Multi-light-source lidar

Abstract

In a multi-light-source lidar, the light from the first illumination source is reflected into the first field of view by a rotating mirror, and the light from the second illumination source is reflected into the second field of view by the rotating mirror. The second field of view can be arranged to partially overlap the first field of view in order to provide a higher resolution in the region of interest.

Description

Technical Field

[0001]

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 344,361, filed May 20, 2022, which is incorporated by reference for all purposes.

Background Art

[0002]

[0002] Three - dimensional (3D) sensors can be applied to various applications including autonomous or semi - autonomous vehicles, drones, robots, security applications, etc. A lidar sensor is a type of 3D sensor that can achieve high angular resolution suitable for such applications. A lidar sensor can include one or more laser sources for emitting laser pulses and one or more detectors for detecting the reflected laser pulses. A lidar sensor can measure the time it takes for each laser pulse to travel from the lidar sensor to an object within the sensor's field of view and then reflect off the object and return to the lidar sensor. A lidar sensor can calculate how far an object is from the lidar sensor based on the time - of - flight of the laser pulse. Some lidar sensors can calculate distance based on the phase shift of light. By sending laser pulses in different directions, a lidar sensor can construct a three - dimensional (3D) point cloud of one or more objects in the environment.

Summary of the Invention

[0003]

[0003] In certain configurations, a lidar system that uses multiple illumination sources and a rotating mirror includes a first illumination source comprising a first plurality of lasers, a second illumination source comprising a second plurality of lasers, a mirror, a detector, and / or one or more memory devices. The mirror is arranged to rotate. The mirror is arranged to reflect light emitted from the first illumination source into the environment. The mirror is arranged to reflect light emitted from the second illumination source into the environment. The detector is arranged to receive light emitted from the first illumination source after the light emitted from the first illumination source has been reflected into the environment by the mirror. The one or more memory devices, when executed by one or more processors, include instructions to calculate the distance to an object in the environment based on the detector receiving light emitted from the first illumination source. In some configurations, the mirror is arranged to direct light from the first illumination source into a first field of view, the mirror is arranged to direct light from the second illumination source into a second field of view, the second field of view at least partially overlaps the first field of view, the second field of view overlaps at least 1 / 8 or 1 / 4 of the first field of view and does not overlap more than 7 / 8 or 3 / 4 of the first field of view, the mirror comprises a first surface and a second surface, and the second illumination source is arranged facing the first illumination source such that the first illumination source illuminates the first surface of the mirror and the second illumination source illuminates the second surface of the mirror. The mirror comprises a first surface and a second surface. The second light source is arranged facing the first light source such that the first light source illuminates the first surface of the mirror and the second light source illuminates the second surface of the mirror. The mirror comprises a first surface and a second surface. The second light source is arranged to illuminate the first surface of the mirror. The first light source illuminates the first surface of the mirror. The detector is a first detector. The distance is a first distance. The object is a first object. The system comprises a second detector. The second detector is arranged to receive the light emitted by the second light source after the light from the second light source is reflected into the environment by the mirror. One or more memory devices, when executed by one or more processors, include instructions to perform steps for calculating a second distance to a second object in the environment based on the second detector that receives the light emitted by the second light source. The mirror is arranged to rotate about a vertical axis to horizontally reflect the light from the first light source into the field of view. The side surface of the mirror is arranged to rotate vertically to vertically reflect the light from the first light source into the field of view. The system comprises a platform. The first light source is installed on the platform (e.g., fixedly coupled thereto). The platform is coupled to a fixed base using a flexure. The first light source comprises a first plurality of laser diodes arranged in a first region and a second plurality of laser diodes arranged in a second region. The first plurality of laser diodes are arranged in the first region at a higher density than the second plurality of laser diodes are arranged in the second region. The system comprises a beam splitter between the first light source and the mirror. The system comprises a first lens and a second lens. The first lens is characterized by a first focal length. The second lens is characterized by a second focal length. The first lens is positioned at a first distance from the mirror. The first distance is equal to the first focal length. The second lens is positioned at a second distance from the first lens and / or the second distance is equal to the sum of the first focal length and the second focal length.

[0004]

[0004] In certain configurations, a method for a lidar using a plurality of illumination sources includes: emitting light from a first illumination source, where the first illumination source comprises a first plurality of lasers; emitting light from a second illumination source, where the second illumination source comprises a second plurality of lasers; rotating a mirror; using the mirror to reflect the light from the first illumination source into the environment; using the mirror to reflect the light from the second illumination source into the environment; and / or using a detector to detect the light emitted from the first illumination source after the light emitted from the first illumination source has been reflected into the environment. In some configurations, the method includes directing the light from the first illumination source into a first field of view and directing the light from the second illumination source into a second field of view, where the second field of view at least partially overlaps the first field of view, the mirror comprises a first surface and a second surface, the second illumination source is arranged facing the first illumination source such that the first illumination source illuminates the first surface of the mirror and the second illumination source illuminates the second surface of the mirror, the first illumination source is installed on a platform, and the platform is coupled to a fixed base using a flexure. The method includes translating the platform relative to the fixed base while reflecting the light from the first illumination source by the mirror, and / or the method includes reflecting the light from the first illumination source using a beam splitter before reflecting the light from the first illumination source with the mirror.

[0005]

[0005] In certain configurations, a system for a lidar that uses a rotating mirror having reflective surfaces of different widths includes an illumination source and a mirror. The mirror is arranged to rotate and has a first side and a second side. The first side has a first width. The second side has a second width. The second width is not equal to the first width. The first side and the second side of the mirror are arranged to reflect light from the illumination source into the environment as the mirror rotates. In some configurations, the system includes a detector arranged to receive light emitted by the illumination source after the light from the illumination source has been reflected into the environment by the mirror, and one or more memory devices include instructions that, when executed by one or more processors, perform steps for calculating the distance to an object in the environment based on the detector receiving the light emitted by the illumination source. The mirror rotates about a vertical axis to reflect light from the illumination source into a horizontal field of view. The first width is greater than the second width and is no more than four times the second width. The mirror has three sides. The first side and the second side have a reflectivity of 90% or more at the wavelength of the illumination source. The illumination source is a laser array including a plurality of lasers. The mirror rotates about a vertical axis to horizontally reflect light from the illumination source into the field of view. The first side of the mirror rotates vertically to vertically reflect light from the illumination source into the field of view. The mirror rotates about a vertical axis to reflect light from the illumination source within a horizontal field of view. The illumination source is arranged to translate vertically and scan in a vertical dimension. The illumination source includes a plurality of lasers arranged in a first row and a second row. The illumination source is arranged to translate vertically and scan in a vertical dimension. The distance of the vertical movement is equal to the distance between the center of the first row and the center of the second row and is ±10% of that distance. The illumination source includes a first plurality of laser diodes arranged in a first region and a second plurality of laser diodes arranged in a second region. The first plurality of laser diodes are arranged in the first region at a higher density than the second plurality of laser diodes are arranged in the second region. The system includes a first lens and a second lens. The first lens is characterized by a first focal length. The second lens is characterized by a second focal length. The first lens is positioned at a first distance from the mirror. The first distance isEqual to the first focal length, the second lens is positioned at a second distance from the first lens, the second distance being equal to the sum of the first focal length and the second focal length. The system comprises a lens, light from an illumination source travels through the lens to a mirror, and light from the mirror travels through the lens to a detector. The illumination source is a first illumination source, the system comprises a second illumination source, the mirror comprises a third side, and the second illumination source is arranged facing the first illumination source such that the first illumination source illuminates a first side of the mirror and the second illumination source illuminates the third side of the mirror, and / or the system comprises a beam splitter between the illumination source and the mirror.,

[0006]

[0006] In certain configurations, a method for using a lidar having a rotating mirror with different widths includes the steps of emitting light from an illumination source, rotating the mirror, reflecting the light from the illumination source into the environment using the mirror while rotating the mirror, and after the light from the illumination source has been reflected into the environment by the mirror, using a detector to detect the light emitted by the illumination source, and / or calculating the distance to an object in the environment based on the detector that detects the light emitted by the illumination source. The mirror comprises a first side and a second side. The first side has a first width. The second side has a second width. The second width is not equal to the first width. In some configurations, the first width is greater than the second width and is no more than four times the second width, and / or the method includes rotating the mirror about a vertical axis to reflect the light from the illumination source within a horizontal field of view, translating the illumination source vertically to vertically displace the light from the illumination source within a vertical field of view, passing the light from the illumination source through a lens to the mirror, and / or passing the light from the mirror through a lens to the detector.,

[0007]

[0007] In certain configurations, a system for a lidar that uses a rotating mirror and vertical scanning includes a platform, an illumination source having a plurality of lasers disposed on the platform, a flexure coupling the platform to a fixed base, a mirror that is arranged to rotate and that is arranged to reflect light from the plurality of lasers into the environment when it rotates, a detector having one or more sensors arranged to receive light emitted by the illumination source after the light from the illumination source has been reflected into the environment by the mirror, and / or one or more memory devices that, when executed by one or more processors, include instructions to perform steps for calculating the distance to an object in the environment based on the detector receiving light emitted by the illumination source. In some configurations, the system includes a lens between the illumination source and the mirror, the platform is arranged to translate vertically when the mirror rotates horizontally about a vertical axis, the plurality of lasers are disposed on the platform with a non-uniform spacing between the lasers, the illumination source is a first illumination source, the mirror includes a first surface and a second surface, the system includes a second illumination source that is arranged opposite the first illumination source such that the first illumination source illuminates the first surface of the mirror and the second illumination source illuminates the second surface of the mirror, the system includes a beam splitter between the illumination source and the mirror, the system includes a first lens and a second lens, the first lens is characterized by a first focal length, the second lens is characterized by a second focal length, the first lens is positioned at a first distance from the mirror, the first distance is equal to the first focal length, the second lens is positioned at a second distance from the first lens, and / or the second distance is equal to the sum of the first focal length and the second focal length.

[0008]

[0008] In certain configurations, a method of using a translational platform and a rotating mirror in a lidar includes translating the platform relative to a fixed base, where a plurality of lasers are disposed on the platform, a flexure couples the platform to the fixed base, and the plurality of lasers are part of an illumination source; emitting light from the plurality of lasers while translating the platform; reflecting the light emitted from the illumination source into the environment using the rotating mirror; and after reflecting the light emitted from the illumination source into the environment, detecting the light from the illumination source using a detector and / or calculating the distance to an object in the environment based on detecting the light from the illumination source. In some configurations, the platform is translated in a vertical dimension and the rotating mirror rotates horizontally about a vertical axis.

[0009]

[0009] The further applicable scope of the present disclosure will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples, while indicating various embodiments, are for illustrative purposes only and do not necessarily limit the scope of the present disclosure.

[0010]

[0010] The present disclosure is described in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0011]

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[0012]

[0029] In the accompanying drawings, similar components and / or features may have the same reference labels. Further, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes the similar components. If only the first reference label is used herein, the description is applicable to any one of the similar components having the same first reference label, regardless of the second reference label.

[0013]

[0030] The following description provides only preferred exemplary embodiments and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the following description of the preferred exemplary embodiments provides those skilled in the art with a possible description for implementing the preferred exemplary embodiments. It is understood that various changes may be made to the functions and arrangements of the elements without departing from the spirit and scope recited in the appended claims.

[0014]

[0031] FIG. 1 shows an embodiment of a lidar sensor 100 for three-dimensional imaging. The lidar sensor 100 includes a transmitting lens 130 and a receiving lens 140. The lidar sensor 100 includes a light source 110-a disposed substantially at the rear focal plane of the transmitting lens 130. The light source 110-a operates to emit light pulses 120 from respective emission positions within the rear focal plane of the transmitting lens 130. The transmitting lens 130 is configured to collimate the light pulses 120 and direct them toward an object 150 located in front of the lidar sensor 100. For a given emission position of the light source 110-a, the collimated light pulse 120' is directed at a corresponding angle toward the object 150.

[0015]

[0032] A part 122 of the light pulse 120' after collimation is reflected from the object 150 toward the light receiving lens 140. The light receiving lens 140 is configured to focus a part 122' of the light pulse reflected from the object 150 to a corresponding detection position within the focal plane of the light receiving lens 140. The lidar sensor 100 further includes a detector 160-a substantially disposed in the focal plane of the light receiving lens 140. The detector 160-a is configured to receive and detect a part 122' of the light pulse 120 reflected from the object at the corresponding detection position. The corresponding detection position of the detector 160-a is optically paired with each emission position of the light source 110-a.

[0016]

[0033] The light pulse 120 may have a short duration, for example, a pulse width of 10 ns. The lidar sensor 100 further includes a processor 190 coupled to the light source 110-a and the detector 160-a. The processor 190 is configured to determine the time of flight (TOF) of the light pulse 120 from emission to detection. Since the light pulse 120 travels at the speed of light, the distance between the lidar sensor 100 and the object 150 may be determined based on the determined time of flight.

[0017]

[0034] One way to scan a laser beam (e.g., optical pulse 120’) across the FOV is to move the light source 110-a laterally with respect to the emission lens 130 within the rear focal plane of the emission lens 130. For example, the light source 110-a may be raster scanned with respect to a plurality of emission positions in the rear focal plane of the emission lens 130 as shown in FIG. 1. The light source 110-a may emit a plurality of optical pulses at a plurality of emission positions. Each optical pulse emitted at each emission position is collimated by the emission lens 130 and directed towards the object 150 at each angle, colliding with a corresponding point on the surface of the object 150. Thus, when the light source 110-a is raster scanned within a certain region in the rear focal plane of the emission lens 130, the corresponding object region on the object 150 is scanned. The detector 160-a may be raster scanned to be positioned at a plurality of corresponding detection positions within the focal plane of the light receiving lens 140 as shown in FIG. 1. The scanning of the detector 160-a is typically performed in synchronization with the scanning of the light source 110-a, and as a result, the detector 160-a and the light source 110-a are always optically paired with each other at a given time.

[0018]

[0035] By determining the flight time of each optical pulse emitted at each emission position, the distance from the lidar sensor 100 to each corresponding point on the surface of the object 150 may be determined. In some embodiments, the processor 190 is coupled to a position encoder that detects the position of the light source 110-a at each emission position. Based on the emission position, the angle of the collimated optical pulse 120’ may be determined. The X-Y coordinates of the corresponding points on the surface of the object 150 may be determined based on the angle and the distance to the lidar sensor 100. Thus, a three-dimensional image of the object 150 may be constructed based on the measured distances from the lidar sensor 100 to various points on the surface of the object 150. In some embodiments, the three-dimensional image may be represented as a point cloud, i.e., a set of X, Y, and Z coordinates of points on the surface of the object 150.

[0019]

[0036] In some embodiments, the intensity of the return light pulse 122' is measured and used to adjust the output of subsequent light pulses from the same emission point to prevent saturation of the detector, improve eye safety, or reduce overall power consumption. The output of the light pulse may be varied by changing the duration of the light pulse, the voltage or current applied to the laser, or the charge stored in a capacitor used to power the laser. In the latter case, the charge stored in the capacitor may be varied by changing the charging time, charging voltage, or charging current to the capacitor. In some embodiments, a reflectivity, as determined by the intensity of the detected pulse, may also be used to add another dimension to the image. For example, the image may include X, Y, and Z coordinates, as well as reflectivity (or luminance).

[0020]

[0037] The field of view angle (AFOV) of the lidar sensor 100 may be estimated as follows, based on the scanning range of the light source 110-a and the focal length of the emission lens 130,

Equation

[0021]

[0038] The light source 110-a may be configured to emit optical pulses in the near-infrared wavelength range. The energy of each optical pulse can be on the order of microjoules, which is typically considered eye-safe for a repetition rate in the kHz range. In the case of light sources operating at wavelengths above about 1500 nm (near-infrared wavelength range), the energy levels can be higher because the eye does not focus on those wavelengths. The detector 160-a may comprise a silicon avalanche photodiode, a photomultiplier tube, a PIN diode, or other semiconductor sensors.

[0022]

[0039] The additional lidar sensors are described in the commonly-owned U.S. Patent Application No. 15 / 267,558, filed Sep. 15, 2016; U.S. Patent Application No. 15 / 971,548, filed May 4, 2018; U.S. Patent Application No. 16 / 504,989, filed Jul. 8, 2019; U.S. Patent Application No. 16 / 775,166, filed Jan. 28, 2020; U.S. Patent Application No. 17 / 032,526, filed Sep. 25, 2020; U.S. Patent Application No. 17 / 133,355, filed Dec. 23, 2020; U.S. Patent Application No. 17 / 205,792, filed Mar. 18, 2021; and U.S. Patent Application No. 17 / 380,872, filed Jul. 20, 2021, the disclosures of which are incorporated by reference for all purposes.

[0023]

[0040] FIG. 2 depicts an embodiment of a lidar system 200 that includes a rotating mirror 204. The mirror 204 can be used to scan a laser beam 206 from an illumination source 208 within the field of view (FOV) 212 of the lidar system 200. Three horizontal rows of points scanned across the FOV 212 at uniform intervals (e.g., uniform density and resolution of points) are shown. The three horizontal rows can be achieved, for example, by having three lasers in the vertical direction (out of the page). The mirror 204 is a polygon mirror. Conventional polygon mirrors are made from mirror segments of equal size in several planes that are manufactured on a rotating rotor and rotate at a uniform rotational speed. Compared to other types of optical scanning devices, such as galvanometer mirrors, polygon mirrors have low vibration, low power requirements, and linear scanning characteristics. The return beam 214 reflects from the mirror 204 and is reflected from the beam splitter 218 towards the detector 222 (e.g., a photodetector for calculating one or more points of the lidar point cloud).

[0024]

[0041] In some lidar applications, it is desirable to have a higher resolution in the central part of the field of view (FOV) or region of interest (ROI). Usually, this cannot be achieved by using a polygon mirror with a uniform rotation speed and mirror segments of equal size.

[0025]

[0042] Figure 3 depicts an embodiment of a lidar system 300 comprising a mirror 304 having side surfaces 305 of different widths. The mirror 304 is a polygon mirror. The side surface 305 is the reflective surface of the mirror 304. The mirror 304 is used to scan one or more laser beams 306 from an illumination source 308 into the field of view (FOV) 312 of the lidar system 300. For example, the side surface 305 of the mirror 304 reflects the light from the illumination source 308 into an annular area within the FOV 312 as the mirror 304 rotates. In some configurations, the illumination source 308 is a laser array comprising a plurality of lasers (e.g., 2 to 64 lasers).

[0026]

[0043] The mirror 304 is arranged or configured to rotate (e.g., at a constant rotation speed). The mirror 304 comprises a first side surface 305-1, a second side surface 305-2, a third side surface 305-3, a fourth side surface 305-4, a fifth side surface 305-5, and a sixth side surface 305-6. The side surfaces 305 are highly reflective (e.g., having a reflectivity of 80, 90, 95, 97, 98, or 99% or more at the wavelength of the illumination source 308).

[0027]

[0044] Although shown with six sides 305, mirror 304 may have more or fewer sides 305 (e.g., 3, 4, 5, 7, or 8 sides). The widths of the sides 305 are not equal. The first side 305-1 and the fourth side 305-4 have a first width w-1. The second side 305-2, the third side 305-3, the fifth side 305-5, and the sixth side 305-6 have a second width w-2. The second width w-2 is not equal to the first width w-1 (e.g., the first width w-1 is wider than the second width w-2). The sides 305 have the same height (e.g., in the vertical direction). Mirror 304 rotates about a vertical axis 316 to horizontally reflect light from the illumination source 308 within the FOV 312.

[0028]

[0045] Within the FOV 312, there are filled-in points (e.g., dots) and unfilled points. The filled-in dots represent reflections from the sides 305 of length w-1. The unfilled dots represent reflections from the sides 305 of length w-2. The unfilled dots scan only the center of the FOV 312. The filled-in dots scan a wider area (e.g., assuming a constant rotation speed of the mirror 304, in some configurations, the mirror 304 can rotate at a variable rotation speed).

[0029]

[0046] The detector is arranged to receive light emitted by the illumination source 308 after the light from the illumination source 308 has been reflected into the environment by the mirror 304. The distance to an object within the environment is calculated based on the detector receiving the light emitted by the illumination source 308 (e.g., a portion of the light emitted by the illumination source 308 is reflected from the object to the mirror 304 and then from the mirror 304 to the detector).

[0030]

[0047] In FIG. 3, planar mirror segments (e.g., side surface 305) are used to encompass different angular ranges. Smaller mirror segments scan the central region of the FOV 312, and wider segments scan the entire FOV 312 horizontally. Together, this results in a higher density of point distribution in the central region or region of interest, and correspondingly, better resolution in the central region or region of interest.

[0031]

[0048] The emission speed of the laser can be modified to be offset with respect to the rotation of the mirror 304 in order to offset points within the FOV 312 to increase coverage. An enlarged view 330 of points 335, which are part of a point group within the FOV 312, is shown in FIG. 3. The enlarged view 330 shows a set of points 335 including a first point 335-1, a second point 335-2, a third point 335-3, a fourth point 335-4, a fifth point 335-5, and a sixth point 335-6. The first point 335-1 is from the reflection of the first side surface 305-1. The second point 335-2 is from the reflection of the second side surface 305-2. The third point 335-3 is from the reflection of the third side surface 305-3. The fourth point 335-4 is from the reflection of the fourth side surface 305-4. The fifth point 335-5 is from the reflection of the fifth side surface 305-5. The sixth point 335-6 is from the reflection of the sixth side surface 305-6. The set of points 335 within the enlarged view 330 is repeated at the center of the FOV 312 based on the emission speed of the laser. The horizontal scanning lines shown within the FOV 312 are for one rotation of the mirror 304. The FOV 312 shows three scanning lines for the scanning of three lasers stacked vertically. In some configurations, a dithering mirror is used to vertically displace the points 335 from one laser.

[0032]

[0049] The pattern of the scanning lines can be configured to repeat every rotation (360 degrees) or every half rotation (180 degrees) of the mirror 304. One frame can be considered as one full rotation of the mirror 304. In some configurations, the scanning line pattern is repeated every N frames, where N is an integer. For example, if N = 10 and there are 10 frames per second, the scanning line pattern is repeated every second. In some configurations, N is 1, 2, 3, 5, or 7 or more, and / or 7, 10, 15, 20, 30, or 50 or less.

[0033]

[0050] In FIG. 3, the first width w-1 is approximately 2.5 times the second width w-2. In some configurations, the first width w-1 is 1.2, 1.5, 1.75, 2, or 2.5 times or more the second width w-2, and / or 5, 4, or 3 times or less the second width w-2.

[0034]

[0051] Six side surfaces 305 are shown in FIG. 3, but the mirror 304 can have a number less than or more than six side surfaces 305. For a wider FOV312, a smaller number of side surfaces can be used. For example, 3 for 120 degrees, 4 for 90 degrees, 5 for 72 degrees, and 6 for 60 degrees. For a narrower FOV312 and / or a higher density of points, more side surfaces can be used.

[0035]

[0052] The mirror 304 may be asymmetric and / or may have different arrangements of the widths of the side surfaces 305. For example, the mirror 304 can have three side surfaces with two long sides and one short side, three sides with three different widths, four side surfaces with three short sides and one long side, or four side surfaces with two short sides and two long sides, depending on the application and the desired density distribution.

[0036]

[0053] FIG. 4 depicts an embodiment of a lidar system 400 having a rotating mirror 404 with a non-planar reflective surface. The mirror 404 has a curved side surface 405. As the mirror 404 rotates, light from the illumination source 408 is reflected at various angles off the side surface 405 of the mirror 404, resulting in a non-uniform scanning speed within the field of view (FOV) 412. By appropriately curving the side surface 405 (e.g., having a concave shape), the scanning becomes slower at the central portion of the side surface 405, resulting in a higher density of lidar image points at the center of the FOV 412.

[0037]

[0054] The side surface 405 is curved one-dimensionally in a direction orthogonal to the rotation axis 416 of the mirror 404 (e.g., curved within the plane of the page of FIG. 4). The rotation axis 416 is parallel to the vertical direction. In some configurations, the side surface 405 is curved in a direction parallel to the rotation axis 416 of the mirror 404 (e.g., in addition to, or instead of, a curvature in a direction orthogonal to the rotation axis 416, curved into and out of the page). The curvature parallel to the rotation axis 416 may be used to increase the density of points at the center of the FOV 412 in the vertical direction (e.g., for either a single laser scanned vertically by a second mirror, or for a plurality of laser beams spaced vertically). The vertical curvature may be used to counter the astigmatism effect that can be caused by the side surface 405 that is curved only in the horizontal direction. In some configurations, an optical element 420 for astigmatism correction (e.g., a cylindrical lens) may be incorporated into the beam path to correct the astigmatism from the curved side surface 405 of the mirror 404. The curvature of the side surface 405 of the mirror 404 may have multiple sub-segments and be non-uniform (e.g., having a non-uniform radius of curvature) in some cases to match the point density of each part of the FOV 412. The curvature may be adjusted to add a lens or focusing effect to the beam path.

[0038]

[0055] Figure 5 depicts an embodiment of a lidar system 500 with a rotating mirror having a rotating side surface 505. Light from the illumination source 508 is reflected by the side surface 505 of the mirror 504 into the field of view (FOV) 512. The mirror 504 rotates about the vertical axis 516 to reflect the light from the illumination source 508 within the horizontal field of view, and the side surface 505 of the mirror 504 rotates (e.g., tilts) vertically and / or horizontally to reflect the light from the illumination source 508 vertically and / or horizontally into the FOV 512.

[0039]

[0056] In Figure 5, each side surface 505 of the mirror 504 is mounted on an adjustable pedestal that can be tilted horizontally and / or vertically in real time. The side surface 505 may be held by a pivot bearing or flexure. The drive mechanism 507 can be an electric motor, stepper motor, voice coil, piezoelectric device, and / or other drive mechanism. In some configurations, the pitch of each side surface 505 is mechanically set (e.g., by a mechanism similar to that used to set the pitch of a helicopter blade). During operation, the side surface 505 can be tilted as the mirror 504 spins, thus changing the direction of the scanning beam. Using appropriate control logic, the scanning pattern can be arranged to place more points within a given ROI and fewer points outside the ROI, thus providing a higher resolution within the ROI.

[0040]

[0057] Figure 6 depicts a side view of an embodiment of a lidar system 600 with a rotating mirror 604. Light from the illumination source 608 (e.g., after passing through the collimating lens 614) is reflected by the mirror 604 into the far-field pattern 613 as the mirror 604 rotates about the vertical axis 616. The illumination source 608 comprises one or more lasers 620. The lasers 620 shown in Figure 6 are arranged in a vertical column. As the rotation of the mirror 604 scans in the horizontal direction, the lasers 620 are mechanically scanned in the vertical direction, thus achieving a two-dimensional scanning profile in the far-field pattern 613.

[0041]

[0058] FIG. 7 depicts a time series of one embodiment of a lidar system 700 showing vertical scanning using a flexure 702. Scanning of the laser 620 may be achieved by placing the laser 620 on a substrate 706 (e.g., a platform) (e.g., flexibly) coupled to a base 710 (e.g., a fixed base) by a flexure 702 that enables controllable movement of the laser 620 in the vertical (and / or, in some configurations, horizontal) direction. The laser 620 is fixedly coupled to the substrate 706 such that no relative movement occurs between the laser 620 and the substrate 706. The position of the laser 620 (e.g., with respect to the mirror 604) may be scanned using a voice coil, a linear motor, a piezoelectric transducer, or other drive mechanism. In some implementations, the flexure 702 may be driven at its resonant frequency to reduce power constraints. The laser 620 may be a fiber-coupled laser in some implementations and / or one or more optical fibers may be used to flexibly attach the laser output section to the substrate 706 using one or more laser modules in the base 710.

[0042]

[0059] When the light from the laser 620 passes through the side surface 605 of the mirror 604, the laser 620 is at a different vertical position, thus resulting in a more dense arrangement of points in the vertical dimension. One or more detectors may be placed on the substrate 706 (e.g., to scan in synchronization with the laser 620).

[0043]

[0060] In the configuration shown in FIG. 7, the mirror 604 rotates about the vertical axis 616 to reflect light from an illumination source (e.g., the laser 620) within a horizontal field of view. The illumination source (e.g., the laser 620 placed on the substrate 706) is arranged to translate vertically and scan in the vertical dimension. In some configurations, it may also be advantageous to scan the illumination source in a two-dimensional manner to improve the horizontal and vertical resolutions.

[0044]

[0061] FIG. 7 shows simplified time series for T = 1, T = 2, and T = 3. Mirror 604 includes a first side 605-1, a second side 605-2, a third side 605-3, a fourth side 605-4, a fifth side 605-5, and a sixth side. At time T = 1, while the light from laser 620 is reflected by the fourth side 605-4 as mirror 604 rotates, substrate 706 is in a lower vertical position (e.g., lower than the neutral vertical position). At time T = 2, while the light from laser 620 is reflected by the fifth side 605-5 as mirror 604 rotates, substrate 706 is in the neutral vertical position. At time T = 3, while the light from laser 620 is reflected by the sixth side as mirror 604 rotates, substrate 706 is in a higher vertical position (e.g., higher than neutral).

[0045]

[0062] In FIG. 7, laser 620 can represent a row of lasers 620 (e.g., extending into and out of the page). In some configurations, the vertical movement of substrate 706 is equal to or does not exceed the distance between lasers 620 or a row of lasers 620 (e.g., + / −1, 5, 10, 15, or 20%), because scan line 708 can be arranged to vertically fill the field of view as the illumination source translates vertically (e.g., at time T = 3 as shown in FIG. 7). In some configurations, the illumination source includes a plurality of lasers 620 arranged in a first row 714-1 and a second row 714-2, the illumination source is arranged to translate vertically and scan in the vertical dimension, and the distance of vertical movement (e.g., of substrate 706) is equal to the distance d between the center of the first row and the center of the second row, plus or minus 10% of that distance.

[0046]

[0063] In some configurations, a second illumination source is arranged (e.g., on platform 706 or on a second platform) to illuminate mirror 604 (e.g., as described in connection with FIGS. 10 and / or 11).

[0047]

[0064] FIG. 8 depicts an embodiment of a laser 620 disposed within an illumination source 804. FIG. 8 depicts a first illumination source 804-1, a second illumination source 804-2, and a third illumination source 804-3. In FIG. 8, one or two rows are shown for the illumination source 804, but the illumination source 804 can have more horizontal and / or vertical rows.

[0048]

[0065] The first illumination source 804-1 has lasers 620 arranged in two rows with a constant pitch (e.g., the spacing between lasers) in the vertical dimension.

[0049]

[0066] The second illumination source 804-2 has lasers 620 arranged vertically with a varying or non-uniform pitch (e.g., in one dimension). The pitch (e.g., in the vertical direction) is finer in the central portion 808 of the second illumination source 804-2 than in the peripheral portion 812 of the second illumination source 804-2. This results in more points and higher resolution in the central portion of the FOV compared to the peripheral portions (e.g., the top and bottom) of the FOV.

[0050]

[0067] In the third illumination source 804-3, the lasers 620 are arranged alternately in the central portion 808. The lasers 620 are arranged alternately (e.g., when the desired pitch of the laser array and / or detector array is smaller than the physical size of the lasers 620 or detectors) to enable, for example, a greater number of lasers (and / or detectors) to be arranged in the vertical dimension.

[0051]

[0068] For the second light source 804-2 and the third light source 804-3, a first plurality (or first set) of lasers 620 (e.g., laser diodes) are arranged in a first region (e.g., in the central portion 808). A second plurality (or second set) of lasers 620 are arranged in a second region (e.g., the peripheral portion 812). The lasers 620 in the first region are arranged at a first pitch 816-1. The lasers 620 in the second region are arranged at a second pitch 816-2. Since the first pitch 816-1 is smaller than the second pitch 816-2, the first plurality of lasers 620 are arranged in the first region at a higher density than the second plurality of lasers 620 in the second region.

[0052]

[0069] FIG. 9 shows a flowchart of an embodiment of a process 900 for lidar scanning using a mirror having reflective surfaces of different widths. Process 900 begins at step 904 by emitting light from a light source. For example, light is emitted from the light source 308 of FIG. 3. At step 908, a mirror (e.g., mirror 304 of FIG. 3) is rotated. At step 912, the light from the light source is reflected by the mirror into the environment (e.g., FOV 312 of FIG. 3) while the mirror is rotating. The mirror comprises a first side surface and a second side surface (e.g., the first side surface 305-1 and the second side surface 305-2). The first side surface has a first width. The second side surface has a second width. The second width is not equal to the first width.

[0053]

[0070] At step 916, after the light from the light source is reflected into the environment by the mirror, a detector is used to detect the light emitted by the light source. At step 920, based on the detector that detects the light emitted by the light source, the distance to an object in the environment is calculated.

[0054]

[0071] FIG. 10 depicts an embodiment of a lidar system 1000 having a rotating mirror 1004 and a plurality of illumination sources 1008. Light from the illumination source 1008 is reflected into the field of view (FOV) 1012 of the lidar system 1000 by one or more sides 1005 of the mirror 1004.

[0055]

[0072] The first illumination source 1008-1 includes a first plurality of lasers 1020. The second illumination source 1008-2 includes a second plurality of lasers 1020. The second illumination source 1008-2 emits light having the same wavelength as the light from the first illumination source 1008-1. In some embodiments, the second illumination source 1008-2 emits light at a wavelength different from the light from the first illumination source 1008-1. In some embodiments, the illumination source 1008 can have lasers or diodes that emit at different center wavelengths. Although a row of five lasers 1020 is shown for the illumination source 1008, the illumination source 1008 can have a plurality of rows and / or columns. For example, the illumination source can have one, two, three, or more columns of 1, 2, 3, 4, 5, 8, 16, or 32 lasers 1020.

[0056]

[0073] Mirror 1004 is arranged to rotate the light emitted from the first light source 1008-1 and the second light source 1008-2 and reflect it into the environment. The light from the first light source 1008-1 is emitted within the first FOV 1024-1 of the first light source 1008-1. The light from the second light source 1008-2 is emitted within the second FOV 1024-2 of the second light source 1008-2. The first FOV 1024-1 at least partially overlaps with the second FOV 1024-2. In FIG. 10, the first FOV 1024-1 partially overlaps with the second FOV 1024-2, but does not completely overlap with the second FOV 1024-2. In some configurations, the first FOV 1024-1 does not overlap with the second FOV 1024-2 by more than 7 / 8, 3 / 4, 5 / 8, 1 / 2, 1 / 3, or 1 / 4 of the first FOV 1024-1, and / or at least 1 / 8, 1 / 4, 1 / 3, or 1 / 2 of the first FOV 1024-1 only at least overlaps with the second FOV 1024-2. For example, the second field of view overlaps at least 1 / 8 or 1 / 4 of the first field of view and does not overlap by more than 7 / 8 or 3 / 4 of the first field of view, overlaps at least 1 / 8 of the first field of view and does not overlap by more than 7 / 8 of the first field of view, overlaps at least 1 / 4 of the first field of view and does not overlap by more than 3 / 4 of the first field of view, overlaps at least 1 / 4 of the first field of view and does not overlap by more than 7 / 8 of the first field of view, overlaps at least 1 / 8 of the first field of view and does not overlap by more than 3 / 4 of the first field of view, overlaps half of the first field of view, or overlaps at least half of the first field of view and not more than 5 / 8, 2 / 3, 3 / 4, or 7 / 8 of the first field of view. The FOV 1012 of the lidar system 1000 is a combination of the first FOV 1024-1 and the second FOV 1024-2 of the light source 1008. The FOV 1012 of the lidar system 1000 has a higher density of points at the center of the FOV 1012.

[0057]

[0074] The second light source 1008-2 is separated from the first light source 1008-1. The second light source 1008-2 is separated from the first light source 1008-1 such that the field of view of the second light source 1008-2 does not completely overlap with the field of view of the first light source 1008-1. In some configurations, the overlap of the field of view of the first light source 1008-1 by the field of view of the second light source 1008-2 is 2 / 3, 1 / 2, 1 / 3, 1 / 4, or less than 1 / 5. In some configurations, the field of view of the second light source 1008-2 does not overlap with the field of view of the first light source 1008-1.

[0058]

[0075] The first detector and the second detector are arranged to receive the light emitted by the first light source 1008-1 and the second light source 1008-2 after the light emitted from the light source 1008 is reflected into the environment by the mirror 1004. One or more memory devices, when executed by one or more processors, include instructions for calculating one or more distances to one or more objects in the environment based on the detectors receiving the light emitted from the light source 1008.

[0059]

[0076] The first light source 1008-1 and the second light source 1008-2 are arranged such that the light emitted from the first light source 1008-1 and the second light source 1008-2 simultaneously illuminates the same side 1005 of the mirror 1004. Thus, the second light source 1008-2 is arranged to illuminate the side 1005 of the mirror, and the first light source 1008-1 illuminates the same side 1005 of the mirror. In some configurations, the mirror 1004 has sides 1005 of equal width. In some configurations, the sides 1005 of the mirror 1004 are of different widths (e.g., as shown in FIG. 3) and / or non-planar (e.g., as shown in FIG. 4).

[0060]

[0077] As shown in FIG. 10, the illumination source 1008 spreads horizontally. The first illumination source 1008-1 scans the first side of the FOV 1012, and the second illumination source 1008-2 scans the second side of the FOV 1012. The scanning may be arranged such that the density of points increases by a factor of two at the center of the FOV 1012. Other arrangements of the laser columns and / or the laser spacing are also possible. For example, more columns and / or rows of lasers may be used.

[0061]

[0078] FIG. 11 depicts an embodiment of a lidar system 1100 having a rotating mirror 1004 and a plurality of illumination sources 1008 on both sides of the rotating mirror 1004. The mirror 1004 includes a first side surface 1005-1 and a second side surface 1005-2. The mirror 1004 is arranged to reflect the light emitted from the first illumination source 1008-1 into the environment using the first side surface 1005-1 of the mirror, and to reflect the light emitted from the second illumination source 1008-2 into the environment using the second side surface 1005-2 of the mirror 1004. On the other hand, the first side surface 1005-1 of the mirror 1004 is used to reflect the light from the first illumination source 1008-1. The first detector is arranged to receive the light emitted from the first illumination source 1008-1 after the light emitted from the first illumination source 1008-1 is reflected into the environment by the mirror 1004. The second detector is arranged to receive the light emitted from the second illumination source 1008-2 after the light emitted from the second illumination source 1008-2 is reflected into the environment by the mirror 1004.

[0062]

[0079] In FIG. 11, the second illumination source 1008-2 is arranged facing the first illumination source 1008-1 (e.g., with respect to the mirror 1004). This enables a single polygon mirror to scan a plurality of illumination sources 1008 (e.g., multiple sets of lasers). The overlap between the lights from the illumination sources 1008 within the FOV 1012 can be adjusted by changing the position of the illumination sources 1008 with respect to the mirror 1004. Therefore, the ROI can also be changed.

[0063]

[0080] In some configurations, the detector of the first light source 1008-1 is arranged on the opposite side of the first light source 1008-1 (e.g., adjacent to the second light source 1008-2). In some configurations, the second light source is not used, and the detector of the first light source 1008-1 is on the opposite side of the mirror 1004. This can avoid the use of a beam splitter for separating the emitted laser beam from the return beam.

[0064]

[0081] In FIG. 11, the fields of view 1024 are shown overlapping, but in some configurations, the fields of view 1024 do not overlap and are used to create a wider FOV 1012.

[0065]

[0082] FIG. 12 depicts another embodiment of a lidar system 1200 having a mirror 1204 arranged to rotate and a plurality of light sources 1208 on both sides of the mirror 1204. The lidar system 1200 includes a mirror 1204, a first light source 1208-1, a second light source 1208-2, a first detector 1212-1, and a second detector 1212-2. The lidar system 1200 includes a lens 1216 and a steering mirror 1220.

[0066]

[0083] The first light source 1208-1 includes a first plurality of lasers housed within a first housing. The second light source 1208-2 includes a second plurality of lasers housed within a second housing. The first detector 1212-1 includes a first plurality of sensors (e.g., diodes) arranged within a third housing (however, in some embodiments, the sensors of the first detector 1212-1 are housed within the first housing or the second housing). The second detector 1212-2 includes a second plurality of sensors (e.g., diodes) arranged within a fourth housing (however, in some embodiments, the sensors of the second detector 1212-2 are housed within the second housing or the first housing). In some configurations, the number of sensors within the detector 1212 matches the number of lasers within the light source 1208.

[0067]

[0084] The first detector 1212-1 is arranged to detect light from the first light source 1208-1, and the second detector 1212-2 is arranged to detect light from the second light source 1208-2 after the light from the light source 1208 has propagated into the environment. In some embodiments, the first detector 1212-1 is arranged to detect light from the second light source 1208-2, and the second detector 1212-2 is arranged to detect light from the first light source 1208-1 (e.g., as described in connection with FIG. 11).

[0068]

[0085] Light from the light source 1208 is reflected by being directed (e.g., in the case of the transmission path) from the mirror 1220 to the mirror 1204 and (e.g., in the case of the return path) from the mirror 1204 to the detector 1212. The lens 1216 is a collimating lens. One or more distances to one or more objects in the environment are measured using the light source 1208 and the detector 1212. For example, the first distance to the first object in the environment is measured using the first light source 1208-1 and the first detector 1212-1, and the second distance to the first object or to the second object is measured using the second light source 1208-2 and the second detector 1212-2. Light from the first light source 1208-1 travels along a first optical path to the mirror 1204, and light from the second light source 1208-2 travels along a second optical path to the mirror 1204, and the second optical path is a different horizontal direction from the first optical path. For example, the first steering mirror 1220-1 directs light from the first light source 1208-1 in the positive x direction toward the mirror 1204, and the second steering mirror 1220-2 directs light from the second light source 1208-2 in the negative x direction toward the mirror 1204.

[0069]

[0086] The second light source 1208-2 is separated from the first light source by a distance that is 0.5, 0.75, 1, 1.5, or 1.7 times or more the width of the mirror 1204 and / or 3, 2, or 1.7 times or less the width of the mirror.

[0070]

[0087] The illumination source 1208 is shown at the top of the detector 1212, but they may be arranged side by side, or the illumination source 1208 may be below the detector 1212.

[0071]

[0088] FIG. 13 depicts an image of overlapping fields of view of an embodiment of a lidar system having two illumination sources. A first field of view 1324-1 from a first illumination source overlaps a second field of view 1324-2 from a second illumination source. The overlapping region has a higher density of measurement points than the sides of the non-overlapping fields of view 1324.

[0072]

[0089] FIG. 14 depicts an embodiment of a lidar system 1400 having a compound lens. The compound lens comprises a first lens 1402-1 and a second lens 1402-2. The compound lens is inserted between a mirror 1404 (e.g., a rotating polygon mirror) and an illumination source 1408 (e.g., one or more lasers and GRIN lenses). The focal length of the lens 1402 is f. The first lens 1402-1 is separated from the second lens 1402-2 by a length of 2f. The compound lens can be used as an optical relay that can correlate an input and an output of an optical beam. The input (e.g., at the galvo mirror 1410) is 1f from the first lens 1402-1, and the output (e.g., at the mirror 1404) is 1f from the second lens 1402-2.

[0073]

[0090] A detector 1412 (e.g., an avalanche photodiode) receives light reflected from an object 1413. A transmission path 1416 and a reception path 1420 are shown.

[0074]

[0091] The configuration of FIG. 14 shows an optical system of two lens elements of 4f, but as the angle of illumination of the mirror 1404 is changed, other optical relay configurations that change the angle of illumination at the mirror 1404 without substantially changing its position may be used.

[0075]

[0092] One possible advantage of this design in a galvo / polygon system is that the output position does not change when the galvo mirror 1410 is scanned. Thus, the constraints on the aperture size of the system can be reduced or minimized.

[0076]

[0093] In some configurations, the system includes a first lens (e.g., first lens 1402-1) and a second lens (e.g., second lens 1402-2). The first lens is characterized by a first focal length (e.g., f). The second lens is characterized by a second focal length (e.g., f or g, where g is not equal to f). The first lens is positioned at a first distance from a mirror (e.g., galvo mirror 1410 or mirror 1404). The first distance is equal to the first focal length. The second lens is positioned at a second distance from the first lens. The second distance is equal to the sum of the first focal length and the second focal length (e.g., 2f if the first focal length is equal to the second focal length, or f + g).

[0077]

[0094] FIG. 15 depicts one embodiment of an integrated optical assembly 1500 for a lidar. The integrated optical assembly has a coaxial design. FIG. 15 shows the optical path of light emitted by the illumination source 1508 and returning to the detector 1512, i.e., the coaxial path 1502. The returning photons travel basically the same path as the light from the laser beam, but in the opposite direction. Some kind of beam splitting optics is used to separate the outgoing beam from the returning photons.

[0078]

[0095] FIGS. 15 and 16 show examples of combinations of integrated optical assemblies that can be used to implement a beam splitting function. By integrating the optical components into a single small subassembly, the size and / or cost can be reduced.

[0079]

[0096] In FIG. 15, mirror 1516 is arranged to direct light from illumination source 1508 along coaxial path 1502 and / or to direct return photons to detector 1512. Mirror 1516 is a segment of a conical arrangement. In some embodiments, mirror 1516 is a conical mirror. Detector 1512 is orthogonal to illumination source 508. In some configurations, a prism (e.g., using total internal reflection) is positioned instead of mirror 1516 that is farthest from illumination source 1508.

[0080]

[0097] FIG. 16 depicts an embodiment of an integrated optical system 1600 having lens 1602 and beam splitter 1606. Lens 1602 can be convex (e.g., to collimate light and / or to focus light onto a detector) or concave (e.g., to help shape the divergence of a laser beam into a more symmetric distribution). Beam splitter 1606 is a mirror beam splitter. The lens is a microlens (e.g., having a width or diameter of 0.5, 1, or 2 mm or more and / or 2, 3, 5, or 10 mm or less). Light from illumination source 1508 travels through lens 1602 to a rotating mirror (e.g., mirror 304 of FIG. 3) and then from the rotating mirror through lens 1602 to detector 1512. In some configurations, lens 1602 is used to collimate light from a laser and / or to focus light onto detector 1512.

[0081]

[0098] The components of integrated optical assembly 1500 and / or integrated optical system 1600 can include mirrors, beam splitters, microlenses, and / or diffractive optical elements. In some configurations, the overall size of integrated optical assembly 1500 of FIG. 15 or integrated optical system 1600 of FIG. 16 is in the range of 1 to 3 mm on each side.

[0082]

[0099] The integrated optical assembly 1500 and the integrated optical system 1600 are examples of beam splitters optically positioned between the illumination source and the rotating mirror and between the detector and the rotating mirror such that the light from the illumination source and the light returning to the detector share an optical path (e.g., a coaxial path) between the beam splitter rather than the rotating mirror.

[0083]

[0100] FIG. 17 shows a flowchart of one embodiment of a process 1700 for a lidar using a plurality of illumination sources. The process 1700 begins, at step 1704, by emitting light from a first illumination source and a second illumination source. The first illumination source comprises a first plurality of lasers. The second illumination source comprises a second plurality of lasers. For example, the first illumination source is the first illumination source 1008-1 of FIG. 10 or FIG. 11, and the second illumination source is the second illumination source 1008-2 of FIG. 10 or FIG. 11.

[0084]

[0101] At step 1708, the mirror is rotated. For example, the mirror 1004 of FIG. 10 or FIG. 11 is rotated.

[0085]

[0102] At step 1712, while rotating the mirror, the light from the first illumination source and the second illumination source is reflected into the environment. For example, the light is reflected into the field of view 1012 of FIG. 10 or FIG. 11 by the mirror 1004.

[0086]

[0103] After the light is reflected into the environment, at step 1716, the light is detected. For example, the light is detected using the first detector 1212-1 and the second detector 1212-2 of FIG. 12. The distance to one or more objects in the environment is calculated based on detecting the light received from the environment.

[0087]

[0104] FIG. 18 shows a flowchart of one embodiment of process 1800 for a lidar using a translational platform and a rotating mirror. Process 1800 starts, in step 1804, by translating the platform relative to a fixed base, with a plurality of lasers of the illumination source being installed on the platform (e.g., substrate 706 of FIG. 7 is translated relative to base 710). In step 1808, as the mirror is rotated, light is emitted from the plurality of lasers while the platform is being translated.

[0088]

[0105] In step 1812, as the mirror is rotated, light from the illumination source is reflected into the environment. For example, in FIG. 7, as mirror 604 rotates, light from laser 620 is reflected by mirror 604.

[0089]

[0106] After the light is reflected into the environment, in step 1816, the light is detected. The distance to one or more objects in the environment is calculated based on detecting the light received from the illumination source after the light from the illumination source has been reflected into the environment.

[0090]

[0107] In some configurations, the platform is translated in a vertical dimension and the mirror rotates horizontally about a vertical axis (as shown, for example, in FIG. 7). In some configurations, the platform is translated in only one dimension (e.g., the vertical dimension to simplify calculations). In some configurations, the platform is translated two-dimensionally.

[0091]

[0108] The various features described herein, such as methods, apparatuses, computer-readable media, etc., can be implemented using a combination of dedicated components, programmable processors, and / or other programmable devices. Some of the processes described herein can be implemented on the same processor or different processors. If some components are described as being configured to perform certain operations, such a configuration can be achieved, for example, by designing an electronic circuit to perform the operation, by programming a programmable electronic circuit (such as a microprocessor) to perform the operation, or by a combination thereof. Further, although the above-described embodiments may refer to specific hardware and software components, different combinations of hardware and / or software components may equally be used, and it will be understood by those skilled in the art that a particular operation described as being implemented in hardware may be implemented in software or vice versa.

[0092]

[0109] In the above description, details have been provided to facilitate understanding of the embodiments. However, it is understood that the embodiments can be implemented without some of the specific details. Examples from different figures may be combined in various ways to improve performance or modified for a particular application. For example, the vertical movement of the light source in FIG. 7 may be combined with the variable laser spacing in FIG. 8, or the mirror 405 in FIG. 4 may be used as the mirror 1004 in FIG. 10. In some examples, well-known circuits, processes, algorithms, structures, and techniques are not shown in the figures.

[0093]

[0110] Although the principles of the present disclosure have been described above in connection with specific apparatus and methods, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the present disclosure. Embodiments have been selected and described in order to explain the principles and practical applications thereof for enabling those skilled in the art to utilize the invention in various embodiments with various modifications as are suited to the particular applications contemplated. It is to be understood that the description is intended to cover modifications and equivalents.

[0094]

[0111] Also, note that embodiments may be described as a process depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. A flowchart can describe operations as a series of processes, but many of the operations can be performed in parallel or simultaneously. Further, the order of the operations may be rearranged. A process ends when its operations are completed, but can have additional steps not included in the figures. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

[0095]

[0112] The recitation of “a,” “an,” or “the” is intended to mean “one or more” unless specifically indicated to the contrary. Patents, patent applications, publications, and descriptions referred to herein are incorporated by reference in their entirety for all purposes. There is no admission that any of the foregoing is prior art.

[0096]

[0113] The specific details of particular embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present invention. However, other embodiments of the present invention may be directed to specific embodiments relating to each individual aspect, or to specific combinations of these individual aspects.

[0097]

[0114] The above description of the embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms described, and many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to explain the principles of the invention and its practical application, thereby enabling those skilled in the art to utilize the invention in various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A system for a lidar using a plurality of illumination sources and a rotating mirror, the system comprising a first illumination source comprising a first plurality of lasers, a second illumination source comprising a second plurality of lasers, a mirror, wherein the mirror is arranged to rotate, wherein the mirror is arranged to reflect light emitted from the first illumination source into the environment, the mirror being arranged to reflect light emitted from the second illumination source into the environment, a detector arranged to receive light emitted from the first illumination source after the light emitted from the first illumination source has been reflected into the environment by the mirror, one or more memory devices including instructions that, when executed by one or more processors, perform steps for calculating a distance to an object in the environment based on the detector receiving the light emitted from the first illumination source.

2. The mirror is arranged to direct light from the first illumination source into a first field of view, the mirror is arranged to direct light from the second illumination source into a second field of view, the second field of view at least partially overlapping the first field of view, The system according to claim 1.

3. The system according to claim 2, wherein the second field of view overlaps at least 1 / 8 or 1 / 4 of the first field of view and does not overlap more than 7 / 8 or 3 / 4 of the first field of view.

4. The mirror comprises a first surface and a second surface, the second illumination source being arranged facing the first illumination source such that the first illumination source illuminates the first surface of the mirror and the second illumination source illuminates the second surface of the mirror, The system according to claim 2.

5. The mirror comprises a first surface and a second surface, the second illumination source being arranged facing the first illumination source such that the first illumination source illuminates the first surface of the mirror and the second illumination source illuminates the second surface of the mirror, The system according to claim 1.

6. The mirror comprises a first surface and a second surface, the second illumination source being arranged to illuminate the first surface of the mirror and the first illumination source being arranged to illuminate the first surface of the mirror, The system according to claim 1.

7. The detector is a first detector, The distance is a first distance, The object is a first object, The system comprises a second detector, The second detector is arranged to receive light emitted by the second light source after the light from the second light source is reflected into the environment by the mirror, The one or more memory devices, when executed by the one or more processors, include instructions to perform steps for calculating a second distance to a second object in the environment based on the second detector that receives the light emitted by the second light source, The system according to claim 1.

8. The mirror is arranged to rotate about a vertical axis to horizontally reflect light from the first light source into the field of view, The side surface of the mirror is arranged to rotate vertically to vertically reflect light from the first light source into the field of view, The system according to claim 1.

9. Further comprising a platform, The first light source is installed on the platform, The platform is coupled to a fixed base using a flexure, The system according to claim 1.

10. The first light source, A first plurality of laser diodes arranged in a first region, And a second plurality of laser diodes arranged in a second region, The first plurality of laser diodes are arranged in the first region with a higher density than the second plurality of laser diodes are arranged in the second region, The system according to claim 1.

11. The system according to claim 1, further comprising a beam splitter between the first light source and the mirror.

12. Further comprising a first lens and a second lens, The first lens is characterized by a first focal length, The second lens is characterized by a second focal length, The first lens is positioned at a first distance from the mirror, The first distance is equal to the first focal length, The second lens is positioned at a second distance from the first lens, The second distance is equal to the sum of the first focal length and the second focal length, The system according to claim 1.

13. A method for a lidar using a plurality of light sources, the method comprising A step of emitting light from a first light source, wherein the first light source comprises a first plurality of lasers; A step of emitting light from a second light source, wherein the second light source comprises a second plurality of lasers; A step of rotating a mirror; A step of using the mirror to reflect the light from the first light source into the environment; A step of using the mirror to reflect the light from the second light source into the environment; A method comprising a step of using a detector to detect the light emitted from the first light source after the light emitted from the first light source is reflected in the environment.

14. A step of guiding the light from the first light source into a first field of view; A step of guiding the light from the second light source into a second field of view, wherein the second field of view at least partially overlaps with the first field of view; The method according to claim 13, comprising the above steps.

15. The mirror comprises a first surface and a second surface; The second light source is arranged facing the first light source such that the first light source illuminates the first surface of the mirror and the second light source illuminates the second surface of the mirror. The method according to claim 13.

16. The first light source is installed on a platform; The platform is coupled to a fixed base using a flexure; The method comprises a step of translating the platform relative to the fixed base while reflecting the light from the first light source by the mirror. The method according to claim 13.

17. The first light source Comprises a first plurality of laser diodes arranged in a first region; And a second plurality of laser diodes arranged in a second region; The first plurality of laser diodes are arranged in the first region with a higher density than the second plurality of laser diodes arranged in the second region. The method according to claim 13.

18. The method according to claim 13, comprising a step of using a beam splitter to reflect the light from the first light source before reflecting the light from the first light source with the mirror.

19. A system for a lidar using a plurality of light sources and a rotating mirror, comprising A first light source; A second light source; A mirror including a first side and a second side, The mirror is arranged to rotate, the mirror is arranged to reflect the light emitted from the first illumination source into the environment using the first side surface of the mirror, the mirror is arranged to direct the light from the first illumination source into a first field of view, while the first side surface of the mirror is used to reflect the light from the first illumination source, the mirror is arranged to reflect the light emitted from the second illumination source into the environment using the second side surface of the mirror, the mirror is arranged to direct the light from the second illumination source into a second field of view, the second field of view at least partially overlaps with the first field of view, a mirror, a detector arranged to receive the light emitted from the first illumination source after the light emitted from the first illumination source is reflected into the environment by the mirror, one or more memory devices including instructions that, when executed by one or more processors, perform steps for calculating the distance to an object in the environment based on the detector receiving the light emitted from the first illumination source. A system comprising.

20. The second illumination source is arranged facing the first illumination source such that the first illumination source illuminates the first side surface of the mirror and the second illumination source illuminates the second side surface of the mirror. The system according to claim 19.

21. A system for a lidar using a rotating mirror having different-width reflecting surfaces, the system comprising an illumination source, a mirror, the mirror is arranged to rotate, the mirror comprises a first side surface and a second side surface, the first side surface has a first width, the second side surface has a second width, the second width is not equal to the first width, the first side surface and the second side surface of the mirror are arranged to reflect the light from the illumination source into the environment when the mirror rotates. A system comprising a mirror.

22. The system a detector arranged to receive the light emitted by the illumination source after the light from the illumination source is reflected into the environment by the mirror, One or more memory devices that, when executed by one or more processors, include instructions to perform steps for calculating the distance to an object in the environment based on the detector receiving the light emitted by the illumination source The mirror rotates about a vertical axis and reflects light from the illumination source into a horizontal field of view The system according to claim 21 **Claim 23** The system according to claim 21, wherein the first width is greater than the second width and is at most four times the second width **Claim 24** The system according to claim 21, wherein the mirror has three sides **Claim 25** The system according to claim 21, wherein the first side and the second side have a reflectivity of 90% or more at the wavelength of the illumination source **Claim 26** The system according to claim 21, wherein the illumination source is a laser array including a plurality of lasers **Claim 27** The mirror rotates about a vertical axis and reflects light from the illumination source horizontally within the field of view The first side of the mirror rotates vertically and reflects light from the illumination source vertically within the field of view The system according to claim 21 **Claim 28** The mirror rotates about a vertical axis and reflects light from the illumination source within a horizontal field of view The illumination source is arranged to translate vertically and scan in a vertical dimension The system according to claim 21 **Claim 29** The illumination source includes a plurality of lasers arranged in a first row and a second row The illumination source is arranged to translate vertically and scan in a vertical dimension The distance of vertical movement is equal to the distance between the center of the first row and the center of the second row, plus or minus 10% of that distance The system according to claim 21 **Claim 30** The illumination source A first plurality of laser diodes arranged in a first region And a second plurality of laser diodes arranged in a second region The first plurality of laser diodes are arranged in the first region with a higher density than the second plurality of laser diodes are arranged in the second region The system according to claim 21 **Claim 31** Further comprising a first lens and a second lens The first lens is characterized by a first focal length The second lens is characterized by a second focal length The first lens is positioned at a first distance from the mirror The first distance is equal to the first focal length The second lens is positioned at a second distance from the first lens, wherein the second distance is equal to the sum of the first focal length and the second focal length, The system according to claim 21.

32. Comprising a lens, Light from the illumination source travels through the lens to the mirror, The light travels from the mirror through the lens to the detector. The system according to claim 21.

33. The illumination source is a first illumination source, The system comprises a second illumination source, The mirror has a third side, The second illumination source is arranged facing the first illumination source such that the first illumination source illuminates the first side of the mirror and the second illumination source illuminates the third side of the mirror. The system according to claim 21.

34. The system according to claim 21, further comprising a beam splitter between the illumination source and the mirror.

35. A method for a lidar, the method comprising: emitting light from an illumination source; rotating a mirror; while rotating the mirror, using the mirror to reflect light from the illumination source into the environment, wherein the mirror has a first side and a second side, the first side has a first width, the second side has a second width, the second width is not equal to the first width; after the light from the illumination source is reflected into the environment by the mirror, using a detector to detect the light emitted by the illumination source; calculating the distance to an object in the environment based on the detector detecting the light emitted by the illumination source.

36. The method according to claim 35, wherein the first width is greater than the second width and at most four times the second width.

37. rotating the mirror about a vertical axis to reflect light from the illumination source within a horizontal field of view; translating the illumination source vertically to vertically displace the light from the illumination source within a vertical field of view; The method according to claim 35, comprising.

38. The illumination source comprises a first plurality of laser diodes arranged in a first region and a second plurality of laser diodes arranged in a second region. The plurality of first laser diodes are arranged in the first region at a higher density than the plurality of second laser diodes are arranged in the second region. The method according to claim 35.

39. Advancing light from the illumination source through a lens to the mirror; Advancing light from the mirror through the lens to the detector. The method according to claim 35.

40. A system for a lidar using a rotating mirror having reflective surfaces of different widths, the system comprising: An illumination source; A mirror, The mirror is arranged to rotate, The mirror has a first side surface and a second side surface, The first side surface has a first width, The second side surface has a second width, The second width is not equal to the first width, The first side surface and the second side surface of the mirror are arranged to reflect light from the illumination source into the environment when the mirror rotates; a mirror; A detector arranged to receive light emitted by the illumination source after the light from the illumination source is reflected into the environment by the mirror; One or more memory devices including instructions that, when executed by one or more processors, perform steps for calculating a distance to an object in the environment based on the detector receiving the light emitted by the illumination source. A system comprising.

41. A system for a lidar using a rotating mirror and vertical scanning, the system comprising: A platform; An illumination source comprising a plurality of lasers installed on the platform; A flexure coupling the platform to a fixed base; A mirror, The mirror is arranged to rotate, The mirror is arranged to reflect light from the plurality of lasers into the environment when the mirror rotates; a mirror; A detector comprising one or more sensors arranged to receive light emitted by the illumination source after the light from the illumination source is reflected into the environment by the mirror; One or more memory devices including instructions that, when executed by one or more processors, perform steps for calculating a distance to an object in the environment based on the detector receiving the light emitted by the illumination source. A system comprising.

42. The system according to claim 41, comprising a lens between the illumination source and the mirror.

43. The system according to claim 41, wherein the platform is arranged to translate vertically when the mirror rotates horizontally about a vertical axis.

44. The system according to claim 41, wherein the plurality of lasers are installed on the platform with a non-uniform spacing between the lasers.

45. The illumination source is a first illumination source, the mirror comprises a first surface and a second surface, the system comprises a second illumination source, the second illumination source is arranged facing the first illumination source such that the first illumination source illuminates the first surface of the mirror and the second illumination source illuminates the second surface of the mirror. The system according to claim 41.

46. The system according to claim 41, further comprising a beam splitter between the illumination source and the mirror.

47. Further comprising a first lens and a second lens, the first lens is characterized by a first focal length, the second lens is characterized by a second focal length, the first lens is positioned at a first distance from the mirror, the first distance is equal to the first focal length, the second lens is positioned at a second distance from the first lens, the second distance is equal to the sum of the first focal length and the second focal length. The system according to claim 41.

48. A method for a lidar using a translation platform and a rotating mirror, the method comprising: translating the platform relative to a fixed base, a plurality of lasers are installed on the platform, a flexure couples the platform to the fixed base, the plurality of lasers are part of the illumination source, emitting light from the plurality of lasers while translating the platform, using the rotating mirror to reflect the light emitted from the illumination source into the environment, after reflecting the light emitted from the illumination source into the environment, using a detector to detect the light from the illumination source, calculating the distance to an object in the environment based on detecting the light from the illumination source.

49. The platform is translated in a vertical dimension. The rotary mirror rotates horizontally about a vertical axis. The method according to claim 48.

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