Lidar window with glitch reduction

Abstract

Various methods and systems are disclosed to reduce false alarms in a LiDAR having a LiDAR window by increasing propagation losses for a portion of incident light that propagates within the thickness of the LiDAR window (200) surrounding the LiDAR system (100) and may be directed towards a detection system of the LiDAR via an indirect path. Alternatively or in addition, the shape of the LiDAR window may be tailored to direct portions of incident light propagating within the thickness of the LiDAR window away from the LiDAR detection system.

Description

[0001] Incorporation by reference into any priority application

[0002] This application claims the benefit of priority to U.S. Patent Application No. 17 / 931,057, filed on September 9, 2022, entitled “FALSE SIGNAL REDUCING LIDAR WINDOW”, which claims the benefit of priority to U.S. Provisional Application No. 63 / 321,438, filed on March 18, 2022, entitled “FALSE SIGNAL REDUCING LIDAR WINDOW”. The above applications are each hereby incorporated by reference in their entirety. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Figure 1 is a diagram illustrating a LiDAR system that detects objects in an environment by emitting an optical probe beam and receiving a corresponding reflected optical beam.

[0004] Figure 2A It is a diagram illustrating a perspective view of a LiDAR having a cylindrical protective window.

[0005] Figure 2B is a diagram illustrating the emission of two optical probe beams by a LiDAR including a protective window (LiDAR window) having a circular cross-section and the reception of corresponding reflected beams.

[0006] Figure 3A is a diagram illustrating partial scattering of an optical beam incident on a LiDAR window, and reception of the resulting guided optical beam by the LiDAR detection system.

[0007] Figure 3B is a diagram illustrating a scenario in which a LiDAR system receives multiple guided optical beams via a LiDAR window, which results in the generation of false positive return point clouds and false return point clouds at multiple distances, which cover azimuth angles larger than the azimuth angle of the actual angular width of a single near-field object from which the reflected optical beam is received.

[0008] Figure 4A is a diagram illustrating that a reflected optical beam incident on a LiDAR window is partially scattered by an artifact of the LiDAR window, and the resulting guided optical beam is received by a LiDAR detection system.

[0009] Figure 4B is a diagram illustrating that a scattered optical beam incident on a LiDAR window is scattered by an artifact portion of the LiDAR window, and the resulting guided optical beam is received by a LiDAR detection system.

[0010] FIG. 5A to FIG. 5DA perspective view illustrating four different LiDAR windows with different shapes. Light guided within the thickness of these LiDAR windows can be directed away from the detection system of the LiDAR placed at the center of each LiDAR window.

[0011] Figure 6 is an example environment in which a vehicle including one or more components of an autonomous system may be implemented.

[0012] Figure 7 is a diagram of one or more systems of a vehicle including an autonomous system.

[0013] Figure 8 yes Figure 6 and Figure 7 A diagram of one or more devices and / or components of one or more systems.

[0014] Fig. 9 is a diagram of some components of an autonomous system. DETAILED DESCRIPTION

[0015] LiDAR System Overview

[0016] The autonomous vehicle preferably includes highly accurate and reliable sensors to detect objects and calculate the distance of these objects relative to the vehicle. Among the various technologies developed for object detection and ranging, laser-based rangefinders are often used in autonomous driving systems due to their high resolution and accuracy. In addition to autonomous driving systems, laser-based rangefinders can be used in other applications where it is desired to detect objects in the environment and determine the position and / or speed of the object relative to a reference frame. Laser-based rangefinders or laser rangefinders are sometimes referred to as light detection and ranging (LiDAR) or laser detection and ranging (LaDAR). The acronyms "LiDAR" and "LaDAR" can be used interchangeably to refer to an optical system that uses lasers to detect objects.

[0017] The LiDAR system uses a light beam (e.g., a laser beam) to detect objects in the environment around the LiDAR and determine the distance of these objects relative to the LiDAR. In some cases, the LiDAR can also determine the speed of the object relative to the LiDAR. The high resolution (e.g., high spatial resolution for detecting objects) and accuracy of the LiDAR system have made them the preferred sensors for many applications. In particular, the LiDAR system is used in various autonomous driving systems to continuously scan the surroundings of the vehicle to avoid collisions between the vehicle and the objects in the environment. The LiDAR system detects objects by sending an optical detection beam to the environment and receiving a corresponding optical beam reflected from an object in the environment. The detection system of the LiDAR can receive a reflected optical beam and generate a return signal (i.e., an electronic signal) indicating that a portion of the optical detection beam reflected by the object in the environment has been detected. Subsequently, the LiDAR can use the return signal to determine the distance between the object and the LiDAR and / or the speed of the object relative to the LiDAR.

[0018] In some cases, the LiDAR system may include a LiDAR window through which an optical probe beam is emitted to the environment and a corresponding reflected optical beam is received from the environment. In some such cases, a portion of the beam incident on the LiDAR window (e.g., a reflected or scattered optical beam associated with the optical probe beam emitted by the LiDAR) may be transformed by a defect or particle on the LiDAR window or within the thickness of the LiDAR window into a guided optical beam propagating within the thickness of the LiDAR window. In some cases, a portion of the guided optical beam may be scattered toward the LiDAR detection system, which results in the generation of a false return signal indicating the presence of a false object at a false distance.

[0019] The present application solves excessive noise, false positive alarms, inaccurate range and other problems associated with light coupled to a LiDAR window and guided within the thickness of the LiDAR window by increasing propagation losses for the guided light or directing the guided light away from the LiDAR's detection system. In one embodiment, the optical absorption of the LiDAR window can be selected so that when the guided light propagates within the thickness of the LiDAR window, the intensity of the guided light drops to a level below the detectability threshold of the LiDAR's detection system before it is received by the LiDAR's detection system. For example, the optical absorption of the material forming the LiDAR window can be increased by adding a light absorbing dopant to the material. In another embodiment, the shape of the LiDAR window can be customized so that the guided light is directed away from the LiDAR's detection system when it propagates within the thickness of the LiDAR window.

[0020] The designs, systems and methods described below may be incorporated into various types of autonomous vehicles and self-driving cars, such as those disclosed in U.S. patent application publication No. 17 / 444,956, filed on August 12, 2021, entitled “END-TO-END SYSTEM TRAINING USING FUSEDIMAGES,” and U.S. patent application publication No. 17 / 443,433, filed on July 26, 2021, entitled “VEHICLELOCATION USING COMBINED INPUTS OF REDUNDANT LOCALIZATION PIPELINES,” the entire contents of which are incorporated herein by reference and become a part of this specification.

[0021] In some cases, the optical detection beam emitted by the LiDAR system may include an optical detection signal. In some such cases, the LiDAR can detect an object and determine the distance between the object and the LiDAR by irradiating the object with the optical detection beam and receiving a reflected optical beam associated with the reflection of the optical detection beam by the object. In some cases, the reflected optical beam may include a reflected optical signal associated with the optical detection signal. The LiDAR can determine the distance between the object and the LiDAR by measuring the delay between the emission of the optical detection signal and the reception of the corresponding reflected optical signal. In some cases, the emitted optical detection beam and the reflected optical beam can propagate in substantially parallel directions. In some cases, a portion of the optical detection beam may be reflected or scattered by the object along a direction that is substantially not parallel to the optical detection beam. In an example, the angle between the emitted optical detection beam and the corresponding reflected optical beam may be less than 2 degrees, less than 5 degrees, or less than 10 degrees. In some cases, the angle between the emitted optical detection beam and the corresponding reflected optical beam may be from 4 degrees to 5 degrees, or from 5 degrees to 6 degrees. In some cases, a portion of the reflected optical beam may be propagated directly from the object to the LiDAR detection system along an almost straight or non-reflecting optical path extending from the object to the LiDAR (without being reflected by any other surface). In some cases, the almost straight or non-reflecting optical path may include refraction of light when passing through the thickness of the LiDAR window. The LiDAR may detect the reflected optical signal associated with the directly received portion of the reflected optical beam to determine the distance between the object and the LiDAR. In some such cases, at least a portion of the reflected optical beam may not propagate toward the LiDAR detection system along an almost straight optical path. For example, a portion of the reflected optical beam may be further reflected or scattered by one or more surfaces (e.g., the surface of the LiDAR window) before being received by the LiDAR detection system. In some cases, the portion that is not directly received by the LiDAR detection system via a straight or almost straight optical path extending from the object to the detection system of the LiDAR may cause the detection system to generate a false return signal.

[0022] In some embodiments, the optical probe beam may have a wavelength within the operating wavelength range of the LiDAR. In some examples, the LiDAR window may have a high optical transparency for wavelengths within the operating wavelength range of the LiDAR, and the LiDAR detection system may have a higher level of detectivity (or responsiveness) for wavelengths within the operating wavelength range of the LiDAR system.

[0023] In some cases, the incident optical detection signal may include a temporal variation in the optical properties (e.g., amplitude, phase, frequency, polarization) of a laser beam emitted by the LiDAR. For example, the optical detection signal may be a laser pulse (e.g., a variation in laser intensity), and the LiDAR may determine the distance relative to the object by measuring the delay or time of flight (TOF) between the transmission of the incident laser pulse and the reception of the corresponding reflected laser pulse. In some cases, a LiDAR that determines the distance relative to an object based on the time of flight of a laser pulse may be referred to as a TOF LiDAR. A time of flight (TOF) LiDAR may generate a return signal that may be used to determine the position of an object and the reflectivity of the surface of the object.

[0024] In some applications (e.g., for controlling and guiding an autonomous vehicle in a complex driving environment), a LiDAR may continuously scan an environment (e.g., the environment surrounding a vehicle) at a relatively high scanning rate to capture changes in the positions of objects in the environment. For example, a LiDAR may scan the surrounding environment by rotating one or more optical probe beams (e.g., laser beams) about an axis of rotation while scanning the propagation direction of the laser beam in a plane parallel to the axis of rotation.

[0025] In some implementations, the LiDAR may include a protective LiDAR window (also referred to as a "ring lens") that protects the LiDAR system while allowing light to be transmitted from the environment to the LiDAR and from the LiDAR to the environment. In some examples, the LiDAR window may have an inner surface, and an outer surface separated from the inner surface by the thickness of the LiDAR window. In some such examples, an optical probe beam emitted by the LiDAR may become incident on the inner surface of the LiDAR window, and a reflection of the optical probe beam received from the environment may become incident on the outer surface of the LiDAR window. In some cases, a portion of the optical probe beam and a reflection of the optical probe beam may pass through the thickness of the LiDAR window without being reflected or scattered by the inner or outer surfaces of the LiDAR window.

[0026] In some cases, imperfections and contamination of the LiDAR window can scatter light (e.g., received from the environment or emitted by the LiDAR) such that a portion of the light is guided and propagates within the thickness of the LiDAR window, for example, by total internal reflection (TIR), between the inner and outer surfaces of the LiDAR window. After traveling a certain distance within the thickness of the LiDAR window, a portion of this guided light may be scattered toward the LiDAR's detection system by the same or other imperfections or contamination. In some cases, for example, when the guided light is associated with reflections from near-field objects, a portion of the guided light scattered toward the LiDAR system may be strong enough to be detected by the LiDAR and falsely identified as reflected light received directly from the object. As such, particularly in the presence of imperfections and contamination on the surface of the LiDAR window or within the thickness of the LiDAR window, the LiDAR may generate a false return signal indicating the presence of an unreal object (also referred to as a false object) and an erroneous distance associated with light that is coupled into and outside the thickness of the LiDAR window by imperfections and contamination on or within the LiDAR window (collectively referred to as artifacts) and is directed toward the detection system of the LiDAR by multiple reflections from the surface of the LiDAR window. Given that the guided light associated with an optical beam reflected by a near-field object may have a higher intensity (or power) than the guided light associated with an optical beam reflected by a far-field object, the scattered portion of the guided light associated with the light beam received from the near-field object may generate a false return signal associated with the indirectly received guided light with a higher probability. As such, the false return signal is sometimes referred to as near-field false positive noise.

[0027] In order to eliminate the propagation of light coupled into the thickness of the LiDAR window toward the detection system of the LiDAR, in some previous designs, the LiDAR window is divided into separate optically isolated segments. However, such designs may only be applicable to dual-static LiDAR architectures. In addition, due to parallax, these designs may not allow detection of near-field objects.

[0028] As such, new methods are needed that can improve the reliability of LiDAR systems in the presence of contamination on the surface of the LiDAR window or defects within the thickness of the LiDAR window.

[0029] The various designs described below can reduce the probability of generating false signals by light guided and scattered within the LiDAR window by increasing the attenuation of light guided within the thickness of the LiDAR window, so that the light intensity (or power) of the scattered portion of the guided light drops below the detection threshold of the LiDAR detection system.

[0030] In some cases, the attenuation of guided light propagating within the thickness of the LiDAR window can be carefully tailored to reduce near-field false positive noise without significantly affecting the attenuation of the light beam transmitted through the thickness of the LiDAR window (without being scattered, guided and / or reflected by the LiDAR window). In some such cases, for light having a wavelength within the operating wavelength range of the LiDAR window, the attenuation of guided light propagating within the thickness of the LiDAR window can be tailored by adjusting the optical absorption coefficient of the material forming the LiDAR window (referred to herein as the window material). For example, the optical absorption of the window material can be selected to be greater than the optical absorption lower limit and less than the optical absorption upper limit. In some cases, the attenuation of guided light propagating within the thickness of the LiDAR window can be increased by forming the LiDAR window from a material having an optical absorption coefficient between the optical absorption lower limit and the optical absorption upper limit for light having a wavelength within the operating wavelength range of the LiDAR window. Thus, some of the designs and solutions described below can include providing a window material having an optical absorption coefficient between the optical absorption lower limit and the optical absorption upper limit for light having a wavelength within the operating wavelength range of the LiDAR window. In some cases, providing such a material may include modifying or selecting a window material, or controlling the concentration of certain light absorbing impurities (e.g., dyes) in the window material. In some implementations, the optical absorption coefficient of the window material may be selected or modified based at least in part on the geometry of the LiDAR window (e.g., diameter, average diameter, or thickness). In some implementations, the optical absorption coefficient of the window material may be selected or modified based at least in part on the field of view of the LiDAR detection system, the detection threshold of the LiDAR detection system, and / or the position of the LiDAR detection system (e.g., relative to the LiDAR window).

[0031] Advantageously, these designs can be implemented without modifying the original design of the LiDAR window or the LiDAR system, and are compatible with co-axial LiDAR architectures to enable near-field detection while mitigating near-field false positive noise.

[0032] Some other methods and designs described below may include a LiDAR window geometry that reduces the probability that the scattered portion of the guided light is received and / or detected by the LiDAR's detection system. In some cases, one or more geometric parameters of the LiDAR window may be tailored so that light guided within the thickness of the LiDAR window propagates away from the LiDAR and cannot reach the LiDAR's detection system or a sensor in the LiDAR's detection system.

[0033] LiDAR System Operation

[0034] Figure 1An example of a LiDAR system 100 (or LiDAR 100) is shown that detects objects in an environment surrounding the LiDAR 100 and determines a distance between the object and the LiDAR 100. In some cases, the LiDAR system 100 may additionally determine a velocity of the object, for example, relative to the LiDAR 100. The LiDAR 100 includes a LiDAR transmitting system 102 that transmits an optical probe beam, and a LiDAR detecting system 104 that receives a reflected optical beam (e.g., the optical probe beam is reflected by an object in the environment) and generates a return signal based at least in part on the reflected optical beam.

[0035] The LiDAR system 100 can detect an object 110 by emitting an optical detection beam 108 (e.g., a laser beam) and receiving a reflected optical beam 109 corresponding to a reflection of the optical detection beam 108. As described above, in some cases, the reflected optical beam 109 can propagate from the object 110 to the LiDAR 100 along a straight optical path. In some cases, the optical detection beam 108 can include one or more optical detection signals, and the reflected optical beam 109 can include one or more reflected optical signals. The optical detection signal can be a time variation of an optical property (e.g., amplitude, phase, or frequency) of the corresponding optical detection beam. In some implementations, the LiDAR system 100 can include a transmitting system 102, a detection system 104, and a LiDAR signal processing system 106. In some cases, the transmitting system 102 can emit an optical detection beam 108 toward the object 110, and the detection system 104 can receive the reflected optical beam 109. In some examples, the optical detection beam 108 may include an optical signal (e.g., an optical pulse) emitted by the emission system 104 at the emission time (t1), and the reflected optical beam 109 may include the reflected optical signal received by the optical detection system 104. In some such examples, the detection system 104 may determine the amplitude and arrival time (t2) of the reflected optical signal received by the LiDAR detection system 104. In some cases, the detection system 104 may determine the delay (t2-t1) between the emission time (t1) and the arrival time (t2). In some implementations, the detection system 104 may convert the reflected optical signal into an electrical signal (e.g., a photocurrent or a photovoltage) and generate a return signal 120. In some cases, the return signal 120 may include an electrical signal or an amplified version of the converted electrical signal. In some cases, the return signal 120 may indicate the arrival time (t2), amplitude (e.g., power or intensity), and / or the delay between the emission time (t1) and the arrival time (t2) of the reflected optical signal. In some cases, return signal 120 may include multiple return signals associated with different sensing elements (eg, pixels) of LiDAR detection system 104 .

[0036] The LiDAR system 100 may also include a LiDAR signal processing system 106 that receives the return signal and determines the presence of an object 110 in the environment, and calculates a distance between the LiDAR system 100 and the object 110 based at least in part on the return signal 120. In some examples, where the return signal 120 indicates an arrival time (t2), the LiDAR signal processing system 106 may determine a delay between the transmission time (t1) and the arrival time (t2), and use the delay to calculate the distance between the LiDAR system 100 and the object 110.

[0037] In various implementations, optical probe beam 108 may have a wavelength in the infrared (IR) wavelength range. In some examples, optical probe beam 108 may have a wavelength in the near IR wavelength range (e.g., from 800 nm to 1800 nm). In some cases, the operating wavelength range of LiDAR system 100 may be in the mid-IR wavelength range (e.g., from 1800 nm to 5000 nm or greater).

[0038] In some embodiments, the LiDAR detection system 104 (also referred to as a “detection system”) may include an optical system, a LiDAR sensor (e.g., a photodetector that converts light into an electrical signal), and a readout system. The optical system may direct light received through a field of view (FOV) 122 of the detection system 104 toward the sensor. In some cases, the FOV 122 may include a range of propagation directions along which light propagating toward the LiDAR detection system 104 is directed to the LiDAR sensor included in the LiDAR detection system 104. The LiDAR sensor may generate a plurality of photocurrents based on the light received from the optical system (e.g., by converting the received light into a photocurrent proportional to the intensity of the received light). The readout system may receive a plurality of photocurrents from the LiDAR sensor (also referred to as a “sensor”) and use the plurality of photocurrents to generate a return signal. The return signal may be used to determine the presence of an object in the environment and estimate the distance between the LiDAR and the object.

[0039] The LiDAR sensor may include a plurality of pixels, each of which is configured to generate a photocurrent when illuminated by light received from an optical system. The optical system may be reconfigured to direct all or a portion of the light received via its FOV to all or a portion of the pixels of the sensor. In some implementations, the sensor may generate a plurality of photocurrents, each of which is generated by one or more than one pixel of the sensor. In some cases, a pixel may include a plurality of micro-units (sub-pixels).

[0040] In some cases, the LiDAR detection system 104 may include a readout circuit configured to receive and process one or more photocurrents from the sensor. In some cases, the readout circuit may use one or more photocurrents to generate one or more return signals. In some cases, the return signal may be generated by the photocurrent received from a single pixel of the sensor. In some such cases, the return signal may be proportional to the received photocurrent. The readout circuit may use the photocurrent received from the pixel and generate a return signal indicating the optical power and arrival time of the optical signal (e.g., reflected optical signal) received by the pixel via the optical system. In some other cases, the readout circuit may use multiple photocurrents received from a group of pixels and generate one or more return signals indicating the optical power and arrival time of the optical signal (e.g., reflected optical signal) received by the group of pixels via the optical system. In some cases, the readout circuit may determine the rise time, peak time, peak value, area, and time shape of the optical signal based on one or more photocurrents. In some examples, the power and timing calculations may be based on the edges, peaks, and shapes of the optical signal.

[0041] In some cases, the signal processing system of the LiDAR (e.g., TOF LiDAR) can use the arrival time of photons received by one or more pixels or micro-cells to calculate the distance between the object reflecting the photons and the LiDAR. In some cases, the signal processing system of the LiDAR (e.g., TOF LiDAR) can use the arrival time of photons received by one or more pixels or micro-cells to calculate the distance between the object reflecting the photons and the LiDAR. In some cases, the signal processing system can additionally use the time behavior (e.g., shape) of the photocurrent received from the sensor 320 to determine the distance.

[0042] In some cases, a scanning LiDAR system (e.g., a TOF scanning LiDAR system) can scan one or more narrow optical probe beams across a field of view (e.g., a wide field of view) of a detection system of the LiDAR system and detect corresponding reflected optical beams received through the field of view. In some cases, one or more beams can be generated by an optical scanning system (e.g., a rotating mirror) that receives a beam from a laser source and redirects the beam in different directions at different times. In some examples, the optical scanning system can rotate the optical probe beam between different angular positions relative to the transmitting system.

[0043] In some cases, a flash LiDAR system can illuminate a field of view (e.g., a large field of view) using a single optical probe beam (e.g., a highly divergent beam) generated by a transmitting system. A detection system of the flash LiDAR system can use a two-dimensional (2D) array of detectors (e.g., pixels) to receive reflected portions of the optical probe beam via different segments of the field of view. The pixels and the optical system (e.g., one or more lenses) can be configured so that each pixel detects light received from a specific portion of the field of view (e.g., received from a specific direction).

[0044] In some cases, a mechanical LiDAR system can illuminate a narrow field of view (e.g., a large field of view) using a single optical detection beam (e.g., a low divergence optical beam) generated by a transmission system of the mechanical LiDAR system. The mechanical LiDAR system can rotate the optical detection beam to scan the environment. The mechanical LiDAR system may include a detection system for measuring reflections of the optical detection beam received via the field of view of the detection system. The mechanical LiDAR system can rotate the detection system and the corresponding field of view together with the transmission system so that the optical detection beam and its reflection are transmitted and received within a narrow angular width of the target object.

[0045] In various implementations, any of the above-described LiDAR systems may be TOF LiDAR systems, and they may include a LiDAR window surrounding the LiDAR system. The various methods and systems described below may be implemented in any of the above-described LiDAR systems to reduce or eliminate the generation of erroneous or false return signals associated with light received by the LiDAR detection system via an indirect optical path, wherein at least a portion of the optical path includes a guided optical path within the thickness of the LiDAR window.

[0046] As described above, the LiDAR may include a LiDAR window through which an optical detection beam is emitted to the environment and a corresponding reflected optical beam is received. In some cases, the LiDAR window may be a protective window that isolates the LiDAR from the surrounding environment and protects the LiDAR from possible contamination (e.g., dust and moisture, etc.). In some such cases, the LiDAR window may include a surface (e.g., a cylindrical surface, a spherical surface, or a surface having other shapes) that surrounds the LiDAR so that the optical detection beam and the reflected optical beam emitted or received in any direction pass through the LiDAR window in the following manner: the optical path between the entry point to the LiDAR window and the exit point from the LiDAR window is a straight optical path. In some examples, the LiDAR window may be a cylindrical window including a cylindrical shell having a thickness, and the LiDAR may be placed inside the cylindrical shell (e.g., close to the axis of the cylinder). In some cases, the LiDAR window may be referred to as an annular lens. In some cases, the LiDAR window may have other shapes. For example, a LiDAR window may include a shell including an inner surface and an outer surface that are parallel to the shell axis and have a non-circular cross-section in a plane perpendicular to the axis. In some cases, a LiDAR window may include a conical shell.

[0047] In some cases, the detection system 104 can be configured to receive light or light beams within a field of view (FOV) 122 of the detection system 104. For example, light or light beams incident on an entry aperture of the detection system 104 and propagating along a direction associated with the field of view 122 can be received by a LiDAR sensor (e.g., one or more photoelectric converters or photodiodes) of the detection system 104, which generates an electrical signal proportional to the power or intensity of the received light. In this way, in addition to the reflected optical beam 109 received from the object via a straight optical path, the detection system 104 can also receive one or more additional optical beams propagating within the FOV 122 of the detection system 104 toward the entry aperture of the detection system 104.

[0048] In some cases, artifacts on or within the LiDAR window can redirect a portion of the light incident on the LiDAR window such that the redirected portion is captured and guided by the LiDAR window via total internal reflection (TIR). In some such cases, the guided light can be coupled out of the LiDAR window and reach the LiDAR, resulting in the generation of false and / or erroneous return signals.

[0049] For example, a portion of the optical beam reflected by the object 110 may be guided by the LiDAR window (e.g., propagates within the thickness of the LiDAR window), and may ultimately be scattered along directions within the FOV 122 toward the entry aperture of the detection system 104. In some cases, this may cause the LiDAR detection system 104 to generate a false return signal if the intensity of the scattered light propagating along directions within the FOV 122 toward the entry aperture of the detection system 104 is above the detection threshold of the detection system 104. A false return signal may be a return signal that is not associated with a reflection of an optical probe beam received from an object via a nearly straight or non-reflecting optical path. In some cases, a false return signal may indicate the presence of an unreal or false object.

[0050] In some cases, the optical detection beam of the LiDAR may include a narrow beam with a low divergence. In some such cases, the divergence of the optical detection beam may be less than 0.1 degrees, less than 1 degree, less than 5 degrees, or less than 10 degrees. In some cases, the optical detection beam of the LiDAR may include a wide beam with a large divergence. In various embodiments, the LiDAR system may move and rotate one or more optical detection beams relative to the rotation axis of the LiDAR within an azimuth range to scan the environment. In some cases, the detection system of the LiDAR may have a wide field of view (FOV) or a narrow field of view (FOV). In some cases, the field of view of the LiDAR may have an azimuth width and a polar angle width greater than 10 degrees, greater than 30 degrees, or greater than 50 degrees. In some cases, the field of view of the LiDAR system may have an azimuth width of about 60 degrees and a polar angle width of about 50 degrees.

[0051] Figure 2A is a diagram illustrating a perspective view of a LiDAR 100 placed inside a cylindrical LiDAR window 200. The cylindrical LiDAR window 200 may include a cylindrical shell having an outer diameter (D), an inner diameter (d), an outer surface 201a, an inner surface 201b, and a thickness (W) substantially equal to the distance between the outer surface 201a and the inner surface 201b in a radial direction (e.g., a direction perpendicular to the outer surface 201a and the inner surface 201b). The cylindrical window 200 may have a height (H) extending between the bottom surface and the top surface of the cylindrical shell. In some cases, an anti-reflection (AR) layer may be disposed on the outer surface 201a and / or the inner surface 201b of the LiDAR window 200 to reduce reflection of light by these surfaces. The AR layer may include one or more dielectric layers configured to reduce reflection of light having a wavelength within the operating wavelength range of the LiDAR.

[0052] In some examples, the thickness (W) can be 1 mm to 2 mm, 2 mm to 3 mm, 3 mm to 4 mm, 4 mm to 5 mm, or any range formed by any of these values ​​or greater or lesser values.

[0053] In some examples, the outer diameter (D) can be 5 cm to 10 cm, 10 cm to 20 cm, 30 cm to 40 cm, 40 cm to 50 cm, or any range formed by any of these values ​​or greater or lesser values.

[0054] In some examples, the height (H) can be 5 cm to 10 cm, 10 cm to 20 cm, 30 cm to 40 cm, or any range formed by any of these values ​​or larger or smaller values.

[0055] In some cases, the window material may include different types of glass, thermoplastic polymers (eg, polycarbonate), or other materials.

[0056] In some implementations, the LiDAR 100 may emit a light beam (e.g., a laser beam) that rotates about a rotation axis 206 (e.g., a vertical rotation axis such as the z-axis shown in the figure) to scan the environment around the LiDAR 100. In some cases, the rotation axis 206 may be parallel to or may overlap with the axis of the cylindrical LiDAR window 200 (e.g., the symmetry axis of the cylindrical LiDAR window perpendicular to its top and bottom surfaces).

[0057] At a given time during a rotation cycle, the LiDAR may emit multiple optical detection beams propagating in different directions relative to the emission axis 208. In some examples, the emission axis or emission direction may be perpendicular to the rotation axis. In some embodiments, the propagation directions of the multiple beams relative to the emission axis 208 may be within an azimuth range in a plane perpendicular to the rotation axis 206, and within a polar angle range in a plane parallel to the rotation axis 206. In some examples, multiple beams may be associated with multiple LiDAR channels. Each channel of the LiDAR 100 may emit one or more than one beam, and the beams emitted by a single LiDAR channel may be substantially parallel to each other. In some cases, the angle between the beams emitted by a single LiDAR channel may be less than 2 degrees. In some cases, the number of beams emitted by the LiDAR may be 5 to 10, 10 to 20, 20 to 30, 30 to 40, 40 to 50, 50 to 70, 70 to 100, 100 to 200, or any number greater or less.

[0058] LiDAR100 can emit multiple light beams via the LiDAR exit aperture. In some cases, the LiDAR exit aperture can have a height along the rotation axis 206 and a width along a direction perpendicular to the rotation axis. In some cases, a single beam is emitted by a single channel of the LiDAR. In some implementations, multiple light beams can include light beams directed to different directions at different times using a movable optical reflector of LiDAR100. For example, LiDAR100 can include a movable mirror that scans the surrounding environment by reflecting a light beam (e.g., a laser beam) generated by a light source (e.g., a laser source) of the LiDAR in different directions. The mirror can rotate around the rotation axis 206 while scanning the polar angle of the mirror relative to the rotation axis 206 back and forth within a set polar angle range, so that during the rotation cycle, the reflected light beam rotates around the rotation axis 206 while its propagation direction changes within the set polar angle range.

[0059] In some cases, transmit axis 208 may rotate about rotation axis 206 of LiDAR 100 in a rotational period or scanning period (T). Multiple transmit beams may rotate about rotation axis 206 such that the propagation direction of each beam relative to transmit axis 208 remains constant during the rotational period.

[0060] Figure 2B 2 is a diagram illustrating the emission of two optical probe beams by a LiDAR 100 placed inside a LiDAR window 200 (e.g., a cylindrical LiDAR window) and the reception of corresponding reflected beams (reflected from an object 110). In some cases, an optical probe beam 202a emitted by the LiDAR 100 may become incident on the surface of the object 110 at a normal angle (incident angle 0). In some such cases, a corresponding reflected optical beam 202b (a reflection of the optical probe beam 202a) may overlap with the optical probe beam 202a and may be received by the LiDAR 100 within its FOV. In some cases, an optical probe beam 204a emitted by the LiDAR 100 may be incident on the surface of the object 110 at a non-zero incident angle. In some such cases, a corresponding reflected optical beam 204b (a reflection of the optical probe beam 202a) may propagate back to the LiDAR along a direction different from the propagation direction of the optical probe beam 204a and may be received by the LiDAR 100 within its FOV. The angle between the optical detection beam 204a and the reflected optical beam 204b may be less than 2 degrees, or less than 5 degrees. In some implementations, the detection system 104 of the LiDAR 100 may receive the reflected optical beams 202b and / or 204b and generate a return signal that may be used (e.g., by the LiDAR processing system 106) to determine the distance L between the object 110 and the LiDAR 100. Figure 2BAs shown, reflected optical beams 202b and 204b are transmitted through the LiDAR window 200 before being received by the LiDAR 100. The reflected optical beams 202b and 204b may be transmitted through the LiDAR window by entering and exiting the thickness of the LiDAR window 200 via the outer surface 201a and the inner surface 201b, respectively. In some cases, more than 90%, 95%, or 98% of the light intensity (or power) associated with the reflected optical beams 202b and 204b incident on the LiDAR window 200 may be transmitted through the thickness (W) of the LiDAR window 200 and directly reach the LiDAR 100 without being scattered or reflected by the inner surface 201b or the outer surface 201a of the LiDAR window 200.

[0061] In some implementations, the LiDAR window 200 can be formed of a material having very low optical absorption for light having a wavelength within the operating wavelength range of the LiDAR. In some cases, the optical absorption of the window material (e.g., used to form a conventional LiDAR window) can be selected so that for a propagation distance equal to the thickness (W) of the LiDAR window 200, the attenuation of an optical beam (e.g., a probe optical beam or a reflected optical beam) propagating through the window material can be less than 10%, less than 8%, less than 4%, less than 2%, or less than 1%. In some examples, the window material of the conventional LiDAR window can be selected so that the reflected optical beams 202b and 204b are attenuated (due to optical absorption) by less than 0.1 dB, less than 0.05 dB, or less than 0.01 dB after passing through the thickness W of the LiDAR window 200. The thickness of the window can be the distance between the inner surface 201b and the outer surface 201a along a direction perpendicular to the inner surface 201b and the outer surface 201a.

[0062] False return signals are generated by light guided within the thickness of the LiDAR window

[0063] In some cases, at least a portion of the optical beam incident on the LiDAR window may be received by the LiDAR detection system via an indirect optical path after being reflected by the object. In some cases, the indirect optical path may include at least one reflection from the surface of the LiDAR window. For example, a portion of the incident optical beam 204b may be received by the detection system of LiDAR100 via an indirect optical path after being reflected once or more than once by the outer surface 201a and / or the inner surface 201b of the LiDAR window 200. In some cases, the indirect optical path between the object and the LiDAR may be longer than the distance between the LiDAR and the first object detected by the LiDAR. In some such cases, based on the longer delay associated with the indirect optical path, the return signal generated by the LiDAR may falsely indicate that at least the second object is located at a farther distance relative to the first object. In some cases, at least a portion of the indirect optical path may be defined by the inner surface 201b and the outer surface 201a of the LiDAR window 200 and extend from a first location on the inner surface 201b or the outer surface 201a of the LiDAR window 200 to a second location on the inner surface 201b or the outer surface 201a of the LiDAR window 200.

[0064] In some cases, the incident optical beam may be a reflection of the optical detection beam. In some cases, the incident optical beam may be a scattering of the optical detection beam. In some cases, the reflected optical beam and the scattered optical beam may be generated by an object detected based on the optical detection beam that generated the reflected optical beam and the scattered optical beam.

[0065] In some cases, a portion of an optical beam incident on a LiDAR window, after being reflected or scattered by an object, may be scattered by a first artifact at a first location of the LiDAR window in a direction different from the original propagation direction in which it propagated. In some such cases, the portion of the optical beam scattered by the artifact may be guided within the thickness of the LiDAR window via total internal reflection (TIR) ​​by the inner and outer surfaces of the LiDAR window. Subsequently, the guided light may be scattered outside the thickness of the LiDAR window by the first artifact or the second artifact at the second location. The light scattered outside the thickness of the window may propagate toward the detection system of the LiDAR along a direction within the FOV of the detection system.

[0066] In some cases, the optical path length for a portion of the incident optical beam received by the detection system after being directed by the LiDAR window can be longer than the optical path length for another portion of the incident optical beam received directly by the detection system without being scattered and / or reflected (e.g., via a substantially straight optical path).

[0067] In some cases, the power or intensity of the portion of the incident optical beam received by the detection system after being directed by the LiDAR window may be large enough (e.g., greater than a detection threshold of the detection system) to cause the detection system to generate a return signal. Such a return signal generated by indirectly received light may indicate the presence of an unreal object at a distance longer than the distance between the object from which the incident light beam originated and the LiDAR.

[0068] Considering that the energy and intensity of the reflected optical beam propagating toward the LiDAR decrease according to the inverse square law, the optical power and intensity of the optical beam reflected by the near-field object may be compared (e.g., by more than 10) to the energy and intensity of the optical beam reflected by the far-field object until it becomes incident on the LiDAR window. 2 , 10 3 , 10 6 , 10 9 In some examples, when an object is within the near-field range of the LiDAR, the intensity and / or power of the reflected optical beam associated with the optical probe beam emitted by the LiDAR and reflected from the object can be so great that even a small portion of the reflected optical beam received by the detection system via indirect and guided optical paths defined by the thickness of the LiDAR window still causes the detection system to generate a return signal. In various examples, the power of the portion of the incident light beam received by the detection system via an indirect path (including the portion guided within the thickness of the LiDAR window) can be less than 6%, 5%, 2%, 1%, or 0.1% of the power of the incident light beam.

[0069] In some cases, near-field objects may be objects located in the near-field range of the LiDAR, and may include objects located at a distance shorter than 2 meters relative to the LiDAR. In some cases, far-field objects may be objects located in the far-field range of the LiDAR, and may include objects located at a distance longer than 2 meters relative to the LiDAR.

[0070] In some cases, the generation of false return signals associated with light indirectly received via a guided light path defined by the thickness of a LiDAR window may interfere with the proper performance of two remote LiDARs designed to detect far-field objects (e.g., objects located within the far-field range of the LiDAR). For example, in some cases, a portion of an optical probe beam emitted by a far-field LiDAR toward a far-field object may be scattered or reflected by a near-field object and transformed by artifacts on the LiDAR window into guided light propagating within the thickness of the LiDAR window. Given that the intensity of the reflected optical beam associated with the reflection of the optical probe beam from the far-field object may be much lower than the intensity of even a small portion of the same optical probe beam reflected from the near-field object, the guided light, when directed to the detection system, may result in the generation of a return signal that is larger than the return signal generated by the reflection of the optical probe beam by the far-field object.

[0071] In some cases, artifacts on or within the thickness of the LiDAR window may include water droplets, particles (e.g., dust particles), defects in the LiDAR window (e.g., local variations in thickness or refractive index or material composition), or any optical scattering centers that may redirect at least a portion of an incident light beam from its original propagation direction or from a path associated with refraction of light at an interface between the LiDAR window and the surrounding medium (e.g., air).

[0072] In some cases, light received by the detection system of the LiDAR via an indirect optical path and directed by the LiDAR window can generate noise and reduce the signal-to-noise ratio of the return signal generated by reflection of the optical probe beam by near-field objects. In some cases, the noise associated with the portion of light received via the indirect optical path and directed by the LiDAR window can be referred to as near-field noise.

[0073] In some cases, a portion of the incident optical beam scattered by small scattering centers on or within the LiDAR window may generate more than one false return signal. For example, light directed by the LiDAR window may travel around the perimeter of the LiDAR window several times, and during each round trip, at least one false return signal may be generated by scattering of a portion of the directed light toward the detection system.

[0074] Figure 3A3 is a diagram illustrating an optical beam 302a incident on the LiDAR window 200 at a first point 304 on the LiDAR window 200. In some cases, the optical beam 302a may be a reflected optical beam or a scattered optical beam associated with an optical probe beam sent by the LiDAR 100 placed inside the LiDAR window 200. The first point may include a first artifact that scatters a portion of the optical beam 302a such that the resulting scattered optical beam 302b becomes incident on the inner surface 201b of the LiDAR window 200. In some cases, the incident angle of the optical beam 302b relative to the inner surface 201b may be equal to or greater than the critical angle (θ ) for the interface between air and the material constituting the LiDAR window. c ). For example, the incident angle of the optical beam 302b on the inner surface 201b may be greater than Sin -1 (1 / n), where n is the refractive index of the material for light of a wavelength substantially equal to the wavelength of the incident optical beam 302a. In some cases, the optical beam 302b may be partially or fully reflected by the inner surface 201b, and the resulting reflected optical beam 302c may become incident on the outer surface 201a. In some cases, the incident angle of the optical beam 302c relative to the outer surface 201a may be equal to or greater than the critical angle (θ c ). The optical beam 302c may be partially or fully reflected a second time by the outer surface 201a and become incident on the inner surface 201b again. This sequence of being reflected by the inner surface 201b and the outer surface 201a of the LiDAR window may be repeated several times, which results in the guided light propagating within the thickness (W) of the LiDAR window 200. In some cases, the portion of the incident beam 302a scattered by the first scattering center may be coupled into a bounded optical mode of the LiDAR window (defined by the inner and outer surfaces of the LiDAR window). In this case, the LiDAR window may be used as an optical waveguide for guiding the scattered portion of the incident beam 302a around the perimeter of the LiDAR window. In some cases, the second artifact may scatter at least a portion of the guided light (or optical mode) outside the thickness of the LiDAR window 200. In some examples, the first artifact and the second artifact may be on the inner surface 201b, on the outer surface 201a, or within the thickness of the LiDAR window 200.

[0075] exist Figure 3AIn the example shown, the guided optical beam may be scattered by a second artifact at a second point 306 of the outer surface 201a of the LiDAR window 200 toward the LiDAR 100 in a direction within the FOV 122 of the LiDAR system 100 (the FOV of the detection system of the LiDAR). The relative angular position 308 between the first point 304 where the guided propagation of the scattered optical beam 302b begins and the second point 306 where the guided optical beam is coupled outside the thickness of the LiDAR window may be greater than 180 degrees, 200 degrees, 270 degrees, or 300 degrees.

[0076] In some cases, the location of the second artifact (e.g., point 306) and the propagation direction of the optical beam 302d scattered by the second artifact can cause the scattered optical beam 302d (the light coupled outside the thickness of the window) to propagate toward the aperture of the LiDAR detection system in a direction within the FOV 122 of the detection system. In some such cases, the scattered optical beam 302d can cause the LiDAR detection system to generate a return signal (a false return signal) when the light intensity (or power) of the scattered optical beam 302d is greater than a threshold intensity (or threshold power) detectable by the detection system. Such a return signal may falsely indicate the presence of an object in the direction in which the detection system received the scattered light. In some cases, where the incident optical beam 302a is associated with the reflection of the optical detection signal by the object, the false return signal may indicate an incorrect distance between the object and the LiDAR, which is substantially equal to the distance between the object and the LiDAR 100 (from which the incident optical beam 302a originates) + a false distance associated with the guided optical path length between the first point 304 and the second point 306.

[0077] In some cases, the first point 304 and the second point 306 may be in a plane perpendicular to the axis (e.g., z-axis) of the LiDAR window 200, and the guided light may propagate in the same plane. In some other cases, the first point 304 and the second point 306 may be in two different planes perpendicular to the axis (e.g., z-axis) of the LiDAR window 200, and the guided light may propagate along a spiral-shaped optical path.

[0078] In some cases, the light guided by the LiDAR window 200 may propagate several times inside the thickness (W) of the LiDAR window 200 around the perimeter of the LiDAR window 200. In some such cases, during each round trip, a portion of the guided optical beam may be coupled outside the thickness of the window by one or more artifacts along the perimeter of the LiDAR window. Some of the optical beams coupled outside the thickness of the window may propagate toward the LiDAR detection system within the FOV of the detection system. In these cases, if the portion of the guided light scattered toward the LiDAR detection system has an optical intensity (or power) greater than a threshold intensity (or power) detectable by the LiDAR detection system (a detection threshold of the LiDAR detection system), one or more false return signals may be generated by the detection system during each round trip of the guided optical beam. Each false return signal may indicate a false distance between an unreal object and the LiDAR. In this way, a single artifact or scattering center around the perimeter of the window may generate multiple false return signals associated with the scattering of light by the artifact during different round trips.

[0079] In some cases, where the incident optical beam (converted into a portion of the guided light) is associated with the interaction of the optical detection signal with an object, a false return signal generated by the scattered optical beam 302d coupled out of the LiDAR window after N complete round trips around the perimeter of the LiDAR window may indicate that the distance between the unreal object and the LiDAR is substantially equal to the distance between the object (from which the incident optical beam originated) and the LiDAR + a false distance including the N round trips and the optical path length within the thickness of the LiDAR window between a first artifact that transforms a portion of the incident optical beam into guided light and a second artifact that scatters a portion of the guided light toward the detection system. Continued with reference to Figure 3A In some examples, the guided light generated at point 304 may complete N round trips around the LiDAR window 200 (starting from point 304 and returning to point 304 (or near point 304), which corresponds to a 360-degree rotation) before being scattered toward the detection system at point 306. Assuming that the relative angular position 308 between point 304 and point 306 is φ degrees, the false light path indicated by the return signal generated by the scattered optical beam 302d can be estimated as [N+(φ / 2π)]×n e ×πD a , where n e is the effective refractive index for guiding light propagation within the thickness (W) of the LiDAR window 200, and D a is the average diameter of the LiDAR window. In some cases, D a can be estimated as (D+d) / 2.

[0080] As described above, the sensor of the detection system may include multiple sensing elements (pixels) to convert received light into photocurrent. In some cases, these sensing elements may be located at different positions relative to the entrance window of the detection system. In some cases, when the LiDAR steers the optical detection beam, a group of pixels may be activated substantially simultaneously. In some such cases, when the reflected light from the object is scattered by an artifact (e.g., on or within the LiDAR window) and the guided light so obtained is received by the detection system, the activated group of pixels may generate a photocurrent indicating the presence of multiple false objects that form a first halo around the actual object (from which the reflected light is received). In some cases, when the guided light propagates multiple round trips within the thickness of the window, multiple halos may be formed (e.g., as a result of the guided light coupling outside the window thickness), which indicate different distances farther from the LiDAR than the actual object and the first halo.

[0081] Figure 3B is a diagram illustrating an example of the effect of receiving multiple guided optical beams via a LiDAR window by a LiDAR detection system on the angular width of detected objects and the identification of multiple false objects having falsely enlarged angular widths. Figure 3B 1 shows that when a LiDAR system receives multiple guided optical beams via a LiDAR window, a reflected optical beam from a single near-field object can generate a false positive return point cloud covering an azimuth angle greater than the azimuth angle of the actual angular width of the single near-field object, and also produces a cloud of false points at multiple distances. In the example shown, reflection of an optical probe beam by a small object 330 having an angular width of 1 degree can cause the detection system to generate multiple return signals indicating multiple points forming a first halo 333 and a second halo 337, wherein the total angular width 342 of the first halo and the second halo is about 32 degrees, and the angular width of the first segment 332 of the first halo 333 and the first segment 336 of the second halo 337 is about 16 degrees. In some cases, the first halo 333 can be associated with a scattered portion of the guided light during a first round trip, and the second halo can be associated with a scattered portion of the guided light during a second round trip. In this way, in the presence of artifacts (scatter centers) on or inside the window, a single small near-field object can cause a return signal indicating a cloud of concentric false points to be generated.

[0082] Figure 4Ais a diagram illustrating an example detection of an object 110 by a LiDAR 100 surrounded by a LiDAR window 200 having one or more scattering centers. In some cases, the object 110 may be an object located in the near-field range of the LiDAR 100. The scattering center may be on a surface or within the LiDAR window 200. The LiDAR 100 may emit an optical probe beam 310 that passes through the thickness (W) of the LiDAR window 200 and propagates toward the object 110. The surface of the object 110 may reflect at least a portion of the incident optical probe beam 310 toward the LiDAR window 200. In some cases, the reflection of the incident optical probe beam 310 from the object 110 may be a specular reflection. The reflected optical beam 312a may become incident on a point 314 on the surface of the LiDAR window 200. In some cases, at least a portion 312b of the reflected optical beam 312a may be transmitted through the thickness (W) of the LiDAR window 200 without being scattered or reflected, and become incident on the detection system of the LiDAR 100, which causes the detection system to generate a return signal indicating the presence of the object 110 at a distance L relative to the LiDAR 100. In some cases, a scattering center (e.g., a dust particle, a water droplet, a surface defect, or a defect below the surface) located at the point of incidence 314 may partially scatter at least a portion 312c of the reflected optical beam 312a and cause the portion to propagate and be guided within the thickness (W) of the LiDAR window 200 along an optical path defined by the inner surface 201b and the outer surface 201a of the LiDAR window 200. In some cases, at a certain point around the perimeter of the LiDAR window (e.g., point 316), a portion 312d of the guided portion 312c of the reflected optical beam 312a may be scattered toward the LiDAR 100 by another scattering center. In some such cases, when optical beam 312d (the portion of the guided light that is scattered outside the thickness of the window) is received by the detection system and its intensity exceeds the detection threshold of the detection system, this can result in the generation of a false return signal indicating that a second object (false object) is located at a distance L+S1, where S1 is the longer optical path length between point 314 and point 316 defined by the thickness of the LiDAR window.

[0083] Figure 4Bis a diagram illustrating another example of detection of an object 110 by a LiDAR 100 surrounded by a LiDAR window 200 having one or more scattering centers. In this example, the reflection of an incident optical probe beam 310 from the object 110 may include diffuse reflection or diffraction in addition to specular reflection. In some cases, at least a portion of the reflected optical beam 312a may be transmitted through the thickness (W) of the LiDAR window 200 and become incident on the detection system of the LiDAR 100, which causes the detection system to generate a return signal indicating the presence of the object 110 at a distance L relative to the LiDAR 100. In some cases, a portion 324a of the incident optical probe beam 310 that is diffused or scattered by the object 110 may become incident on a point 326 on the LiDAR window 200. In some such cases, a scattering center located at the incident point 326 may partially scatter at least a portion 324b of the scattered or diffused optical beam 324a and cause the portion to propagate within the thickness (W) of the LiDAR window 200 along an optical path defined by the inner surface 201b and the outer surface 201a of the LiDAR window 200. At some point around the perimeter of the LiDAR window (e.g., point 328), a portion 324c of the guided portion 324b may be scattered toward the LiDAR 100 by another scattering center. When the optical beam 324c (the portion of the guided light that is scattered outside the thickness of the window) is received by the detection system and its intensity exceeds the detection threshold of the detection system, this may result in the generation of a false return signal indicating that a second object (false object) is located at a distance L+S2, where S2 is the longer optical path length between point 326 and point 328 defined by the thickness of the LiDAR window.

[0084] refer to Figure 4A and Figure 4B , false return signals generated by portions of the guided light that are scattered outside the thickness of the LiDAR window (e.g., optical beams 312d and 324c) can cause the LiDAR system to falsely indicate that multiple objects are located at different distances relative to the LiDAR (rather than a single object).

[0085] In various implementations, the LiDAR window can be configured to reduce the probability of generating a false return signal by the portion of the guided light (e.g., optical beams 312d and 324c) that is scattered outside the thickness of the LiDAR window 200. In some examples, optical propagation losses for light propagating within the thickness of the LiDAR window can be increased to reduce the intensity of the guided light. In some examples, the shape of the window can be customized to direct the guided light away from the field of view of the LiDAR's detection system.

[0086] Attenuates light propagating within the thickness of the LiDAR window

[0087] As described above, a portion of the light directed within the thickness of the LiDAR window 200 may be scattered by the artifacts (scattering centers) in directions within the FOV 122 of the detection system of the LiDAR 100 and may therefore be received and detected by the detection system. Figure 3A , Figure 4A and Figure 4B When the intensity of the incident optical beam 302a, 312a, or 324a in the LiDAR window is sufficiently large (e.g., when the object 110 is a near-field object), the intensity of the portion of the guided light received by the detection system can exceed a threshold intensity (detection threshold) required to cause the detection system to generate a false return signal. In some cases, the threshold intensity or detection threshold can be an intensity above which the photocurrent generated by the sensor of the detection system becomes greater than the background photocurrent (or background noise) of the detection system. The false return signal can indicate a false or erroneous distance between the LiDAR and the object, or the presence of an unreal object at a false distance. The false distance can include the distance between the LiDAR and the object, and a false distance associated with the optical path length between an entry point (through which the optical beam incident on the LiDAR window is transformed (e.g., an artifact) into light guided by the boundaries of the LiDAR window (e.g., the inner surface 201b and the outer surface 201a)) and an exit point (from which the light is scattered toward the detection system). Figure 3A , Figure 4A and Figure 4B In the example shown, the false distance may be the length of the optical path between point 304 and point 306, point 314 and point 316, or point 326 and point 328, where the optical path is bounded by inner surface 201b and outer surface 201a of the LiDAR window. In some cases, the false distance may be the longer optical path between point 304 and point 306, point 314 and point 316, or point 326 and point 328, where the optical path is bounded by inner surface 201b and outer surface 201a of the LiDAR window. In some cases, the false distance may be estimated as [N+(φ / 2π)]×n e ×πD a , where n e is the effective refractive index for the propagation of guided light within the thickness of the LiDAR window, D a =(D+d) / 2 is the average diameter of the LiDAR window, N is an integer (0, 1, 2, 3, ..), and φ is the larger angular difference between point 304 and point 306, point 314 and point 316, or point 326 and point 328. In some cases, φ may be the reflex angle. In some cases, φ may be the smaller angular distance between point 304 and point 306, point 314 and point 316, or point 326 and point 328.

[0088] In some implementations, a lower limit on the optical absorption coefficient of the LiDAR window material may be selected such that for a given range of powers (or intensities) of an incident optical beam (e.g., incident optical beams 302a, 312a, or 324a), the powers (or intensities) of the corresponding optical beams (e.g., optical beams 302d, 312d, and 324c) scattered outside the LiDAR window remain below a detection threshold intensity of the detection system. In these implementations, an upper limit on the optical absorption coefficient may be determined based on the thickness (W) of the LiDAR window such that for a range of powers (or intensities) of an optical probe beam emitted by the LiDAR, the powers (or intensities) of the corresponding reflected optical beams (e.g., incident optical beams 302d, 312d, and 324c) received from the object remain below a detection threshold intensity of the detection system. Figure 4A and Figure 4B The reflected optical beam 312a in the optical beam is transmitted via a direct path (eg, Figure 4A and Figure 4B The transmitted optical beam 312b in the LiDAR window can be detected by the LiDAR detection system after passing through the window. In some cases, both the lower and upper limits of the optical absorption for the LiDAR window can be estimated based at least in part on the power (or intensity) range of the optical detection beam (e.g., optical detection beam 310) emitted by the LiDAR and the operating distance (or detection range) of the LiDAR.

[0089] In some cases, the window material may be selected such that for a first propagation distance equal to a selected, calculated, or estimated attenuation distance for the LiDAR system, attenuation of light having a wavelength within the operating wavelength range of the LiDAR and propagating inside the window material is greater than 10 times, greater than 100 times, greater than 1000 times, or greater than 10,000 times as compared to a second propagation distance equal to the thickness (W) of the LiDAR window. In some cases, the attenuation distance may be substantially equal to the pseudo distance or optical path associated with directing propagation of light within the LiDAR window. The thickness (W) of the LiDAR window (also referred to as the window thickness) may be the distance between the inner and outer surfaces of the LiDAR window along a direction perpendicular to the inner and outer surfaces of the LiDAR window.

[0090] In some examples, the attenuation distance may be the length of a guided light path between a first point (e.g., point 304, 314, or 326) at which a first artifact scatters a portion of an optical beam incident on the window (e.g., incident optical beam 302a, 312a, or 324a) and a second point (e.g., point 306, 316, or 328), where the guided light path passes through the thickness of the LiDAR window (e.g., LiDAR window 200) and is defined by the inner and outer surfaces of the LiDAR window. In some cases, the attenuation distance may be the longer guided light path between the first point and the second point. In some cases, the attenuation distance may be the shorter guided light path between the first point and the second point.

[0091] In some implementations, the attenuation distance may be estimated based at least in part on the diameter of the LiDAR window (e.g., inner diameter d, outer diameter D) and the FOV of the LiDAR detection system. In some cases, the operating distance range of the LiDAR (e.g., near field or far field) and / or certain characteristics of objects in the environment may be considered when estimating the attenuation distance.

[0092] In some cases, the attenuation distance can be estimated as [N+(φ / 2π)]×πD a , where D a =(D+d) / 2 is the average diameter of the LiDAR window, and N is an integer (0, 1, 2, 3, ..). In some cases, φ is the angular difference between a first point (e.g., point 304, 314, or 326) at which a first artifact scatters a portion of an optical beam incident on the window (e.g., incident optical beam 302a, 312a, or 324a) and a second point (e.g., point 306, 316, or 328) from which the corresponding guided light is scattered toward the LiDAR 100, where the path is defined by the inner and outer surfaces of the LiDAR window. In some cases, φ may be the smaller angular distance between the first and second points. In some cases, φ may be the reflex angle. In some cases, φ may be the smaller angular distance between the first and second points. In some cases, φ may be an acute angle or an obtuse angle.

[0093] In some cases, the attenuation distance may be substantially equal to the perimeter (π×D) or average perimeter (π×D / 2+π×d / 2) of the LiDAR window. In various implementations, the attenuation distance of the LiDAR may be from 20 cm to 30 cm, from 30 cm to 50 cm, from 50 cm to 100 cm, from 100 cm to 500 cm, from 500 cm to 1000 cm, or any range formed by any of these values ​​or greater or lesser values.

[0094] refer to Figure 3A , Figure 4A and Figure 4B In some cases, the window material may be selected such that: the propagation of the guided light from the first point to the second point within the thickness of the window attenuates the guided light so that the intensity of the optical beam (e.g., optical beams 302d, 312c, 324c) coupled out of the thickness of the window at the second point is less than the intensity of the portion of the incident beam scattered at the first point (e.g., optical beams 302b, 312b, 324b) by a factor of more than 10, more than 100, more than 1000, or more than 10,000, and the guided light is emitted. In some cases, the window material may be selected such that after propagating within the thickness of the window for a distance equal to the propagation distance, the guided light is attenuated by a factor of more than 10, more than 100, more than 1000, or more than 10,000.

[0095] In various implementations, for a LiDAR window (e.g., the cylindrical LiDAR window 200) having a given outer diameter (D) and thickness (W), the attenuation of light propagating within the thickness of the LiDAR window between a first point and a second point around the perimeter of the LiDAR window can be customized by selecting a window material and / or adjusting the composition of a given window material. For example, the window material can be selected to have an optical absorption coefficient that is greater than a minimum or lower value determined based on an estimated attenuation distance for the LiDAR and the LiDAR window. In addition, the window material can be selected to have an optical absorption coefficient that is less than a maximum or upper value estimated based at least on the thickness (W) of the LiDAR window.

[0096] The lower and upper values ​​of the optical absorption coefficient of the window material may be values ​​associated with absorption of light having a wavelength within the operating wavelength range of the LiDAR. In some implementations, the lower and upper values ​​of the optical absorption coefficient of the window material may be estimated based at least in part on the intensity or intensity range of an optical probe beam (e.g., optical probe beam 310) emitted by the LiDAR.

[0097] In some examples, the initial strength I 0 The beam can be calculated according to the equation I(z) = I 0 ×e -αz Attenuation, where: I(s) is the absorption coefficient of the beam at the wavelength of the beam (unit: cm -1 ) after propagating z centimeters in the material. Thus, the optical beam is attenuated by e by passing through the thickness (W) of the LiDAR window in the radial direction perpendicular to the surface of the window. -αW , and propagates in the window material for a distance equal to the attenuation distance (s), which can cause the optical beam to attenuate e -αs Therefore, the first beam propagating inside the window material along a propagation distance equal to the attenuation distance of the LiDAR can be attenuated more than the second beam propagating inside the window material along a propagation distance equal to the window thickness (W). α(s-W) times.

[0098] The intensity I of the incident beam (e.g., 302a, 312a, or 324a) 1 and the intensity I of the corresponding light beams (e.g., 302d and 312d) coupled out of the window thickness (W) and received by the LiDAR detection system 2 The relationship between can be written as 2 =I 1 ×e -α(s) ×β entry ×β exit , where β entry and β exit are the inbound coupling efficiency coefficient and the outbound coupling efficiency coefficient. For example, βentry ×I 2 can be the intensity of the guiding light generated by the incident beam at the incident point (e.g., points 304, 314, 326). If the intensity of the guiding light at the exit point (e.g., points 306, 316, 328) is I 3 , then the intensity of the light coupled outside the window thickness at the exit point can be β exit ×I 3 . The intensity I 1 of the incident beam (e.g., 312a) and the intensity I 4 of the corresponding light beam passing through the thickness (W) of the LiDAR window along the radial direction perpendicular to the surface of the window 4 can be written as I 1 =I -α(w) ×e entry ×γ, where γ is the transmission coefficient for air-window and window-air at near-normal incidence. Thus, the ratio of the attenuation of the light received by the LiDAR detection system via the guiding optical path having a length equal to the attenuation distance (s) to the attenuation of the light received by the LiDAR detection system via the direct optical path through the window can be expressed as [(β exit ) / γ]×e α(s-W) .

[0099] In some cases, the lower limit of the optical absorption coefficient of the window material can be estimated using the inequality e α(s-W) >M1 or α>ln(M1) / (s - W), where M1 is the desired factor by which the attenuation through the attenuation distance of the LiDAR should exceed the attenuation through the thickness of the LiDAR window (where ln represents the natural logarithm). In some cases, M1 can be from 10 to 100, from 100 to 1000, from 10 3 to 10 4 , from 10 4 to 10 5 , or any range formed by any of these values or larger or smaller values.

[0100] In some cases, the lower limit of the optical absorption coefficient of the window material can be estimated using the inequality e -αs <M2 or α>ln(M2) / s, where M2 is the desired factor by which the optical beam should attenuate after propagating through a distance equal to the attenuation distance of the LiDAR in the window material. In some cases, M2 can be from 5 to 10, from 10 to 100, from 100 to 1000, from 10 3 to 10 4 , from 10 4 to 10 5 , or any range formed by any of these values or larger or smaller values.

[0101] In some cases, the upper limit of the optical absorption coefficient of the window material can be obtained using the inequality e -αW >M3 or α<-ln(M3) / W, where M3 is the expected transmittance of the optical beam through the thickness (W) of the LiDAR window in the radial direction perpendicular to the surface of the LiDAR window. In some cases, M3 can be from 90% to 94%, from 94% to 97%, or from 97% to 100%.

[0102] In some cases, the lower limit of the optical absorption coefficient of the window material can be obtained using the inequality [(β entry ×β exit ) / γ]×e α(s-W) >M4 or α>ln(M1 / [(β entry ×β exit ) / γ]) / (sW), where M4 is a desired factor by which the intensity of the first portion of the incident optical beam received by the detection system via an indirect guided optical path (within the thickness of the window) should be less than the intensity of the second portion of the incident optical beam received by the detection system via a direct optical path (through the thickness of the window). In some cases, M4 can be from 5 to 10, from 10 to 100, from 100 to 1000, from 10 3 to 10 4 , from 10 4 to 10 5 , or any range formed by any of these values ​​or larger or smaller values.

[0103] In various implementations, the optical absorption coefficient of the window material may be capped at 1 cm -1 Up to 2cm -1 , from 2cm -1 Up to 3cm -1 , from 3cm -1 Up to 5cm -1 , or any range formed by any of these values ​​or larger or smaller values. In various implementations, the lower limit of the optical absorption coefficient of the window material can be from 0.05 cm -1 To 0.07cm -1 , from 0.07cm -1 To 0.1cm -1 , from 0.1cm -1 To 0.5cm -1 , or any range formed by any of these values ​​or larger or smaller values.

[0104] In some examples, the lower limit of the optical absorption coefficient may be the value of the absorption coefficient required to reduce the probability of generating a false positive signal associated with light directed within the thickness of the LiDAR window to below a threshold.

[0105] In some cases, a lower limit on the optical absorption coefficient can be estimated based on a longer guided optical path length between a first point (from which an incident optical beam can be scattered and guided by the LiDAR window) and a second point (from which the guided light can be redirected toward the detection system and generate a return signal). In some examples, the location of the second point can be determined based at least in part on the FOV of the LiDAR detection system.

[0106] In some cases, a lower limit on the optical absorption coefficient can be estimated based on a shorter optical path length between a first point from which an incident optical beam can be scattered and guided by the LiDAR window and a second point from which the guided light can be redirected toward the detection system and generate a return signal. In some examples, the location of the second point can be determined based at least in part on the FOV of the LiDAR detection system.

[0107] In some cases, the longer optical path length and the shorter optical path length between the first point and the second point for the LiDAR window may be determined based at least on a diameter of the LiDAR window, a thickness (W) of the LiDAR window, and a FOV of a detection system of the LiDAR inside the LiDAR window.

[0108] In some cases, the longer optical path length between the first point and the second point for the LiDAR window may be determined based at least on a diameter or average diameter of the LiDAR window, a thickness (W) of the LiDAR window, and a FOV of a detection system of the LiDAR inside the LiDAR window.

[0109] In some cases, the lower limit of the optical absorption coefficient for the LiDAR window may be the value of the optical absorption coefficient required to attenuate an optical beam having a wavelength within the operating wavelength range of the LiDAR by a factor of M after propagating along an optical path having a length equal to the attenuation distance determined for the LiDAR window. In some cases, the lower limit of the optical absorption coefficient for the LiDAR window may be the value of the optical absorption coefficient required to attenuate light having a wavelength within the operating wavelength range of the LiDAR and propagating inside the window material by more than a factor of M for a first propagation distance equal to the attenuation distance determined for the LiDAR window as compared to a second propagation distance equal to the thickness of the LiDAR window. In various implementations, M may be greater than 10, 10 ...0, 10000000, 10000000, 10000000, 10000000, 10000000, 100000000, 100000000 4 , 10 5 , 10 6 , but less than 10 7 .

[0110] In some cases, the attenuation distance for the LiDAR window may be equal to the perimeter, average perimeter, portion of the perimeter, or portion of the average perimeter of the LiDAR window. The perimeter of the LiDAR window may be the perimeter of a circular cross-section of the LiDAR window in a plane perpendicular to the axis of symmetry of the LiDAR window and parallel to the inner and outer surfaces of the LiDAR window. In this way, a lower limit on the optical absorption coefficient for the LiDAR window (or a material forming the LiDAR window) may be determined at least in part based on the diameter or average diameter of the LiDAR window. In some cases, where the cross-section of the LiDAR window is non-circular (e.g., a cross-section in a plane perpendicular to the surface of the LiDAR window), the average diameter of the LiDAR window may be estimated based on the maximum and minimum diameters of the outer surface of the LiDAR window, or by integrating the change in the diameter of the outer surface of the LiDAR window.

[0111] In some cases, the upper limit of the optical absorption coefficient of the window material can be the value of the optical absorption coefficient required to attenuate light having a wavelength within the operating wavelength range of the LiDAR and propagating a distance within the window material substantially equal to the thickness (W) of the window by less than 10%, less than 5%, less than 3%, less than 2%, or less.

[0112] In some examples, the window material may include a doped glass or a doped polymer containing a dopant. The optical absorption coefficient of the window material can be adjusted by changing the concentration of the dopant (e.g., dye) inside the glass or polymer. The absorption spectrum of the dopant may have an absorption line that at least partially overlaps the operating wavelength range of the LiDAR. In some cases, the absorption line may include a wavelength within an absorption bandwidth centered on the peak absorption wavelength of the dopant. In some cases, the wavelength of the optical detection beam is within the absorption line of the dopant. For example, the spectral distance between the wavelength of the optical detection beam emitted by the LiDAR and the peak absorption wavelength of the absorption line of the dopant may be less than the absorption bandwidth of the corresponding absorption line. In some cases, the absorption line of the dopant may be within the operating wavelength range of the sensor used in the LiDAR detection system. In some cases, the LiDAR window can be manufactured using injection molding. In some such cases, the concentration of the dopant (e.g., dye) inside the window can be customized by adjusting the concentration of the dopant in the molten material before injecting it into the mold. The upper limit of the concentration of the dopant in the window material can be determined at least in part based on the estimated upper limit of the optical absorption coefficient of the window material. In some cases, a lower limit on the concentration of the dopant in the window material can be determined based at least in part on an estimated lower limit on the optical absorption coefficient of the window material. In some cases, lower and upper limits on the optical absorption coefficient of the window material can be estimated based on the thickness and diameter of the LiDAR window, and the expected values ​​of M, M1, M2, or M3 as described above.

[0113] In some cases, the optical absorption coefficient of the window material can be adjusted, selected or chosen so that the attenuation of a light beam having a wavelength within the operating wavelength range of the optical system and propagating inside the window material is greater than 10 dB, 20 dB, 30 dB, 40 dB, 50 dB or 60 dB for a first propagation distance than for a second propagation distance. In some cases, the optical absorption coefficient of the window material can be adjusted, selected or chosen so that after propagating a distance equal to the first propagation distance, the light beam is attenuated by more than 10 dB, 11 dB, 12 dB, 13 dB, 14 dB, 15 dB, 20 dB, 22 dB, 30 dB, 32 dB, 42 dB, 52 dB, 62 dB. In some cases, the optical absorption coefficient of the window material can be adjusted, selected or chosen so that after propagating a distance equal to the second propagation distance, the light beam is attenuated by less than 1 dB, 1.5 dB, 2 dB, 2.5 dB, 3 dB or 4 dB.

[0114] In some cases, the first propagation distance is equal to the attenuation distance, and the second propagation distance is equal to the window thickness. In some cases, the first propagation distance is substantially equal to the attenuation distance, and the second propagation distance is equal to the window thickness. In some cases, the first propagation distance may be substantially equal to the average perimeter of the LiDAR window. In some cases, the first propagation distance may be longer than the window thickness. In some cases, the first propagation distance may be determined based at least in part on the geometry of the LiDAR window, the field of view of the detection system of the LiDAR, the detection threshold of the detection system, and / or the relative position of the entrance aperture of the detection system relative to the LiDAR window.

[0115] Control the direction of light directed by the LiDAR window

[0116] In some cases, the shape of the LiDAR window can be customized to reduce the probability that light directed within the thickness of the LiDAR window will be scattered outside the thickness of the LiDAR window at a location and in a direction that can be received by the LiDAR's detection system. Figure 5A An example LiDAR window includes a cylindrical shell having a height H (the normal distance between the base and the upper surface of the cylindrical shell), an outer diameter D, and an inner diameter d. Figure 2A As shown, the LiDAR can be positioned at the center of such a cylindrical shell. For example, the rotation axis of the LiDAR can be parallel to or overlap the axis of the cylindrical shell, and the distance between the center of the LiDAR and the base of the cylindrical shell can be substantially equal to H / 2. In various implementations, the thickness of the LiDAR can be customized by changing the thickness of the LiDAR along its axis (in a direction perpendicular to its base). Figure 5A The shape of the LiDAR window shown. In some cases, the thickness of the window can vary along the axis of the cylindrical shell (e.g., monotonically). Figure 5B For example, a LiDAR window comprises a cylindrical shell having a constant outer diameter D along its axis, and an inner diameter that decreases (e.g., monotonically) along its axis from a first value (d1) at the base of the cylindrical shell to a second value (d2) at the top surface of the cylindrical shell.

[0117] In some cases, the LiDAR window may include a truncated cone shell having a lower diameter, an upper diameter different from the lower diameter, and an inner surface and an outer surface. The lower diameter may be the diameter of the outer surface at the base of the truncated cone shell, and the upper diameter may be the diameter of the inner surface at the top of the truncated cone shell. The upper diameter may be greater than or less than the lower diameter. The diameter of the outer shell may change from the lower diameter to the upper diameter (e.g., monotonically). The thickness of the LiDAR window may be the distance between the inner surface and the outer surface of the truncated cone shell along a direction perpendicular to the inner surface and the outer surface. In some cases, the thickness of the window may change along the axis of the truncated cone shell. Figure 5C An example LiDAR window includes a truncated conical shell having an inner diameter d that is constant along its axis, and an outer diameter that increases (e.g., monotonically) along its axis from a first value or lower diameter (D1) at the base of the truncated conical shell to a second value or upper diameter (D2) at the top surface of the shell. Figure 5D An example LiDAR window includes a truncated conical shell having an outer diameter that decreases (e.g., monotonically) along its axis from a first value or lower diameter (D1) at the base of the shell to a second value or upper diameter (D2) at the top surface of the shell, and an inner diameter that decreases (e.g., monotonically) along its axis from a first value (d1) at the base of the shell to a second value (d2) at the top surface of the shell. It should be understood that FIG. 5B to FIG. 5D The illustrated shapes are examples of possible shapes where the thickness of a cylindrical shell varies along its axis, and many other shapes are possible.

[0118] In various implementations, when the beam is incident on a LiDAR window having a customized thickness along an axis (e.g., FIG. 5B to FIG. 5D When a LiDAR window with a customized thickness is placed on a LiDAR window (as shown in the figure), the portion of the incident light that is transformed into an optical beam that propagates within the thickness of the LiDAR window can be directed in a direction away from the LiDAR or the detection system of the LiDAR. For example, instead of propagating along a circular path in a plane perpendicular to the axis of the cylinder, the guided light can propagate along a spiral path toward the base or top surface of the cylinder. In some cases, a LiDAR window with a customized thickness may not allow the guided light to propagate in a closed path around the perimeter of the LiDAR window. In such a LiDAR window, the probability of the guided light being scattered multiple times in the same direction and / or by the same scattering center during different round trips can be reduced. In some cases, the above-described method for detecting a LiDAR window with a customized thickness can be used to reduce the probability of the guided light being scattered multiple times in the same direction and / or by the same scattering center during different round trips. Figure 3A , Figure 4A and Figure 4B The method and design described are selected or customized FIG. 5B to FIG. 5D Optical absorption of a LiDAR window as shown or a LiDAR window having a thickness and / or diameter that varies along the axis of a cylindrical shell or a truncated conical shell.

[0119] Sample Application

[0120] The LiDAR windows disclosed above can be used on LiDAR devices and systems incorporated into vehicles as disclosed below. In some aspects and / or embodiments, the above-described devices and methods can be used in a LiDAR sensor of an autonomous system included in a vehicle to improve the autonomous driving capabilities of the vehicle by reducing the probability of the LiDAR sensor generating false alarms (e.g., false alarms associated with indirect light received by the LiDAR detection system).

[0121] Reference now Figure 6 , illustrates an example environment 600 in which vehicles including autonomous systems and vehicles not including autonomous systems operate. As illustrated, the environment 600 includes vehicles 602a-602n, objects 604a-604n, routes 606a-606n, areas 608, vehicle-to-infrastructure (V2I) devices 610, a network 612, a remote autonomous vehicle (AV) system 614, a fleet management system 616, and a V2I system 618. The vehicles 602a-602n, the vehicle-to-infrastructure (V2I) devices 610, the network 612, the autonomous vehicle (AV) system 614, the fleet management system 616, and the V2I system 618 are interconnected (e.g., establish connections for communication, etc.) via wired connections, wireless connections, or a combination of wired or wireless connections. In some embodiments, objects 604a-604n are interconnected with at least one of vehicles 602a-602n, vehicle-to-infrastructure (V2I) devices 610, networks 612, autonomous vehicle (AV) systems 614, fleet management systems 616, and V2I systems 618 via wired connections, wireless connections, or a combination of wired or wireless connections.

[0122] Vehicles 602a-602n (individually referred to as vehicles 602 and collectively referred to as vehicles 602) include at least one device configured to transport goods and / or people. In some embodiments, vehicle 602 is configured to communicate with V2I device 610, remote AV system 614, queue management system 616, and / or V2I system 618 via network 612. In some embodiments, vehicle 602 includes a car, bus, truck, and / or train, etc. In some embodiments, vehicle 602 is similar to vehicle 700 described herein (see Figure 7 ). In some embodiments, vehicles 700 in the set of vehicles 700 are associated with an autonomous queue manager. In some embodiments, vehicles 602 travel along respective routes 606a-606n (individually referred to as routes 606 and collectively referred to as routes 606) as described herein. In some embodiments, one or more vehicles 602 include an autonomous system (e.g., an autonomous system that is the same as or similar to autonomous system 702).

[0123] Objects 604a-604n (individually referred to as objects 604 and collectively referred to as objects 604) include, for example, at least one vehicle, at least one pedestrian, at least one cyclist, and / or at least one structure (e.g., a building, a sign, a fire hydrant, etc.), etc. Each object 604 is stationary (e.g., located at a fixed location and over a period of time) or moves (e.g., has a speed and is associated with at least one trajectory). In some embodiments, objects 604 are associated with corresponding locations in area 608.

[0124] Routes 606a-606n (individually referred to as routes 606 and collectively referred to as routes 606) are each associated with (e.g., specifying) a series of actions (also referred to as trajectories) connecting states along which the AV can navigate. Each route 606 begins at an initial state (e.g., a state corresponding to a first spatiotemporal location and / or speed, etc.) and ends at a final target state (e.g., a state corresponding to a second spatiotemporal location different from the first spatiotemporal location) or a target zone (e.g., a subspace of acceptable states (e.g., terminal states)). In some embodiments, the first state includes a location where one or more individuals will board the AV, and the second state or zone includes one or more locations where one or more individuals boarding the AV will disembark. In some embodiments, routes 606 include multiple acceptable state sequences (e.g., multiple spatiotemporal location sequences) that are associated with (e.g., define multiple trajectories). In an example, routes 606 include only high-level actions or imprecise state locations, such as a series of connecting roads indicating a change of direction at a roadway intersection, etc. Additionally or alternatively, route 606 may include more precise actions or states, such as, for example, specific target lanes or precise locations within lane regions and target velocities at those locations, etc. In an example, route 606 includes multiple precise state sequences along at least one high-level action with a limited look-ahead horizon to an intermediate target, where a combination of consecutive iterations of the limited horizon state sequences cumulatively correspond to multiple trajectories that together form a high-level route terminating at a final target state or region.

[0125] Area 608 includes a physical area (e.g., a geographic region) in which vehicle 602 can navigate. In an example, area 608 includes at least one state (e.g., a country, a province, a separate state of multiple states included in a country, etc.), at least a portion of a state, at least one city, at least a portion of a city, etc. In some embodiments, area 608 includes at least one named thoroughfare (referred to herein as a "road"), such as a highway, an interstate highway, a parkway, a city street, etc. Additionally or alternatively, in some examples, area 608 includes at least one unnamed road, such as a driveway, a section of a parking lot, a section of an open space and / or undeveloped area, a dirt road, etc. In some embodiments, a road includes at least one lane (e.g., a portion of a road that vehicle 602 can traverse). In an example, a road includes at least one lane associated with (e.g., identified based on at least one lane marking line).

[0126] Vehicle-to-infrastructure (V2I) devices 610 (sometimes referred to as vehicle-to-infrastructure or vehicle-to-everything (V2X) devices) include at least one device configured to communicate with vehicle 602 and / or V2I system 618. In some embodiments, V2I devices 610 are configured to communicate with vehicle 602, remote AV system 614, queue management system 616, and / or V2I system 618 via network 612. In some embodiments, V2I devices 610 include radio frequency identification (RFID) devices, signs, cameras (e.g., two-dimensional (2D) and / or three-dimensional (3D) cameras), lane markings, street lights, parking meters, etc. In some embodiments, V2I devices 610 are configured to communicate directly with vehicle 602. Additionally or alternatively, in some embodiments, the V2I device 610 is configured to communicate with the vehicle 602, the remote AV system 614, and / or the fleet management system 616 via the V2I system 618. In some embodiments, the V2I device 610 is configured to communicate with the V2I system 618 via the network 612.

[0127] The network 612 includes one or more wired and / or wireless networks. In an example, the network 612 includes a cellular network (e.g., a long-term evolution (LTE) network, a third generation (3G) network, a fourth generation (4G) network, a fifth generation (5G) network, a code division multiple access (CDMA) network, etc.), a public land mobile network (PLMN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a telephone network (e.g., a public switched telephone network (PSTN)), a private network, an ad hoc network, an intranet, the Internet, a fiber-based network, a cloud computing network, etc., and / or a combination of some or all of these networks, etc.

[0128] The remote AV system 614 includes at least one device configured to communicate with the vehicle 602, the V2I device 610, the network 612, the fleet management system 616, and / or the V2I system 618 via the network 612. In an example, the remote AV system 614 includes a server, a server group, and / or other similar devices. In some embodiments, the remote AV system 614 is co-located with the fleet management system 616. In some embodiments, the remote AV system 614 participates in the installation of some or all of the components of the vehicle (including autonomous systems, autonomous vehicle computing, and / or software implemented by autonomous vehicle computing, etc.). In some embodiments, the remote AV system 614 maintains (e.g., updates and / or replaces) these components and / or software during the life of the vehicle.

[0129] The queue management system 616 includes at least one device configured to communicate with the vehicle 602, the V2I device 610, the remote AV system 614, and / or the V2I system 618. In an example, the queue management system 616 includes a server, a server group, and / or other similar devices. In some embodiments, the queue management system 616 is associated with a ridesharing company (e.g., an organization for controlling the operation of multiple vehicles (e.g., vehicles including autonomous systems and / or vehicles not including autonomous systems)).

[0130] In some embodiments, the V2I system 618 includes at least one device configured to communicate with the vehicle 602, the V2I device 610, the remote AV system 614, and / or the fleet management system 616 via the network 612. In some examples, the V2I system 618 is configured to communicate with the V2I device 610 via a connection different from the network 612. In some embodiments, the V2I system 618 includes a server, a server group, and / or other similar devices. In some embodiments, the V2I system 618 is associated with a municipality or a private agency (e.g., a private agency for maintaining the V2I device 610, etc.).

[0131] supply Figure 6 The number and arrangement of elements illustrated are examples. Figure 6 There may be additional elements, fewer elements, different elements, and / or differently arranged elements than those illustrated. Additionally or alternatively, at least one element of environment 600 may be described as being Figure 6 Additionally or alternatively, at least one set of elements of environment 600 may perform one or more functions described as being performed by at least one different set of elements of environment 600.

[0132] Reference now Figure 7 , vehicle 700 (which can be Figure 6 700) includes, or is associated with, autonomous system 702, powertrain control system 704, steering control system 706, and braking system 708. In some embodiments, vehicle 700 is similar to vehicle 602 (see Figure 6 ). In some embodiments, the autonomous vehicle 702 is configured to give the vehicle 700 autonomous driving capabilities (e.g., implementing at least one of the following driving automatic or maneuvering-based functions, features, and / or devices, etc., which enable the vehicle 700 to partially or completely operate without human intervention, including but not limited to fully autonomous vehicles (e.g., vehicles that abandon reliance on human intervention, such as Level 5 ADS-operated vehicles, etc.), highly autonomous vehicles (e.g., vehicles that abandon reliance on human intervention in certain situations, such as Level 4 ADS-operated vehicles, etc.), and / or conditionally autonomous vehicles (e.g., vehicles that abandon reliance on human intervention in limited situations). In one embodiment, the autonomous system 702 includes the operational or tactical functionality required to enable the vehicle 700 to operate in on-road traffic and continuously perform part or all of the dynamic driving tasks (DDT). In another embodiment, the autonomous system 702 includes an advanced driver assistance system (ADAS) including driver support features. The autonomous system 702 supports various levels of driving automation ranging from no driving automation (e.g., level 0) to full driving automation (e.g., level 5). For a detailed description of fully autonomous vehicles and highly autonomous vehicles, reference may be made to SAE International's standard J3016: Taxonomy and Definitions for Terms Related to On-Road Motor Vehicle Automated Driving Systems, the entire contents of which are incorporated by reference. In some embodiments, the vehicle 700 is associated with an autonomous queue manager and / or a ride-sharing company.

[0133] Autonomous system 702 includes a sensor suite that includes one or more devices such as a camera 702a, a LiDAR sensor 702b, a Radar sensor 702c, and a microphone 702d. In some embodiments, autonomous system 702 may include more or fewer devices and / or different devices (e.g., ultrasonic sensors, inertial sensors, GPS receivers (discussed below), and / or odometer sensors for generating data associated with an indication of the distance that vehicle 700 has traveled, etc.). In some embodiments, autonomous system 702 uses one or more devices included in autonomous system 702 to generate data associated with environment 600 described herein. The data generated by one or more devices of autonomous system 702 can be used by one or more systems described herein to observe the environment (e.g., environment 600) in which vehicle 700 is located. In some embodiments, autonomous system 702 includes a communication device 702e, an autonomous vehicle computing 702f, a drive-by-wire (DBW) system 702h, and a safety controller 702g.

[0134] In some cases, at least the LiDAR sensor 702b may have a LiDAR window that includes one or more of the features described above with respect to reducing the intensity of light indirectly received by a corresponding LiDAR detection system via optical guiding within the thickness of the LiDAR window.

[0135] The camera 702a includes a camera configured to communicate with the communication device 702e, the autonomous vehicle computer 702f, and / or the safety controller 702g via a bus (e.g., Figure 8The camera 702a includes at least one device for communicating with the bus 802 (the same or similar bus as the bus 802 of FIG. 80). The camera 702a includes at least one camera (e.g., a digital camera using a light sensor such as a charge coupled device (CCD), a thermal camera, an infrared (IR) camera, and / or an event camera, etc.) for capturing images including physical objects (e.g., cars, buses, curbs, and / or people, etc.). In some embodiments, the camera 702a generates camera data as output. In some examples, the camera 702a generates camera data including image data associated with the image. In this example, the image data may specify at least one parameter corresponding to the image (e.g., image characteristics such as exposure, brightness, and / or image timestamp, etc.). In such an example, the image may be in a format (e.g., RAW, JPEG, and / or PNG, etc.). In some embodiments, the camera 702a includes a plurality of independent cameras configured (e.g., positioned) on a vehicle to capture images for the purpose of stereoscopic imaging (stereoscopic vision). In some examples, the camera 702a includes a computer 702f that generates image data and transmits the image data to the autonomous vehicle and / or fleet management system (e.g., with Figure 6 In some embodiments, the autonomous vehicle computing 702f determines a depth to one or more objects in a field of view of at least two of the plurality of cameras based on image data from the at least two cameras. In some embodiments, the camera 702a is configured to capture images of objects within a distance relative to the camera 702a (e.g., up to 600 meters and / or up to 1 kilometer, etc.). Thus, the camera 702a includes features such as sensors and lenses that are optimized for sensing objects at one or more distances relative to the camera 702a.

[0136] In an embodiment, the camera 702a includes at least one camera configured to capture one or more images associated with one or more traffic lights, street signs, and / or other physical objects that provide visual navigation information. In some embodiments, the camera 702a generates traffic light data associated with the one or more images. In some examples, the camera 702a generates TLD (traffic light detection) data associated with one or more images including a format (e.g., RAW, JPEG, and / or PNG, etc.). In some embodiments, the camera 702a that generates TLD data differs from other systems incorporating cameras described herein in that the camera 702a may include one or more cameras with a wide field of view (e.g., a wide-angle lens, a fisheye lens, and / or a lens with a viewing angle of about 120 degrees or greater, etc.) to generate images related to as many physical objects as possible.

[0137] The light detection and ranging (LiDAR) sensor 702b includes a communication device 702e, an autonomous vehicle computing device 702f, and / or a safety controller 702g configured to communicate with the communication device 702e via a bus (e.g., Figure 8 The LiDAR sensor 702b includes at least one device that communicates with a bus (the same or similar bus as bus 802 of the embodiment of the present invention). The LiDAR sensor 702b includes a system configured to emit light from a light emitter (e.g., a laser emitter). The light emitted by the LiDAR sensor 702b includes light outside the visible spectrum (e.g., infrared light, etc.). In some embodiments, during operation, the light emitted by the LiDAR sensor 702b encounters a physical object (e.g., a vehicle) and is reflected back to the LiDAR sensor 702b. In some embodiments, the light emitted by the LiDAR sensor 702b does not penetrate the physical object encountered by the light. The LiDAR sensor 702b also includes at least one light detector that detects the light emitted from the light emitter after encountering the physical object. In some embodiments, at least one data processing system associated with the LiDAR sensor 702b generates an image (e.g., a point cloud and / or a combined point cloud, etc.) representing objects included in the field of view of the LiDAR sensor 702b. In some examples, at least one data processing system associated with the LiDAR sensor 702b generates an image representing the boundaries of the physical object and / or the surface of the physical object (e.g., the topology of the surface), etc. In such examples, the image is used to determine the boundaries of the physical object in the field of view of the LiDAR sensor 702b.

[0138] The radio detection and ranging (Radar) sensor 702c includes a sensor configured to communicate with the communication device 702e, the autonomous vehicle computing 702f, and / or the safety controller 702g via a bus (e.g., Figure 8The Radar sensor 702c includes at least one device that communicates with a bus (same or similar bus as the bus 802 of the Radar sensor 702c). The Radar sensor 702c includes a system configured to transmit (pulsed or continuous) radio waves. The radio waves emitted by the Radar sensor 702c include radio waves within a predetermined spectrum. In some embodiments, during operation, the radio waves emitted by the Radar sensor 702c encounter physical objects and are reflected back to the Radar sensor 702c. In some embodiments, the radio waves emitted by the Radar sensor 702c are not reflected by some objects. In some embodiments, at least one data processing system associated with the Radar sensor 702c generates a signal representing an object included in the field of view of the Radar sensor 702c. For example, at least one data processing system associated with the Radar sensor 702c generates an image representing the boundary of a physical object and / or the surface of a physical object (e.g., the topology of the surface), etc. In some examples, the image is used to determine the boundary of a physical object in the field of view of the Radar sensor 702c.

[0139] The microphone 702d includes a microphone configured to communicate with the communication device 702e, the autonomous vehicle computing device 702f, and / or the safety controller 702g via a bus (e.g., Figure 8 The microphone 702d includes at least one device for communicating with the vehicle 700 (the same or similar bus as the bus 802 of FIG. 802 ). The microphone 702d includes one or more microphones (e.g., an array microphone and / or an external microphone, etc.) that capture an audio signal and generate data associated with (e.g., representing) the audio signal. In some examples, the microphone 702d includes a transducer device and / or a similar device. In some embodiments, one or more systems described herein can receive the data generated by the microphone 702d and determine the position (e.g., distance, etc.) of the object relative to the vehicle 700 based on the audio signal associated with the data.

[0140] The communication device 702e includes at least one device configured to communicate with the camera 702a, the LiDAR sensor 702b, the Radar sensor 702c, the microphone 702d, the autonomous vehicle computing 702f, the safety controller 702g, and / or the DBW (drive-by-wire) system 702h. For example, the communication device 702e may include at least one device configured to communicate with the camera 702a, the LiDAR sensor 702b, the Radar sensor 702c, the microphone 702d, the autonomous vehicle computing 702f, the safety controller 702g, and / or the DBW (drive-by-wire) system 702h. Figure 8 The communication device 702e may be a device that is the same as or similar to the communication interface 814 of the vehicle. In some embodiments, the communication device 702e includes a vehicle-to-vehicle (V2V) communication device (eg, a device for enabling wireless communication of data between vehicles).

[0141] Autonomous vehicle computing 702f includes at least one device configured to communicate with camera 702a, LiDAR sensor 702b, Radar sensor 702c, microphone 702d, communication device 702e, safety controller 702g and / or DBW system 702h. In some examples, autonomous vehicle computing 702f includes devices such as client devices, mobile devices (e.g., cellular phones and / or tablet computers, etc.), and / or servers (e.g., computing devices including one or more central processing units and / or graphics processing units, etc.). In some embodiments, autonomous vehicle computing 702f is the same or similar to autonomous vehicle computing 400 described herein. Additionally or alternatively, in some embodiments, autonomous vehicle computing 702f is configured to communicate with an autonomous vehicle system (e.g., with Figure 6 remote AV system 614 of the same or similar autonomous vehicle system), a fleet management system (e.g., Figure 6 of the same or similar queue management system as the queue management system 616), V2I devices (e.g., Figure 6 V2I device 610 that is the same as or similar to V2I device) and / or V2I system (e.g., Figure 6 The V2I system 618 may communicate with the same or similar V2I system.

[0142] Safety controller 702g includes at least one device configured to communicate with camera 702a, LiDAR sensor 702b, Radar sensor 702c, microphone 702d, communication device 702e, autonomous vehicle computing 702f, and / or DBW system 702h. In some examples, safety controller 702g includes one or more controllers (electrical controllers and / or electromechanical controllers, etc.) configured to generate and / or transmit control signals to operate one or more devices of vehicle 700 (e.g., powertrain control system 704, steering control system 706, and / or braking system 708, etc.). In some embodiments, safety controller 702g is configured to generate control signals that take precedence over (e.g., override) control signals generated and / or transmitted by autonomous vehicle computing 702f.

[0143] The DBW system 702h includes at least one device configured to communicate with the communication device 702e and / or the autonomous vehicle computing 702f. In some examples, the DBW system 702h includes one or more controllers (e.g., electrical controllers and / or electromechanical controllers, etc.) configured to generate and / or transmit control signals to operate one or more devices of the vehicle 700 (e.g., powertrain control system 704, steering control system 706, and / or braking system 708, etc.). Additionally or alternatively, one or more controllers of the DBW system 702h are configured to generate and / or transmit control signals to operate at least one different device of the vehicle 700 (e.g., turn signals, headlights, door locks, and / or windshield wipers, etc.).

[0144] The powertrain control system 704 includes at least one device configured to communicate with the DBW system 702h. In some examples, the powertrain control system 704 includes at least one controller and / or actuator, etc. In some embodiments, the powertrain control system 704 receives a control signal from the DBW system 702h, and the powertrain control system 704 causes the vehicle 700 to perform longitudinal vehicle movement (such as starting to move forward, stopping to move forward, starting to move backward, stopping to move backward, accelerating in a certain direction, decelerating in a certain direction, etc.), or to perform lateral vehicle movement (such as making a left turn and / or making a right turn, etc.). In an example, the powertrain control system 704 increases, maintains the same, or decreases the energy (e.g., fuel and / or electricity, etc.) provided to the motor of the vehicle, thereby rotating or not rotating at least one wheel of the vehicle 700.

[0145] The steering control system 706 includes at least one device configured to rotate one or more wheels of the vehicle 700. In some examples, the steering control system 706 includes at least one controller and / or actuator, etc. In some embodiments, the steering control system 706 rotates the two front wheels and / or the two rear wheels of the vehicle 700 to the left or right to make the vehicle 700 turn left or right. In other words, the steering control system 706 causes the activity required to regulate the y-axis component of the vehicle's motion.

[0146] Braking system 708 includes at least one device configured to actuate one or more brakes to decelerate and / or hold vehicle 700 stationary. In some examples, braking system 708 includes at least one controller and / or actuator configured to cause one or more calipers associated with one or more wheels of vehicle 700 to close on respective rotors of vehicle 700. Additionally or alternatively, in some examples, braking system 708 includes an automatic emergency braking (AEB) system and / or a regenerative braking system, etc.

[0147] In some embodiments, vehicle 700 includes at least one platform sensor (not explicitly illustrated) for measuring or inferring a property of a state or condition of vehicle 700. In some examples, vehicle 700 includes platform sensors such as a global positioning system (GPS) receiver, an inertial measurement unit (IMU), wheel rate sensors, wheel brake pressure sensors, wheel torque sensors, engine torque sensors, and / or steering angle sensors. Although braking system 708 is Figure 7 Although illustrated as being located on the proximal side of the vehicle 700 , the braking system 708 can be located anywhere in the vehicle 700 .

[0148] Reference now Figure 8 , a schematic diagram of an exemplary device 800. As illustrated, the device 800 includes a processor 804, a memory 806, a storage component 808, an input interface 810, an output interface 812, a communication interface 814, and a bus 802. In some embodiments, the device 800 corresponds to at least one device of the vehicle 602a-602n, at least one device of the vehicle 700, and / or one or more devices of the network 612. In some embodiments, one or more devices of the vehicles 602a-602n and / or one or more devices of the network 612 include at least one device 800 and / or at least one component of the device 800. Figure 8 As shown, apparatus 800 includes a bus 802 , a processor 804 , a memory 806 , a storage component 808 , an input interface 810 , an output interface 812 , and a communication interface 814 .

[0149] The bus 802 includes components that permit communication between components of the device 800. In some cases, the processor 804 includes a processor (e.g., a central processing unit (CPU), a graphics processing unit (GPU), and / or an accelerated processing unit (APU), etc.), a microphone, a digital signal processor (DSP), and / or any processing component that can be programmed to perform at least one function (e.g., a field programmable gate array (FPGA) and / or an application specific integrated circuit (ASIC), etc.). The memory 806 includes a random access memory (RAM), a read-only memory (ROM), and / or another type of dynamic and / or static storage device (e.g., flash memory, magnetic memory, and / or optical memory, etc.) that stores data and / or instructions for use by the processor 804.

[0150] The storage component 808 stores data and / or software related to the operation and use of the device 800. In some examples, the storage component 808 includes a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optical disk, and / or a solid-state disk, etc.), a compact disk (CD), a digital versatile disk (DVD), a floppy disk, a cassette, a tape, a CD-ROM, a RAM, a PROM, an EPROM, a FLASH-EPROM, an NV-RAM, and / or another type of computer-readable medium, and a corresponding drive.

[0151] The input interface 810 includes components that permit the device 800 to receive information, such as via user input (e.g., a touch screen display, a keyboard, a keypad, a mouse, a button, a switch, a microphone, and / or a camera, etc.). Additionally or alternatively, in some embodiments, the input interface 810 includes a sensor for sensing information (e.g., a global positioning system (GPS) receiver, an accelerometer, a gyroscope, and / or an actuator, etc.). The output interface 812 includes components for providing output information from the device 800 (e.g., a display, a speaker, and / or one or more light emitting diodes (LEDs), etc.).

[0152] In some embodiments, the communication interface 814 includes a transceiver-like component (e.g., a transceiver and / or a separate receiver and transmitter, etc.) that allows the device 800 to communicate with other devices via a wired connection, a wireless connection, or a combination of a wired connection and a wireless connection. In some examples, the communication interface 814 allows the device 800 to receive information from another device and / or provide information to another device. In some examples, the communication interface 814 includes an Ethernet interface, an optical interface, a coaxial interface, an infrared interface, a radio frequency (RF) interface, a universal serial bus (USB) interface, interface and / or cellular network interface, etc.

[0153] In some embodiments, the device 800 performs one or more processes described herein. The device 800 performs these processes based on the processor 804 executing software instructions stored by a computer-readable medium such as a memory 806 and / or a storage component 808. Computer-readable media (e.g., non-transitory computer-readable media) are defined herein as non-transitory memory devices. Non-transitory memory devices include storage space located within a single physical storage device or storage space distributed across multiple physical storage devices.

[0154] In some embodiments, the software instructions are read into the memory 806 and / or storage component 808 from another computer-readable medium or from another device via the communication interface 814. The software instructions stored in the memory 806 and / or storage component 808, when executed, cause the processor 804 to perform one or more processes described herein. Additionally or alternatively, hardwired circuits are used in place of or in combination with the software instructions to perform one or more processes described herein. Therefore, unless expressly stated otherwise, the embodiments described herein are not limited to any specific combination of hardware circuitry and software.

[0155] The memory 806 and / or the storage component 808 include a data storage unit or at least one data structure (e.g., a database, etc.). The device 800 can receive information from the data storage unit or at least one data structure in the memory 806 or the storage component 808, store information in the data storage unit or at least one data structure, communicate information to the data storage unit or at least one data structure, or search for information stored in the data storage unit or at least one data structure. In some examples, the information includes network data, input data, output data, or any combination thereof.

[0156] In some embodiments, the device 800 is configured to execute software instructions stored in the memory 806 and / or the memory of another device (e.g., another device that is the same or similar to the device 800). As used herein, the term "module" refers to at least one instruction stored in the memory 806 and / or the memory of another device, which, when executed by the processor 804 and / or the processor of another device (e.g., another device that is the same or similar to the device 800), causes the device 800 (e.g., at least one component of the device 800) to perform one or more processes described herein. In some embodiments, the module is implemented in software, firmware, and / or hardware, etc.

[0157] supply Figure 8 The number and arrangement of components illustrated are examples. Figure 8 The device 800 may include additional components, fewer components, different components, or differently arranged components than the components illustrated. Additionally or alternatively, a set of components (e.g., one or more than one component) of the device 800 may perform one or more functions described as being performed by another component or another set of components of the device 800.

[0158] Reference now Fig. 9, illustrates an example block diagram of an autonomous vehicle computing 400 (sometimes referred to as an "AV stack"). As illustrated, the autonomous vehicle computing 400 includes a perception system 402 (sometimes referred to as a perception module), a planning system 404 (sometimes referred to as a planning module), a positioning system 406 (sometimes referred to as a positioning module), a control system 408 (sometimes referred to as a control module), and a database 410. In some embodiments, the perception system 402, the planning system 404, the positioning system 406, the control system 408, and the database 410 are included in and / or implemented in an automatic navigation system of a vehicle (e.g., the autonomous vehicle computing 702f of the vehicle 700). Additionally or alternatively, in some embodiments, the perception system 402, the planning system 404, the positioning system 406, the control system 408, and the database 410 are included in one or more independent systems (e.g., one or more systems that are the same or similar to the autonomous vehicle computing 400, etc.). In some examples, the perception system 402, planning system 404, positioning system 406, control system 408, and database 410 are included in one or more independent systems located in the vehicle and / or at least one remote system as described herein. In some embodiments, any and / or all of the systems included in the autonomous vehicle computing 400 are implemented in software (e.g., software instructions stored in a memory), computer hardware (e.g., by a microprocessor, microcontroller, application specific integrated circuit (ASIC) and / or field programmable gate array (FPGA), etc.), or a combination of computer software and computer hardware. It will also be understood that in some embodiments, the autonomous vehicle computing 400 is configured to communicate with a remote system (e.g., an autonomous vehicle system that is the same or similar to the remote AV system 614, a fleet management system 616 that is the same or similar to the fleet management system 616, and / or a V2I system that is the same or similar to the V2I system 618, etc.).

[0159] In some embodiments, the perception system 402 receives data associated with at least one physical object in the environment (e.g., data used by the perception system 402 to detect at least one physical object) and classifies the at least one physical object. In some examples, the perception system 402 receives image data captured by at least one camera (e.g., camera 702a), the image being associated with (e.g., representing) one or more physical objects within the field of view of the at least one camera. In such examples, the perception system 402 classifies the at least one physical object based on one or more groups of physical objects (e.g., bicycles, vehicles, traffic signs, and / or pedestrians, etc.). In some embodiments, based on the perception system 402 classifying the physical object, the perception system 402 transmits data associated with the classification of the physical object to the planning system 404.

[0160] In some embodiments, the planning system 404 receives data associated with a destination and generates data associated with at least one route (e.g., route 606) along which a vehicle (e.g., vehicle 602) can travel toward the destination. In some embodiments, the planning system 404 periodically or continuously receives data (e.g., data associated with the classification of physical objects described above) from the perception system 402, and the planning system 404 updates at least one trajectory or generates at least one different trajectory based on the data generated by the perception system 402. In other words, the planning system 404 can perform tasks related to tactical functions required to operate the vehicle 602 in traffic on the road. Tactical efforts involve maneuvering the vehicle in traffic during the trip, which includes but is not limited to deciding whether and when to overtake another vehicle, change lanes, or select an appropriate rate, acceleration, deceleration, etc. In some embodiments, the planning system 404 receives data associated with an updated position of the vehicle (e.g., vehicle 602) from the positioning system 406, and the planning system 404 updates at least one trajectory or generates at least one different trajectory based on the data generated by the positioning system 406.

[0161] In some embodiments, the positioning system 406 receives data associated with (e.g., representing) a location of a vehicle (e.g., vehicle 602) in an area. In some examples, the positioning system 406 receives LiDAR data associated with at least one point cloud generated by at least one LiDAR sensor (e.g., LiDAR sensor 702b). In some examples, the positioning system 406 receives data associated with at least one point cloud from multiple LiDAR sensors, and the positioning system 406 generates a combined point cloud based on each point cloud. In these examples, the positioning system 406 compares the at least one point cloud or the combined point cloud with a two-dimensional (2D) and / or three-dimensional (3D) map of the area stored in the database 410. Then, based on the positioning system 406 comparing the at least one point cloud or the combined point cloud with the map, the positioning system 406 determines the position of the vehicle in the area. In some embodiments, the map includes a combined point cloud of the area generated before the navigation of the vehicle. In some embodiments, the map includes, but is not limited to, a high-precision map of roadway geometry, a map describing the connectivity of the road network, a map describing the physical properties of the roadway (such as traffic speed, traffic volume, the number of vehicle and bicycle traffic lanes, lane width, lane traffic direction, or the type and location of lane markings, or a combination thereof), and a map describing the spatial location of road features (such as crosswalks, traffic signs, or various types of other driving signals, etc.) In some embodiments, the map is generated in real time based on data received by the perception system.

[0162] In another example, positioning system 406 receives global navigation satellite system (GNSS) data generated by a global positioning system (GPS) receiver. In some examples, positioning system 406 receives GNSS data associated with a location of a vehicle in an area, and positioning system 406 determines the latitude and longitude of the vehicle in the area. In such an example, positioning system 406 determines the position of the vehicle in the area based on the latitude and longitude of the vehicle. In some embodiments, positioning system 406 generates data associated with the position of the vehicle. In some examples, based on the location of the vehicle determined by positioning system 406, positioning system 406 generates data associated with the position of the vehicle. In such an example, the data associated with the position of the vehicle include data associated with one or more semantic properties corresponding to the position of the vehicle.

[0163] In some embodiments, the control system 408 receives data associated with at least one trajectory from the planning system 404, and the control system 408 controls the operation of the vehicle. In some examples, the control system 408 receives data associated with at least one trajectory from the planning system 404, and the control system 408 controls the operation of the vehicle by generating and transmitting control signals to operate the powertrain control system (e.g., DBW system 702h and / or powertrain control system 704, etc.), the steering control system (e.g., steering control system 706) and / or the braking system (e.g., braking system 708). For example, the control system 408 is configured to perform operational functions such as lateral vehicle motion control or longitudinal vehicle motion control. Lateral vehicle motion control causes the activity required to regulate the y-axis component of the vehicle motion. Longitudinal vehicle motion control causes the activity required to regulate the x-axis component of the vehicle motion. In the example, in the case where the trajectory includes a left turn, the control system 408 transmits a control signal to cause the steering control system 706 to adjust the steering angle of the vehicle 700, thereby causing the vehicle 700 to turn left. Additionally or alternatively, the control system 408 generates and transmits control signals to cause other devices of the vehicle 700 (eg, headlights, turn signals, door locks, and / or windshield wipers, etc.) to change states.

[0164] In some embodiments, the perception system 402, planning system 404, positioning system 406, and / or control system 408 implement at least one machine learning model (e.g., at least one multi-layer perceptron (MLP), at least one convolutional neural network (CNN), at least one recurrent neural network (RNN), at least one autoencoder, and / or at least one transformer, etc.). In some examples, the perception system 402, planning system 404, positioning system 406, and / or control system 408 implement at least one machine learning model alone or in combination with one or more of the above systems. In some examples, the perception system 402, planning system 404, positioning system 406, and / or control system 408 implement at least one machine learning model as part of a pipeline (e.g., a pipeline for identifying one or more objects located in an environment, etc.). The database 410 stores data transmitted to, received from, and / or updated by the perception system 402, planning system 404, positioning system 406, and / or control system 408. In some examples, database 410 includes a storage component (e.g., a computer program that is used to store data and / or software related to operations and to use at least one system of autonomous vehicle computing 400) Figure 8In some embodiments, database 410 stores data associated with a 2D and / or 3D map of at least one area. In some examples, database 410 stores data associated with a 2D and / or 3D map of a portion of a city, portions of multiple cities, multiple cities, counties, states, and / or countries (State) (e.g., a country), etc. In such an example, a vehicle (e.g., a vehicle that is the same or similar to vehicle 602 and / or vehicle 700) can be driven along one or more drivable areas (e.g., single-lane roads, multi-lane roads, highways, remote roads, and / or off-road roads, etc.) and causes at least one LiDAR sensor (e.g., a LiDAR sensor that is the same or similar to LiDAR sensor 702b) to generate data associated with an image representing an object included in the field of view of the at least one LiDAR sensor.

[0165] In some embodiments, database 410 can be implemented across multiple devices. In some examples, database 410 includes a vehicle (e.g., a vehicle that is the same or similar to vehicle 602 and / or vehicle 700), an autonomous vehicle system (e.g., an autonomous vehicle system that is the same or similar to remote AV system 614), a fleet management system (e.g., a vehicle that is the same or similar to remote AV system 614), and a fleet management system (e.g., a vehicle that is the same or similar to remote AV system 614). Figure 6 616) and / or a V2I system (e.g., Figure 6 The V2I system 618 is the same as or similar to the V2I system) and the like.

[0166] Example Embodiments

[0167] Some additional non-limiting examples of the embodiments discussed above are provided below. These should not be understood as limiting the breadth of the present disclosure in any way.

[0168] Example 1. A system comprising:

[0169] an optical system configured to transmit an optical probe beam to an environment and receive reflections of the optical probe beam from the environment, wherein a wavelength of the optical probe beam is within an operating wavelength range of the optical system and the reflections of the optical probe beam are detected by a detection system of the optical system; and

[0170] a LiDAR window having a window diameter and a window thickness, the LiDAR window surrounding the optical system such that the optical probe beam is transmitted from the optical system through the LiDAR window to the environment and a reflection of the optical probe beam is received by the detection system from the environment through the LiDAR window,

[0171] wherein the LiDAR window comprises a window material having an optical absorption coefficient, wherein the optical absorption coefficient is configured such that, when a light beam having a wavelength within an operating wavelength range of the optical system propagates inside the window material, attenuation of the light beam is greater than 10 times for a first propagation distance than for a second propagation distance, and

[0172] Wherein, the first propagation distance is determined at least in part based on the window diameter, and the second propagation distance is equal to the window thickness.

[0173] Example 2. A system according to Example 1, wherein the LiDAR window comprises a shell having an inner surface and an outer surface, wherein the window thickness is the distance between the inner surface and the outer surface along a direction perpendicular to the inner surface and the outer surface, and wherein the window diameter is the diameter of the outer surface.

[0174] Example 3. A system according to Example 1 or 2, wherein the optical absorption coefficient is further configured such that the light beam attenuates by more than 11 dB after propagating a distance equal to the first propagation distance.

[0175] Example 4. A system according to any one of Examples 1 to 3, wherein the optical absorption coefficient is further configured such that the light beam attenuates by less than 1 dB after propagating a distance equal to the second propagation distance.

[0176] Example 5. A system according to any one of Examples 1 to 4, wherein the window thickness is less than 5 mm.

[0177] Example 6. A system according to any one of Examples 1 to 5, wherein the first propagation distance is greater than 30 cm.

[0178] Example 7. A system according to any one of Examples 1 to 6, wherein the window diameter is greater than 50 mm.

[0179] Example 8. A system according to any one of Examples 2 to 7, wherein the LiDAR window surrounds the optical system so that an optical detection beam emitted by the optical system is incident on an inner surface of the shell and a reflection of the optical detection beam received from the environment is incident on an outer surface of the shell.

[0180] Example 9. A system according to any of Examples 2 to 8, wherein the first propagation distance is equal to an average circumference of the shell.

[0181] Example 10. A system according to any of Examples 2 to 8, wherein the first propagation distance is shorter than the outer circumference of the shell and longer than the window thickness.

[0182] Example 11. A system according to any of Examples 2 to 10, wherein a portion of an optical beam received from the environment and incident on the LiDAR window at a first position on the perimeter of the LiDAR window propagates within the thickness of the shell along an optical path defined by the inner surface and the outer surface, is scattered outside the thickness of the shell at a second position on the perimeter of the LiDAR window different from the first position, and is received by a detection system.

[0183] Example 12. A system according to any one of Examples 7 to 11, wherein the light beam incident on the LiDAR window includes a reflected optical beam associated with the optical detection beam emitted by the optical system or a scattered optical beam associated with the optical detection beam emitted by the optical system.

[0184] Example 13. A system according to Example 12, wherein the scattered optical beam or the reflected optical beam is associated with an interaction of the optical detection beam with an object in the environment located within the near field range of the optical system.

[0185] Example 14. A system according to any of Examples 11 to 13, wherein the length of the optical path is equal to the first propagation distance, and the intensity of the portion of the optical beam incident on the LiDAR window received by the detection system is below a detection threshold of the detection system.

[0186] Example 15. A system according to any one of Examples 11 to 14, wherein the first propagation distance is equal to the length of the optical path from the first position to the second position.

[0187] Example 16. A system according to any one of Examples 1 to 15, wherein the detection system has a field of view and the first propagation distance is determined at least in part based on the field of view of the detection system.

[0188] Example 17. The system of any of Examples 1 to 16, wherein the window material comprises a doped material comprising a dopant.

[0189] Example 18. The system of Example 17, wherein the dopant has an absorption line that at least partially overlaps with a wavelength of the optical probe beam.

[0190] Example 19. The system of Example 17, wherein the optical absorption coefficient of the window material is correlated with the concentration of the dopant in the window material.

[0191] Example 20. The system of Example 17, wherein the doping material comprises glass.

[0192] Example 21. The system of Example 17, wherein the doping material comprises polycarbonate.

[0193] Example 22. A system according to any of Examples 2 to 21, wherein the window thickness varies along the axis of the shell.

[0194] Example 23. The system of Example 1, wherein the LiDAR window comprises a truncated cone shell having:

[0195] Inner and outer surfaces,

[0196] a lower diameter and an upper diameter different from the lower diameter;

[0197] wherein the lower diameter and the upper diameter comprise different diameters of the outer surface; and

[0198] The window thickness is the distance between the inner surface and the outer surface along a direction perpendicular to the inner surface and the outer surface.

[0199] Example 24. The system of Example 23, wherein the lower diameter is smaller than the upper diameter.

[0200] Example 25. The system of Example 23, wherein the lower diameter is greater than the upper diameter.

[0201] Example 26. The system of any of Examples 23 to 25, wherein the window thickness varies along an axis of the truncated conical shell.

[0202] Example 27. A system according to any of Examples 23 to 26, wherein at least a portion of an optical beam received from the environment and incident on the LiDAR window at a first location on the perimeter of the LiDAR window propagates within the thickness of the cylindrical shell along an optical path defined by the inner surface and the outer surface, and is directed to exit from the thickness of the truncated conical shell at a second location on the perimeter of the LiDAR window different from the first location in a direction away from the field of view of the detection system.

[0203] Example 28. A method for reducing false signals in an optical system, the optical system being configured to transmit an optical probe beam to an environment and receive reflections of the optical probe beam from the environment, wherein a wavelength of the optical probe beam is within an operating wavelength range of the optical system and the reflections of the optical probe beam are detected by a detection system of the optical system, the method comprising:

[0204] Select window material;

[0205] forming a LiDAR window having a window diameter and a window thickness using the selected window material, wherein the LiDAR window surrounds the optical system such that the optical probe beam is transmitted from the optical system through the LiDAR window to the environment and a reflection of the optical probe beam is received by the detection system from the environment through the LiDAR window,

[0206] wherein selecting the window material comprises: selecting an absorption coefficient of the window material such that, when a light beam having a wavelength within the operating wavelength range of the optical system propagates inside the window material, attenuation of the light beam is greater than 10 times for a first propagation distance than for a second propagation distance, and

[0207] Wherein, the first propagation distance is determined at least in part based on the window diameter, and the second propagation distance is equal to the window thickness.

[0208] Example 29. A method according to Example 28, wherein the LiDAR window comprises a shell having an inner surface and an outer surface, wherein the window thickness is the distance between the inner surface and the outer surface along a direction perpendicular to the inner surface and the outer surface, and wherein the window diameter is the diameter of the outer surface.

[0209] Example 30. A method according to any one of Examples 28 to 29, wherein selecting the window material further comprises selecting a window material having an absorption coefficient such that the light beam is attenuated by more than 11 dB after propagating a distance equal to the first propagation distance.

[0210] Example 31. A method according to any one of Examples 28 to 30, wherein selecting the window material also includes selecting a window material having an absorption coefficient such that the light beam attenuates by less than 1 dB after propagating a distance equal to the second propagation distance.

[0211] Example 32. A method according to any one of Examples 28 to 31, wherein the window thickness is less than 5 mm.

[0212] Example 33. A method according to any one of Examples 28 to 32, wherein the first propagation distance is greater than 30 cm.

[0213] Example 34. A method according to any one of Examples 28 to 33, wherein the LiDAR diameter is greater than 50 mm.

[0214] Example 35. A method according to any one of Examples 29 to 34, wherein the LiDAR window surrounds the optical system so that an optical detection beam emitted by the optical system is incident on an inner surface of the shell, and a reflection of the optical detection beam received from the environment is incident on an outer surface of the cylindrical shell.

[0215] Example 36. A method according to any one of Examples 29 to 35, wherein the first propagation distance is equal to an average circumference of the shell.

[0216] Example 37. A method according to any one of Examples 29 to 35, wherein the first propagation distance is shorter than the outer circumference of the cylindrical shell and longer than the window thickness.

[0217] Example 38. A method according to any one of Examples 29 to 37, wherein a portion of an optical beam received from the environment and incident on the LiDAR window at a first position on the perimeter of the LiDAR window propagates within the thickness of the shell along an optical path defined by the inner surface and the outer surface, is scattered outside the thickness of the shell at a second position on the perimeter of the LiDAR window different from the first position, and is received by the detection system.

[0218] Example 39. A method according to Example 38, wherein the light beam incident on the LiDAR window includes a reflected optical beam associated with the optical detection beam emitted by the optical system or a scattered optical beam associated with the optical detection beam emitted by the optical system.

[0219] Example 40. A method according to Example 39, wherein the scattered optical beam or the reflected optical beam is associated with an interaction of the optical detection beam with an object in the environment located within the near field range of the optical system.

[0220] Example 41. A method according to any one of Examples 38 to 40, wherein the length of the optical path is equal to the first propagation distance, and the intensity of the portion of the optical beam incident on the LiDAR window received by the detection system is lower than a detection threshold of the detection system.

[0221] Example 42. A method according to any one of Examples 38 to 41, wherein the first propagation distance is equal to the length of the optical path from the first position to the second position.

[0222] Example 43. A method according to any one of Examples 28 to 42, wherein the detection system has a field of view and the first propagation distance is determined at least in part based on the field of view of the detection system.

[0223] Example 44. The method of any one of Examples 28 to 43, wherein the window material comprises a doping material comprising a dopant.

[0224] Example 45. A method according to Example 44, wherein the dopant has an absorption line that at least partially overlaps with the wavelength of the optical detection beam.

[0225] Example 46. The method of Example 44, wherein a concentration of the dopant in the window material is determined based at least in part on an optical absorption coefficient selected for the window material.

[0226] Example 47. The method of Example 44, wherein the doping material comprises glass.

[0227] Example 48. The method of Example 44, wherein the doping material comprises polycarbonate.

[0228] Example 49. A method according to any one of Examples 29 to 18, wherein the window thickness varies along the axis of the shell.

[0229] Example 50. The system of Example 28, wherein the LiDAR window comprises a truncated cone shell having:

[0230] Inner and outer surfaces,

[0231] a lower diameter and an upper diameter different from the lower diameter;

[0232] wherein the lower diameter and the upper diameter comprise different diameters of the outer surface; and

[0233] The window thickness is the distance between the inner surface and the outer surface along a direction perpendicular to the inner surface and the outer surface.

[0234] Example 51. A method according to Example 50, wherein the lower diameter is smaller than the upper diameter.

[0235] Example 52. A method according to Example 50, wherein the lower diameter is larger than the upper diameter.

[0236] Example 53. A method according to any one of Examples 50 to 52, wherein the window thickness varies along the axis of the truncated conical shell.

[0237] Example 54. A method according to any one of Examples 50 to 53, wherein at least a portion of an optical beam received from the environment and incident on the LiDAR window at a first position on the perimeter of the LiDAR window propagates within the thickness of the cylindrical shell along an optical path defined by the inner surface and the outer surface, and is directed to exit from the thickness of the truncated conical shell at a second position on the perimeter of the LiDAR window different from the first position in a direction away from the field of view of the detection system.

[0238] Example 55. A system according to any one of Examples 1 to 27, wherein the shell comprises a cylindrical shell extending in a vertical direction parallel to a rotation axis of the optical system, wherein the optical detection beam rotates about the rotation axis.

[0239] Example 56. A method according to any one of Examples 28 to 54, wherein the shell comprises a cylindrical shell extending in a vertical direction parallel to a rotation axis of the optical system, wherein the optical detection beam rotates around the rotation axis.

[0240] the term

[0241] In the following description, for the purpose of explanation, many specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it is apparent that the embodiments described in the present disclosure can be implemented without these specific details. In some instances, well-known structures and devices are illustrated in block diagram form to avoid unnecessarily obscuring aspects of the present disclosure.

[0242] In the accompanying drawings, for ease of description, the specific arrangement or order of schematic elements (such as those representing systems, devices, modules, instruction blocks and / or data elements, etc.) is illustrated. However, those skilled in the art will understand that, unless explicitly described, the specific order or arrangement of schematic elements in the accompanying drawings is not intended to mean that a specific processing order or sequence, or separation of processing is required. In addition, unless explicitly described, the inclusion of schematic elements in the accompanying drawings is not intended to mean that such elements are required in all embodiments, nor is it intended to mean that the features represented by such elements cannot be included in some embodiments or cannot be combined with other elements in some embodiments.

[0243] Although the terms "first", "second", and / or "third", etc. are used to describe various elements, these elements should not be limited by these terms. The terms "first", "second", and / or "third" are only used to distinguish one element from another element. For example, a first contact may be referred to as a second contact, and similarly, a second contact may be referred to as a first contact without departing from the scope of the described embodiments. Both the first contact and the second contact are contacts, but they are not the same contact.

[0244] The terms used in the specification of the various embodiments described herein are included only for the purpose of describing specific embodiments and are not intended to be limiting. As used in the specification of the various embodiments described and the appended claims, the singular forms "a", "an" and "the" are also intended to include plural forms and can be used interchangeably with "one or more than one" or "at least one", unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and includes any and all possible combinations of one or more than one of the associated listed items. It will also be understood that when the terms "include", "comprise", "have" and / or "have" are used in this specification, the stated features, integers, steps, operations, elements and / or components are specifically stated, but the presence or addition of one or more than one other features, integers, steps, operations, elements, components and / or groups thereof are not excluded.

[0245] As used herein, the term "if" is optionally interpreted to mean "when," "at," "in response to being determined to," and / or "in response to being detected," etc., depending on the context. Similarly, the phrases "if it is determined to be" or "if [the stated condition or event] is detected" are optionally interpreted to mean "upon determining to," "in response to being determined to" or "upon detecting [the stated condition or event]," and / or "in response to detecting [the stated condition or event]," etc., depending on the context. Furthermore, as used herein, the terms "have," "have," or "possess," etc. are intended to be open-ended terms. Furthermore, unless expressly stated otherwise, the phrase "based on" is intended to mean "based at least in part on."

[0246] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments described. However, it will be apparent to one of ordinary skill in the art that the various embodiments described may be implemented without these specific details. In other cases, well-known methods, processes, components, circuits, and networks have not yet been described in detail in order not to unnecessarily obscure aspects of the embodiments.

Claims

1. A system, include: an optical system configured to transmit an optical probe beam to an environment and receive reflections of the optical probe beam from the environment, wherein a wavelength of the optical probe beam is within an operating wavelength range of the optical system and the reflections of the optical probe beam are detected by a detection system of the optical system; and a light detection and ranging window, i.e., a LiDAR window, having a window diameter and a window thickness, the LiDAR window surrounding the optical system such that the optical detection beam is transmitted from the optical system through the LiDAR window to the environment, and a reflection of the optical detection beam is received by the detection system from the environment through the LiDAR window, wherein the LiDAR window comprises a window material having an optical absorption coefficient, wherein the optical absorption coefficient is configured such that, when a light beam having a wavelength within an operating wavelength range of the optical system propagates inside the window material, attenuation of the light beam is greater than 10 times for a first propagation distance than for a second propagation distance, and Wherein, the first propagation distance is determined at least in part based on the window diameter, and the second propagation distance is equal to the window thickness.

2. The system according to claim 1, in, The LiDAR window comprises a shell having an inner surface and an outer surface, wherein the window thickness is a distance between the inner surface and the outer surface along a direction perpendicular to the inner surface and the outer surface, and wherein the window diameter is an average diameter of the LiDAR window.

3. The system according to claim 1 or 2, in, The optical absorption coefficient is also configured such that the light beam attenuates by more than 11 dB after propagating a distance equal to the first propagation distance.

4. The system according to any one of claims 1 to 3, in, The optical absorption coefficient is also configured such that the light beam attenuates by less than 1 dB after propagating a distance equal to the second propagation distance.

5. The system according to any one of claims 2 to 4, in, The first propagation distance is equal to an average circumference of the shell.

6. A system according to any one of claims 2 to 5, in, The first propagation distance is shorter than an outer circumference of the shell and longer than the window thickness.

7. A system according to any one of claims 2 to 6, in, A portion of an optical beam received from the environment and incident on the LiDAR window at a first location on the perimeter of the LiDAR window propagates within the thickness of the shell along an optical path defined by the inner and outer surfaces of the shell, is scattered outside the thickness of the shell at a second location on the perimeter of the LiDAR window different from the first location, and is received by the detection system.

8. The system according to claim 7, in, The length of the optical path is equal to the first propagation distance, and the intensity of the portion of the optical beam incident on the LiDAR window received by the detection system is below a detection threshold of the detection system.

9. The system according to any one of claims 1 to 8, in, The window material includes a dopant material including a dopant.

10. The system according to claim 9, in, The optical absorption coefficient of the window material is related to the concentration of the dopant in the window material.

11. A method for reducing false signals in an optical system, the optical system being configured to transmit an optical probe beam into an environment and to receive reflections of the optical probe beam from the environment, in, The wavelength of the optical probe beam is within the operating wavelength range of the optical system, and reflection of the optical probe beam is detected by a detection system of the optical system, the method comprising: providing a window material having an absorption coefficient; using the provided window material to form a LiDAR window having a window diameter and a window thickness, wherein the LiDAR window surrounds the optical system such that the optical probe beam is transmitted from the optical system through the LiDAR window to the environment, and a reflection of the optical probe beam is received by the detection system from the environment through the LiDAR window, wherein, in the case of a light beam having a wavelength within the operating wavelength range of the optical system propagating inside the provided window material, attenuation of the light beam is more than 10 times greater for a first propagation distance than for a second propagation distance, and Wherein, the first propagation distance is determined at least in part based on the window diameter, and the second propagation distance is equal to the window thickness.

12. The method according to claim 11, in, The LiDAR window comprises a shell having an inner surface and an outer surface, wherein the window thickness is a distance between the inner surface and the outer surface along a direction perpendicular to the inner surface and the outer surface, and wherein the window diameter is an average diameter of the LiDAR window.

13. The method according to claim 11 or 12, in, Providing the window material further comprises providing a window material having an absorption coefficient such that the light beam is attenuated by more than 11 dB after propagating a distance equal to the first propagation distance.

14. The method according to any one of claims 11 to 13, in, Providing the window material further comprises providing a window material having an absorption coefficient such that the light beam is attenuated by less than 1 dB after propagating a distance equal to the second propagation distance.

15. The method according to any one of claims 12 to 14, in, The first propagation distance is equal to an average circumference of the shell.

16. The method according to any one of claims 12 to 14, in, The first propagation distance is shorter than an outer circumference of the shell and longer than the window thickness.

17. The method according to any one of claims 12 to 16, in, A portion of an optical beam received from the environment and incident on the LiDAR window at a first location on a perimeter of the LiDAR window propagates within the thickness of the shell along an optical path defined by the inner surface and the outer surface, is scattered out of the thickness of the shell at a second location on the perimeter of the LiDAR window different from the first location, and is received by the detection system.

18. The method according to claim 17, in, The length of the optical path is equal to the first propagation distance, and the intensity of the portion of the optical beam incident on the LiDAR window received by the detection system is below a detection threshold of the detection system.

19. The method according to any one of claims 11 to 18, in, The provided window material includes a doped material including a dopant.

20. The method according to claim 19, in, The concentration of the dopant in the window material is determined based at least in part on an optical absorption coefficient of a provided window material.

21. The system according to any one of claims 1 to 10, in, The housing comprises a cylindrical housing extending in a vertical direction parallel to an axis of rotation of the optical system about which the optical probe beam rotates.

22. The method according to any one of claims 11 to 20, in, The housing comprises a cylindrical housing extending in a vertical direction parallel to an axis of rotation of the optical system about which the optical probe beam rotates.

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