 400. The communication path 312 couples the fiber-based laser source 400 to a control circuitry 350 (as Figure 3as shown), such that components of the fiber-based laser source 400 can be controlled by or otherwise communicate with the control circuitry 350. Alternatively, the fiber-based laser source 400 can include its own dedicated controller. Instead of the control circuitry 350 directly communicating with components of the fiber-based laser source 400, the dedicated controller of the fiber-based laser source 400 communicates with the control circuitry 350 and controls and / or communicates with components of the fiber-based laser source 400. The fiber-based laser source 400 can also include other components not shown, such as one or more power connectors, a power supply, and / or power lines.

[0074] Reference Figure 3 , typical operating wavelengths of the light source 310 include, for example, approximately 850 nm, approximately 905 nm, approximately 940 nm, approximately 1064 nm, and approximately 1550 nm. For laser safety, the upper limit of the maximum available laser power is set by the regulations of the U.S. Food and Drug Administration (FDA). The optical power limit at a wavelength of 1550 nm is much higher than the optical power limits of the other wavelengths mentioned above. Additionally, at 1550 nm, the optical power loss in the fiber is very low. These characteristics at a wavelength of 1550 nm make it more favorable for long-range LiDAR applications. The amount of optical power output from the light source 310 can be characterized by its peak power, average power, pulse energy, and / or pulse energy density. Peak power is the ratio of pulse energy to pulse width (e.g., full width at half maximum or FWHM). Thus, for a fixed amount of pulse energy, a smaller pulse width can provide a larger peak power. The pulse width can be in the range of nanoseconds or picoseconds. Average power is the product of pulse energy and pulse repetition rate (PRR). As described in more detail below, the PRR represents the frequency of the pulsed laser. Generally, the smaller the time interval between pulses, the higher the PRR. The PRR typically corresponds to the maximum range that the LiDAR system can measure. The light source 310 can be configured to generate pulses at a high PRR to meet the desired number of data points in the point cloud generated by the LiDAR system. The light source 310 can also be configured to generate pulses at a medium or low PRR to meet the desired maximum detection range. Wall plug efficiency (WPE) is another factor for evaluating the total power consumption, which can be a useful metric for evaluating the efficiency of the laser. For example, as Figure 1 shown, multiple LiDAR systems can be attached to a vehicle, which can be an electric vehicle or a vehicle with limited fuel or battery power. Therefore, high WPE and an intelligent way of using laser power are generally important considerations when selecting and configuring the light source 310 and / or designing a laser delivery system for in-vehicle LiDAR applications.

[0075] It should be understood that the above description provides a non - limiting example of the light source 310. The light source 310 can be configured to include many other types of light sources (e.g., laser diodes, short - cavity fiber lasers, solid - state lasers, and / or external - cavity tunable diode lasers), which are configured to generate one or more optical signals at various wavelengths. In some examples, the light source 310 includes an amplifier (e.g., a pre - amplifier and / or a booster amplifier), which can be a doped - fiber amplifier, a solid - state bulk amplifier, and / or a semiconductor optical amplifier. The amplifier is configured to receive and amplify the optical signal with a desired gain.

[0076] Return reference Figure 3 , the LiDAR system 300 further includes a transmitter 320. The light source 310 provides laser light (e.g., in the form of a laser beam) to the transmitter 320. The laser light provided by the light source 310 can be amplified laser light having a pre - determined or controlled wavelength, pulse repetition rate, and / or power level. The transmitter 320 receives the laser light from the light source 310 and emits the laser light with a low divergence into the steering mechanism 340. In some embodiments, the transmitter 320 can include, for example, optical components (e.g., lenses, optical fibers, mirrors, etc.) for emitting one or more laser beams directly or via the steering mechanism 340 into the field of view (FOV). Although Figure 3 the transmitter 320 and the steering mechanism 340 are illustrated as separate components, in some embodiments, they can be combined or integrated into one system. The steering mechanism 340 will be described in more detail below.

[0077] The laser beam provided by the light source 310 may diverge as it propagates to the transmitter 320. Therefore, the transmitter 320 typically includes a collimating lens, which is configured to collect the diverging laser beam and produce a more parallel beam with a reduced or minimized divergence. The collimated beam can then be further directed through various optical devices, such as mirrors and lenses. The collimating lens can be, for example, a single plano - convex lens or a lens group. The collimating lens can be configured to achieve any desired characteristics, such as beam diameter, divergence, numerical aperture, focal length, etc. The beam propagation ratio or beam quality factor (also known as the M 2 factor) is used to measure the quality of the laser beam. In many LiDAR applications, it is important to have good laser beam quality in the generated transmitted laser beam. The M 2 factor represents the degree of variation of the beam relative to an ideal Gaussian beam. Therefore, the M 2 factor reflects how well the collimated laser beam can be focused on a small spot, or how well the diverging laser beam can be collimated. Therefore, the light source 310 and / or the transmitter 320 can be configured to meet, for example, the scanning resolution requirements while maintaining a desired M 2 factor.

[0078] One or more of the light beams provided by the emitter 320 are scanned into the FOV by the steering mechanism 340. The steering mechanism 340 scans the light beam in multiple dimensions (e.g., in the horizontal dimension and the vertical dimension) to facilitate the LiDAR system 300 to map the environment by generating a 3D point cloud. The horizontal dimension can be a dimension parallel to the horizon or a surface associated with the LiDAR system or the vehicle (e.g., the road surface). The vertical dimension is perpendicular to the horizontal dimension (i.e., the vertical dimension forms a 90-degree angle with the horizontal dimension). The steering mechanism 340 will be described in more detail below. The laser scanned into the FOV may be scattered or reflected by an object in the FOV. At least a portion of the scattered light or the reflected light forms the return light that returns to the LiDAR system 300. Figure 3 Further illustrated is an optical receiver and a photodetector 330 configured to receive the return light. The optical receiver and the photodetector 330 include an optical receiver configured to collect the return light from the FOV. The optical receiver may include optical devices (e.g., lenses, optical fibers, mirrors, etc.) for receiving, redirecting, focusing, amplifying, and / or filtering the return light from the FOV. For example, the optical receiver typically includes a collection lens (e.g., a single plano-convex lens or a lens group) to collect the return light and / or focus the collected return light onto the photodetector.

[0079] The photodetector detects the return light focused by the optical receiver and generates a current and / or voltage signal proportional to the incident intensity of the return light. Based on such a current and / or voltage signal, the depth information of the object in the FOV can be derived. An exemplary method for deriving such depth information is based on direct TOF (time of flight), which will be described in more detail below. The photodetector can be characterized by its detection sensitivity, quantum efficiency, detector bandwidth, linearity, signal-to-noise ratio (SNR), anti-overload ability, anti-interference ability, etc. Based on the application, the photodetector can be configured or customized to have any desired characteristics. For example, the optical receiver and the photodetector 330 can be configured such that the photodetector has a large dynamic range while having good linearity. Photodetector linearity indicates the ability of the detector to maintain a linear relationship between the input optical signal power and the detector output. A detector with good linearity can maintain a linear relationship within a large dynamic input optical signal range.

[0080] To achieve desired detector characteristics, the structure of the photodetector and / or the material system of the detector can be configured or customized. Various detector structures can be used for the photodetector. For example, the photodetector structure can be a PIN-based structure that has an undoped intrinsic semiconductor region (i.e., the "I" region) between a p-type semiconductor and an n-type semiconductor region. Other photodetector structures include, for example, APD (avalanche photodiode)-based structures, PMT (photomultiplier tube)-based structures, SiPM (silicon photomultiplier)-based structures, SPAD (single-photon avalanche diode)-based structures, and / or quantum wires. For the material system used in the photodetector, Si, InGaAs, and / or Si / Ge-based materials can be used. It should be understood that many other detector structures and / or material systems can be used in the optical receiver and the photodetector 330.

[0081] A photodetector (e.g., an APD-based detector) can have internal gain such that the input signal is amplified when an output signal is generated. However, due to the internal gain of the photodetector, noise may also be amplified. Common types of noise include signal shot noise, dark current shot noise, thermal noise, and amplifier noise. In some embodiments, the optical receiver and the photodetector 330 can include a preamplifier of a low-noise amplifier (LNA). In some embodiments, the preamplifier can further include a transimpedance amplifier (TIA) that converts a current signal into a voltage signal. For a linear detector system, the input equivalent noise or noise equivalent power (NEP) measures the sensitivity of the photodetector to weak signals. Thus, they can be used as an indicator of the overall system performance. For example, the NEP of a photodetector specifies the power of the weakest signal that can be detected, and thus it further specifies the maximum range of the LiDAR system. It should be understood that various photodetector optimization techniques can be used to meet the requirements of the LiDAR system 300. Such optimization techniques can include selecting different detector structures, materials, and / or implementing signal processing techniques (e.g., filtering, noise reduction, amplification, etc.). For example, in addition to or instead of using direct detection of the returned signal (e.g., by using ToF), coherent detection can also be used for the photodetector. Coherent detection allows the detection of the amplitude and phase information of the received light by interfering the received light with a local oscillator. Coherent detection can improve the detection sensitivity and noise immunity.

[0082] Figure 3The LiDAR system 300 is further illustrated to include a steering mechanism 340. As described above, the steering mechanism 340 directs the light beam from the transmitter 320 for multi-dimensional scanning of the FOV. The steering mechanism is referred to as a raster mechanism, a scanning mechanism, or simply an optical scanner. Scanning the light beam in multiple directions (e.g., in the horizontal and vertical directions) facilitates the LiDAR system to map the environment by generating an image or a 3D point cloud. The steering mechanism can be based on mechanical scanning and / or solid-state scanning. Mechanical scanning uses a rotating mirror to steer the laser beam or physically rotates the LiDAR transmitter and receiver (collectively referred to as the transceiver) to scan the laser beam. Solid-state scanning guides the laser beam to various positions through the FOV without mechanically moving any macroscopic components, such as the transceiver. Solid-state scanning mechanisms include, for example, steering based on optical phased arrays and steering based on flash LiDAR. In some embodiments, since the solid-state scanning mechanism does not physically move macroscopic components, the steering performed by the solid-state scanning mechanism can be referred to as effective steering. A LiDAR system using solid-state scanning can also be referred to as a non-mechanical scanning or simply a non-scanning LiDAR system (a flash LiDAR system is an exemplary non-scanning LiDAR system).

[0083] The steering mechanism 340 can be used in conjunction with a transceiver (e.g., the transmitter 320 and the optical receiver and light detector 330) to scan the FOV for generating an image or a 3D point cloud. As an example, to implement the steering mechanism 340, a two-dimensional mechanical scanner can

[0084] be used with a single-point or a few single-point transceivers. The single-point transceiver emits a single light beam or a small number of light beams (e.g., 2 - 8 light beams) into the steering mechanism. The two-dimensional mechanical steering mechanism includes, for example, a polygon mirror, an oscillating mirror, a rotating prism, a rotating tilted mirror surface, a single-plane or multi-plane mirror, or a combination thereof. In some embodiments, the steering mechanism 340 can include a non-mechanical steering mechanism, such as a solid-state steering mechanism. For example, the steering mechanism 340 can be based on the tuned wavelength of the laser that combines refraction effects, and / or based on a reconfigurable grating / phase array. In some embodiments, the steering mechanism 340 can use a single scanning device to achieve two-dimensional scanning, or use a combination of multiple scanning devices to achieve two-dimensional scanning.

[0085] As another example, to implement the steering mechanism 340, a one-dimensional mechanical scanner can be used with an array or a large number of single-point transceivers. Specifically, the transceiver array can be mounted on a rotating platform to achieve a 360-degree horizontal field of view. Alternatively, a static transceiver array can be combined with a one-dimensional mechanical scanner. The one-dimensional mechanical scanner includes a polygon mirror, an oscillating mirror, a rotating prism, a rotating tilted mirror surface, or a combination thereof, for obtaining a forward-looking horizontal field of view. The steering mechanism using a mechanical scanner can provide robustness and reliability in large-scale production for automotive applications.

[0086] As another example, to implement the steering mechanism 340, a two-dimensional transceiver can be used to directly generate a scanned image or a 3D point cloud. In some embodiments, stitching or micro-displacement methods can be used to increase the resolution of the scanned image or the field of view being scanned. For example, using a two-dimensional transceiver, signals generated in one direction (e.g., the horizontal direction) and signals generated in another direction (e.g., the vertical direction) can be integrated, interleaved, and / or matched to generate a higher or full-resolution image or 3D point cloud representing the scanned FOV.

[0087] Some implementations of the steering mechanism 340 include one or more optical redirecting elements (e.g., mirrors or lenses) that steer the returned optical signal along the receiving path (e.g., by rotation, vibration, or guiding) to direct the returned optical signal to the optical receiver and photodetector 330. The optical redirecting elements that guide the optical signal along the emission path and the receiving path can be the same component (e.g., shared), separate components (e.g., dedicated), and / or a combination of shared and separate components. This means that in some cases, the emission path and the receiving path are different, although they may partially overlap (or in some cases, substantially overlap or completely overlap).

[0088] Still referring to Figure 3 , the LiDAR system 300 further includes control circuitry 350. The control circuit 350 can be configured and / or programmed to control various parts of the LiDAR system 300 and / or perform signal processing. In a typical system, the control circuit 350 can be configured and / or programmed to perform one or more control operations, including, for example, controlling the light source 310 to obtain desired laser pulse timing, pulse repetition rate, and power; controlling the steering mechanism 340 (e.g., controlling speed, direction, and / or other parameters) to scan the FOV and maintain pixel registration and / or alignment; controlling the optical receiver and photodetector 330 (e.g., controlling sensitivity, noise reduction, filtering, and / or other parameters) such that it is in an optimal state; and monitoring the overall system health / functional safety status (e.g., monitoring the safety of the laser output power and / or the operating status of the steering mechanism).

[0089] The control circuitry 350 can also be configured and / or programmed to perform signal processing on the raw data generated by the optical receiver and photodetector 330 to obtain distance and reflectivity information, and perform data packing and communicate with the vehicle perception and planning system 220, such as Figure 2Communication as shown). For example, the control circuit 350 determines the time taken from transmitting an optical pulse to receiving the corresponding returned optical pulse; determines when no returned optical pulse of the transmitted optical pulse is received; determines the direction of the transmitted optical pulse / returned optical pulse (e.g., horizontal information and / or vertical information); determines the estimated range in a specific direction; derives the reflectivity of an object in the FOV, and / or determines any other type of data related to the LiDAR system 300.

[0090] The LiDAR system 300 can be disposed in a vehicle, which can operate in many different environments, including hot or cold weather, rough road conditions that may cause strong vibrations, high or low humidity, dusty areas, etc. Thus, in some embodiments, the optical and / or electronic components of the LiDAR system 300 (e.g., the optics in the transmitter 320, the optical receiver and the photodetector 330, and the steering mechanism 340) are arranged and / or configured in a manner that maintains long-term mechanical and optical stability. For example, the components in the LiDAR system 300 can be fixed and sealed so that they can operate under all conditions that the vehicle may encounter. As an example, a moisture-proof coating and / or an airtight seal can be applied to the optical components of the transmitter 320, the optical receiver and the photodetector 330, and the steering mechanism 340 (and other components vulnerable to moisture). As another example, a housing, a shroud, a fairing, and / or a window can be used in the LiDAR system 300 to provide desired characteristics such as hardness, Ingress Protection (IP) rating, self-cleaning ability, chemical resistance, and impact resistance, etc. Additionally, an efficient and economical method for assembling the LiDAR system 300 can be used to meet the LiDAR operation requirements while maintaining low cost.

[0091] Those of ordinary skill in the art should understand that Figure 3 and the above description is for illustrative purposes only, and the LiDAR system can include other functional units, blocks, or segments, and can include variations or combinations of these above functional units, blocks, or segments. For example, the LiDAR system 300 can also include Figure 3 other components not shown in, such as a power bus, a power supply, an LED indicator, a switch, etc. Additionally, there can be other connections between components, such as a direct connection between the light source 310 and the optical receiver and the photodetector 330, so that the photodetector 330 can accurately measure the time from when the light pulse is emitted from the light source 310 to when the returned light pulse is detected by the photodetector 330.

[0092] Figure 3The components shown are coupled together using communication paths 312, 314, 322, 332, 342, 352, and 362. These communication paths represent communication (bidirectional or unidirectional) between various LiDAR system components, but do not have to be physical components themselves. Although the communication paths can be implemented by one or more wires, buses, or optical fibers, the communication paths can also be wireless channels or free-space optical paths, such that there is no physical communication medium. For example, in an exemplary LiDAR system, communication path 314 includes one or more optical fibers; communication path 352 represents an optical path; and communication paths 312, 322, 342, and 362 are all wires that carry electrical signals. The communication paths can also include more than one of the above types of communication media (e.g., they can include optical fibers and optical paths, or one or more optical fibers and one or more wires).

[0093] As described above, some LiDAR systems use the time-of-flight (ToF) of optical signals (e.g., optical pulses) to determine the distance to an object in the optical path. For example, referring to Figure 5A , exemplary LiDAR system 500 includes a laser light source (e.g., a fiber laser), a steering mechanism (e.g., a system of one or more moving mirrors), and a light detector (e.g., a photodetector with one or more optical devices). LiDAR system 500 can be implemented using, for example, the above-described LiDAR system 300. LiDAR system 500 emits optical pulse 502 along optical path 504 determined by the steering mechanism of LiDAR system 500. In the depicted example, optical pulse 502 generated by the laser light source is a short pulse of laser light. Additionally, the signal manipulation mechanism of LiDAR system 500 is a pulsed signal steering mechanism. However, it should be understood that a LiDAR system can operate by generating, emitting, and detecting non-pulsed optical signals and using techniques other than time-of-flight to derive the distance to an object in the surrounding environment. For example, some LiDAR systems use frequency-modulated continuous wave (i.e., “FMCW”). It should also be understood that any techniques described herein for time-of-flight-based systems using pulsed signals can also be applicable to LiDAR systems that do not use one or both of these techniques.

[0094] Return reference Figure 5A(For example, a time-of-flight LiDAR system using optical pulses is illustrated), when the optical pulse 502 reaches the object 506, the optical pulse 502 scatters or reflects to form a returned optical pulse 508. The returned optical pulse 508 can return to the system 500 along the optical path 510. The time from when the emitted optical pulse 502 leaves the LiDAR system 500 to when the returned optical pulse 508 returns to the LiDAR system 500 can be measured (e.g., by a processor or other electronic device within the LiDAR system, such as the control circuit 350). This time of flight combined with the knowledge of the speed of light can be used to determine the distance / distance from the LiDAR system 500 to the portion of the object 506 where the optical pulse 502 is scattered or reflected.

[0095] By directing a number of optical pulses, such as Figure 5B depicted, the LiDAR system 500 scans the external environment (e.g., by directing the optical pulses 502, 522, 526, 530 along the optical paths 504, 524, 528, 532 respectively). As Figure 5C depicted, the LiDAR system 500 receives the returned optical pulses 508, 542, 548 (corresponding to the emitted optical pulses 502, 522, 530 respectively). The returned optical pulses 508, 542, and 548 are formed by scattering or reflecting the emitted optical pulses by one of the objects 506 and 514. The returned optical pulses 508, 542, and 548 can return to the LiDAR system 500 along the optical paths 510, 544, and 546 respectively. Based on the direction of the emitted optical pulses (as determined by the LiDAR system 500) and the calculated distance from the LiDAR system 500 to the portion of the object that scatters or reflects the optical pulses (e.g., portions of the objects 506 and 514), the external environment within the detectable range (e.g., the field of view between the paths 504 and 532, inclusive) can be accurately mapped or drawn (e.g., by generating a 3D point cloud or an image).

[0096] If no corresponding optical pulse is received for a particular emitted optical pulse, the LiDAR system 500 can determine that there is no object within the detectable range of the LiDAR system 500 (e.g., the object is outside the maximum scan distance of the LiDAR system 500). For example, in Figure 5B , the optical pulse 526 may not have a corresponding returned optical pulse (as Figure 5C illustrated), because the optical pulse 526 may not generate a scattering event along its transmission path 528 within a pre-determined detection range. The LiDAR system 500 or an external system communicating with the LiDAR system 500 (e.g., a cloud system or service) can interpret the absence of a returned optical pulse as there being no object along the optical path 528 within the detectable range of the LiDAR system 500.

[0097] InFigure 5B In this case, the optical pulses 502, 522, 526, and 530 can be emitted in any order, serially, in parallel, or based on other timings relative to each other. Additionally, although Figure 5B the emitted optical pulses are depicted as being guided in one dimension or one plane (e.g., the plane of the paper), the LiDAR system 500 can also guide the emitted optical pulses along other dimensions or planes. For example, the LiDAR system 500 can also guide the emitted optical pulses in a dimension or plane perpendicular to Figure 5B the dimension or plane shown, thereby forming a two-dimensional transmission of the optical pulses. This two-dimensional transmission of the optical pulses can be point-by-point, line-by-line, all-at-once, or in other ways. That is, the LiDAR system 500 can be configured to perform point scanning, line scanning, non-scanning single scans, or combinations thereof. A point cloud or image from a one-dimensional transmission of the optical pulses (e.g., a single horizontal line) can generate two-dimensional data (e.g., (1) data from the horizontal transmission direction and (2) the range or distance to the object). Similarly, a point cloud or image from a two-dimensional transmission of the optical pulses can generate three-dimensional data (e.g., (1) data from the horizontal transmission direction),

[0098] (2) data from the vertical emission direction, and (3) the range or distance to the object. Generally, a LiDAR system that performs an n-dimensional transmission of optical pulses generates (n + 1)-dimensional data. This is because the LiDAR system can measure the depth or the distance to the object, which provides an additional data dimension. Thus, a 2D scan performed by the LiDAR system can generate a 3D point cloud for mapping the external environment of the LiDAR system.

[0099] The density of the point cloud refers to the number of measurements (data points) in each region performed by the LiDAR system. The point cloud density is related to the LiDAR scan resolution. Generally, at least for the region of interest (ROI), a greater point cloud density is desired and thus a higher resolution is required. The point density in the point cloud or image generated by the LiDAR system is equal to the number of pulses divided by the field of view. In some embodiments, the field of view can be fixed. Thus, to increase the density of the points generated by a set of transmit-receive optics (or transceiver optics), the LiDAR system may need to generate pulses more frequently. In other words, the light source in the LiDAR system can have a higher pulse repetition rate (PRR). On the other hand, by generating and emitting pulses more frequently, the maximum distance that the LiDAR system can detect may be limited. For example, if a return signal from a distant object is received after the system emits the next pulse, the return signal may be detected in an order different from the order in which the corresponding signal was emitted, resulting in ambiguity if the system cannot correctly associate the return signal with the emitted signal.

[0100] For illustration, consider an exemplary LiDAR system that can emit laser pulses with a pulse repetition rate between 500 kHz and 1 MHz. Based on the time it takes for a pulse to return to the LiDAR system and to avoid confusion of return pulses from consecutive pulses in a typical LiDAR design, for 500 kHz and 1 MHz, the maximum distance that the LiDAR system can detect can be 300 meters and 150 meters, respectively. The point density of a LiDAR system with a repetition frequency of 500 kHz is half that of 1 MHz. Thus, this example shows that increasing the repetition rate from 500 kHz to 1 MHz (and thus increasing the point density of the system) may decrease the detection range of the system if the system cannot correctly correlate the return signals that arrive out of order. Various techniques are used to mitigate the trade-off between a higher PRR and a limited detection range. For example, multiple wavelengths can be used to detect objects in different ranges. Optical and / or signal processing techniques (e.g., pulse coding techniques) are also used to correlate the transmitted optical signal with the returned optical signal.

[0101] The various systems, devices, and methods described herein can be implemented using digital circuits or using one or more computers that utilize well-known computer processors, memory units, storage devices, computer software, and other components. Generally, a computer includes a processor for executing instructions and one or more memories for storing the instructions and data. The computer may also include or be coupled to one or more mass storage devices, such as one or more disks, internal hard drives and removable disks, magneto-optical disks, optical disks, and the like.

[0102] The various systems, devices, and methods described herein can be implemented using computers operating in a client-server relationship. Generally, in such a system, the client computers are located at a location remote from the server computer and interact via a network. The client-server relationship can be defined and controlled by computer programs running on the respective client and server computers. Examples of client computers can include desktop computers, workstations, portable computers, cellular smartphones, tablet computers, or other types of computing devices.

[0103] The various systems, devices, and methods described herein can be implemented using a computer program product tangibly embodied in an information carrier, such as in a non-transitory machine-readable storage device, for execution by a programmable processor; and the method processes and steps described herein (including Figures 1 to 13One or more steps of at least some of them) may be implemented using one or more computer programs executable by such a processor. A computer program is a set of computer program instructions that can be used directly or indirectly in a computer to perform a specific activity or produce a specific result. A computer program may be written in any form of programming language, including compiled or interpreted languages, and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0104] Figure 6 FIG. illustrates a simplified block diagram of an exemplary apparatus that may be used to implement the systems, devices, and methods described herein. Apparatus 600 includes a processor 610 operatively coupled to a persistent storage device 620 and a main memory device 630. Processor 610 controls the overall operation of apparatus 600 by executing computer program instructions that define these operations. The computer program instructions may be stored in the persistent storage device 620 or other computer-readable medium and loaded into the main memory device 630 when it is desired to execute the computer program instructions. For example, processor 610 may be used to implement one or more components and systems described herein, such as control circuitry 350 ( Figure 3 as shown), vehicle perception and planning system 220 ( Figure 2 as shown), and vehicle control system 280 ( Figure 2 as shown). Accordingly, Figures 1 to 13 method steps of at least some of them may be defined by computer program instructions stored in the main memory device 630 and / or the persistent storage device 620 and controlled by processor 610 that executes the computer program instructions. For example, the computer program instructions may be implemented as computer-executable code programmed by those skilled in the art to perform an algorithm defined by method steps discussed in conjunction with Figures 1 to 13 at least some of them. Accordingly, by executing the computer program instructions, processor 610 performs an algorithm defined by the method steps of these foregoing figures. Apparatus 600 also includes one or more network interfaces 680 for communicating with other devices via a network. Apparatus 600 may also include one or more input / output devices 690 that enable a user to interact with apparatus 600 (e.g., a display, keyboard, mouse, speakers, buttons, etc.).

[0105] Processor 610 may include both a general-purpose microprocessor and a special-purpose microprocessor, and may be the sole processor of device 600 or one of a plurality of processors. Processor 610 may include one or more central processing units (CPUs) and one or more graphics processing units (GPUs), and the GPUs may, for example, work separately from one or more CPUs and / or perform multitasking with one or more CPUs to accelerate processing, for example, for various image processing applications described herein. Processor 610, persistent storage device 620, and / or main memory device 630 may include one or more application-specific integrated circuits (ASICs) and / or one or more field-programmable gate arrays (FPGAs), or be supplemented by one or more ASICs and / or one or more FPGAs, or incorporated into one or more ASICs and / or one or more FPGAs.

[0106] Persistent storage device 620 and main memory device 630 each include a tangible non-transitory computer-readable storage medium. Persistent storage device 620 and main memory device 630 may each include high-speed random access memory, such as dynamic random access memory (DRAM), static random access memory (SRAM), double data rate synchronous dynamic random access memory (DDR RAM), or other random access solid-state memory devices, and may include non-volatile memory, for example, one or more disk storage devices, such as internal hard disks and removable disks, magneto-optical storage devices, optical disc storage devices, flash memory devices, semiconductor storage devices (such as erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)), compact disc read-only memory (CD-ROM), digital versatile disc read-only memory (DVD-ROM) discs, or other non-volatile solid-state storage devices.

[0107] Input / output device 690 may include peripheral devices, such as printers, scanners, displays, etc. For example, input / output device 690 may include a display device (such as a cathode ray tube (CRT), plasma, or liquid crystal display (LCD) monitor) for displaying information to a user, a keyboard, and a pointing device (such as a mouse or trackball) that the user may use to provide input to device 600.

[0108] Any or all of the functions of the systems and devices discussed herein may be performed by processor 610 and / or incorporated into a device or system such as LiDAR system 300. Additionally, LiDAR system 300 and / or device 600 may utilize one or more neural networks or other deep learning techniques performed by processor 610 or other systems or devices discussed herein.

[0109] Those skilled in the art will recognize that the implementation of an actual computer or computer system may have other structures and may also include other components, and Figure 6 is a simplified representation of some of the components of such a computer for illustrative purposes.

[0110] Figure 7 is a diagram illustrating an exemplary LiDAR system 700 including a plurality of transmitter groups according to some embodiments. As Figure 7 shown, the LiDAR system 700 includes a plurality of transmitter groups 710A, 710B, and 710C. Figure 7 Only three transmitter groups 710A, 710B, and 710C are illustrated, but it should be understood that more or fewer transmitter groups may be included. The transmitter groups 710A, 710B, and 710C are collectively referred to as the transmitter group 710. Each of the plurality of transmitter groups 710A-C includes a plurality of transmitters. In one example, the plurality of transmitter groups 710A-C form a plurality of transmitter arrays. Each of the transmitter arrays includes a plurality of transmitters aligned with each other in at least one of a horizontal dimension and a vertical dimension, thereby forming a two-dimensional transmitter array. This will be described in further detail below with reference to Figures 8A to 8E and

[0111] As Figure 7 shown, the plurality of transmitter groups 710A-C are configured to emit transmitted beams 740. In some embodiments, a collimating lens ( Figure 7 not shown in Figure 9 ) is optically coupled to each transmitter group 710 and is configured to collimate the transmitted beam 740. This will be described in further detail below with reference to Figure 7 and FIG. 10. In some embodiments,

[0112] the transmitted beam 740 shown in Figure 4The fiber-based laser source 400 shown). In some embodiments, at least two of the multiple emitter groups 710A-C include different types of laser sources. In some embodiments, at least two of the multiple emitter groups 710A-C are configured to emit transmission beams 740 having different wavelengths. For example, the side emitter groups 710A or 710C include one or more semiconductor-based laser sources (e.g., 905 nm diode lasers for short-range detection in a low-cost manner). The central emitter group 710B includes one or more fiber-based laser sources (e.g., 1550 nm fiber-based lasers that generate high-quality point clouds for long-range detection). Further details will be described below with reference to Figures 8A to 8C The emitter group including one or more fiber-based laser sources will be described in further detail.

[0113] The LiDAR system 700 further includes an optical scanner (e.g., Figure 3 The steering mechanism 340 shown). The optical scanner is configured to steer the transmission beam 740 vertically and horizontally into the FOV 750 and receive the return light 760 formed based on the steered transmission beam 740. In some embodiments, as Figure 7 shown, the optical scanner includes a movable mirror 720 and a polygon mirror 730. The multiple emitter groups 710A-C of the optical scanner and the movable mirror 720 are optically coupled together such that the transmission beam 740 emitted by the multiple emitter groups can be received by the movable mirror 720. As Figure 7 shown, the movable mirror 720 is configured to direct the transmission beam 740 to the polygon mirror 730. The movable mirror 720 can move around an axis 724 to facilitate scanning the transmission beam 740 along a first dimension (e.g., the vertical dimension) of the FOV 750. In some embodiments, the movable mirror 720 is a vibrating mirror. The movable mirror is controlled to oscillate around the axis 724 between two predefined angular positions. In some embodiments, the movable mirror 720 is a galvanometer mirror configured to control the oscillation around the axis 724. As Figure 7 shown, the polygon mirror 730 includes a plurality of reflective surfaces 732 configured to redirect the transmission beam 740 from the movable mirror 720 to irradiate one or more objects in the FOV 750. The polygon mirror 730 rotates around an axis 734 to facilitate scanning the transmission beam 740 along a second dimension (e.g., the horizontal dimension) of the FOV 750. The second dimension is orthogonal to the first dimension. When the transmission beam 740 propagates to irradiate one or more objects in the FOV 750, at least a portion of the transmission beam 740 is reflected or scattered to form the return light 760. As Figure 7As shown, the polygon mirror 730 receives the return light 760 and guides the return light 760 to the movable mirror 720. The movable mirror 720 redirects the return light 760 to the collection lens 770. Finally, the collection lens 770 guides the collected return light 760 to other components (e.g., a photodetector) of the LiDAR system 700. In some embodiments, as Figure 7 shown, the LiDAR system 700 further includes a housing 780. A light scanner including the movable mirror 720 and the polygon mirror 730 and a plurality of emitter groups 710A-C are disposed within the housing 780. In one example, the housing 780 includes a window for passing the beam 740 and the return light 760.

[0114] The LiDAR system 700 further includes a control device 790 (e.g., Figure 3 the control circuit 350 shown therein) configured to control the plurality of emitter groups 710A-C. As Figure 7 shown, the control device 790 selectively controls one or more of the plurality of emitter groups 710A-C to emit a transmitted beam 740 toward the light scanner (e.g., the movable mirror 720). As Figure 7 shown, at least two of the plurality of emitter groups are disposed at different positions relative to the light scanner (e.g., the movable mirror 720) such that the scanning regions corresponding to the at least two emitter groups are different. This will be described in further detail below with reference to FIGS. 11 to 12.

[0115] In some embodiments, the control device 790 is configured to selectively control one or more of the plurality of emitter groups 710A-C by controlling at least one of the following: the on / off state of each emitter group in one or more of the plurality of emitter groups 710A-C; the pulse repetition rate of each transmitted beam 740 emitted by one or more of the plurality of emitter groups 710A-C; the power level of each transmitted beam 740 emitted by one or more of the plurality of emitter groups 710A-C; the wavelength of each transmitted beam 740 emitted by one or more of the plurality of emitter groups 710A-C; the coding or modulation scheme of each transmitted beam 740 emitted by one or more of the plurality of emitter groups 710A-C; and the combination of emitter groups 710 that emit the transmitted beam 740 toward the light scanner (e.g., the movable mirror 720).

[0116] In some embodiments, the control device 790 is configured to selectively control one or more of the plurality of emitter groups 710A-C based on one or more sensing requirements. An example of a sensing requirement is related to turning at an intersection. When a vehicle having the LiDAR system 700 turns left, the control device 790 selectively controls two emitter groups 710A and 710B to emit transmitted light beams 740. The control device 790 can turn off the emitter group 710A that may be located on the right side of the emitter groups 710B and 710C to save energy, or reduce the power level of the transmitted light beam 740 emitted by the emitter group 710A such that it is in an energy-saving mode. Similarly, when the vehicle turns right, the control device 790 can turn off the emitter group 710C that is located on the left side of the emitter groups 710A and 710B, or reduce the power level of the transmitted light beam 740 emitted by the emitter group 710C, thereby improving the energy efficiency of the LiDAR system 700.

[0117] In another example, to facilitate complex sensing requirements, the control device 790 can selectively control the wavelength of the transmitted light beams 740 provided by different emitter groups 710. For example, the control device 790 can control the transmitted light beam 740 emitted by the central emitter group 710B to have a wavelength of 1550 nm for long-range detection. The control device 790 can selectively control the transmitted light beams 740 emitted by the side emitter groups 710A and 710C to have a wavelength of 905 nm for short-range detection. Additionally, by using low-cost diode lasers as the light source in the two side emitter groups 710A and 710C, the cost efficiency of the LiDAR system can be improved.

[0118] In another example, if the central region of the FOV 750 needs to have a higher scanning resolution, the control device 790 can selectively control the central emitter group 710B to emit a beam with a high pulse repetition rate to obtain a high point cloud density in the central scanning region. To save energy, the control device 790 can further selectively control the two side emitter groups 710A and 710C to emit beams with a low pulse repetition rate.

[0119] Furthermore, the control device 790 can selectively adjust the transmitted orientation and the set position of the plurality of emission groups 710A-C relative to the light scanner (e.g., the movable mirror 720). Thus, the shape and the point cloud density distribution can be customized in the LiDAR system 700. It should be understood that the pulse repetition rate, the shape, and the point cloud density distribution associated with any one of the emitter groups 710A-710C can be configured in any desired manner.

[0120] Figures 8A to 8EFIG. is an example diagram of a transmitter group 800-840 according to some embodiments. In some embodiments, each of the transmitter groups 800-840 can be Figure 7 any one of the multiple transmitter groups 710A-C shown. As Figures 8A to 8E shown, each of the transmitter groups 800-840 includes a plurality of transmitters 812. In some examples, the multiple transmitter groups 800-840 can form multiple transmitter arrays 801-841. Each of the transmitter arrays 801-841 includes a plurality of transmitters 812 that are aligned with each other in at least one of a horizontal dimension and a vertical dimension. Any one of the multiple transmitter arrays 801-841 can include an n×m array; where 1≤n≤100 and 1≤m≤100.

[0121] Figure 8A FIG. is an example diagram of a transmitter group 800 according to one embodiment. The transmitter group 800 includes a transmitter array 801. The transmitter array 801 includes two transmitters 812A and 812B (collectively 812) that are aligned with each other in the horizontal dimension. As Figure 8A shown, the two transmitters 812A and 812B can be semiconductor-based laser sources and / or fiber-based laser sources configured to emit a transmitted beam 813. The transmitter group 800 further includes two optical fibers 814A and 814B arranged in a 1×2 optical fiber array.

[0122] Figure 8B FIG. is an example diagram of another transmitter group 810 according to one embodiment. The transmitter group 810 includes a transmitter array 811. The transmitter array 811 includes three transmitters 812A, 812B, and 812C (collectively 812) that are aligned with each other in the horizontal dimension. As Figure 8B shown, the three transmitters 812A, 812B, and 812C can be semiconductor-based laser sources and / or fiber-based laser sources configured to emit a transmitted beam 813. As Figure 8B shown, the transmitter group 810 further includes three optical fibers 814A, 814B, and 814C arranged in a 1×3 optical fiber array.

[0123] Figure 8C FIG. is an example diagram of another transmitter group 820 according to one embodiment. The transmitter group 820 includes a transmitter array 821. The transmitter array 821 includes four transmitters 812A, 812B, 812C, and 812D (collectively 812) that are aligned with each other in the horizontal dimension. As Figure 8C shown, the four transmitters 812A-D can be semiconductor-based laser sources and / or fiber-based laser sources configured to emit a transmitted beam 813. As Figure 8CAs shown, the transmitter group 820 further includes four optical fibers 814A, 814B, 814C, and 814D arranged in a 1×4 optical fiber array.

[0124] Figure 8D FIG. is a diagram illustrating an example of a transmitter group 830 according to an embodiment. The transmitter group 830 includes a transmitter array 831. The transmitter array 831 includes three transmitters 812A, 812B, and 812C aligned with each other in the vertical dimension. In some embodiments, the transmitter group 830 includes one or more semiconductor-based laser sources configured to emit a transmission beam 813. In some embodiments, the transmitter group 830 includes one or more fiber-based laser sources configured to emit a transmission beam 813.

[0125] Figure 8E FIG. is a diagram illustrating an example of a transmitter group 840 according to an embodiment. The transmitter group 830 includes a transmitter array 841. The transmitter array 841 is a 3×2 array that includes six transmitters 812A-F aligned with each other in the horizontal and vertical dimensions. Figure 8E Only six transmitters 812A-F are illustrated, but it should be understood that more transmitters may be included. Similarly, it should be understood that multiple transmitters may be arranged in an n×m array; where 1≤n≤100 and 1≤m≤100. In some embodiments, the transmitter group 840 includes one or more semiconductor-based laser sources configured to emit a transmission beam 813. In some embodiments, the transmitter group 840 includes one or more fiber-based laser sources configured to emit a transmission beam 813.

[0126] Figure 9 FIG. is a diagram illustrating an example of a transmitter group optically coupled to a collimating lens for guiding a transmission beam according to some embodiments. As Figure 9 shown, the transmitter group 910 includes multiple transmitters configured to emit a transmission beam 940. In some embodiments, the multiple transmitters of the transmitter group 910 form a transmitter array. The transmitter group 910 can be any of the transmitter groups 710A-C shown in Figure 7 and the transmitter groups 800-840 shown in Figures 8A to 8E . As Figure 9 shown, the collimating lens 920 is positioned to be optically coupled to the transmitter group 910 to receive the transmission beam 940. When the transmission beams 940 propagate in free space towards the collimating lens 920, their spatial cross-sectional areas expand. When they reach the collimating lens 920, the transmission beams 940 spatially overlap. As Figure 9As shown, the collimating lens 920 receives the transmitted beam 940 and collimates the transmitted beam to form a collimated transmitted beam 942. Compared with the transmitted beam 940, the collimated beam 942 has a much smaller divergence, which allows them to reach a farther distance with concentrated energy. The collimated transmitted beam 942 can correspond to Figure 7 the transmitted beam 740 shown. By using one collimating lens 920 optically coupled to multiple emitters in the emitter group 910 (e.g., the four emitters shown by four dashed / solid lines in Figure 9 ), the size of the emitter group 910 does not increase too much, thus keeping the LiDAR system compact.

[0127] Figure 10A and Figure 10B Figs. illustrate examples of assemblies 1000 and 1001 for optically coupling multiple emitter groups to multiple collimating lenses and collecting lenses. In each of assemblies 1000 and 1001, there are multiple emitter groups 1010A, 1010B, and 1010C (collectively referred to as emitter group 1010). The emitter group 1010 can be used to implement Figure 7 the emitter group 710 shown, Figures 8A to 8E any one of the emitter groups 800 - 840 shown, and Figure 9 the emitter group 910 shown. As shown in Figure 10A and Figure 10B , the collimating lenses 1020A, 1020B, and 1020C (collectively referred to as collimating lens 1020) are configured to collimate the beams emitted from the multiple emitter groups 1010A - C. One collimating lens 1020 is optically coupled to one emitter group 1010. To implement a LiDAR system with a very compact size, the multiple emitter groups 1010A - C can share a single collecting lens (e.g., the collecting lens 1070 or 1072 shown in Figure 10A and Figure 10B ). The collecting lens corresponds to Figure 7 the collecting lens 770 shown. Compared with the multiple collimating lenses 1020A - C, the collecting lens has a larger light receiving aperture and is configured to collect as much return light as possible. The return light is formed based on the transmitted beams 1042A - C provided by the multiple emitter groups 1010A - C.

[0128] Figure 10A Fig. illustrates that the collecting lens 1070 includes an opening 1071. The opening 1071 can be a rectangular opening, a circular opening, a square opening, a slot, a hole, a slit, or an opening of any other shape. As shown in Figure 10AAs shown, the opening 1071 is formed from the curved front surface to the flat rear surface of the collection lens 1070. In some embodiments, at least one of the plurality of emitter groups 1010A - C is at least partially disposed in the opening 1071 or on one side of the collection lens 1070. As Figure 10A shown, the emitter groups 1010A and 1010C optically coupled to the collimating lenses 1020A and 1020C respectively are disposed at the sides of the collection lens 1070. In some embodiments, the assembly 1000 may further include one or more beam shifting systems coupled to the emitter groups 1010A and / or 1010C. The beam shifting system includes a periscope prism configured to shift the transmitted beam 1042A or 1042C to be positioned within the light receiving aperture of the collection lens 1070.

[0129] As Figure 10A shown, the emitter group 1010B optically coupled to the collimating lens 1020B is disposed in the opening 1071 of the collection lens 1070. Due to the opening 1071, the transmitted beam 1042B can be transmitted through the collection lens 1071 to scan the FOV. The position of the collimating lens 1020B can be configured such that the collimated transmitted beam 1042B is positioned at a selected position within the light receiving aperture of the collection lens 1070 to optimize the collection of the return light. In one embodiment, the opening 1071 is located at or around the center of the light receiving aperture of the collection lens 1070.

[0130] Figure 10B Another example of the assembly 1001 is illustrated, which includes a collection lens 1072 having two openings 1073 and 1074. The openings 1073 and 1074 can be rectangular openings, circular openings, square openings, slots, holes, slits or openings of any other shape. As Figure 10B shown, the emitter group 1010A optically coupled to the collimating lens 1020A is disposed in the opening 1073 of the collection lens 1072. The emitter group 1010B optically coupled to the collimating lens 1020B is disposed in the opening 1074 of the collection lens 1072. Due to the openings 1073 and 1074, the transmitted beams 1042A and 1042B can be transmitted through the collection lens 1072 to scan the FOV. To optimize the collection of the return light, the positions of the collimating lenses 1020A and 1020B can be configured such that the collimated transmitted beams 1042A and 1042B are positioned at selected positions within the light receiving aperture of the collection lens 1072. As Figure 10AAs shown, a transmitter group 1010C optically coupled to a collimating lens 1020C is disposed on one side of a collection lens 1072. In some embodiments, the assembly 1001 may further include a beam shifting system coupled to the transmitter group 1010C to shift the transmitted beam 1042C into the light receiving aperture of the collection lens 1072. Figure 10A and Figure 10B FIGs. illustrate two examples of positioning a collimating lens and an aperture relative to a collection lens. It should be understood that other configurations may be employed for transmitting a beam through or around the collection lens.

[0131] Figures 11A to 11C is a diagram illustrating an example of a plurality of transmitter groups optically coupled to an optical scanner according to some embodiments. As Figures 11A to 11C shown, there are a plurality of transmitter groups 1110A, 1110B, and 1110C (collectively referred to as transmitter group 1110) configured to emit transmitted beams 1140A, 1140B, and 1140C to the optical scanner 1120, respectively. Each transmitter group 1110 includes a plurality of transmitters. One transmitter group 1110 may be used to implement Figure 7 the transmitter group 710 shown in Figures 8A to 8E any one of the transmitter groups 800 - 840 shown in Figure 9 the transmitter group 910 shown in Figures 10A to 10B and the transmitter group 1010 shown in Figures 11A to 11C As shown, the optical scanner 1120 is a movable mirror configured to steer the transmitted beams 1140A - C to the FOV. The optical scanner 1120 is also configured to receive the return light formed based on the steered transmitted beams 1140A - C. Referring back to Figure 7 , the optical scanner 1120 corresponds to the reflecting surface 732 of the movable mirror 720 or the polygon mirror 730 shown in Figure 7 .

[0132] Still referring to Figures 11A to 11C , in some embodiments, the plurality of transmitter groups 1110A - C and the movable mirror of the optical scanner 1120 are optically coupled together such that the transmitted beams 1140A - C emitted by the plurality of transmitter groups 1110A - C can be received by the movable mirror 1120. As Figures 11A to 11C shown, the control device 1190 is configured to selectively control one or more of the plurality of transmitter groups 1110A - C to emit the transmitted beams 1140A - C to the optical scanner 1120. The control device 1190 may be the same as or similar to the control device 790 shown in Figure 7 and / or the control circuit 350 shown in Figure 3 . As Figures 11A to 11CAs shown, multiple emitter groups 1110A - C can be arranged at different positions relative to the optical scanner 1120 such that the scanning areas corresponding to the emitter groups 1110A - C are different. The control device 1190 selectively controls the encoding or modulation scheme of each transmitted beam 1140A - C emitted by one or more of the multiple emitter groups 1110A - C. For example, the transmitted beam 1140A can have amplitude modulation, while the transmitted beam 1140B can have phase modulation. In another example, the encoding of the transmitted beams 1140A - C can be different such that the return light formed based on different transmitted beams can be distinguished based on different encoding schemes. As Figures 11A to 11C shown, the control device 1190 can selectively adjust the transmission orientation and the set position of the multiple emission groups 1110A - C relative to the optical scanner 1120. Thus, a scanning pattern with a customizable shape and point cloud density distribution is obtained. This will be described in further detail below with reference to Figures 12A to 12C further details.

[0133] As Figures 11A to 11C shown, the multiple emitter groups 1110A - C include a first emitter group 1110A, a second emitter group 1110B, and a third emitter group 1110C. The second emitter group 1110B is disposed to the left of the first emitter group 1110A. The third emitter group 1110C is disposed to the right of the first emitter group 1110A. The control device 1190 is configured to control the combination of the three emitter groups 1110A - C that emit the transmitted beams 1140A - C to the optical scanner 1120 to achieve a customized scanning pattern configuration. This will be described in further detail below with reference to Figures 12A to 12C further details.

[0134] In some embodiments, one or more characteristics associated with the multiple emitter groups 1110A - C are configured based on at least one of a vertical FOV requirement or a horizontal FOV requirement. As Figures 11A to 11C shown, the horizontal scale and the vertical scale on the optical scanner 1120 illustrate the relative positions of the transmitted beams 1140A - C corresponding to the FOV. One or more characteristics include the horizontal distance between the multiple emitter groups 1110A - C, the vertical distance between the multiple emitter groups 1110A - C, and the tilt angles θa, θb, and θc associated with each of the multiple emitter groups 1110A - C. As Figures 11A to 11C shown, the tilt angles θa, θb, or θc are the angles between the normal direction of the optical scanner 1120 and the corresponding transmitted beams 1140A, 1140B, or 1140C, respectively. The transmitted beams 1140A - 1140C are emitted from the corresponding emitter groups 1110A - 1110C towards the optical scanner 1120.

[0135] Figure 11AIllustrated in one embodiment, multiple emitter groups 1110A-C have different horizontal positions, different vertical positions, and / or different tilt angles (i.e., a1≠θb1≠θc1). The letters a, b, or c in the subscript represent the tilt angles associated with the corresponding emitter groups 1110A, 1110B, or 1110C. The number 1 in the subscript represents the tilt angle at a specific angular position of the light scanner 1120 as shown in Figure 11A As described above, the light scanner 1120 can be controlled to oscillate, and thus the tilt angle of the light beam 1140 emitted by a specific emitter 1110 at any specific angular position can be different from the tilt angle at another angular position. As shown in Figure 11A The second emitter group 1110B and the third emitter group 1110C are spaced asymmetrically (i.e., θb1≠θc1) from the first emitter group 1110A. The horizontal distances between the multiple emitter groups 1110A-C are configured such that the horizontal FOV that the transmitted light beams 1140A-C emitted from the multiple emitter groups 1110A-C can scan is greater than or different from the horizontal FOV that the transmitted light beam 1140A emitted from a single emitter group 1110A can scan. Similarly, the vertical distances between the multiple emitter groups 1110A-C are configured such that the vertical FOV that the transmitted light beams 1140A-C emitted from the multiple emitter groups 1110A-C can scan is greater than or different from the vertical FOV that the transmitted light beam 1140A emitted from a single emitter group 1110A can scan. The scanning pattern resulting from such a configuration will be described in further detail below with reference to Figure 12A

[0136] Figure 11B Illustrated that the first emitter group 1110A is positioned and / or oriented such that the transmitted light beam 1140A is directed to a position 1122 that is aligned with the central optical axis of the movable mirror of the light scanner 1120. As shown in Figure 11B The position 1122 that is aligned with the central optical axis of the movable mirror of the light scanner 1120 corresponds to the origin of the horizontal dimension of the FOV. Thus, the scanning pattern generated by using the transmitted light beam 1140A emitted by the first emitter group 1110A has a negative scanning range that is substantially the same as the positive scanning range in the horizontal dimension of the FOV. In the configuration shown in Figure 11B The scanning pattern generated by using the transmitted light beam 1140B emitted by the second emitter group 1110B has a negative scanning range that is greater than the positive scanning range in the horizontal dimension of the FOV. The scanning pattern generated by using the transmitted light beam 1140C emitted by the third emitter group 1110C has a negative scanning range that is less than the positive scanning range in the horizontal dimension of the FOV. This will be described in further detail below with reference to Figure 12B

[0137] As shown in Figure 11B ​​As shown, the tilt angles θa2, θb2, and θc2 associated with the multiple emitter groups 1110A-C are configured such that the transmitted light beams 1140A-C emitted from adjacent emitter groups converge. The letters a, b, or c in the subscript indicate the tilt angles associated with the corresponding emitter groups 1110A, 1110B, or 1110C. The number 2 in the subscript indicates the tilt angle at a specific angular position of the optical scanner 1120 shown in Figure 11B In addition, in this example, the second emitter group 1110B and the third emitter group 1110C are symmetrically spaced (i.e., θb2 = θc2) from the first emitter group 1110A. The scanning pattern resulting from such a symmetrically spaced configuration will be described in further detail below with reference to Figure 12B

[0138] Figure 11C Figure 11C FIG. illustrates another example in which the first emitter group 1110A is positioned and / or oriented such that the transmitted light beam 1140A is directed to a position 1122 that is aligned with the central optical axis of the movable mirror of the optical scanner 1120. The tilt angles θa3, θb3, and θc3a associated with the multiple emitter groups 1110A-C are configured such that the transmitted light beams 1140A-C emitted from adjacent emitter groups diverge. The letters a, b, or c in the subscript indicate the tilt angles associated with the corresponding emitter groups 1110A, 1110B, or 1110C. The number 3 in the subscript indicates the tilt angle at a specific angular position of the optical scanner 1120 shown in Figure 11C In the example shown in Figure 11C In this example, the second emitter group 1110B and the third emitter group 1110C are spaced asymmetrically (i.e., θb3 ≠ θc3) from the first emitter group 1110A. The scanning pattern resulting from such an asymmetrically spaced configuration will be described in further detail below with reference to Figure 12C

[0139] Figure 11A In the above example shown in Figure 11A the emitter groups 1110B and 1110c are spaced asymmetrically from the emitter group 1110A and are configured such that the FOV that the transmitted light beams 1140A-C emitted from the multiple emitter groups 1110A-C can scan is greater than or different from the FOV that the transmitted light beam 1140A emitted from the single emitter group 1110A can scan. In the above example shown in Figure 11B the emitter groups 1110B and 1110C are spaced symmetrically from 1110A and are configured (e.g., oriented with a specific pitch, yaw, roll) such that the transmitted light beams 1140A-C converge. In Figure 11CIn the above-described example, the emitter groups 1110B and 1110C are asymmetrically spaced from 1110A and are configured (e.g., oriented with a specific pitch, yaw, roll) such that the transmitted beams 1140A-C diverge. It should be understood that other configurations and positions of the emitter groups 1110A-1110C can be implemented according to different scanning requirements.

[0140] Figures 12A to 12C FIG. is an example diagram illustrating a scan pattern generated by a plurality of emitter groups according to some embodiments. Figures 12A to 12C The illustrated scan patterns 1210A-C are respectively generated by Figures 11A to 11C the plurality of emitter groups 1110A-C shown. As Figures 12A to 12C shown, the shape of the FOV and the point cloud density distribution can be configured based on one or more characteristics associated with the plurality of emitter groups 1110A-C. Referring to Figures 11A to 11C , one or more characteristics include the horizontal distance between the plurality of emitter groups 1110A-C, the vertical distance between the plurality of emitter groups 1110A-C, and the tilt angle associated with each emitter group of the plurality of emitter groups 1110A-C.

[0141] Figure 12A FIG. illustrates an extended FOV in both the horizontal and vertical dimensions generated by the plurality of emitter groups 1110A-C. One or more characteristics associated with the plurality of emitter groups 1110A-C are shown in Figure 11A . As Figure 12A shown, the scan patterns 1210A-C generated by the transmitted beams emitted from two or more of the plurality of emitter groups 1110A-C at least partially overlap. The overlapping region is a high-density point cloud region. The term "overlap" in the present disclosure refers to the overlap between scan patterns, which may or may not correspond to the overlap in the horizontal scan range and / or the vertical scan range. As an example, there may or may not be overlap between two scan patterns having similar horizontal scan ranges, depending on their vertical scan ranges. There may or may not be overlap between two scan patterns having similar vertical scan ranges, depending on their horizontal scan ranges. In another example, two scan patterns having similar horizontal scan ranges and similar vertical scan ranges can have overlap between them.

[0142] As Figure 12A shown, the scan patterns 1210B and 1210C are asymmetric because the second emitter group 1110B and the third emitter group 1110C are asymmetrically spaced from Figure 11A the first emitter group 1110A shown.

[0143] As Figure 12AAs shown, each of the scan patterns 1210A, 1210B, or 1210C generated by a single emitter group is a limited FOV. By using multiple emitter groups set at different positions with the same / different orientations relative to each other, an extended FOV can be obtained based on the combination of the limited FOVs. The horizontal FOV that the transmitted light beams emitted from two or more of the multiple emitter groups can scan is greater than or different from the horizontal FOV that the transmitted light beam emitted from a single emitter group among the multiple emitter groups can scan. Similarly, the vertical FOV that the transmitted light beams emitted from two or more of the multiple emitter groups can scan is greater than or different from the vertical FOV that the transmitted light beam emitted from a single emitter group among the multiple emitter groups can scan.

[0144] Figure 12B FIG. illustrates another example of the scan patterns 1210A-C generated by the multiple emitter groups 1110A-C. One or more characteristics associated with the multiple emitter groups 1110A-C are shown in Figure 11B FIG. Referring to Figure 11B FIG., the tilt angles associated with each of the multiple emitter groups 1110A-C are configured such that the transmitted light beams 1140A-C emitted from adjacent emitter groups converge. Thus, Figure 12B FIG. shows that there is an overlap between the scan patterns 1210A and 1210B, and there is another overlap between the scan patterns 1210A and 1210C. Additionally, in some examples, there may be a high-density point cloud region at the center of the horizontal FOV that is overlapped by the three scan patterns 1210A-C. In other examples, the scan patterns 1210A and 1210C do not overlap.

[0145] As shown in Figure 12B FIG., the scan patterns 1210B and 1210C are symmetric because the second emitter group 1110B and the third emitter group 1110C are symmetrically spaced from the first emitter group 1110A as shown in Figure 11B FIG. As shown in Figure 12B FIG., the scan pattern 1210A generated by using the transmitted light beam emitted from the first emitter group 1110A has a negative scan range that is substantially the same as the positive scan range in the horizontal dimension of the FOV. This is because the first emitter group 1110A is set at a position aligned with the central optical axis of the movable mirror of the optical scanner. The scan pattern 1210B generated by using the transmitted light beam emitted from the second emitter group 1110B has a negative scan range that is greater than the positive scan range in the horizontal dimension of the FOV. The scan pattern 1210C generated by using the transmitted light beam emitted from the third emitter group 1110C has a negative scan range that is less than the positive scan range in the horizontal dimension of the FOV.

[0146] Figure 12CIllustrated is another example of scan patterns 1210A-C generated by a plurality of emitter groups 1110A-C. One or more characteristics associated with the plurality of emitter groups 1110A-C are shown in Figure 11C . Referring to Figure 11C , the tilt angles associated with each of the plurality of emitter groups 1110A-C are configured such that the transmitted light beams 1140A-C emitted from adjacent emitter groups diverge. Thus, Figure 12C it is shown that there may be no overlap between the scan patterns 1210A-C.

[0147] Figure 12B and Figure 12C illustrate configuring the overlap of the scan patterns by adjusting the tilt angles associated with the plurality of emitter groups 1110A-C to obtain a high point cloud density.

[0148] As Figure 12C shown, the scan patterns 1210B and 1210C are asymmetric in Figure 12C because the second emitter group 1110B and the third emitter group 1110C are spaced asymmetrically from the first emitter group 1110A, as Figure 11C shown. Similar to Figure 12B , the scan pattern 1210A has a negative scan range that is substantially the same as the positive scan range in the horizontal dimension of the FOV shown in Figure 12C because the first emitter group 1110A is disposed at a position aligned with the central optical axis of the movable mirror of the optical scanner. Also as Figure 12C shown, in some examples, the emitter groups (e.g., 1110A-1110C) are configured such that the scan pattern 1210B has a negative scan range that is greater than the positive scan range in the horizontal dimension of the FOV. The scan pattern 1210C is entirely in the positive horizontal angle region. In some examples, the scan pattern 1210B generated by using the transmitted light beam emitted by the second emitter group 1110B may be entirely in the negative angle region. The scan pattern 1210C generated by using the transmitted light beam emitted by the third emitter group 1110C has a negative scan range that is less than the positive scan range in the horizontal dimension of the FOV. Figure 12CNone of the scan patterns 1210A - 1210C overlap, while they may have the same or similar vertical scan ranges. In other embodiments, the scan patterns 1210A - 1210C may be different vertical scan ranges and they may not overlap. For example, the emitter groups (e.g., 1110A - 1110C) may be configured (positioned and / or oriented) such that the scan pattern 1210B covers a different vertical scan range than the scan pattern 1210A and has no overlap with the scan pattern 1210A in the vertical and / or horizontal directions. The scan pattern 1210B may or may not be entirely within the negative scan range. Similarly, the emitter groups (e.g., 1110A - 1110C) may be configured (positioned and / or oriented) such that the scan pattern 1210C covers a different vertical scan range than the scan pattern 1210A and has no overlap with the scan pattern 1210A in the vertical and / or horizontal directions. The scan pattern 1210C may or may not be entirely within the positive scan range.

[0149] The above description illustrates that an extended FOV (e.g., greater than 120 degrees) can be obtained using multiple emitter groups (e.g., Figures 11A to 11C 1110A - C as shown) disposed at different positions relative to the optical scanner 1120, thereby increasing the scan range of the LiDAR system and increasing the scan resolution in at least some overlapping regions. Additionally, the shape of the scan pattern and the point cloud density distribution are highly customizable. This enables the LiDAR system to meet complex sensing requirements. Figures 12A to 12C Only three examples of scan patterns generated by multiple emitter groups are illustrated, but it should be understood that other configurations of the scan patterns can be obtained by adjusting the tilt angles associated with the multiple emitter groups.

[0150] Figure 13 A flowchart showing an exemplary method 1300 for controlling a LiDAR system according to some embodiments is illustrated. The LiDAR system includes an optical scanner (e.g., Figure 7 the movable mirror 720 and the polygon mirror 730 as shown, and Figures 11A to 11C the optical scanner 1120 as shown) and multiple emitter groups (e.g., Figure 7 the emitter groups 710A - C as shown, and Figures 11A to 11C the emitter groups 1110A - C as shown) that can be optically coupled to the optical scanner.

[0151] In step 1310 of method 1300, the control device selectively controls one or more of the multiple emitter groups to emit transmitted light beams towards the optical scanner. At least two of the multiple emitter groups are disposed at different positions relative to the optical scanner such that the scan regions corresponding to the at least two emitter groups are different.

[0152] In some embodiments, selectively controlling one or more of a plurality of emitter groups includes controlling at least one of the following: an on / off state of each emitter group among one or more of the plurality of emitter groups; a pulse repetition rate of each transmitted light beam emitted by one or more of the plurality of emitter groups; a power level of each transmitted light beam emitted by one or more of the plurality of emitter groups; a wavelength of each transmitted light beam emitted by one or more of the plurality of emitter groups; an encoding or modulation scheme of each transmitted light beam emitted by one or more of the plurality of emitter groups; and a combination of emitter groups that emit transmitted light beams toward an optical scanner. In some embodiments, selectively controlling one or more of the plurality of emitter groups is based on at least one of a predetermined setting or a vehicle sensing requirement.

[0153] In step 1320 of method 1300, the optical scanner turns the transmitted light beam vertically and horizontally to the FOV. In step 1330 of method 1300, the optical scanner receives the returned light formed based on the turned transmitted light beam.

[0154] The foregoing specification is to be understood as illustrative and exemplary in every respect and not restrictive, and the scope of the invention disclosed herein is not determined by the specification but by the claims as interpreted in accordance with all that is permitted under patent law. It should be understood that the embodiments shown and described herein are merely illustrative of the principles of the invention and that those skilled in the art may make various modifications without departing from the scope and spirit of the invention. Various other combinations of features may be implemented by those skilled in the art without departing from the scope and spirit of the invention.

Claims

1. A system for optical ranging and detection (LiDAR), the system comprising: An optical scanner; A plurality of emitter groups, the plurality of emitter groups being optically coupled to the optical scanner, each emitter group of the plurality of emitter groups including a plurality of emitters, wherein at least two emitter groups of the plurality of emitter groups are disposed at different positions relative to the optical scanner such that the scanning regions corresponding to the at least two emitter groups are different; A control device configured to selectively control one or more of the plurality of emitter groups to emit a transmitted beam towards the optical scanner, wherein the optical scanner is configured to: Vertically and horizontally steer the transmitted beam into a field of view (FOV), and Receive the return light formed based on the steered transmitted beam.

2. The system according to claim 1, the system further comprising a housing, wherein the optical scanner and the plurality of emitter groups are disposed within the housing.

3. The system according to claim 1 or 2, wherein, The optical scanner includes: A galvanometer mirror and a polygon mirror, the galvanometer mirror being configured to direct the transmitted beam to the polygon mirror, wherein: The galvanometer mirror facilitates scanning of the transmitted beam along a first dimension of the FOV, and The polygon mirror facilitates scanning of the transmitted beam along a second dimension of the FOV, the second dimension being orthogonal to the first dimension.

4. The system according to any one of claims 1 to 3, wherein, The plurality of emitter groups and the movable mirror of the optical scanner are optically coupled together such that the transmitted beam emitted by the plurality of emitter groups can be received by the movable mirror.

5. The system according to claim 4, wherein, The transmitted beam emitted by the plurality of emitter groups is optically coupled to one or more collimating lenses or lens groups.

6. The system according to any one of claims 1 to 5, the system further comprising a collection lens, wherein one or more of the plurality of emitter groups are at least partially disposed within one or more openings of the collection lens or on the side of the collection lens.

7. The system according to any one of claims 1 to 6, wherein, One or more characteristics associated with the plurality of emitter groups are configured based on at least one of a vertical FOV requirement or a horizontal FOV requirement.

8. The system according to claim 7, wherein, The one or more characteristics include a horizontal distance between the plurality of emitter groups, a vertical distance between the plurality of emitter groups, and an inclination angle associated with each emitter group of the plurality of emitter groups.

9. The system according to claim 8, wherein, The horizontal distance between the plurality of emitter groups is configured such that the horizontal FOV that can be scanned by the transmitted beam emitted by two or more of the plurality of emitter groups is greater than or different from the horizontal FOV that can be scanned by the transmitted beam emitted by one emitter group of the plurality of emitter groups.

10. The system according to claim 8 or 9, wherein, The vertical distance between the plurality of emitter groups is configured such that the vertical FOV that can be scanned by the transmitted light beams emitted from two or more of the plurality of emitter groups is greater than or different from the vertical FOV that can be scanned by the transmitted light beam emitted from one of the plurality of emitter groups.

11. The system according to any one of claims 8 to 10, wherein, the tilt angle associated with each of the plurality of emitter groups is configured such that the transmitted light beams emitted from adjacent emitter groups converge.

12. The system according to any one of claims 8 to 11, wherein, the tilt angle associated with each of the plurality of emitter groups is configured such that the transmitted light beams emitted from adjacent emitter groups diverge.

13. The system according to any one of claims 1 to 12, wherein, the plurality of emitter groups includes a first emitter group, a second emitter group, and a third emitter group, wherein the second emitter group is disposed to the left of the first emitter group, and wherein the third emitter group is disposed to the right of the first emitter group.

14. The system according to claim 13, wherein, the second emitter group and the third emitter group are symmetrically spaced apart from the first emitter group.

15. The system according to claim 13, wherein, the second emitter group and the third emitter group are asymmetrically spaced apart from the first emitter group.

16. The system according to any one of claims 13 to 15, wherein, the transmitted light beam emitted from the first emitter group is guided to a position aligned with the central optical axis of the movable mirror of the optical scanner, such that the negative scan range of the scan pattern generated by using the transmitted light beam emitted from the first emitter group is substantially the same as the positive scan range in the horizontal dimension of the FOV.

17. The system according to any one of claims 13 to 16, wherein, the negative scan range of the scan pattern generated by using the transmitted light beam emitted from the second emitter group is greater than the positive scan range in the horizontal dimension of the FOV.

18. The system according to any one of claims 13 to 17, wherein, the negative scan range of the scan pattern generated by using the transmitted light beam emitted from the third emitter group is less than the positive scan range in the horizontal dimension of the FOV.

19. The system according to any one of claims 13 to 18, wherein, each of the first emitter group, the second emitter group, and the third emitter group includes a 1×4 fiber optic array.

20. The system according to any one of claims 13 to 19, wherein, the first emitter group includes a 1×4 fiber optic array, and wherein each of the second emitter group and the third emitter group includes a 1×2 fiber optic array or a 1×3 fiber optic array.

21. The system according to any one of claims 1 to 20, wherein, at least two of the plurality of emitter groups include different types of laser sources.

22. The system according to any one of claims 1 to 21, wherein, the plurality of emitter groups includes one or more semiconductor-based laser sources and / or one or more fiber-based laser sources.

23. The system according to any one of claims 1 to 22, wherein, at least two of the plurality of emitter groups are configured to emit transmitted light beams having different wavelengths.

24. The system according to any one of claims 1 to 23, wherein, the plurality of emitter groups includes a plurality of emitter arrays, and each emitter array in the emitter arrays includes a plurality of emitters aligned with each other in at least one of a horizontal dimension and a vertical dimension.

25. The system according to claim 24, wherein, any one of the plurality of emitter arrays includes an n×m array, where 1≤n≤100 and 1≤m≤100.

26. The system according to any one of claims 1 to 25, wherein, the control device is configured to selectively control one or more of the plurality of emitter groups by controlling at least one of the following: the on / off state of each emitter group in one or more of the plurality of emitter groups; the pulse repetition rate of each transmitted light beam emitted by the one or more of the plurality of emitter groups; the power level of each transmitted light beam emitted by the one or more of the plurality of emitter groups; the wavelength of each transmitted light beam emitted by the one or more of the plurality of emitter groups; the coding or modulation scheme of each transmitted light beam emitted by the one or more of the plurality of emitter groups; and the combination of emitter groups that emit transmitted light beams towards the optical scanner.

27. The system according to any one of claims 1 to 26, wherein, the control device is configured to selectively control one or more of the plurality of emitter groups based on one or more sensing requirements.

28. The system according to any one of claims 1 to 27, wherein, the scanning patterns generated by transmitted light beams emitted from two or more of the plurality of emitter groups at least partially overlap.

29. A vehicle, the vehicle including the system for optical ranging and detection (LiDAR) according to any one of claims 1 to 28.

30. A method for controlling an optical ranging and detection (LiDAR) system, the method including an optical scanner and a plurality of emitter groups capable of being optically coupled to the optical scanner, the method including: selectively controlling, by a control device, one or more of the plurality of emitter groups to emit transmitted light beams towards the optical scanner, wherein at least two of the plurality of emitter groups are disposed at different positions relative to the optical scanner such that the scanning areas corresponding to the at least two emitter groups are different; vertically and horizontally steering, by the optical scanner, the transmitted light beams into a field of view (FOV), and Return light formed based on the steered transmitted light beam is received by the light scanner.

31. The method according to claim 30, wherein selectively controlling one or more of the plurality of emitter groups includes controlling at least one of the following: the on / off state of each emitter group of one or more of the plurality of emitter groups; the pulse repetition rate of each transmitted light beam emitted by one or more of the plurality of emitter groups; the power level of each transmitted light beam emitted by one or more of the plurality of emitter groups; the wavelength of each transmitted light beam emitted by one or more of the plurality of emitter groups; the coding or modulation scheme of each transmitted light beam emitted by one or more of the plurality of emitter groups; and the combination of emitter groups that emit transmitted light beams towards the light scanner.

32. The method according to claim 30 or 31, wherein selectively controlling one or more of the plurality of emitter groups is based on at least one of a predetermined setting or a vehicle sensing requirement.

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