Beam control techniques for correcting scan line compression in lidar devices

Abstract

A light detection and ranging (LiDAR) device, the LiDAR device comprising: at least one illumination source configured to emit illumination light; an optical scanning device disposed in an optical path of the at least one illumination source to redirect the illumination light emitted by the at least one illumination source from the LiDAR device into a three-dimensional (3-D) environment; at least one scanning mechanism configured to rotate the optical scanning device about at least one axis; and at least one controller. The at least one controller is configured to determine a desired scan pattern of the LiDAR device, generate at least one drive waveform corresponding to (i) the desired scan pattern and (ii) a scan line compression profile of the optical scanning device, and operating the at least one scanning mechanism based on the at least one drive waveform to provide the desired scanning pattern.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. patent application serial number 17 / 741,304, filed on May 10, 2022, the entirety of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to light detection and ranging ("LiDAR") technology, and more particularly, to beam steering techniques for correcting scanline compression in LiDAR devices. Background Art

[0004] A LiDAR system measures properties of its surroundings (e.g., the shape of a target, the outline of a target, the distance to a target, etc.) by illuminating a target with light (e.g., a laser) and measuring the reflected light with a sensor. The differences in laser return times and / or wavelengths can then be used to make a digital three-dimensional ("3D") representation of the surroundings. LiDAR technology can be used for a variety of applications, including autonomous vehicles, advanced driver assistance systems, mapping, security, surveying, robotics, geological and soil science, agriculture, unmanned aerial vehicles, aerial obstacle detection (e.g., obstacle detection systems for aircraft), and the like. Depending on the application and the associated field of view, multiple channels or laser beams can be used to produce images of the desired resolution. A LiDAR system with a greater number of channels can generally generate a greater number of pixels.

[0005] In a multi-channel LiDAR device, optical transmitters may be paired with optical receivers to form multiple "channels." In operation, the transmitter of each channel may emit an optical signal (e.g., a laser) into the environment of the device, and the receiver of the channel may detect the portion of the signal that is reflected back into the channel by the surrounding environment. In this way, each channel may provide a "point" measurement of the environment, which may be aggregated with the point measurements provided by other channels to form a "point cloud" of environmental measurements.

[0006] The measurements collected by the LiDAR channel can be used to determine the distance ("range") from the device to a surface in the environment that reflects the channel's transmitted light signal back to the channel's receiver. In some cases, the range to the surface can be determined based on the flight time of the channel's signal (e.g., the time elapsed from the time the transmitter transmits the light signal to the time the receiver receives the return signal reflected by the surface). In other cases, the range can be determined based on the wavelength (or frequency) of the return signal reflected by the surface.

[0007] In some cases, LiDAR measurements can be used to determine the reflectivity of the surface that reflected the optical signal. The reflectivity of the surface can be determined based on the strength of the returned signal, which typically depends not only on the reflectivity of the surface, but also on the range to the surface, the grazing angle of the transmitted signal relative to the surface, the power level of the channel's transmitter, the alignment of the channel's transmitter and receiver, and other factors.

[0008] The foregoing examples of the related art and limitations thereof are intended to be illustrative and not exclusive, and are not admitted to be “prior art.” Other limitations of the related art will become apparent to those skilled in the art upon a reading of the specification and a study of the drawings. Summary of the invention

[0009] Beam steering techniques for correcting scanline compression in LiDAR systems and devices are disclosed herein.

[0010] At least one aspect of the present disclosure relates to a light detection and ranging (LiDAR) device. The LiDAR device includes: at least one illumination source, the at least one illumination source configured to emit illumination light; an optical scanning device, the optical scanning device disposed in an optical path of the at least one illumination source to redirect the illumination light emitted by the at least one illumination source from the LiDAR device into a three-dimensional (3-D) environment; at least one scanning mechanism, the at least one scanning mechanism configured to rotate the optical scanning device around at least one axis; and at least one controller. The at least one controller is configured to determine a desired scanning pattern of the LiDAR device, generate at least one drive waveform, the at least one drive waveform corresponding to (i) the desired scanning pattern and (ii) a scan line compression profile of the optical scanning device, and operate the at least one scanning mechanism based on the at least one drive waveform to provide the desired scanning pattern.

[0011] Another aspect of the present disclosure relates to a vehicle including at least one LiDAR device having one or more of the above features. Each LiDAR device is configured to provide navigation and / or mapping for the vehicle and is disposed inside the vehicle and / or outside the vehicle.

[0012] Another aspect of the present disclosure relates to a method of operating a light detection and ranging (LiDAR) device. The method includes determining a desired scanning pattern of the LiDAR device, emitting illumination light from at least one illumination source, generating at least one drive waveform corresponding to (i) the desired scanning pattern and (ii) a scan line compression profile of an optical scanning device disposed in an optical path of the at least one illumination source, and controlling at least one scanning mechanism based on the at least one drive waveform. The optical scanning device is configured to redirect the illumination light emitted by the at least one illumination source from the LiDAR device into a three-dimensional (3-D) environment, and the at least one scanning mechanism is configured to rotate the optical scanning device around at least one axis to provide the desired scanning pattern.

[0013] Various embodiments of these aspects of the present disclosure may include the following features. The at least one scanning mechanism may be controlled (e.g., by controlling the at least one controller) by controlling (i) a first scanning mechanism configured to rotate the optical scanning device around a first axis to deflect the illumination light in a first scanning direction and (ii) a second scanning mechanism configured to rotate the optical scanning device around a second axis to deflect the illumination light in a second scanning direction. In some embodiments, the second axis is orthogonal to the first axis.

[0014] In various embodiments, the scan line compression profile corresponds to a percentage of deflection of the optical scanning device within an optical scanning range in the first scanning direction. In some embodiments, the percentage of deflection represents an actual amount of deflection provided by the optical scanning device in the second scanning direction relative to an expected amount of deflection provided by the optical scanning device in the second scanning direction. In certain embodiments, the at least one drive waveform is configured to compensate for a difference between the expected amount of deflection and the actual amount of deflection to provide the desired scanning pattern.

[0015] In some embodiments, the scan line compression profile of the optical scanning device provides an indication of at least one geometric compression region in the field of view of the LiDAR device. In certain embodiments, the at least one geometric compression region corresponds to at least a portion of the optical scan range in the first scan direction.

[0016] In various embodiments, the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scan direction at a variable rate based on the scan line compression profile. In some embodiments, the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scan direction at a non-linear rate over the at least one geometric compression region. In certain embodiments, the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scan direction at a substantially linear rate outside of the at least one geometric compression region.

[0017] The above-mentioned and other preferred features will now be described in more detail with reference to the accompanying drawings and pointed out in the claims, including various novel details of specific implementations and event combinations. It will be understood that the specific systems and methods described herein are shown only by way of illustration and not as a limitation. As will be understood by those skilled in the art, the principles and features described herein can be adopted in various and numerous embodiments without departing from the scope of any one of the present invention. It can be understood from the foregoing and following descriptions that each feature described herein and each combination of two or more such features are included within the scope of the present disclosure, as long as the features included in such a combination are not mutually contradictory. In addition, any feature or combination of features can be clearly excluded from any embodiment of any one of the present invention.

[0018] The foregoing summary including a description of some embodiments, its motivations and / or its advantages is intended to aid the reader in understanding the present disclosure and does not in any way limit the scope of any of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated as a part of this specification, illustrate presently preferred embodiments, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain and teach the principles described herein.

[0020] Figure 1 is an illustration of an exemplary LiDAR system according to some embodiments.

[0021] Figure 2A is a diagram of the operation of a LiDAR system according to some embodiments.

[0022] Figure 2B is an illustration of optical components of a channel of a LiDAR system with a movable mirror, according to some embodiments.

[0023] Figure 2C is an illustration of an example of a 3D LiDAR system according to some embodiments.

[0024] Figure 3is an illustration of an example continuous wave (CW) coherent LiDAR system, according to some embodiments.

[0025] Figure 4 is an illustration of an example frequency modulated continuous wave (FMCW) coherent LiDAR system, according to some embodiments.

[0026] Figure 5A is a graph of frequency chirp in a transmitted laser signal and a reflected signal as a function of time according to some embodiments.

[0027] Figure 5B is a graph illustrating the beat frequency of a mixing signal according to some embodiments.

[0028] Figure 6 is a functional block diagram of a LiDAR system including a single reflective surface, according to some embodiments.

[0029] Fig. 7A is an illustration of an ideal scanning pattern for a LiDAR system according to some embodiments.

[0030] Figure 7B is an illustration of an actual scanning pattern of a LiDAR system according to some embodiments.

[0031] Figure 8 is a graphical representation of a compressed outline of a LiDAR system according to some embodiments.

[0032] Fig. 9 is a graphical representation of an ideal scanning pattern and corresponding driving waveform for a LiDAR system according to some embodiments.

[0033] Fig.10 is a flow chart of a method for generating a drive waveform for a LiDAR system according to some embodiments.

[0034] Fig.11 is a flow chart of a method for operating a LiDAR system according to some embodiments.

[0035] Fig.12 is a diagram of a vehicle including multiple sensors according to some embodiments.

[0036] Fig.13 is a diagram of exemplary hardware and software systems that implement the systems and methods described herein, according to some embodiments.

[0037] Fig.14 is a block diagram of a computing device / information processing system according to some embodiments.

[0038] Although the present disclosure is subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail herein. The present disclosure should be understood as not being limited to the particular forms disclosed, but on the contrary, the present disclosure is intended to cover all modifications, equivalents, and substitutes falling within the spirit and scope of the present disclosure. DETAILED DESCRIPTION

[0039] Provided herein are exemplary systems and methods for correcting scanline compression in a LiDAR system using a single reflective surface. In at least one embodiment, a drive waveform is generated to adjust the deflection of the reflective surface to correct for scanline compression. In one example, the deflection of the reflective surface is adjusted by the drive waveform at a variable rate. In some examples, the deflection of the reflective surface is adjusted at a nonlinear rate over one or more geometrically compressed regions of the field of view ("FOV") of the LiDAR system. By correcting for scanline compression, the resolution and / or accuracy of the collected scan data can be improved. Similarly, the quality of the point cloud and image obtained from the scan data can be improved.

[0040] Some Examples of LiDAR Systems

[0041] LiDAR systems can be used to measure the shape and contours of the environment surrounding the system. LiDAR systems can be applied to many applications, including autonomous navigation and aerial mapping of surfaces. Generally speaking, the light emitted by the LiDAR system is then reflected by objects in the environment in which the system operates. In some examples, the LiDAR system is configured to emit light pulses. The travel time of each pulse from being emitted to being received (i.e., time of flight, "TOF" or "ToF") can be measured to determine the distance between the LiDAR system and the object that reflected the pulse. In other examples, the LiDAR system can be configured to emit continuous wave (CW) light. The wavelength (or frequency) of the received reflected light can be measured to determine the distance between the LiDAR system and the object that reflected the light. In some examples, the LiDAR system can measure the speed of an object. The science of the LiDAR system is based on the physics of light and optics.

[0042] In a LiDAR system, light can be emitted from a rapidly firing laser. The laser travels through the medium and reflects off surface points in the environment (e.g., surfaces of buildings, tree branches, vehicles, etc.). The reflected light energy returns to the LiDAR detector, where it can be recorded and used to map the environment.

[0043] Figure 1 The operation of the LiDAR system 100 is depicted according to some embodiments. Figure 1In an example of the invention, the LiDAR system 100 includes a LiDAR device 102, which may include a transmitter 104 that generates and transmits an optical signal 110, a receiver 106 that detects a return optical signal 114, and a control and data acquisition module 108. The transmitter 104 may include a light source (e.g., a laser), an electrical component operable to activate (e.g., drive) and deactivate the light source in response to an electrical control signal, and an optical component suitable for shaping and redirecting the light emitted by the light source. The receiver 106 may include an optical detector (e.g., a photodiode) and optical components suitable for shaping the return optical signal 114 and directing these signals to the detector. In some specific implementations, one or more optical components (e.g., lenses, reflectors, etc.) may be shared by the transmitter and the receiver. The LiDAR device 102 may be referred to as a LiDAR transceiver or "channel". In operation, the emitted (e.g., illuminating) optical signal 110 propagates through a medium and reflects from an object 112, whereby the return optical signal 114 propagates through the medium and is received by the receiver 106.

[0044] The control and data acquisition module 108 can control the light emission of the transmitter 104, and can record data obtained from the return light signal 114 detected by the receiver 106. In some embodiments, the control and data acquisition module 108 controls the power level at which the transmitter 104 operates when emitting light. For example, the transmitter 104 can be configured to operate at a plurality of different power levels, and the control and data acquisition module 108 can select the power level at which the transmitter 104 operates at any given time. Any suitable technique can be used to control the power level at which the transmitter 104 operates. In some embodiments, the control and data acquisition module 108 determines (e.g., measures) a particular characteristic of the return light signal 114 detected by the receiver 106. For example, the control and data acquisition module 108 can measure the intensity of the return light signal 114 using any suitable technique.

[0045] The LiDAR transceiver 102 may include one or more optical lenses and / or mirrors (not shown) to redirect and shape the transmitted light signal 110 and / or redirect and shape the return light signal 114. The transmitter 104 may transmit a laser beam (e.g., a beam having a plurality of pulses in a particular sequence). Design elements of the receiver 106 may include its horizontal FOV and its vertical FOV. Those skilled in the art will recognize that the FOV parameter effectively defines the visible area associated with a particular LiDAR transceiver 102. More generally, the horizontal FOV and vertical FOV of the LiDAR system 100 may be defined by a single LiDAR device (e.g., a sensor), or may involve multiple configurable sensors (which may be specifically LiDAR sensors or may include different types of sensors). The FOV may be considered a scanning area of ​​the LiDAR system 100. A scanning mirror and / or a rotating assembly may be used to obtain a scanned FOV.

[0046] In some implementations, the LiDAR system 100 may include or be electrically coupled to a data analysis and interpretation module 109 that may receive outputs from the control and data acquisition module 108 (e.g., via connection 116) and perform data analysis functions on the outputs. The connection 116 may be implemented using wireless or contactless communication technology.

[0047] Figure 2A The operation of the LiDAR system 202 is shown in accordance with some embodiments. Figure 2A In the example of , two return light signals 203 and 205 are shown. A laser beam generally tends to diverge as it travels through a medium. Due to the beam divergence of a laser, a single laser shot may hit multiple objects at different ranges from the LiDAR system 202, generating multiple return signals 203, 205. The LiDAR system 202 may analyze the multiple return signals 203, 205 and report one of the return signals (e.g., the strongest return signal, the last return signal, etc.) or more than one (e.g., all) of the return signals. Figure 2A In the example of FIG. 2 , a LiDAR system 202 transmits a laser in the direction of a near wall 204 and a far wall 208. As shown, a majority of the transmitted light hits the near wall 204 at region 206, generating a return signal 203, and another portion of the transmitted light hits the far wall 208 at region 210, generating a return signal 205. The return signal 203 may have a shorter TOF and a stronger received signal strength than the return signal 205. In both single-return and multi-return LiDAR systems, it is important that each return signal is accurately associated with the transmitted light signal so that one or more properties of the object reflecting the light signal (e.g., range, velocity, reflectivity, etc.) can be correctly calculated.

[0048] Some embodiments of LiDAR systems can capture range data in a two-dimensional ("2D") (e.g., single-plane) point cloud format. These LiDAR systems can be used in industrial applications, or for surveying, mapping, autonomous navigation, and other purposes. Some embodiments of these systems rely on the use of a single laser emitter / detector pair in combination with a movable reflector to achieve scanning across at least one plane. The reflector can reflect emitted light from a transmitter (e.g., a laser diode) and / or can reflect return light to a receiver (e.g., to a detector). Using a movable (e.g., oscillating) reflector in this manner can enable the LiDAR system to achieve an azimuth (horizontal) view of 90-180-360 degrees while simplifying both system design and manufacturability. Many applications require more data than just a 2D plane. A 2D point cloud can be expanded to form a 3D point cloud, where multiple 2D point clouds are used, each of which points to a different elevation (e.g., vertical) angle. Design elements of the receiver of the LiDAR system 202 may include a horizontal FOV and a vertical FOV.

[0049] Figure 2B A LiDAR system 250 with a movable (e.g., oscillating) mirror is depicted according to some embodiments. Figure 2B In the example of FIG. 2 , a LiDAR system 250 uses a single emitter 252 / detector 262 pair combined with a fixed mirror 254 and a movable mirror 256 to effectively scan across a plane. The distance measurements obtained by such a system can be effectively two-dimensional (e.g., planar), and the captured distance points can be rendered as a 2D (e.g., single-plane) point cloud. In some embodiments, but not limited to, the movable mirror 256 can oscillate at a very fast speed (e.g., thousands of cycles per minute).

[0050] The emitted laser signal 251 may be directed to a fixed mirror 254, which may reflect the emitted laser signal 251 to a movable mirror 256. As the movable mirror 256 moves (e.g., oscillates), the emitted laser signal 251 may be reflected by an object 258 on its propagation path. The reflected return signal 253 may be coupled to a detector 262 via the movable mirror 256 and the fixed mirror 254. Design elements of the LiDAR system 250 include a horizontal FOV and a vertical FOV, which define a scanning area.

[0051] Figure 2C A 3D LiDAR system 270 is depicted according to some embodiments. Figure 2CIn the example of , the 3D LiDAR system 270 includes a lower housing 271 and an upper housing 272. The upper housing 272 includes a cylindrical shell element 273 made of a material transparent to infrared light (e.g., light having a wavelength in the 700 nanometer to 1,700 nanometer spectral range). In one example, the cylindrical shell element 273 is transparent to light having a wavelength centered at 905 nanometers.

[0052] In some embodiments, the 3D LiDAR system 270 includes a LiDAR transceiver 102 operable to emit a laser beam 276 through a cylindrical shell element 273 of an upper housing 272. Figure 2C In the example of FIG. 2 , each individual arrow in the group of arrows 275, 275' pointing outward from the 3D LiDAR system 270 represents a laser beam 276 emitted by the 3D LiDAR system. Each beam emitted from the system 270 may diverge slightly so that each emitted beam forms an illumination light cone emitted from the system 270. In one example, the beam emitted from the system 270 illuminates a spot size of 20 centimeters in diameter at a distance of 100 meters from the system 270.

[0053] In some embodiments, the transceiver 102 transmits each laser beam 276 transmitted by the 3D LiDAR system 270. The direction of each transmitted beam can be determined by the angular orientation ω of the transmitter 104 of the transceiver relative to the central axis 274 of the system and by the angular orientation ψ of the movable mirror 256 of the transmitter relative to the oscillation (or rotation) axis of the mirror. For example, the direction of the transmitted beam in the horizontal dimension can be determined by the angular orientation ω of the transmitter, and the direction of the transmitted beam in the vertical dimension can be determined by the angular orientation ψ of the movable mirror of the transmitter. Alternatively, the direction of the transmitted beam in the vertical dimension can be determined by the angular orientation ω of the transmitter, and the direction of the transmitted beam in the horizontal dimension can be determined by the angular orientation ψ of the movable mirror of the transmitter. (For illustrative purposes, the beam 275 is shown as being at one angular orientation relative to the non-rotating coordinate system of the 3D LiDAR system 270, and the beam 275' is shown as being at another angular orientation relative to the non-rotating coordinate system).

[0054] The 3D LiDAR system 270 can scan a specific point (e.g., pixel) in its field of view by adjusting the orientation ω of the transmitter and the orientation ψ of the movable mirror of the transmitter to a desired scanning point (ω, ψ) and emitting a laser beam from the transmitter 104. Similarly, the 3D LiDAR system 270 can scan a specific point (e.g., pixel) in its field of view by adjusting the orientation ω of the transmitter and the orientation ψ of the movable mirror of the transmitter to a set of scanning points (ω, ψ). i ,ψ j ) and systematically scans its field of view by emitting a laser beam from a transmitter 104 at each of the scanning points.

[0055] Assuming that the optical components of the LiDAR transceiver (e.g., the movable mirror 256) remain stationary during the time period after the transmitter 104 transmits a laser beam 110 (e.g., a pulsed laser beam or "pulse" or CW laser beam) and before the receiver 106 receives the corresponding return beam 114, the return beam generally forms a spot centered at (or near) the stationary position "L0" on the detector. This time period is referred to herein as the "ranging period" of the scan point associated with the transmitted beam 110 and the return beam 114.

[0056] In many LiDAR systems, the optical components of the LiDAR transceiver do not remain stationary during the ranging cycle of a scan point. Instead, during the ranging cycle of a scan point, the optical components may be moved to an orientation associated with one or more other scan points, and a laser beam may be sent to scan these other scan points. In such systems, without compensation, the center position "Li" of the spot at which the transceiver's detector receives the return beam 114 typically depends on the change in orientation of the transceiver's optical components during the ranging cycle, which depends on the angular scanning rate (e.g., the angular motion rate of the movable mirror 256) and the range to the object 112 that reflected the transmitted light. The distance between the position "Li" of the spot formed by the return beam and the nominal position "L0" of the spot that would have been formed without the intervening rotation of the optical components during the ranging cycle is referred to herein as "discrete".

[0057] Some Examples of Continuous Wave (CW) LiDAR Systems

[0058] As discussed above, some LiDAR systems may use continuous wave (CW) lasers to detect the range and / or speed of a target, rather than pulsed TOF techniques. Such systems include continuous wave (CW) coherent LiDAR systems and frequency modulated continuous wave (FMCW) coherent LiDAR systems. For example, any of the above-described LiDAR systems 100, 202, 250, and 270 may be configured to operate as a CW coherent LiDAR system or a FMCW coherent LiDAR system.

[0059] A LiDAR system configured to operate as a CW system or FMCW system can avoid the eye safety hazards of high peak power associated with pulsed LiDAR systems. In addition, coherent detection can be more sensitive than direct detection and can provide better performance, including single-pulse velocity measurement and immunity from interference from sun glare and other light sources—including other LiDAR systems and devices.

[0060] Figure 3An exemplary CW coherent LiDAR system 300 configured to determine a radial velocity of a target is shown. The LiDAR system 300 includes a laser 302 configured to generate a laser signal that is provided to a splitter 304. The laser 302 may provide a laser signal having a substantially constant laser frequency.

[0061] In one example, the splitter 304 provides the first split laser signal Tx1 to a direction selection device 306, which provides (e.g., forwards) the signal Tx1 to a scanner 308. In some examples, the direction selection device 306 is a circulator. The scanner 308 uses the first laser signal Tx1 to transmit the light emitted by the laser 302 and receives the light reflected by the target 310 (e.g., "reflected light" or "reflection"). The reflected light signal Rx is provided (e.g., passed back) to the direction selection device 306. The second laser signal Tx2 and the reflected light signal Rx are provided to a coupler (also called a mixer) 312. The mixer can use the second laser signal Tx2 as a local oscillator (LO) signal and mix it with the reflected light signal Rx. The mixer 312 can be configured to mix the reflected light signal Rx with the local oscillator signal LO. The mixer 312 can provide the mixed light signal to a differential photodetector 314, which can generate a beat frequency f representing the mixed light signal. beat The electrical signal, where f beat =|Tx2−Rx| (the absolute value of the difference between the amplitudes of the mixed optical signals). In some embodiments, the current generated by the differential photodetector 314 based on the mixed light may be proportional to the beat frequency f beat The current may be converted by an amplifier (e.g., a transimpedance amplifier (TIA)) into a voltage, which may be provided (e.g., fed) to an analog-to-digital converter (ADC) 316 configured to convert the analog voltage signal into digital samples for an object detection module 318. The object detection module 318 may be configured to generate a signal based on a signal having a beat frequency f. beat The radial velocity of the target 310 is determined (eg, calculated) based on the digital sampled signal.

[0062] In one example, the target detection module 318 may use the beat frequency f beat To identify Doppler shifts, and based on these shifts, determine the radial velocity of target 310. For example, the velocity of target 310 may be calculated using the following relationship:

[0063]

[0064] Among them, f d is the Doppler shift, λ is the wavelength of the laser signal, and v tis the radial velocity of target 310. In some examples, the direction of target 310 is determined by the Doppler shift f d For example, a positive Doppler shift may indicate that target 310 is moving toward system 300 , and a negative Doppler shift may indicate that target 310 is moving away from system 300 .

[0065] In one example, a Fourier transform calculation is performed using the digital samples from the ADC 316 to recover the desired frequency content (e.g., Doppler shift) from the digital sampled signal. For example, the controller (e.g., the target detection module 318) can be configured to perform a discrete Fourier transform (DFT) on the digital samples. In some examples, a fast Fourier transform (FFT) can be used to calculate the DFT of the digital samples. In some examples, the Fourier transform calculation (e.g., DFT) can be iteratively performed on different groups of digital samples to generate a target point cloud.

[0066] Although the LiDAR system 300 is described above as being configured to determine the radial velocity of a target, it should be understood that the system can be configured to determine the range and / or radial velocity of a target. For example, the LiDAR system 300 can be modified to use laser chirp to detect the velocity and / or range of a target.

[0067] Figure 4 An exemplary FMCW coherent LiDAR system 400 configured to determine the range and / or radial velocity of a target is shown. The LiDAR system 400 includes a laser 402 configured to generate a laser signal that is fed into a splitter 404. The laser is "chirped" (e.g., the center frequency of the emitted laser beam increases ("ramp up" or "chirp up") or decreases ("ramp down" or "chirp down") over time, or equivalently, the center wavelength of the emitted laser beam varies over time within a band). In various embodiments, the laser frequency is rapidly chirped so that multiple phase angles are obtained. In one example, the frequency of the laser signal is modulated by changing a laser operating parameter (e.g., current / voltage) or using a modulator included in the laser source 402; however, in other examples, an external modulator may be placed between the laser source 402 and the splitter 404.

[0068] In other examples, the laser frequency can be "chirped" by modulating the phase of the laser signal (or light) generated by the laser 402. In one example, the phase of the laser signal is modulated using an external modulator placed between the laser source 402 and the splitter 404; however, in some examples, the laser source 402 can be modulated directly by changing operating parameters (e.g., current / voltage) or including an internal modulator. Similar to frequency chirping, the phase of the laser signal can increase ("ramp up") or decrease ("ramp down") over time.

[0069] Some examples of systems with FMCW-based LiDAR sensors have been described. However, the techniques described herein may be implemented using any suitable type of LiDAR sensor, including but not limited to any suitable type of coherent LiDAR sensor (e.g., a phase-modulated coherent LiDAR sensor). Using a phase-modulated coherent LiDAR sensor, the LiDAR system may use a phase modulator placed between the laser 402 and the splitter 404 to generate a discrete phase-modulated signal that may be used to measure range and radial velocity, rather than chirping the frequency of the light generated by the laser (as described above with reference to the FMCW technique).

[0070] As shown, the splitter 404 provides the first split laser signal Tx1 to the direction selection device 406, which provides (e.g., forwards) the signal Tx1 to the scanner 408. The scanner 408 uses the first laser signal Tx1 to transmit the light emitted by the laser 402 and receive the light reflected by the target 410. The reflected light signal Rx is provided (e.g., transmitted back) to the direction selection device 406. The second laser signal Tx2 and the reflected light signal Rx are provided to the coupler (also called a mixer) 412. The mixer can use the second laser signal Tx2 as a local oscillator (LO) signal and mix it with the reflected light signal Rx. The mixer 412 can be configured to mix the reflected signal Rx with the local oscillator signal LO to generate a beat frequency f beat . With a beat frequency f beat The mixed signal may be provided to a differential photodetector 414, which is configured to generate a current based on the received light. The current may be converted to a voltage by an amplifier (e.g., a transimpedance amplifier (TIA)), which may be provided (e.g., fed) to an analog-to-digital converter (ADC) 416, which is configured to convert the analog voltage into digital samples for an object detection module 418. The object detection module 418 may be configured to generate a current based on a light beam having a beat frequency f. beat The digital sampled signal is used to determine (eg, calculate) the range and / or radial velocity of target 410.

[0071] Laser chirping may be useful for range (distance) measurements of a target. In contrast, Doppler frequency measurements are often used to measure target velocity. The resolution of the range may depend on the bandwidth size of the chirp frequency band, such that a larger bandwidth corresponds to a finer resolution according to the following relationship:

[0072] Range resolution: and range: Where c is the speed of light, BW is the bandwidth of the chirped laser signal, and f beat is the beat frequency, and T ChirpRampis the time period during the frequency ramp-up of the chirped laser (e.g., the time period corresponding to the ramp-up portion of the chirped laser). For example, for a range resolution of 3.0 cm, a frequency bandwidth of 5.0 GHz can be used. Linear chirp can be an effective way to measure range, and range accuracy can depend on the chirp linearity. In some cases, when chirp is used to measure the range of a target, there may be range ambiguity and velocity ambiguity. Specifically, the reflected signal used to measure velocity (e.g., via Doppler) may affect the range measurement. Therefore, some exemplary FMCW coherent LiDAR systems may rely on two measurements with different slopes (e.g., a negative slope and a positive slope) to remove this ambiguity. Two measurements with different slopes can also be used to simultaneously determine range measurements and velocity measurements.

[0073] Figure 5A 5 is a graph of an ideal (or desired) frequency chirp as a function of time in a transmitted laser signal Tx (e.g., signal Tx2) depicted as a solid line 502 and a reflected optical signal Rx depicted as a dashed line 504. As depicted, the ideal Tx signal has a positive linear slope between time t1 and time t3, and a negative linear slope between time t3 and time t6. Thus, the ideal reflected optical signal Rx returned with a time delay td of approximately t2-t1 has a positive linear slope between time t2 and time t5, and a negative linear slope between time t5 and time t7.

[0074] Figure 5B is the ideal beat frequency f of the mixing signal Tx2×Rx. beat 505. Note that the beat frequency f beat 505 has a constant value between time t2 and time t3 (corresponding to the overlapping upper slopes of signals Tx2 and Rx) and between time t5 and time t6 (corresponding to the overlapping lower slopes of signals Tx2 and Rx).

[0075] Positive slope ("slope P") and negative slope ("slope N") (also referred to as positive ramp (or up ramp) and negative ramp (or down ramp)) can be used to determine range and / or speed. In some cases, reference FIG. 5A to FIG. 5B , when a positive and negative ramp pair is used to measure range and speed simultaneously, the following relationship is used:

[0076] scope: and

[0077] speed: where f beat_P and f beat_N are the beat frequencies generated during the positive (P) and negative (N) slopes of the chirp 502, respectively, and λ is the wavelength of the laser signal.

[0078] In one example, the scanner 408 of the LiDAR system 400 is used to scan the environment and generate a target point cloud from the acquired scan data. In some examples, the LiDAR system 400 may use a processing method including performing one or more Fourier transform calculations, such as a fast Fourier transform (FFT) or a discrete Fourier transform (DFT), to generate a target point cloud from the acquired scan data. Since the system 400 is capable of measuring range, each point in the point cloud may also have a three-dimensional position (e.g., x, y, and z) in addition to radial velocity. In some examples, the xy position of each target point corresponds to the radial position of the target point relative to the scanner 408. Similarly, the z position of each target point corresponds to the distance (e.g., range) between the target point and the scanner 408. In one example, each target point corresponds to a frequency chirp 502 in the laser signal. For example, samples collected by the system 400 during the chirp 502 (e.g., t1 to t6) may be processed to generate a point in the point cloud.

[0079] Beam steering technology to reduce scan line compression

[0080] As described above, pulsed LiDAR systems and coherent LiDAR systems may include scanning mirrors (e.g., movable mirror 256) that are actuated to scan in one or more dimensions (e.g., horizontal and / or vertical). In some examples, such LiDAR systems may include a single reflective surface that is actuated to scan in the horizontal and vertical dimensions. For example, it may be advantageous to use a single reflective surface to reduce the size and / or cost of a LiDAR system. The single reflective surface may be a mirror, a solid-state optical component (e.g., a polygon), or any suitable surface / component capable of providing multi-dimensional deflection. However, LiDAR systems using a single reflective surface may experience scan line compression. In some cases, such scan line compression may reduce the resolution and / or accuracy of the measurements collected by the LiDAR system.

[0081] Thus, provided herein are improved systems and methods for correcting scanline compression in a LiDAR system using a single reflective surface. In at least one embodiment, a drive waveform is generated to adjust the deflection of the reflective surface to correct for scanline compression. In one example, the deflection of the reflective surface is adjusted by the drive waveform at a variable rate. In some examples, the deflection of the reflective surface is adjusted at a nonlinear rate over one or more geometrically compressed regions of the FOV of the LiDAR system.

[0082] Figure 66 is a schematic diagram of an exemplary LiDAR system 600 according to some embodiments. In one example, the LiDAR system 600 can be a pulsed TOF LiDAR system or a FMCW LiDAR system. As shown, the LiDAR system 600 includes a light emission engine 602, a lens 604, and a scanning mirror 606. In some examples, the LiDAR system 600 corresponds to Figure 2B At least a portion of LiDAR system 250. For example, light emission engine 602 may correspond to emitter 252, and scanning mirror 606 may correspond to movable mirror 256.

[0083] As shown, the light emission engine 602 is configured to provide a transmission beam 608 that passes through a lens 604 and is reflected by a scanning mirror 606. In one example, the scanning mirror 606 rotates around a first axis 610 to scan the transmission beam 608 in a horizontal direction. The scanning mirror 606 can rotate around the first axis 610 via a first actuator 612. In some examples, the scanning mirror 606 rotates around the first axis 610 to scan the transmission beam 608 in a horizontal direction within an optical scanning range of 0 to α. In one example, α is 120 degrees. It should be understood that the horizontal optical scanning range can be defined differently. For example, the horizontal optical scanning range can be defined as -α / 2 to +α / 2. Similarly, the scanning mirror 606 can rotate around a second axis 614 to scan the transmission beam 608 in a vertical direction. The scanning mirror 606 can rotate around the second axis 614 via a second actuator 616. In some examples, scanning mirror 606 rotates about second axis 614 to scan transmit beam 608 in the vertical direction within an optical scanning range of -β to +β. In one example, β is 1 degree. It should be understood that the physical rotation range of scanning mirror 606 can be much smaller than the corresponding optical scanning range.

[0084] The scanning mirror 606 can rotate around the first axis 610 and the second axis 614 at the same time to provide a scanning pattern. In one example, the first actuator 612 is configured to receive a first control signal from a controller (e.g., the control and data acquisition module 108) to control the rotation of the scanning mirror 606 around the first axis 610. Similarly, the second actuator 616 can be configured to receive a second control signal from the controller to control the rotation of the scanning mirror 606 around the second axis 614. In other examples, the actuators 612, 616 can receive one or more common control signals representing the scanning pattern.

[0085] In some examples, the position of the scanning mirror 606 is dynamically adjusted according to the scanning mode using one or more flexures. For example, the scanning mirror 606 may be included in a scanning mirror mechanism that includes a magnet, a coil, a structure, a position / rotation sensor, and a flexure. Each flexure may be made of a thin metal or a bundle of leads (e.g., parallel leads) (e.g., non-twisted parallel leads) that are structurally fixed at both ends and allowed to be twisted together with the mirror 606 and the mirror mechanism. Any suitable mechanism and technology may be used to control the position of the mirror 606, including but not limited to the technology described in U.S. patent application No. 17 / 392,080, entitled "Scanning Mirror Mechanisms for LiDAR Systems, and Related Methods and Apparatus" filed on August 2, 2021, the entire text of which is hereby incorporated by reference herein. . In some examples, the scanning mirror 606 is a dual-axis micro-electromechanical system (MEMS) mirror.

[0086] Although the above example includes one transmit beam 608, it should be understood that the scanning mirror 606 can reflect multiple transmit beams simultaneously. For example, the light emission engine 602 can be configured to provide multiple transmit beams reflected by the scanning mirror 606 to provide a scanning pattern. Any suitable number of light sources (e.g., 1 to 128 light sources or more) can be included in the light emission engine 602. In some embodiments, some or all of the light sources can be arranged in an array (e.g., a one-dimensional ("1-D") array), and each light source in the array can be configured to emit a transmit beam onto the surface of the scanning mirror 606. In some embodiments, the light sources of the array can be aligned along an axis parallel to the first axis 610 of the scanning mirror 606. In other examples, the LiDAR system 600 may include multiple instances of the light engine 602 to provide multiple transmit beams.

[0087] Fig. 7AAn ideal (or desired) scanning pattern 700 of a LiDAR system 600 according to some embodiments is shown. As shown, the scanning pattern 700 includes a plurality of partial scanning patterns 702. Each partial scanning pattern may correspond to a different channel of the LiDAR system. In one example, each partial scanning pattern corresponds to a trajectory of a transmission beam provided by a corresponding transmitter (e.g., a light emission engine 602). The transmission beam is reflected by a scanning reflector 606 in different parallel vertical regions of the FOV of the LiDAR system. For example, a first transmission beam corresponding to a first partial scanning pattern 702a may be provided by a first transmitter and reflected in a first vertical region of the FOV, a second transmission beam corresponding to a second partial scanning pattern 702b may be provided by a second transmitter and reflected in a second vertical region of the FOV, and so on. In other examples, the light emission engine 602 may be configured to provide each of the transmission beams (e.g., using an array of light sources).

[0088] As described above, the scanning mirror 606 can rotate about the first axis 610 to scan in the horizontal direction within the optical scanning range of 0 to α, and rotate about the second axis 614 to scan in the vertical direction within the optical scanning range of -β to +β. Fig. 7A In an attempt of scanning pattern 700 of FIG. 702 , the LiDAR system 700 operates with α being 130 degrees and β being 1 degree. For example, a first partial scanning pattern 702a covers a horizontal (or azimuth) optical range of 0 to 130 degrees, wherein the vertical (or elevation) optical range is 2 to 4 degrees (e.g., ±1 degree). Similarly, a second partial scanning pattern 702b covers a horizontal optical range of 0 to 130 degrees, wherein the vertical optical range is 0 to 2 degrees, a third partial scanning pattern 702c covers a horizontal optical range of 0 to 130 degrees, wherein the vertical optical range is -2 to 0 degrees, and a fourth partial scanning pattern 702d covers a horizontal optical range of 0 to 130 degrees, wherein the vertical optical range is -4 to -2 degrees. Multiple partial scanning patterns 702 may be combined to form scanning pattern 700. In one example, scanning pattern 700 has a horizontal optical range of 130 degrees and a vertical scanning range of 8 degrees. However, because a single reflective surface (eg, scanning mirror 606) is used to scan in both the horizontal and vertical directions, the actual scanning pattern may include undesirable compression.

[0089] Figure 7B The actual scanning mode 750 of the LiDAR system 600 is shown according to some embodiments. In one example, the scanning mode 750 corresponds to when being controlled (or operated) to attempt to provide Fig. 7A700 is an actual scanning pattern provided by the LiDAR system 600 when the ideal scanning pattern 700 is provided. The scanning pattern 750 includes a plurality of partial scanning patterns 752, representing the actual trajectory of the transmitted beam when the scanning mirror 606 is controlled to attempt to provide the ideal pattern 700. As shown, the plurality of partial scanning patterns 752 may experience vertical compression at each end of the horizontal scanning range. In other words, when the scanning mirror 606 is rotated about the first axis 610 to adjust the horizontal scanning direction (e.g., toward 0 degrees or α degrees), the apparent vertical deflection provided by the scanning mirror 606 may decrease as each end of the horizontal scanning range is approached.

[0090] Thus, the actual scanning pattern 750 may include at least one high compression region 754. In one example, the high compression region 754 may be defined relative to α. For example, the first high compression region 754a may be defined as a horizontal optical range below 0.2*α degrees (e.g., 26 degrees); however, in other examples, the first high compression region 754a may be defined differently. In the first high compression region 754a, the apparent vertical deflection provided by the scanning mirror 606 may be 70% or less of the desired (or commanded) vertical deflection. For example, when positioned to provide a vertical deflection of +1 degree, the scanning mirror 606 may provide an actual vertical deflection of approximately +0.7 degrees. Similarly, the second high compression region 754b may be defined as a horizontal optical range above 0.5*α degrees (e.g., 65 degrees); however, in other examples, the second high compression region 754b may be defined differently. In the second high compression region 754b, the apparent vertical deflection provided by the scanning mirror 606 may be 30% or less of the desired (or commanded) vertical deflection. For example, when positioned to provide a vertical deflection of +1 degree, the scanning mirror 606 may provide an actual vertical deflection of approximately +0.3 degrees. Due to the compression in the transmit beam trajectory, undesirable gaps or holes may appear in the scanning pattern 750, particularly in the high compression region 754. As such, the resolution and / or accuracy of the scan data collected from the scanning pattern 750 may be reduced. Likewise, the quality of the point cloud and images derived from the scan data may be degraded.

[0091] A drive waveform may be generated to adjust the deflection of a reflective surface (e.g., scanning mirror 606) while correcting for scan line compression. In one example, the drive waveform is generated based on a compression curve (or response) of scanning mirror 606. The compression curve may alternatively be referred to as a deflection curve (or response) of scanning mirror 606.

[0092] Figure 8An example compression profile 800 is shown according to some embodiments. The compression profile (or curve) 800 represents the scan line compression of the scanning mirror 606 as a deflection percentage within the horizontal (or azimuth) optical scan range. The deflection percentage represents the amount of vertical deflection provided by the scanning mirror 606 relative to the desired (or expected) amount of vertical deflection. For example, if the deflection percentage is 70%, when controlled (or positioned) to provide a vertical deflection of +1.0 degrees, the scanning mirror 606 will provide an actual vertical deflection of approximately 0.7 degrees.

[0093] In one example, the compression profile 800 is calculated based on a reflection matrix corresponding to the properties of the scanning mirror 606. In addition, the reflection matrix may represent the properties of the LiDAR system configuration (e.g., the position of the light emission engine 602 relative to the scanning mirror 606). In some examples, the reflection matrix is ​​derived using one or more closed-form equations. In other examples, the compression profile 800 may be calculated via a physical or simulated characterization process. For example, when the scanning mirror 606 rotates around the first axis 610 to scan within a horizontal optical scanning range of 0 degrees to α degrees, the light emission engine 602 may be activated. At certain intervals (e.g., every 5 degrees), the scanning mirror 606 is positioned to provide the desired amount of vertical deflection. The actual deflection provided by the scanning mirror 606 can then be measured / observed. The deflection percentage of each measured deflection is calculated. In one example, each deflection percentage corresponds to a ratio of the measured deflection to the desired (or expected) deflection.

[0094] like Figure 8 As shown, high compression areas 802a, 802b can be identified from the compression profile 800. In one example, the high compression areas 802a, 802b correspond to Figure 7B The high compression regions 754a, 754b of FIG. The high compression regions 802a, 802b may represent regions of the horizontal optical range where the deflection percentage is below a predetermined threshold (eg, 85%, 75%, etc.).

[0095] The compression profile 800 may be used to generate a drive waveform for controlling the scanning mirror 606 to correct for scan line compression. Fig. 9 9 is a graph 900 including a desired scan pattern 902 and a drive waveform 904. In one example, the scan pattern 902 corresponds to Figure 6 In some examples, the scanning pattern 902 may be similar to Fig. 7A 902. For example, scan pattern 902 covers a horizontal (or azimuth) optical range of 0 to 130 degrees, with a vertical (or elevation) optical range of -1 to +1 degree (eg, ±1 degree).

[0096] As described above, the scanning mirror 606 is configured to receive one or more control signals (e.g., drive waveforms) to control the rotation of the scanning mirror 606 around the first axis 610 and the second axis 614. The control signals can be used to operate the actuators 612, 616 or any other steering mechanism associated with the scanning mirror 606. Instead of providing a control signal that is directly mapped to the desired scanning pattern 902, the drive waveform 904 can be used to control the scanning mirror 606 to prevent (or reduce) the compression of the scan lines in the actual scanning pattern. In one example, the drive waveform 904 is based on the relationship between the compression profile 800 and the desired scanning pattern 902. In some examples, the drive waveform 904 is the product of the desired scanning pattern 902 and the inverse of the compression profile 800. For example, the vertical deflection of the drive waveform 904 across the horizontal optical scanning range can be calculated using the following relationship:

[0097]

[0098] Among them, DW v is the vertical deflection of the drive waveform 904, SP is the desired scan pattern 902, CP is the compression profile 800, and n is the horizontal scan angle.

[0099] In some examples, the drive waveform 904 is configured to adjust the amount of vertical deflection provided by the scanning mirror 606 at a variable rate based on the compression profile 800. For example, the drive waveform 904 may adjust the amount of vertical deflection provided by the scanning mirror 606 at a substantially linear rate over regions within the horizontal scan range that have low or allowable compression (e.g., a high deflection percentage). In some examples, the rate of the drive waveform 904 may be substantially similar to the rate of the desired scanning pattern 902 in these low compression regions. Conversely, the drive waveform 904 may adjust the amount of vertical deflection provided by the scanning mirror 606 at a nonlinear rate over regions within the horizontal scan range that have high compression (e.g., a low deflection percentage). Fig. 9 As shown, drive waveform 904 includes regions 906a and 906b where the vertical deflection of scanning mirror 606 increases or decreases at a nonlinear rate. In some examples, the vertical deflection of scanning mirror 606 can be adjusted at an exponential rate (e.g., in region 906b). In one example, nonlinear regions 906a and 906b correspond to Figure 8 The high compression regions 802a, 802b.

[0100] In some examples, the drive waveform 904 controls the scanning mirror 606 to prevent (or reduce) scan line compression in the actual scanning pattern. By compensating for scan line compression, the drive waveform 904 enables the scanning mirror 606 (or the LiDAR system 600) to provide the scanning pattern required for data collection. In other words, the drive waveform 904 enables the LiDAR system 600 to achieve a scanning pattern that is substantially similar to the desired (or ideal) scanning pattern. In this way, the resolution and / or accuracy of the scanning data collected using the scanning mirror 606 can be improved. Similarly, the quality of the point cloud and image obtained from the scanning data can be improved. In addition, such improvements can be achieved without relying on post-processing correction techniques, which can be very complex, resource-intensive, and performance-limited.

[0101] Fig.10 1 is a flow chart of a method 1000 for generating a drive waveform to correct for scanline compression according to some embodiments. In one example, the method 1000 is used in conjunction with a LiDAR system that includes a single reflective surface that is actuated to scan in both the horizontal and vertical dimensions (e.g., Figure 6 LiDAR system 600).

[0102] At step 1002, a compression curve (e.g., compression profile 800) of LiDAR system 600 is calculated. In one example, compression profile 800 represents the scan line compression of scanning mirror 606 as a deflection percentage within the horizontal (or azimuth) optical scan range. The deflection percentage represents the actual amount of vertical deflection provided by scanning mirror 606 relative to the desired (or expected) amount of vertical deflection. In some examples, compression profile 800 is calculated based on a reflectance matrix corresponding to the properties of scanning mirror 606 and the configuration of LiDAR system 600. In other examples, compression profile 800 can be calculated via a physical or simulated characterization process.

[0103] At step 1004, a desired scanning pattern is determined. In one example, the desired scanning pattern corresponds to a desired trajectory of the transmit beam 608. For example, the desired scanning pattern may cover a horizontal (or azimuth) optical range of 0 to 130 degrees, with a vertical (or elevation) optical range of -1 to +1 degrees (e.g., ±1 degrees). In other examples, the desired scanning pattern may correspond to forming a combined scanning pattern (e.g., Fig. 7A In some examples, the desired scanning pattern may cover the FOV of the LiDAR system 600; however, in other examples, the desired scanning pattern may only cover a portion of the FOV of the LiDAR system 600.

[0104] At step 1006, a drive waveform (e.g., drive waveform 904) for controlling the scanning mirror 606 is calculated. The drive waveform 904 can be used to control the scanning mirror 606 to prevent (or reduce) scan line compression in the actual scanning pattern. In one example, the drive waveform 904 is based on the relationship between the compression profile 800 and the desired scanning pattern 902. In some examples, the drive waveform 904 is the product of the desired scanning pattern 902 and the inverse of the compression profile 800. In some examples, the drive waveform 904 adjusts the amount of vertical deflection provided by the scanning mirror 606 at a variable rate based on the compression profile 800. For example, the drive waveform 904 can adjust the amount of vertical deflection provided by the scanning mirror 606 at a substantially linear rate over an area within the horizontal scanning range with low or allowable compression (e.g., a high deflection percentage). Conversely, the drive waveform 904 can adjust the amount of vertical deflection provided by the scanning mirror 606 at a nonlinear rate over an area within the horizontal scanning range with high compression (e.g., a low deflection percentage).

[0105] At step 1008, the scanning mirror 606 is controlled to perform scanning using the drive waveform 904. In one example, the drive waveform 904 is used to operate the actuators 612, 616 or any other steering mechanism associated with the scanning mirror 606. In some examples, the control signal for operating the actuators 612, 616 (or any other steering mechanism) can be derived from the drive waveform 904. The drive waveform 904 enables the scanning mirror 606 (or the LiDAR system 600) to achieve a scanning pattern that is substantially similar to a desired (or ideal) scanning pattern. The drive waveform 904 controls the scanning mirror 606 to prevent (or reduce) scan line compression in an actual scanning pattern.

[0106] Fig.11 1 is a flow chart of a method 1100 suitable for implementation by a LiDAR system as described herein, according to some embodiments. In some embodiments, Figure 1 The LiDAR system 100 depicted in FIG. Fig.11 The method 1100 operation is shown. However, in general, the execution of the method 1100 is not limited to the reference Figure 1 In some examples, a LiDAR system including a LiDAR device and / or device array as provided herein may be configured according to Fig.11 The LiDAR system 600 can be operated according to the method 1100 shown. For example, the LiDAR system 600 can be operated according to the method 1100. These illustrations and corresponding explanations are provided by way of example, as many other embodiments and operating examples are contemplated.

[0107] In step 1101, a plurality of illumination beams (eg, pulsed illumination light) are emitted from a plurality of illumination sources (eg, pulsed illumination sources) into a 3-D environment. Each of the plurality of illumination beams is incident on a beam scanning device.

[0108] In step 1102, each illumination beam of a plurality of illumination beams is redirected to a different direction based on an optical interaction between each illumination beam and a beam scanning device.

[0109] In step 1103, each amount of return light reflected from the 3-D environment illuminated by each illumination beam is redirected based on an optical interaction between the amount of return light and the beam scanning device.

[0110] In step 1104, each amount of returned light reflected from the 3-D environment illuminated by each illumination beam is detected (eg, by a photosensitive detector).

[0111] In step 1105, an output signal is generated that is indicative of the amount of detected return light associated with each illumination light beam.

[0112] In step 1106, distances between multiple illumination sources and one or more objects in the 3-D environment are determined based on the difference between the time when each illumination beam is emitted from the LiDAR device and the time when each photosensitive detector detects an amount of light reflected from the object illuminated by the illumination beam.

[0113] Fig.12 A carrier 1200 with a plurality of sensors 1202 is shown according to some embodiments. As shown, a first sensor 1202a, a second sensor 1202b, a third sensor 1202c, and a fourth sensor 1202d may be positioned at a first location (e.g., top) on (or within) the carrier 1200. Similarly, a fifth sensor 1202e may be positioned at a second location (e.g., front of the carrier 1200) on (or within) the carrier 1200, and a sixth sensor 1202f may be positioned at a third location (e.g., back of the carrier 1200) on (or within) the carrier 1200. In other examples, different numbers or configurations of sensors may be used.

[0114] In some examples, at least one sensor in the plurality of sensors 1202 is configured to provide (or enable) 3-D mapping of the vehicle's surroundings. In some examples, at least one sensor in the plurality of sensors 1202 is used to provide navigation for the vehicle 1200 within the environment. In one example, each sensor 1202 includes at least one LiDAR system, device, or chip. The LiDAR system included in each sensor 1202 may correspond to Figure 6The LiDAR system 600 included in each sensor 1202 can be based on Fig.10 In some examples, at least one of the plurality of sensors 1202 may be a different type of sensor (e.g., a camera, a radar, etc.). In one example, the vehicle 1200 is a car; however, in other examples, the vehicle 1200 may be a truck, a boat, an airplane, a drone, a vacuum cleaner (e.g., a robotic vacuum cleaner), a robot, a train, a tractor, an ATV, or any other type of vehicle or movable object.

[0115] As described above, improved systems and methods are provided for correcting scanline compression in a LiDAR system using a single reflective surface. In at least one embodiment, a drive waveform is generated to adjust the deflection of the reflective surface to correct for scanline compression. In one example, the deflection of the reflective surface is adjusted by the drive waveform at a variable rate. In some examples, the deflection of the reflective surface is adjusted at a nonlinear rate over one or more geometrically compressed regions of the FOV of the LiDAR system.

[0116] Some Examples of Computing Devices and Information Processing Systems

[0117] In an embodiment, various aspects of the techniques described herein (e.g., timing the transmission of a transmitted signal, processing a received return signal, etc.) may be implemented for or on an information processing system / computing system. For purposes of this disclosure, a computing system may include any means or collection of means operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, generate, route, switch, store, display, communicate, indicate, detect, record, reproduce, dispose of, or utilize any form of information, intelligence, or data for commercial, scientific, control, or other purposes. For example, a computing system may be a personal computer (e.g., a laptop computer), a tablet computer, a tablet phone, a personal digital assistant (PDA), a smart phone, a smart watch, a smart bag, a server (e.g., a blade server or a rack server), a network storage device, or any other suitable device, and may vary in size, shape, performance, functionality, and price.

[0118] Fig.131300. A general purpose computer, network device, mobile device, or other electronic system may also include at least multiple portions of system 1300. System 1300 includes processor 1310, memory 1320, storage device 1330, and input / output device 1340. Each of components 1310, 1320, 1330, and 1340 may be interconnected, for example, using a system bus 1350. Processor 1310 is capable of processing instructions for execution within system 1300. In some implementations, processor 1310 is a single-threaded processor. In some implementations, processor 1310 is a multi-threaded processor. Processor 1310 is capable of processing instructions stored in memory 1320 or on storage device 1330.

[0119] The memory 1320 stores information within the system 1300. In some implementations, the memory 1320 is a non-transitory computer readable medium. In some implementations, the memory 1320 is a volatile memory unit. In some implementations, the memory 1320 is a non-volatile memory unit.

[0120] Storage device 1330 can provide mass storage for system 1300. In some specific implementations, storage device 1330 is a non-transient computer readable medium. In various different specific implementations, storage device 1330 may include, for example, a hard disk device, an optical disk device, a solid state hard disk drive, a flash drive, or a certain mass storage device. For example, a storage device can store long-term data (e.g., database data, file system data, etc.). Input / output device 1340 provides input / output operations for system 1300. In some specific implementations, input / output device 1340 may include one or more of a network interface device (e.g., an Ethernet card), a serial communication device (e.g., an RS-232 port), and / or a wireless interface device (e.g., an 802.11 card, a 3G wireless modem, or a 4G wireless modem). In some specific implementations, input / output device may include a driver device configured to receive input data and send output data to other input / output devices (e.g., a keyboard device, a printer device, and a display device 1360). In some examples, mobile computing devices, mobile communication devices, and other devices may be used.

[0121] In some implementations, at least a portion of the above methods may be implemented by instructions that, when executed, cause one or more processing devices to perform the above processes and functions. Such instructions may include, for example, interpreted instructions, such as script instructions, or executable code, or other instructions stored in a non-transitory computer-readable medium. Storage device 1330 may be implemented in a distributed manner, such as a server farm or a group of widely distributed servers over a network, or may be implemented in a single computing device.

[0122] Although already Fig.13 An example processing system is described in the specification, but the subject matter, functional operations and process embodiments described in this specification may be implemented in other types of digital electronic circuits, in tangibly embodied computer software or firmware, in computer hardware (including the structures disclosed in this specification and their structural equivalents), or in a combination of one or more of them. The embodiments of the subject matter described in this specification may be implemented as one or more computer programs, that is, one or more modules of computer program instructions encoded on a tangible non-volatile program carrier for execution by a data processing device or for controlling the operation of the data processing device. Alternatively or in addition, the program instructions may be encoded on an artificially generated propagation signal (e.g., a machine-generated electrical signal, optical signal, or electromagnetic signal) that is generated to encode information for transmission to a suitable receiver device for execution by a data processing device. The computer storage medium may be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or a combination of one or more of them.

[0123] The term "system" may encompass all kinds of devices, apparatuses, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. A processing system may include special-purpose logic circuits, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). In addition to hardware, a processing system may also include code that creates an execution environment for the computer program in question, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them.

[0124] A computer program (which may also be referred to or described as a program, software, software application, module, software module, script, or code) may be written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or another unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions). A computer program may be deployed to execute on one computer or on multiple computers located at one site or distributed across multiple sites and interconnected by a communications network.

[0125] The processes and logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuits (e.g., FPGAs (field programmable gate arrays) or ASICs (application-specific integrated circuits)), and the apparatus can also be implemented as special purpose logic circuits (e.g., FPGAs or ASICs).

[0126] A computer suitable for executing a computer program may include, for example, a general-purpose microprocessor or a special-purpose microprocessor, or both, or a central processing unit of any other type. Typically, the central processing unit will receive instructions and data from a read-only memory or a random access memory or both. A computer typically includes a central processing unit for performing or executing instructions and one or more memory devices for storing instructions and data. In general, a computer will also include one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, or be operably coupled to the one or more mass storage devices to receive data from the one or more mass storage devices or to transmit data to the one or more mass storage devices, or both. However, a computer does not necessarily have such a device. In addition, a computer may be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a global positioning system (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), etc.

[0127] Computer-readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated in special purpose logic circuits.

[0128] To provide interaction with a user, embodiments of the subject matter described in this specification may be implemented on a computer having a display device, such as a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user, and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices may also be used to provide interaction with the user; for example, feedback provided to the user may be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including sound, speech, or tactile input. In addition, the computer may interact with the user by sending documents to and receiving documents from a device used by the user; for example, by sending a web page to a web browser on a user device of the user in response to a request received from the web browser.

[0129] Embodiments of the subject matter described in this specification may be implemented in a computing system that includes a back-end component, such as a data server, or includes a middleware component, such as an application server, or includes a front-end component, such as a client computer with a graphical user interface or a web browser, through which a user can interact with a specific implementation of the subject matter described in this specification, or includes any combination of one or more such back-end components, middleware components, or front-end components. The components of the system may be interconnected by digital data communication (e.g., a communication network) of any form or media. Examples of communication networks include local area networks ("LANs") and wide area networks ("WANs"), such as the Internet.

[0130] A computing system may include clients and servers. Clients and servers are usually remote from each other and generally interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0131] Although this specification includes many specific implementation details, these should not be interpreted as limitations on the scope of the claimed protection, but as descriptions of features peculiar to specific embodiments. Certain features described in this specification in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations and even initially claimed, one or more features from the claimed combination may be removed from the combination in some cases, and the claimed combination may be directed to a sub-combination or a variation of the sub-combination.

[0132] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in a continuous order, or requiring the execution of all operations shown to achieve desired results. In some cases, multitasking and parallel processing can be advantageous. In addition, the separation of the various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can be integrated together in a single software product or encapsulated in multiple software products.

[0133] Fig.14 A simplified block diagram of a computing device / information handling system (or computing system) according to an embodiment of the present disclosure is depicted. It will be understood that the functionality shown for system 1400 is operable to support various embodiments of an information handling system, but it should be understood that an information handling system may be configured differently and include different components.

[0134] like Fig.14 As shown, the system 1400 includes one or more central processing units (CPUs) 1401 that provide computing resources and control the computer. The CPU 1401 may be implemented with a microprocessor, etc., and may also include one or more graphics processing units (GPUs) 1417 and / or floating point coprocessors for mathematical calculations. The system 1400 may also include a system memory 1402, which may be in the form of a random access memory (RAM), a read-only memory (ROM), or both.

[0135] Multiple controllers and peripherals may also be provided. For example, input controller 1403 represents an interface to various input devices 1404, such as a keyboard, mouse, or stylus. There may also be a wireless controller 1405 that communicates with wireless device 1406. System 1400 may also include a storage controller 1407 for interfacing with one or more storage devices 1408, each of which includes a storage medium such as a tape or disk, or an optical medium that can be used to record instruction programs of operating systems, utilities, and applications, which may include implementations of programs that implement various aspects of the technology described herein. According to some embodiments, storage device 1408 may also be used to store processed data or data to be processed. System 1400 may also include a display controller 1409 for providing an interface to a display device 1411, which may be a cathode ray tube (CRT), a thin film transistor (TFT) display, or other types of displays. Computing system 1400 may also include a car signal controller 1412 for communicating with a car system 1413. The communication controller 1414 may interface with one or more communication devices 1415, which enables the system 1400 to connect to remote devices via any of a variety of networks including the Internet, cloud resources (e.g., Ethernet cloud, Fibre Channel over Ethernet (FCoE) / Data Center Bridging (DCB) cloud, etc.), a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or via any suitable electromagnetic carrier signals including infrared signals.

[0136] In the system shown, all major system components can be connected to bus 1416, which can represent more than one physical bus. However, various system components may or may not be physically close to each other. For example, input data and / or output data can be remotely transmitted from one physical location to another physical location. In addition, programs that implement various aspects of some embodiments can be accessed from a remote location (e.g., a server) through a network. Such data and / or programs can be transmitted by any of a variety of machine-readable media, including but not limited to: magnetic media, such as hard disks, floppy disks, and tapes; optical media, such as CD-ROMs and holographic devices; magneto-optical media; and hardware devices specially configured to store or store and execute program codes, such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), flash memory devices, and ROM and RAM devices. Some embodiments can be encoded with instructions for one or more processors or processing units on one or more non-transient computer-readable media so that the steps are executed. It should be noted that one or more non-transient computer-readable media should include volatile and non-volatile memory. It should also be noted that alternative specific implementations are possible, including hardware specific implementations or software / hardware specific implementations. Hardware-implemented functions may be implemented using ASICs, programmable arrays, digital signal processing circuits, and the like. Thus, the term "means" in any claim is intended to encompass both software- and hardware-implemented implementations. Similarly, the term "one or more computer-readable media" as used herein includes software and / or hardware having a program of instructions embodied thereon, or a combination thereof. In view of these specific implementation alternatives, it should be understood that the drawings and accompanying descriptions provide the functional information necessary for those skilled in the art to write program code (i.e., software) and / or fabricate circuits (i.e., hardware) to perform the desired processing.

[0137] It should be noted that some embodiments may also relate to a computer product having a non-transitory tangible computer-readable medium having computer code thereon for performing various computer-implemented operations. The medium and computer code may be specially designed and constructed for the purposes of the technology described herein, or they may be of a type known or available to a person skilled in the relevant art. Examples of tangible computer-readable media include, but are not limited to: magnetic media, such as hard disks, floppy disks, and tapes; optical media, such as CD-ROMs and holographic devices; magneto-optical media; and hardware devices specially configured to store or store and execute program code, such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), flash memory devices, and ROM and RAM devices. Examples of computer code include machine code, such as machine code generated by a compiler, and files containing high-level code executed by a computer using an interpreter. Some embodiments may be implemented in whole or in part as machine executable instructions, which may be in program modules executed by a processing device. Examples of program modules include libraries, programs, routines, objects, components, and data structures. In a distributed computing environment, program modules may be physically located in a local, remote, or both setting.

[0138] Those skilled in the art will recognize that no computing system or programming language is essential to the practice of the techniques described herein.Those skilled in the art will also recognize that the above-mentioned multiple elements can be physically and / or functionally divided into submodules or combined together.

[0139] the term

[0140] The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0141] Measurement result, size, amount etc. can be presented in the form of range in this article.The description in range format is only provided for the sake of convenience and brevity and should not be interpreted as a fixed limitation to the scope of the present invention.Therefore, the description of scope should be considered to have all possible sub-ranges disclosed and the single numerical value in the described scope.For example, the description of the scope such as 1-20 meters should be considered to have concrete disclosed sub-ranges, such as 1 meter, 2 meters, 1-2 meters, less than 2 meters, 10-11 meters, 10-12 meters, 10-13 meters, 10-14 meters, 11-12 meters, 11-13 meters etc.

[0142] In addition, the connections between components or systems in the figure are not intended to be limited to direct connections. Instead, the data or signals between these components can be modified, reformatted or otherwise changed by intermediate components. In addition, additional or fewer connections can be used. The terms "coupled", "connected" or "communicatively coupled" should be understood to include direct connections, indirect connections through one or more intermediate devices, wireless connections, etc.

[0143] References in the specification to "one embodiment," "preferred embodiments," "some embodiments," or "embodiments" mean that a particular feature, structure, characteristic, or function described in conjunction with the embodiment is included in at least one embodiment of the invention, and may be in more than one embodiment. In addition, the appearances of the above phrases in various places in the specification are not necessarily referring to the same embodiment or embodiments.

[0144] Certain terms used in various places in the specification are for illustrative purposes only and should not be construed as limiting. A service, function, or resource is not limited to a single service, function, or resource; the use of these terms may refer to a group of related services, functions, or resources, which may be distributed or aggregated.

[0145] In addition, those skilled in the art will recognize that: (1) certain steps may be performed optionally; (2) the steps may not be limited to the specific order set forth herein; (3) certain steps may be performed in a different order; and (4) certain steps may be performed simultaneously or concurrently.

[0146] The term "about", the phrase "approximately equal to" and other similar phrases (e.g., "X has a value of approximately Y" or "X is approximately equal to Y") as used in the specification and claims should be understood to mean that one value (X) is within a predetermined range of another value (Y). The predetermined range may be plus or minus 20%, 10%, 5%, 3%, 1%, 0.1%, or less than 0.1%, unless otherwise indicated.

[0147] The indefinite articles "one" and "an", as used in the specification and claims, should be understood to mean "at least one", unless clearly indicated to the contrary. The phrase "and / or", as used in the specification and claims, should be understood to mean "either or both" of the elements so combined, i.e., elements that exist in combination in some cases and separately in other cases. Multiple elements listed with "and / or" should be interpreted in the same way, i.e., "one or more" of the elements so combined. In addition to the elements specifically identified by the "and / or" clause, other elements may optionally be present, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, when used in conjunction with open language (such as "including"), a reference to "A and / or B" may refer to only A (optionally including elements other than B) in one embodiment; in another embodiment, may refer to only B (optionally including elements other than A); in yet another embodiment, may refer to both A and B (optionally including other elements).

[0148] As used in the specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating the items in a list, "or" or "and / or" should be interpreted as inclusive, that is, including at least one of a plurality of or a series of elements, but also including more than one, and optionally including additional unlisted items. Only clearly indicating the opposite terms, such as "only one of..." or "exact one of..." or "consisting of..." when used in the claims will refer to including exactly one element in a plurality of elements or a list of elements. In general, the term "or" as used should only be interpreted as indicating exclusive alternatives (i.e., "one or the other but not both"), when there is an exclusive term in front, such as "any", "one of", "only one of" or "exactly one of". When used in the claims, "consisting essentially of..." should have its ordinary meaning as used in the field of patent law.

[0149] As used in the specification and claims, the phrase "at least one" with respect to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but not necessarily including at least one element of each and every element specifically listed in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows elements other than the elements specifically identified in the list of elements referred to by the phrase "at least one" to be optionally present, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, in one embodiment, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently "at least one of A and / or B") may refer to at least one (optionally including more than one) A, without B (and optionally including elements other than B); in another embodiment, may refer to at least one (optionally including more than one) B, without A (and optionally including elements other than A); in yet another embodiment, may refer to at least one (optionally including more than one) A and at least one (optionally including more than one) B (and optionally including other elements).

[0150] The use of "including," "having," "comprising," "involving," and variations thereof, is meant to encompass the items listed thereafter as well as additional items.

[0151] The use of ordinal terms such as "first," "second," "third," etc., in the claims to modify claim elements does not in itself imply any priority, precedence, or order of one claim element relative to another claim element or a temporal order of the acts of performing a method. Ordinal terms are used only as markers to distinguish one claim element having a certain name from another element having the same name (but using an ordinal term) to distinguish claim elements.

[0152] Specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. For example, the actions recited in the claims can be performed in a different order and still achieve the desired results. As an example, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous. Other steps or levels can be provided, or steps or levels can be eliminated from the described process. Therefore, other implementations are within the scope of the appended claims.

[0153] Those skilled in the art will appreciate that the foregoing examples and embodiments are exemplary and do not limit the scope of the present disclosure. All permutations, enhancements, equivalents, combinations, and improvements that are apparent to those skilled in the art upon reading the specification and studying the drawings are included within the true spirit and scope of the present disclosure. It should also be noted that the elements of any claim may be arranged differently, including with a variety of dependencies, configurations, and combinations.

[0154] Having thus described several aspects of at least one embodiment of the present invention, it will be appreciated that various changes, modifications and improvements will readily occur to those skilled in the art. Such changes, modifications and improvements are intended to be a part of this disclosure and are intended to be within the spirit and scope of the present invention. Therefore, the foregoing description and accompanying drawings are merely exemplary.

Claims

1. A light detection and ranging (LiDAR) device, the LiDAR device comprising: at least one illumination source configured to emit illumination light; an optical scanning device disposed in an optical path of the at least one illumination source to redirect the illumination light emitted by the at least one illumination source from the LiDAR device into a three-dimensional (3-D) environment; at least one scanning mechanism configured to rotate the optical scanning device about at least one axis; and At least one controller, the at least one controller being configured to: determining a desired scanning mode of the LiDAR device; generating at least one drive waveform corresponding to (i) the desired scan pattern and (ii) a scan line compression profile of the optical scanning device; as well as The at least one scanning mechanism is operated based on the at least one drive waveform to provide the desired scanning pattern.

2. The LiDAR device according to claim 1, wherein when operating the at least one scanning mechanism, the at least one controller is configured to control (i) a first scanning mechanism and (ii) a second scanning mechanism, wherein the first scanning mechanism is configured to rotate the optical scanning device around a first axis to deflect the illumination light in a first scanning direction, and the second scanning mechanism is configured to rotate the optical scanning device around a second axis to deflect the illumination light in a second scanning direction, and the second axis is orthogonal to the first axis. 3 . The LiDAR device of claim 2 , wherein the scan line compression profile corresponds to a deflection percentage of the optical scanning device within an optical scanning range in the first scanning direction.

4. The LiDAR device of claim 3, wherein the deflection percentage represents an actual amount of deflection provided by the optical scanning device in the second scanning direction relative to an expected amount of deflection provided by the optical scanning device in the second scanning direction.

5. The LiDAR device of claim 4, wherein the at least one driving waveform is configured to compensate for a difference between the desired deflection amount and the actual deflection amount to provide the desired scanning pattern.

6. The LiDAR device of claim 3, wherein the scanline compression profile of the optical scanning device provides an indication of at least one geometrically compressed region in a field of view of the LiDAR device.

7. The LiDAR device of claim 6, wherein the at least one geometrically compressed region corresponds to at least a portion of the optical scanning range in the first scanning direction.

8. The LiDAR device of claim 6, wherein the at least one drive waveform is configured to adjust an amount of deflection provided by the optical scanning device in the second scan direction at a variable rate based on the scan line compression profile.

9. The LiDAR device of claim 8, wherein the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scanning direction at a non-linear rate over the at least one geometric compression region.

10. The LiDAR device of claim 8, wherein the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scanning direction at a substantially linear rate outside of the at least one geometric compression region.

11. A method of operating a light detection and ranging (LiDAR) device, the method comprising: determining a desired scanning mode of the LiDAR device; emitting illumination light from at least one illumination source; generating at least one drive waveform corresponding to (i) the desired scan pattern and (ii) a scan line compression profile of an optical scanning device disposed in an optical path of the at least one illumination source, the optical scanning device configured to redirect the illumination light emitted by the at least one illumination source from the LiDAR device into a three-dimensional (3-D) environment; as well as At least one scanning mechanism is controlled based on the at least one drive waveform, the at least one scanning mechanism being configured to rotate the optical scanning device about at least one axis to provide the desired scanning pattern.

12. The method of claim 11 , wherein controlling the at least one scanning mechanism comprises controlling (i) a first scanning mechanism configured to rotate the optical scanning device around a first axis to deflect the illumination light in a first scanning direction, and (ii) a second scanning mechanism configured to rotate the optical scanning device around a second axis to deflect the illumination light in a second scanning direction, the second axis being orthogonal to the first axis.

13. The method of claim 12, wherein the scan line compression profile corresponds to a percentage of deflection of the optical scanning device within an optical scanning range in the first scanning direction.

14. The method of claim 13, wherein the deflection percentage represents an actual amount of deflection provided by the optical scanning device in the second scanning direction relative to an expected amount of deflection provided by the optical scanning device in the second scanning direction.

15. The method of claim 14, wherein the at least one drive waveform is configured to compensate for a difference between the desired deflection amount and the actual deflection amount to provide the desired scanning pattern.

16. The method of claim 13, wherein the scanline compression profile of the optical scanning device provides an indication of at least one geometrically compressed region in the field of view of the LiDAR device.

17. The method of claim 16, wherein the at least one geometrically compressed region corresponds to at least a portion of the optical scanning range in the first scanning direction.

18. The method of claim 16, wherein the at least one drive waveform is configured to adjust an amount of deflection provided by the optical scanning device in the second scan direction at a variable rate based on the scan line compression profile.

19. The method of claim 18, wherein the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scanning direction at a non-linear rate over the at least one geometric compression region.

20. The method of claim 18, wherein the at least one drive waveform is configured to adjust the amount of deflection provided by the optical scanning device in the second scanning direction at a substantially linear rate outside of the at least one geometric compression region.

21. A carrier, the carrier include: At least one LiDAR device according to claim 1, wherein each LiDAR device is configured to provide navigation and / or mapping for the vehicle and is disposed inside the vehicle and / or outside the vehicle.

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