Systems and methods for modifying LIDAR field of view

Abstract

This disclosure relates to systems, methods, and vehicles that facilitate optical detection and ranging (LIDAR or lidar) systems utilizing "dead zones," where the lidar system is directed toward a supporting structure or another "uninteresting" feature. In this scenario, the light pulse can be redirected to a feature of greater interest in the environment. One example system includes a lidar system configured to emit a light pulse into the system's environment to provide information indicating objects within a default field of view. The system also includes a reflective surface optically coupled to the lidar system. The reflective surface is configured to reflect at least a portion of the emitted light pulse to provide an extended field of view. The lidar system is further configured to provide information indicating objects within the extended field of view.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Patent Application No. 16 / 569,872, filed September 13, 2019, the contents of which are incorporated herein by reference. Background Technology

[0003] Traditional optical detection and ranging (LIDAR or lidar) systems utilize a light emitter (e.g., a laser diode) to emit light pulses into the environment. The emitted light pulses interact with objects in the environment (e.g., are reflected from objects in the environment) and can be received by a receiver (e.g., a photodetector) in the LiDAR system. Ranging information about objects in the environment can be determined based on the time difference between the initial time of the emitted light pulse and the subsequent time of receiving the reflected light pulse. Summary of the Invention

[0004] This disclosure generally relates to optical detection and ranging (LIDAR or lidar) systems that can be configured to acquire information about their environment. Such lidar devices can be implemented in vehicles such as autonomous and semi-autonomous cars, trucks, motorcycles, and other types of vehicles capable of moving within their respective environments.

[0005] In a first aspect, a system is provided. The system includes a lidar system configured to emit light pulses into the environment of the system to provide information indicating objects within a default field of view. The lidar system includes a rotatable base configured to rotate about a first axis and a rotatable mirror coupled to the rotatable base. The rotatable mirror is configured to rotate about a second axis. The lidar system also includes at least one light source configured to emit light pulses. The emitted light pulses interact with the environment to provide a returning light pulse. The lidar system further includes at least one detector configured to detect at least a portion of the returning light pulse. The system also includes a reflective surface optically coupled to the lidar system. The reflective surface is configured to reflect at least a portion of the emitted light pulse to provide an extended field of view. The lidar system is also configured to provide information indicating objects within the extended field of view.

[0006] In a second aspect, a method is provided. The method includes causing at least one light source of a lidar system to emit light pulses toward a default field of view and a reflective surface configured to reflect a portion of the light pulses toward an extended field of view. The lidar system includes a rotatable base configured to rotate about a first axis and a rotatable mirror coupled to the rotatable base. The rotatable mirror is configured to rotate about a second axis. The lidar system also includes at least one light source configured to emit light pulses. The emitted light pulses interact with the environment to provide a return light pulse. The lidar system further includes at least one detector configured to detect at least a portion of the return light pulse. The emitted light pulse interacts with the environment of the lidar system to provide a return light pulse. The method also includes receiving at least a first portion of the return light pulse from the default field of view as a first detection light signal. The method further includes receiving at least a second portion of the return light pulse from the extended field of view as a second detection light signal. Furthermore, the method includes transmitting point cloud data, wherein the point cloud data is based on the first and second detection light signals and indicates objects within the default and extended fields of view.

[0007] In a third aspect, a vehicle is provided. The vehicle includes a lidar system configured to emit light pulses into the environment of the vehicle to provide information indicating objects within a default field of view. The lidar system includes a rotatable base configured to rotate about a first axis and a rotatable mirror coupled to the rotatable base. The rotatable mirror is configured to rotate about a second axis. The lidar system also includes at least one light source configured to emit light pulses. The emitted light pulses interact with the environment to provide a returning light pulse. The lidar system further includes at least one detector configured to detect at least a portion of the returning light pulse. The vehicle further includes a reflective surface optically coupled to the lidar system. The reflective surface is configured to reflect at least a portion of the emitted light pulse to provide an extended field of view. The lidar system is also configured to provide information indicating objects within the extended field of view.

[0008] Other aspects, embodiments, and implementations will become apparent to those skilled in the art upon reading the following detailed description and with appropriate reference to the accompanying drawings. Attached Figure Description

[0009] Figure 1 The diagram illustrates a system according to an example embodiment.

[0010] Figure 2A The illustration shows a lidar system according to an example embodiment.

[0011] Figure 2B The illustration shows a lidar system according to an example embodiment.

[0012] Figure 2C The illustration is based on an example embodiment. Figure 2A It is part of the lidar system.

[0013] Figure 2D The illustration shows a lidar system according to an example embodiment.

[0014] Figure 3 The diagram illustrates a system according to an example embodiment.

[0015] Figure 4 The diagram illustrates a system according to an example embodiment.

[0016] Figure 5A The illustration shows a vehicle according to an example embodiment.

[0017] Figure 5B The illustration shows a vehicle according to an example embodiment.

[0018] Figure 5C The illustration shows a vehicle according to an example embodiment.

[0019] Figure 5D The illustration shows a vehicle according to an exemplary embodiment.

[0020] Figure 5E The illustration shows a vehicle according to an example embodiment.

[0021] Figure 6 The illustration depicts an operational scenario based on an example embodiment.

[0022] Figure 7 The illustration shows a method according to an example embodiment. Detailed Implementation

[0023] This document describes example methods, devices, and systems. It will be understood that the terms “example” and “exemplary” as used herein mean “example, instance, or illustration.” Any embodiment or feature described herein as an “example” or “exemplary” is not necessarily to be construed as being more preferred or advantageous than other embodiments or features. Other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein.

[0024] Therefore, the exemplary embodiments described herein are not intended to be limiting. As generally described herein and shown in the accompanying drawings, aspects of this disclosure can be arranged, replaced, combined, separated, and designed in a variety of different configurations, all of which are considered herein.

[0025] Furthermore, unless the context otherwise suggests, the features illustrated in each figure can be used in combination with each other. Therefore, the figures should generally be considered as aspects of one or more overall embodiments, and it should be understood that not all illustrated features are necessary for every embodiment.

[0026] I. Overview

[0027] Autonomous and semi-autonomous vehicles can navigate using 3D lidar systems by mapping their environment based on lidar point maps. However, traditional lidar systems have "blind spots," such as a limited range of height that it can see downwards, which may leave unscanned cones or other areas below the lidar.

[0028] An example lidar system includes a rotatable mirror assembly and an optical cavity. The optical cavity includes at least one light emitter device, at least one photodetector, and corresponding optical elements (e.g., lenses). The light emitter device can emit light pulses along the light emission axis that interact with the rotatable mirror assembly, such that the light pulses are redirected into the environment. The light pulses reflected back to the lidar from the environment can be received by the photodetector along the light receiving axis to determine the distance to a target (range measurement) and used to form a point cloud representing the distance determination. In some embodiments, the light pulses can be emitted through two windows located on opposite sides of the lidar system housing. While some embodiments may describe sensing devices utilizing light pulses, it will be understood that other types of three-dimensional sensing techniques utilizing continuous-wave light (e.g., continuous-wave time-of-flight (TOF)) systems are possible and considered.

[0029] In an example embodiment, the optical cavity may be coupled to a rotatable base configured to rotate about a substantially perpendicular first rotation axis. The mirror assembly may be configured to rotate about a second rotation axis that intersects with and is substantially perpendicular to the first rotation axis.

[0030] In such a lidar system, fragments of the lidar point cloud can fall on supporting structures (e.g., structures supporting the lidar system on a vehicle) or other features to which the lidar is applied that are not of interest. For example, in some scenarios, some light pulses can be directed to static (e.g., invariant) or previously characterized portions of the lidar's environment. As described herein, useful point cloud information can be recovered from these "uninterested" light pulses by redirecting them to different parts of the environment using reflective surfaces or mirrors. As described herein, the term "point cloud" can include visualizations of ranging information provided by the lidar and / or the raw ranging data itself. It will be understood that in some embodiments, such ranging data does not need to be stored in the lidar device itself, and such visualizations do not need to be provided by the lidar device itself.

[0031] The system and method described in this paper can utilize scanners to examine "blind spots" in vehicle or supporting structures. In such scenarios, light pulses can be redirected to features of interest in the environment.

[0032] The lidar system disclosed herein can be used in or in conjunction with machine vision and / or perception applications. In some embodiments, the lidar system can be used in transportation applications (e.g., semi-autonomous or fully autonomous vehicles) or in applications related to robotics, security, surveying, agriculture, mining, construction, maritime transport, UAVs, and / or warehousing.

[0033] II. Example System

[0034] Figure 1 The illustration depicts a system 100 according to an example embodiment. System 100 includes a lidar system 200 configured to emit light pulses into the system's environment to provide information indicating objects within a default field of view 102. System 100 also includes a reflective surface 180 optically coupled to the lidar system 200. The reflective surface 180 is configured to reflect at least a portion of the emitted light pulses to provide an extended field of view 182. The lidar system 200 is also configured to provide information indicating objects within the extended field of view 182.

[0035] Although the lidar system 200 is described herein as a laser-based ranging system, it will be understood that other types of 3D sensors can be utilized in the system 100. For example, the system 100 can be used with another type of laser time-of-flight system, a stereo camera, or a camera with a texture projector.

[0036] In some example embodiments, the lidar system 200 may include a rotatable base 110 configured to rotate about a first axis. The rotatable base 110 may include or be coupled to a base actuator 112. In some embodiments, the base actuator 112 may be a brushless motor, a direct current (DC) motor, or another type of rotary actuator. In some examples, the rotatable base 110 may be configured to rotate about the first axis at a speed between 200 revolutions per minute (RPM) and 800 RPM. It will be understood that the rotatable base 110 may operate at other speeds. In some embodiments, the base actuator 112 may be controlled by a controller 150 to rotate at a desired speed. In some embodiments, the lidar system 200 does not need to include a rotatable base. In this scenario, one or more elements of the lidar system 200 may be arranged relative to the first axis. However, in this case, the elements of the lidar system 200 do not need to rotate about the first axis. Therefore, in such embodiments, the lidar system 200 can be used for line scan applications and other possibilities.

[0037] The lidar system 200 also includes a mirror assembly 130. The mirror assembly 130 is configured to rotate about a second axis. In this scenario, the second axis can be substantially perpendicular to the first axis (e.g., within a vertical range of 0 to 10 degrees). In some embodiments, the mirror assembly 130 includes a plurality of reflective surfaces 132. Furthermore, the mirror assembly 130 may include a shaft 134 and a polygon mirror configured to mount the plurality of reflective surfaces 132. The mirror assembly 130 may also include a mirror actuator 136, which may be a brushless motor, a DC motor, or other type of rotary actuator. In this case, the mirror actuator 136 is coupled to the shaft 134. In some embodiments, the mirror actuator 136 may be configured to rotate the polygon mirror about the second axis at speeds between 20,000 RPM and 40,000 RPM. It will be understood that the mirror actuator 136 can operate at various speeds or desired speeds, which can be controlled by the controller 150.

[0038] In this scenario, the plurality of reflective surfaces 132 may include three reflective surfaces arranged symmetrically about a second axis, such that at least a portion of the mirror assembly 130 has a prism shape. It will be understood that the mirror assembly 130 may include more or fewer than three reflective surfaces. Therefore, the mirror assembly 130 may be shaped as a multifaceted prism with more or fewer than three reflective surfaces. For example, the mirror assembly 130 may have four reflective surfaces. In this scenario, the mirror assembly 130 may have a square or rectangular cross-section.

[0039] The lidar system 200 further includes an optical cavity 120 coupled to a rotatable base 110. In this configuration, the optical cavity 120 includes a photodetector 122 and a photodetector lens 124 arranged to define a light-receiving axis. Thus, the arrangement of the photodetector 122 and the photodetector lens 124 provides a light-receiving axis. In some embodiments, the photodetector 122 includes a silicon photomultiplier (SiPM). However, other types of photodetectors, such as avalanche photodiodes (APDs), are also contemplated. Furthermore, although the photodetector 122 is described herein in the singular, it will be understood that systems including multiple photodetectors, such as focal plane arrays, are also possible and considered.

[0040] In an example embodiment, photodetector 122 may provide an output signal to controller 150. For example, the output signal may include information indicating the time of flight of a given light pulse toward a given portion of the ambient field of view. Additionally or alternatively, the output signal may include information indicating at least a portion of a ranging map or point cloud of the environment.

[0041] The lidar system 200 also includes a light emitter device 126 and a light emitter lens 128 arranged to define a light emission axis. The light emitter device 126 may include a laser diode or another type of light emitter. In some embodiments, the light emitter device 126 may be coupled to a laser pulse generator circuit operable to cause the light emitter device 126 to emit one or more laser pulses. In this scenario, the laser pulse generator circuit may be coupled to a trigger source, which may include a controller 150. The light emitter device 126 may be configured to emit infrared laser light (e.g., with a wavelength between 800 and 1600 nanometers). However, other wavelengths of light are also possible and considered. Furthermore, it will be understood that sensing techniques utilizing non-pulsed (e.g., continuous wave) illumination are also conceivable. For example, frequency modulated continuous wave (FM-CW) and continuous wave time-of-flight (CW-TOF) systems are within the scope of this disclosure.

[0042] In some embodiments, the light emitter device 126 is configured to emit light pulses (via light emitter lens 128) that interact with the mirror assembly 130, such that the light pulses are redirected to the environment (e.g., the external environment of the vehicle). In this case, at least a portion of the light pulses is reflected back to the lidar system 200 and received by the photodetector 122 (via photodetector lens 124) to determine at least one of ranging or point cloud.

[0043] At least one light source (e.g., light emitter device 126) of the lidar system 200 can be configured to emit light pulses. The emitted light pulses interact with the environment to provide a return light pulse. At least one detector (e.g., photodetector 122) of the lidar system 200 can be configured to detect at least a portion of the return light pulse.

[0044] The lidar system 200 includes a controller 150. The controller 150 includes at least one of a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). Additionally or alternatively, the controller 150 may include one or more processors 152 and a memory 154. The one or more processors 152 may be a general-purpose processor or a special-purpose processor (e.g., a digital signal processor, etc.). The one or more processors 152 may be configured to execute computer-readable program instructions stored in the memory 154. Thus, the one or more processors 152 can execute program instructions to provide at least some of the functions and operations described herein.

[0045] Memory 154 may include or take the form of one or more computer-readable storage media that can be read or accessed by one or more processors 152. The one or more computer-readable storage media may include volatile and / or non-volatile storage components, such as optical, magnetic, organic, or other memory or disk storage, which may be integrated wholly or partially with at least one of the one or more processors 152. In some embodiments, memory 154 may be implemented using a single physical device (e.g., a single optical, magnetic, organic, or other memory or disk storage unit), while in other embodiments, memory 154 may be implemented using two or more physical devices.

[0046] As described above, memory 154 may include computer-readable program instructions relating to the operation of lidar system 200. Thus, memory 154 may include program instructions to perform or facilitate some or all of the functions described herein.

[0047] As an example, the operation may include causing at least one light source (e.g., light emitter device 126) to emit one or more light pulses.

[0048] The operation may additionally include receiving at least a first portion of the returned light pulse from the default field of view 102 as a first detection light signal.

[0049] The operation may also include receiving at least a second portion of the returned optical pulse from the extended field of view 182 as a second detection optical signal.

[0050] The operation also includes determining a point cloud indicating objects within the default field of view 102 and the extended field of view 182 based on the first and second detection light signals.

[0051] Additionally, the operation may include receiving a reflection map. For example, the reflection map may include reflection information about how the reflecting surface 180 reflects light pulses into the extended field of view 182. In this scenario, the point cloud is further determined based on the reflection map.

[0052] As an example embodiment, the reflection information may include at least one of the angle of the reflecting surface 180, the orientation or orientation of the reflecting surface 180, or the surface curvature of the reflecting surface 180. Additionally or alternatively, the reflection information may include a lookup table (LUT). In this scenario, the LUT may include information indicating the default light pulse emission vector and the reflected light pulse emission vector.

[0053] In various embodiments, the lidar system 200 includes a housing 160 having a plurality of optical windows 162. The optical windows 162 may be substantially transparent to the wavelength of light, such as the emitted light pulse. For example, the optical windows 162 may comprise a transparent material configured to transmit the emitted light pulse with a transmittance greater than 80%. In some embodiments, the housing 160 may comprise two elongated optical windows. The optical windows 162 may be arranged on substantially opposing surfaces of the housing 160. In this scenario, the light pulse can be emitted into the environment via optical transmission through the plurality of optical windows 162.

[0054] In some embodiments, the lidar system 200 may include a prismatic lens 140 configured to refract light pulses. The prismatic lens 140 may include optical elements (e.g., prisms). In some embodiments, the prismatic lens 140 may cause light emitted from an optical cavity to be refracted at an angle different from the axis of the optical cavity. In this way, the optical axis of the beam exiting the cavity itself can be decoupled from the angle of the optical cavity. Using one or more prismatic lenses 140 can provide an asymmetric shifted field of view without having to adjust the optical cavity angle by the same amount. Therefore, the prismatic lens 140 can provide flexibility for a smaller package size. For example, in some embodiments, the optical cavity 120 may remain substantially perpendicular, but the beam emitted from the optical cavity 120 may be angled. Therefore, using a prismatic lens for the optical cavity 120 can provide the benefit of an asymmetric field of view without widening or otherwise physically rearranging the space occupied by the optical cavity 120. In an example embodiment, the prismatic lens 140 may replace the light emitter lens 128. In other embodiments, a prismatic lens 140 may be used in addition to the light emitter lens 128.

[0055] In some embodiments, the prismatic lens 140 may be used in place of the photodetector lens 124, or in combination with the photodetector lens 124. For example, the prismatic lens 140 may be used along the light receiving axis 125 to modify the field of view from which light pulses can be received.

[0056] Additionally or alternatively, light pulses emitted or transmitted through the multiple optical windows 162 can form an asymmetric light emission pattern in the environment. For example, light pulses emitted through a first window of the multiple windows are emitted within a first emission angle range, and light pulses emitted through a second window of the multiple windows are emitted within a second emission angle range, wherein the asymmetric light emission pattern is provided by the difference between the first emission angle range and the second emission angle range.

[0057] In some embodiments, the extended field of view 182 and the default field of view 102 do not completely overlap. For example, the default field of view 102 may include an angled annular region substantially centered on a first axis of the lidar system 200. In a scene where the first axis is perpendicular to the horizon (e.g., vertically), the default field of view 102 may include a pitch angle range between 2 degrees above the horizon and 18 degrees below the horizon. It will be understood that other orientations, geometries, and shapes of the default field of view 102 are possible and considered.

[0058] The extended field of view 182 may include a region that is downward and / or upward relative to a first axis direction of the lidar system 200. In some embodiments, the extended field of view 182 includes a region that does not extend concurrently with the default field of view 102. In such scenarios, the extended field of view 182 can provide a larger overall area in which the lidar system 200 can detect objects. For example, the default field of view 102 may define at least one blind zone. In such scenarios, the extended field of view 182 may overlap with at least a portion of the at least one blind zone.

[0059] Additionally or alternatively, the extended field of view 182 may include a region that extends together with the default field of view. In this scenario, the common extension of the extended field of view 182 and the default field of view 102 can provide higher rate and / or higher resolution object detection through the lidar system 200.

[0060] In some embodiments, the reflective surface 180 may include at least one of a plane mirror, a convex mirror, a concave mirror, or an array of faceted mirrors. Other types of reflective materials and / or surfaces are possible and considered. In some embodiments, the reflective surface 180 may include a plane mirror having a flatness between λ and λ / 100, as measured by optical interferometry, wherein the light pulses emitted by the light emitting device 126 include a wavelength λ.

[0061] In various embodiments, the lidar system 200 may include at least one baffle 170. In this scenario, the at least one baffle 170 may be configured to reduce stray light within the optical cavity 120. In an example embodiment, the baffle 170 may include an opaque material disposed between the light receiving axis and the light emitting axis.

[0062] The lidar system 200 also includes at least one beam blocker 174. The beam blocker 174 may be optically opaque and may be configured to block beams from being emitted toward the optical window 162 and / or toward the environment. In some embodiments, the beam blocker 174 may be disposed within the housing 160, substantially opposite the optical cavity 120.

[0063] When light emitted from optical cavity 120 interacts with a corner of mirror assembly 130 (e.g., at the intersection between two different reflective surfaces 132), the light is split into two parts, one emitted forward (e.g., toward a first optical window) and the other emitted backward (e.g., toward a second optical window). To avoid a blurred lidar signal due to the two emitted pulses, beam blocker 174 can be positioned near the top of the field of view to block at least one of the two beams from being emitted toward the environment. Furthermore, by adjusting beam blocker 174, the field of view at the top of one side can be expanded or extended at the expense of the field of view near the top of the other side.

[0064] In this scenario, by adjusting the position of the top beam blocker, the field of view can be distributed on both sides of the bottom and top of the field of view.

[0065] Figure 2A , Figure 2B , Figure 2C and Figure 2D The diagram illustrates various views and sections of the LiDAR system 200. Figure 2A The figure shows a perspective view of a lidar system 200 according to an example embodiment. As shown, the lidar system 200 may include a rotatable base 110. The rotatable base 110 may be configured to rotate about a first axis 111. Furthermore, the lidar system 200 may include an optical cavity 120, which may include a light emitter device 126, a light emitter lens 128, a photodetector 122, and a photodetector lens 124. Additionally, in some embodiments, the lidar system 200 may include a mirror assembly 130. The mirror assembly 130 may include a plurality of reflective surfaces 132a, 132b, and 132c and an axis 134. The mirror assembly 130 may be configured to rotate about a second axis 135.

[0066] In some embodiments, the light emitter device 126 and the light emitter lens 128 may form a light emission axis 129. The light pulses emitted by the light emitter device 126 may interact with the reflective surface 132b in the transmitting mirror region 137.

[0067] In some embodiments, photodetector 122 and photodetector lens 124 may form a light receiving axis 125. The light pulse emitted by light emitting device 126 may be reflected or otherwise interact with the environment and may be observed at photodetector 122 through receiving mirror region 139.

[0068] As shown in Figure 2, the lidar system 200 may include a baffle 170. The baffle 170 may include an opening 172, within which a mirror assembly 130 may be disposed. The opening 172 may be shaped to provide the mirror assembly 130 with a degree of freedom of rotation about a second axis 135.

[0069] Figure 2B The figure shows a side view of a lidar system 200 along the -y direction according to an example embodiment. (In conjunction with the above references) Figure 2A Other components described, such as the lidar system 200, may additionally include a housing 160 and multiple optical windows, such as optical window 162a.

[0070] Figure 2C The illustration shows a mirror assembly 130 of a lidar system 200 according to an example embodiment. For example, the mirror assembly 130 may include a plurality of reflective surfaces 132a, 132b, and 132c. The mirror assembly 130 may additionally include a rod 134, which may be configured to rotate about a second axis 135.

[0071] In some embodiments, the light emitter device 126 can emit light pulses along the light emission axis 129 toward the mirror assembly 130. The reflective surface 132b of the mirror assembly 130 can reflect such light pulses in the transmitting mirror region 137, thereby transmitting the light pulses to the external environment.

[0072] In such an example, light from the environment (e.g., reflected light pulses) can be reflected by the reflective surface 132b of the mirror assembly 130 in the receiving mirror region 139. In some embodiments, the received light can be directed to the photodetector 122 along the light receiving axis 125.

[0073] Figure 2D The illustration shows a view of a lidar system 200 along the -x direction according to an example embodiment. The lidar system 200 may include an optical cavity 120, which is configured such that the light emission axis 129 and / or the light receiving axis 125 are substantially parallel to the first axis 111.

[0074] In some embodiments, this arrangement of the optical cavity 120 relative to the first axis 111 can provide a substantially symmetrical emission pattern in the external environment, at least because, based on the rotational position of the mirror assembly 130, the light pulses emitted by the light emitter device 126 are equally likely to be sent to the right (+y direction) through the first optical window 162a or to the left (-y direction) through the second optical window 162b.

[0075] Figure 3 The figure illustrates system 300 according to an example embodiment. In some embodiments, system 300 may be similar to or the same as system 100, as referenced. Figure 1As shown and described. System 300 includes a lidar system 200, as shown and described with reference to FIG. 2. System 300 also includes a reflective surface 180. Figure 3 As shown, the reflective surface 180 may include a flat surface (e.g., a plane mirror). However, other types of surfaces configured to reflect light pulses emitted by the lidar system 200 are possible and considered. In some embodiments, the reflective surface 180 may be positioned within two feet of the lidar system 200. However, the reflective surface 180 may be positioned closer to or further away from the lidar system 200. Furthermore, although Figure 3 The illustration shows the reflective surface 180 separated from the lidar system 200, but it will be understood that in some embodiments, the reflective surface 180 may be incorporated into the lidar system 200.

[0076] In some embodiments, the lidar system 200 may be configured to emit light pulses that do not interact with the reflective surface 180 to provide a default field of view 102. Additionally, the lidar system 200 may be configured to emit light pulses that interact with the reflective surface 180 to provide an extended field of view 182. As shown, in some embodiments, the extended field of view 182 may include a region along a first axis 111 substantially below the lidar system 200 (e.g., along the -z direction).

[0077] In some embodiments, reflective surface 180 may represent a structural support for the lidar system 200 on a vehicle, such as a base or bracket, or a portion thereof. Reflective surface 180 may include another type of static feature that typically does not represent an object of interest within the field of view. In this scenario, extended field of view 182 can provide extended coverage for the lidar system 200 while more effectively utilizing light pulses that might otherwise be ignored. That is, light pulses that would otherwise be reflected back to the lidar system 200 from a static support structure or base can be redirected to extended field of view 182, which may include the object of interest or other types of features (e.g., obstacles). Figure 3 As shown, the extended field of view 182 can effectively include the area directly below the lidar system 200. In this case, the lidar system 200 can be configured to detect objects in the extended field of view 182 in order to sense pedestrians, ground, and / or other types of features.

[0078] like Figure 3As shown, the lidar system 200 can emit light pulses that interact with the reflective surface 180 to provide multiple reflected light pulse emission vectors 310, 312, and 314. The reflected light pulse emission vectors 310, 312, and 314 can form at least a portion of the extended field of view 182. Although three reflected light pulse emission vectors are illustrated, it will be understood that more reflected light pulse emission vectors are possible and considered.

[0079] Figure 4 The illustration shows a system 400 according to an example embodiment. In some embodiments, system 400 may be similar to or the same as system 100 and system 300, as shown in references. Figure 1 and Figure 3 As shown and described. System 400 includes a lidar system 200, as shown and described with reference to FIG. 2. System 400 also includes a reflective surface 180. Figure 4 As shown, the reflective surface 180 may include multiple surfaces. For example, the multiple surfaces may include a first reflective surface 402 and a second reflective surface 404. Other types of surfaces configured to reflect light pulses emitted by the lidar system 200 are possible and considered.

[0080] In some embodiments, the lidar system 200 may be configured to emit light pulses that do not interact with the reflective surface 180 to provide a default field of view 102. Furthermore, the lidar system 200 may be configured to emit light pulses that interact with the first reflective surface 402 to provide an extended field of view 182a. As shown, in some embodiments, the extended field of view 182a may include a region along the first axis 111 substantially below the lidar system 200 (e.g., along the -z direction).

[0081] Additionally, the lidar system 200 can be configured to emit light pulses that interact with the second reflective surface 404 to provide an extended field of view 182b. As shown, in some embodiments, the extended field of view 182b may include a region along the first axis 111 substantially above the lidar system 200 (e.g., along the +z direction).

[0082] In some scenarios, extended fields of view 182a and 182b can provide the lidar system 200 with expanded coverage while making more efficient use of light pulses that might otherwise be ignored. That is, light pulses that would otherwise be reflected back to the lidar system 200 to indicate a static support structure or base can be redirected to the extended field of view 182a or 182b, which may include information about obstacles, other vehicles, pedestrians, or other types of features. For example... Figure 4As shown, the extended field of view 182a can effectively include the region directly below the lidar system 200, and the extended field of view 182b can effectively include the region directly above the lidar system 200. In this case, the lidar system 200 can be configured to detect objects in the extended fields of view 182a and 182b in order to sense pedestrians, ground, and / or other types of features.

[0083] like Figure 4 As shown, the lidar system 200 can emit light pulses that interact with the reflective surface 402 to provide a plurality of reflected light pulse emission vectors 410, 412, and 414. The reflected light pulse emission vectors 410, 412, and 414 can form at least a portion of the extended field of view 182a. Additionally, the lidar system 200 can emit light pulses that interact with the reflective surface 404 to provide a plurality of reflected light pulse emission vectors 416 and 418. The reflected light pulse emission vectors 416 and 418 can form at least a portion of the extended field of view 182b.

[0084] III. Example Vehicle

[0085] Figure 5A , Figure 5B , Figure 5C , Figure 5D and Figure 5E The illustration shows a vehicle 500 according to an example embodiment. Vehicle 500 can be a semi-autonomous or fully autonomous vehicle. Although Figures 5A-5E Vehicle 500 is shown as a car (e.g., a bus), but it will be understood that vehicle 500 may include another type of autonomous vehicle, robot, or drone capable of navigating its environment using sensors and other information about its environment.

[0086] The carrier 500 may include one or more sensor systems 502, 504, 506, 508, and 510. In some embodiments, sensor systems 502, 504, 506, 508, and 510 may include a lidar sensor having a plurality of light emitting devices arranged within an angular range relative to a given plane (e.g., the xy plane).

[0087] One or more of sensor systems 502, 504, 506, 508, and 510 can be configured to rotate about an axis perpendicular to a given plane (e.g., the z-axis) to illuminate the environment around vehicle 500 with light pulses. Information about the environment can be determined based on various aspects of the detected reflected light pulses (e.g., elapsed time of flight, polarization, intensity, etc.).

[0088] In exemplary embodiments, sensor systems 502, 504, 506, 508, and 510 may be configured to provide corresponding point cloud information that may be correlated with physical objects within the environment of vehicle 500. While vehicle 500 and sensor systems 502, 504, 506, 508, and 510 are illustrated to include certain features, it will be understood that other types of sensor systems are contemplated within the scope of this disclosure.

[0089] Example embodiments may include a system having multiple optical transmitter devices. The system may include a transmitting block of lidar devices. For example, the system may be a lidar device of a vehicle (e.g., a car, truck, motorcycle, golf cart, aircraft, boat, etc.), or may be part of such a vehicle. Each of the multiple optical transmitter devices is configured to emit an optical pulse along a corresponding beam elevation angle. The corresponding beam elevation angle may be based on a reference angle or a reference plane. As an example, the reference plane may be based on the axis of motion of vehicle 500. Other reference angles (e.g., azimuth, elevation, etc.) or reference planes (e.g., x, y, and z planes) are considered and possible within the scope of this disclosure.

[0090] While this document describes and illustrates a lidar system with a single light emitter device, lidar systems with multiple light emitter devices (e.g., light emitter devices with multiple laser stripes on a single laser die) are also conceivable. For example, light pulses emitted by one or more laser diodes can be controllably directed toward the environment surrounding the system. The emission angle of the light pulses can be adjusted by scanning devices, such as, for example, mechanical scanning mirrors and / or rotary motors. For example, the scanning device can rotate in a reciprocating motion about a given axis and / or about a vertical axis. In another embodiment, the light emitter device can emit light pulses toward a rotating prism, which, upon interaction with each light pulse, can direct the light pulse toward the environment based on the angle of the prism. Additionally or alternatively, scanning optics and / or other types of optomechanical devices can scan the light pulses around the environment.

[0091] In some embodiments, as described herein, a single optical emitter device can emit optical pulses according to a variable shot schedule and / or with a variable per-shot power. That is, the emission power and / or timing of each laser pulse or shot can be based on the corresponding pitch angle of the shot. Furthermore, the variable shot schedule can be based on providing a desired vertical spacing at a given distance from the lidar system or from a surface (e.g., a front bumper) of a given vehicle supporting the lidar system. As an example, when an optical pulse from the optical emitter device is directed downwards, the per-shot power can be reduced because the expected maximum distance to the target is shorter. Conversely, an optical pulse emitted by the optical emitter device at a pitch angle above a reference plane can have a relatively higher per-shot power to provide a sufficient signal-to-noise ratio for adequately detecting pulses traveling longer distances.

[0092] In some embodiments, the power / energy of each emitted pulse can be controlled dynamically. In other embodiments, the power / energy of each emitted pulse can be controlled for several consecutive pulse groups (e.g., 10 optical pulses). That is, the characteristics of the optical pulse sequence can be changed on a per-pulse basis and / or every few pulses basis.

[0093] Although Figures 5A-5E The illustration shows various lidar sensors attached to vehicle 500, but it will be understood that vehicle 500 may incorporate other types of sensors, such as multiple optical systems (e.g., cameras), radar, or ultrasonic sensors.

[0094] In an example embodiment, vehicle 500 may include a lidar system (e.g., lidar system 200) configured to emit light pulses into the environment of vehicle 500 to provide information indicating objects within a default field of view.

[0095] Furthermore, the vehicle 500 includes reflective surfaces (e.g., reflective surfaces 180a and 180b) optically coupled to the lidar system. In this scenario, the reflective surfaces are configured to reflect at least a portion of the emitted light pulses to provide an extended field of view. The lidar system is also configured to provide information indicating objects within the extended field of view.

[0096] In some embodiments, the reflective surface may include a portion of the vehicle body 500. For example, such as Figure 5A , Figure 5B and Figure 5E As shown, reflective surfaces 180a and 180b may be adjacent to a given lidar system (e.g., sensor systems 508 and 510, respectively).

[0097] In some embodiments, the reflective surface may include at least one of the vehicle's rearview mirrors or side mirrors. Other reflective surfaces, including other body surfaces of the vehicle, are also possible and considered.

[0098] As shown with reference to Figure 2, the carrier 500 may include one or more lidar systems (e.g., lidar system 200), each lidar system may include at least one light source configured to emit light pulses. The emitted light pulses interact with the environment to provide return light pulses.

[0099] The lidar system includes at least one detector configured to detect at least a portion of a returned light pulse. The lidar system also includes a controller (e.g., controller 150) having at least one processor (e.g., processor 152) and at least one memory (e.g., memory 154). The at least one processor executes instructions stored in the at least one memory to perform operations. In some embodiments, the operations include causing at least one light source to emit light pulses. The operations may additionally include receiving at least a first portion of a returned light pulse from a default field of view as a first detection light signal. The operations may also include receiving at least a second portion of a returned light pulse from an extended field of view as a second detection light signal. The operations further include determining a point cloud indicating objects within the default and extended fields of view based on the first and second detection light signals.

[0100] The operation also includes receiving a reflection map. The reflection map may include reflection information about how the reflecting surface reflects light pulses into an extended field of view. In this scenario, point cloud determination may be further based on the reflection map. The reflection information may include at least one of the angle of the reflecting surface, the orientation of the reflecting surface, or information about the surface curvature of the reflecting surface.

[0101] In embodiments including a controller, the operation may include determining one or more stair objects based on returned light pulses. The one or more stair objects may include individual steps of a staircase or other similar objects. It will be understood that other objects and / or obstacles (e.g., doors, corridors, passageways, gates, windows, thresholds, etc.) are considered within the scope of this disclosure.

[0102] In this context, in response to identifying one or more stair objects, operations may include adjusting the vehicle's operational behavior. For example, the operational behavior could be modified from movement across a flat surface to movement through staircases. Other adjustments to the operational behavior are also possible and considered.

[0103] As described in this article, the reflective surface can be positioned within two feet of the lidar system. Alternatively, the reflective surface can be positioned closer to or further away from the lidar system.

[0104] In some embodiments, at least a portion of the extended field of view may be positioned above the lidar system. Additionally or alternatively, at least a portion of the extended field of view may be positioned below the lidar system.

[0105] Figure 6 The figure shows a top view of an operational scenario 600 according to an example embodiment. Operational scenario 600 may include a lidar system 200 mounted along the right side of a vehicle 500, along the right front side panel. In the example embodiment, the lidar system 200 may rotate about a first axis (e.g., first axis 111 and / or the z-axis). When rotating about the first axis, the lidar system 200 may redirect light pulses into its environment using a rotating mirror assembly (e.g., mirror assembly 130). In this scenario, at least some of the light pulses may interact with the reflective surface 180 to reflect some of the light pulses into an extended field of view 182.

[0106] Figure 6 The illustration shows an example light emission pattern along the Earth's surface. Figure 3 As shown, the light emission pattern along the ground can include a portion of the default field of view 102 and a portion of the extended field of view 182. Although Figure 6 The default field of view 102 and the extended field of view 182 are illustrated as not overlapping, but in some embodiments, at least a portion of the default field of view 102 may overlap with the extended field of view 182.

[0107] like Figure 6 As shown, the extended field of view 182 can provide detection of objects located within the proximity range of the vehicle 500, immediately below the lidar system 200. Thus, the extended field of view 182 can be advantageous because it provides lidar coverage in areas not normally covered by lidar. Therefore, operational scenario 600 can illustrate a system with better security than conventional systems.

[0108] IV. Example Method

[0109] Figure 7 The illustration depicts method 700 according to an example embodiment. It will be understood that method 700 may include fewer or more steps or blocks than explicitly illustrated or disclosed herein. Furthermore, the corresponding steps or blocks of method 700 may be executed in any order, and each step or block may be executed once or multiple times. In some embodiments, some or all blocks or steps of method 700 may be executed by controller 150 and / or other elements of systems 100, 300, 400 and lidar system 200, as described respectively. Figure 1 , Figure 3 , Figure 4 and Figures 2A-2D The illustrations and descriptions are as follows.

[0110] Block 702 includes enabling at least one light source (e.g., light emitter device 126) of a lidar system (e.g., lidar system 200) to emit light pulses toward a default field of view (e.g., default field of view 102) and a reflective surface (e.g., reflective surface 180). The reflective surface may be configured to reflect a portion of the light pulses toward an extended field of view (e.g., extended field of view 182). The emitted light pulses interact with the environment of the lidar system to provide a return light pulse.

[0111] Block 704 includes receiving at least a first portion of a returned light pulse from a default field of view as a first detection light signal. In some embodiments, receiving the first portion of the returned light pulse may include detecting a reflected light pulse from the default field of view. The first detection light signal may be formed based on the corresponding detection of the reflected light pulse by one or more detectors (e.g., photodetector 122).

[0112] Block 706 includes receiving at least a second portion of the returned light pulse from the extended field of view as a second detection light signal. In some embodiments, receiving the second portion of the returned light pulse may include detecting a reflected light pulse from the extended field of view. The second detection light signal may be formed based on the corresponding detection of the reflected light pulse by one or more detectors (e.g., photodetector 122).

[0113] Block 708 includes determining a point cloud indicating objects within a default field of view and an extended field of view based on a first detection light signal and a second detection light signal. In some embodiments, determining the point cloud may include associating the first and second detection light signals with a plurality of spatial ranging points. For example, each spatial ranging point may be determined based on the emission angle of each corresponding light pulse and the time of flight between the initial emission time and subsequent detection time.

[0114] In some embodiments, the extended field of view and the default field of view do not completely overlap. For example, the default field of view may define at least one blind zone. In such a scenario, the extended field of view may overlap with at least a portion of the at least one blind zone.

[0115] In some embodiments, method 700 may additionally include receiving a reflection map. In an example, controller 150 may receive the reflection map via a wired or wireless communication interface. In some embodiments, the reflection map may be provided based on a calibration target and / or calibration procedure. The reflection map may be stored in memory 154 or another local memory.

[0116] In some embodiments, the reflection map includes reflection information about how the reflective surface reflects light pulses into the extended field of view. As an example, the reflection map may include a correspondence between the emission angles in the pitch and azimuth angles and the emission vectors of the reflected light pulses intersecting the extended field of view. In this scenario, the point cloud can be further determined based on the reflection map.

[0117] In some examples, the reflection information may include at least one of the angle of the reflecting surface, the orientation of the reflecting surface, or the surface curvature of the reflecting surface.

[0118] Additionally or alternatively, reflection information may include a lookup table (LUT). For example, an LUT may include information indicating the default light pulse emission vector and the reflected light pulse emission vector.

[0119] The arrangements shown in the figures should not be considered limiting. It will be understood that other embodiments may include more or fewer of each element shown in the given figures. Furthermore, some illustrated elements may be combined or omitted. Additionally, illustrative embodiments may include elements not shown in the figures.

[0120] A step or block representing information processing can correspond to a circuit that can be configured to perform a specific logical function of the method or technique described herein. Alternatively or additionally, a step or block representing information processing can correspond to a module, segment, or portion of program code (including associated data). The program code can include one or more instructions executable by a processor for implementing a specific logical function or action in the method or technique. The program code and / or associated data can be stored on any type of computer-readable medium, such as a storage device including a disk, hard disk drive, or other storage medium.

[0121] Computer-readable media can also include non-transitory computer-readable media, such as short-term data storage media like register memory, processor cache, and random access memory (RAM). Computer-readable media can also include long-term storage media for program code and / or data. Therefore, computer-readable media can include auxiliary or permanent long-term storage, such as read-only memory (ROM), optical discs or magnetic disks, and optical disc read-only memory (CD-ROM). Computer-readable media can also be any other volatile or non-volatile storage system. For example, a computer-readable medium can be considered a computer-readable storage medium or a tangible storage device.

[0122] While various examples and embodiments have been disclosed, other examples and embodiments will be apparent to those skilled in the art. The various disclosed examples and embodiments are for illustrative purposes and not for limitation; the true scope is indicated by the appended claims.

Claims

1. A system comprising: A lidar system is configured to emit light pulses into the system's environment to provide information indicating objects within a default field of view, wherein the lidar system includes: A rotatable base is configured to rotate about a first axis; A rotatable mirror, coupled to a rotatable base, wherein the rotatable mirror is configured to rotate about a second axis; At least one light source is configured to emit light pulses, wherein the emitted light pulses interact with the environment to provide a return light pulse; and At least one detector is configured to detect at least a portion of the returned optical pulse; and A reflective surface, optically coupled to the lidar system, wherein the reflective surface is configured to reflect at least a portion of the emitted light pulse to provide an extended field of view, wherein the lidar system is further configured to use a reflection map including reflection information to provide information indicating objects within the extended field of view, wherein the reflection information includes at least one of the angle of the reflective surface, the orientation of the reflective surface, or the surface curvature of the reflective surface.

2. The system according to claim 1, wherein, The extended field of view and the default field of view do not completely overlap.

3. The system according to claim 1, wherein, The default field of view defines at least one blind zone, and the extended field of view overlaps with at least a portion of the at least one blind zone.

4. The system according to claim 1, wherein, The reflective surface includes at least one of a plane mirror, a convex mirror, a concave mirror, or a multi-faceted mirror array.

5. The system according to claim 1, wherein, The light pulse comprises light with a wavelength of λ, wherein the reflective surface comprises a plane mirror having a flatness between λ and λ / 100 as measured by optical interferometry.

6. The system according to claim 1, wherein, The reflective surface is positioned within two feet of the lidar system.

7. The system according to claim 1, further comprising: The controller includes at least one processor and at least one memory, wherein the at least one processor executes instructions stored in the at least one memory to perform operations, the operations including: Cause the at least one light source to emit a light pulse; Receive at least a first portion of the returned light pulse from the default field of view as a first detection light signal; Receive at least a second portion of the returned light pulse from the extended field of view as a second detection light signal; and Based on the first and second detection light signals, a point cloud indicating objects within the default field of view and the extended field of view is determined.

8. The system according to claim 7, wherein, The operation further includes: Receive a reflection map, wherein the reflection map includes reflection information about how the reflective surface reflects light pulses into the extended field of view, wherein the point cloud is further determined based on the reflection map.

9. A method comprising: A lidar system emits light pulses from at least one light source toward a default field of view and toward a reflective surface configured to reflect a portion of the light pulses toward an extended field of view. The emitted light pulses interact with the environment of the lidar system to provide a return light pulse. The lidar system comprises: A rotatable base is configured to rotate about a first axis; A rotatable mirror, coupled to a rotatable base, wherein the rotatable mirror is configured to rotate about a second axis; At least one light source is configured to emit light pulses, wherein the emitted light pulses interact with the environment to provide a return light pulse; and At least one detector is configured to detect at least a portion of the returned optical pulse; Receive at least a first portion of the returned light pulse from the default field of view as a first detection light signal; Receive at least a second portion of the returned optical pulse from the extended field of view as a second detection optical signal; and Send point cloud data, wherein the point cloud data is based on a first detection light signal and a second detection light signal, and indicates objects within a default field of view and an extended field of view, wherein the point cloud data is also based on a reflection map including reflection information, wherein the reflection information includes at least one of the angle of the reflecting surface, the orientation of the reflecting surface, or the surface curvature of the reflecting surface.

10. The method according to claim 9, wherein, The extended field of view and the default field of view do not completely overlap.

11. The method according to claim 9, wherein, The default field of view defines at least one blind zone, and the extended field of view overlaps with at least a portion of the at least one blind zone.

12. The method of claim 9, further comprising: Receive a reflection map, wherein the reflection map includes reflection information about how the reflective surface reflects light pulses into the extended field of view, wherein the point cloud is further determined based on the reflection map.

13. A vehicle comprising: A lidar system is configured to emit light pulses into the environment of a vehicle to provide information indicating objects within a default field of view, wherein the lidar system includes: A rotatable base is configured to rotate about a first axis; A rotatable mirror, coupled to a rotatable base, wherein the rotatable mirror is configured to rotate about a second axis; At least one light source is configured to emit light pulses, wherein the emitted light pulses interact with the environment to provide a return light pulse; and At least one detector is configured to detect at least a portion of the returned optical pulse; and A reflective surface, optically coupled to the lidar system, wherein the reflective surface is configured to reflect at least a portion of the emitted light pulse to provide an extended field of view, wherein the lidar system is further configured to provide information indicating objects within the extended field of view using a reflection map including reflection information, wherein the reflection information includes at least one of the angle of the reflective surface, the orientation of the reflective surface, or the surface curvature of the reflective surface.

14. The vehicle according to claim 13, wherein, The reflective surface is part of the body of the vehicle.

15. The vehicle according to claim 13, wherein, The reflective surface includes at least one of the vehicle's rearview mirror or the vehicle's side mirror.

16. The vehicle according to claim 13, wherein, The lidar system includes: The controller includes at least one processor and at least one memory, wherein the at least one processor executes instructions stored in the at least one memory to perform operations, the operations including: Cause the at least one light source to emit a light pulse; Receive at least a first portion of the returned light pulse from the default field of view as a first detection light signal; Receive at least a second portion of the returned light pulse from the extended field of view as a second detection light signal; Send point cloud data, wherein the point cloud data is based on a first detection light signal and a second detection light signal, and indicates objects within a default field of view and an extended field of view; and Receive a reflection map, which includes reflection information about how the reflective surface reflects light pulses into an extended field of view, wherein point cloud data is further based on the reflection map.

17. The vehicle according to claim 13, further comprising: The controller includes at least one processor and at least one memory, wherein the at least one processor executes instructions stored in the at least one memory to perform operations, the operations including: Cause the at least one light source to emit a light pulse; Receive at least a first portion of the returned light pulse from the default field of view as a first detection light signal; Receive at least a second portion of the returned light pulse from the extended field of view as a second detection light signal; Based on the returned light pulse, identify one or more stair objects; and In response to identifying the one or more stair objects, the vehicle's operational behavior is adjusted.

18. The vehicle according to claim 13, wherein, The reflective surface is positioned within two feet of the lidar system.

19. The vehicle according to claim 13, wherein, At least a portion of the extended field of view is positioned above the lidar system.

20. The vehicle according to claim 13, wherein, At least a portion of the extended field of view is positioned below the lidar system.

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