LIDAR pixel with active polarization control

Abstract

To provide FMCW_LIDAR with improved accuracy.SOLUTION: A LIDAR pixel 150 comprises a polarization controller 180, a diffraction grating coupler 161, and an optical mixer 159. The polarization controller comprises a phase shifter 157 that sets a phase of light in a first arm of the polarization controller and a second arm of the polarization controller.SELECTED DRAWING: Figure 1a

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. regular application Ser. No. 17 / 344,386, filed June 10, 2021, which claims priority to U.S. provisional application Ser. No. 63 / 038,452, filed June 12, 2020. Applications Ser. Nos. 17 / 344,386 and 63 / 038,452 are incorporated herein by reference.

[0002] The present disclosure relates generally to imaging, and more particularly to light detection and ranging (LIDAR). [Background technology]

[0003] Frequency Modulated Continuous Wave (FMCW) LIDAR directly measures the range and velocity of an object by directing a frequency modulated, collimated beam of light at the target. All of the target range and velocity information is derived from the FMCW LIDAR signal. Designs and techniques to increase the accuracy of the LIDAR signal are preferred.

[0004] The automotive industry is currently developing autonomous capabilities to control vehicles in certain situations. According to SAE International Standard J3016, there are six levels of autonomy ranging from Level 0 (no autonomy) to Level 5 (vehicles that can operate without driver input in all conditions). Vehicles with autonomous capabilities utilize sensors to sense the environment in which the vehicle travels. Acquiring and processing data from the sensors allows the vehicle to navigate through this environment. An autonomous vehicle may include one or more FMCW LIDAR devices to sense its environment. Summary of the Invention [Means for solving the problem]

[0005] An embodiment of the present disclosure includes a Light Detection and Ranging (LIDAR) system including a laser, a splitter, a polarization controller, and a dual-polarization grating coupler. The laser is configured to generate light. The splitter is configured to split the light into a plurality of lights. The polarization controller is configured to receive a first split light of the plurality of split lights. The polarization controller includes a first arm and a second arm. The first arm includes a first phase shifter and a second phase shifter configured to set a phase of the first arm relative to the second arm. The dual-polarization grating coupler includes a first port for receiving light from the first arm and a second port configured to receive light from the second arm. The dual-polarization grating coupler is configured to couple light from the first port into a first beam having a first polarization direction. The dual-polarization grating coupler is configured to couple light from the second port into a second beam having a second polarization direction.

[0006] In one embodiment, the LIDAR system further includes an optical mixer configured to receive a second light of the plurality of split lights. The dual polarization grating coupler is configured to couple the reflected light having the first polarization direction into the first arm and the reflected light having the second polarization direction into the second arm. The optical mixer can be configured to output an output signal in response to the reflected light and the second light.

[0007] In one embodiment, the LIDAR system further includes a splitter configured to provide a first portion of the split light to the polarization controller, and the splitter configured to provide a second portion of the split light to the optical mixer.

[0008] In one embodiment, the LIDAR system further includes a first stage and a second stage. The first stage includes a first 2×2 splitter and a first phase shifter. The first 2×2 splitter is connected to an interconnect that feeds the optical mixer. The second stage includes a second 2×2 splitter and a second phase shifter.

[0009] In one embodiment, the first port of the dual polarization grating coupler is optically coupled to a second phase shifter.

[0010] In one embodiment, the second beam having a second polarization direction is orthogonal to the first polarization direction.

[0011] An embodiment of the present disclosure includes a system for an autonomous vehicle including an active polarization controlled coherent pixel array coupled to a LIDAR processing engine. A pixel in the active polarization controlled coherent pixel array includes a polarization controller and a dual polarization grating coupler. The polarization controller includes a first arm and a second arm. The first arm includes a first phase shifter and a second phase shifter controllable to set a phase of the first arm relative to the second arm. The dual polarization grating coupler includes a first port for receiving light from the first arm and a second port configured to receive light from the second arm. The dual polarization grating coupler is configured to couple light from the first port into a first beam having a first polarization direction. The dual polarization grating coupler is configured to couple light from the second port into a second beam having a second polarization direction.

[0012] In one embodiment, a pixel in the active polarization controlled coherent pixel array includes an optical mixer configured to receive the second light. The dual polarization grating coupler is configured to couple the reflected light having the first polarization direction into a first arm and the reflected light having the second polarization direction into a second arm. The optical mixer is configured to output an output signal in response to the reflected light and the remaining portion of the split light.

[0013] In one embodiment, a pixel in the active polarization controlled coherent pixel array includes a splitter configured to provide a first portion of the split light to a polarization controller and the splitter configured to provide a remaining portion of the split light to an optical mixer.

[0014] In one embodiment, the first port of the dual polarization grating coupler is optically coupled to a second phase shifter.

[0015] An embodiment of the present disclosure includes an autonomous vehicle system for an autonomous vehicle including a LIDAR pixel and one or more processors. The LIDAR pixel includes a polarization controller, a grating coupler, and an optical mixer. The polarization controller is configured to receive a first portion of the split light. The polarization controller includes a first arm and a second arm. A phase shifter of the polarization controller sets a phase of a first light propagating in the first arm relative to a second light propagating in the second arm. The grating coupler is configured to output an output beam by receiving the first light and the second light. The grating coupler is configured to receive a reflected beam of the output beam. The optical mixer is configured to output a beat signal by receiving the remaining portion of the split light and the reflected beam. The one or more processors are configured to control the phase shifter by receiving the beat signal from the pixel.

[0016] In one embodiment, the grating coupler is a dual polarization grating coupler configured to couple a first light from a first arm into a first beam having a first polarization direction, and the dual polarization grating coupler is configured to couple a second light from a second arm into a second beam having a second polarization direction that is orthogonal to the first polarization direction.

[0017] In one embodiment, the one or more processors control the phase shifter to increase the signal level of the beat signal.

[0018] In one embodiment, the one or more processors control the phase shifter to maximize the signal level of the beat signal.

[0019] In one embodiment, a system for an autonomous vehicle includes a control system configured to control a powertrain of the autonomous vehicle in response to a beat signal.

[0020] In one embodiment, the output beam is an infrared output beam.

[0021] In one embodiment, a system for an autonomous vehicle includes a splitter configured to provide a first portion of the split light to a polarization controller, and the splitter configured to provide a remaining portion of the split light to an optical mixer.

[0022] In one embodiment, the polarization controller includes a second phase shifter.

[0023] In one embodiment, the polarization controller includes a first stage and a second stage. The first stage includes a first 2×2 splitter and a phase shifter. The first 2×2 splitter is coupled to an interconnect that feeds an optical mixer. The second stage includes a second 2×2 splitter and a second phase shifter.

[0024] In one embodiment, the first port of the grating coupler is optically coupled to a second phase shifter. [Brief description of the drawings]

[0025] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings, in which like reference numbers refer to like parts throughout the various drawings unless otherwise specified.

[0026] [Figure 1a] 1 illustrates an exemplary LIDAR device including LIDAR pixels with active polarization control according to embodiments of the present disclosure.

[0027] [Figure 1b] 1 illustrates an exemplary LIDAR pixel including a first phase shifter and a second phase shifter for active polarization control according to an embodiment of the present disclosure.

[0028] [Diagram 2] 1 illustrates how two or more coherent pixels with active polarization control according to embodiments of the present disclosure can be combined into a focal plane array (FPA).

[0029] [Diagram 3] 1 illustrates how an array of coherent pixels with active polarization control according to an embodiment of the present disclosure can be used in an FMCW LIDAR system.

[0030] [Figure 4a] 1 illustrates an autonomous vehicle including an exemplary array of sensors according to an embodiment of the present disclosure.

[0031] [Figure 4b] FIG. 1 illustrates a top view of an autonomous vehicle including an exemplary array of sensors according to an embodiment of the present disclosure.

[0032] [Figure 4c] 1 illustrates an exemplary vehicle control system including a sensor, a powertrain, and a control system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] An embodiment of active polarization control for LIDAR pixels is described herein. In the following description, numerous specific details are described to provide a thorough understanding of the embodiments. However, a person of ordinary skill in the relevant art will recognize that the techniques described herein may be implemented without one or more specific details, or may be implemented with other methods, components, or materials. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.

[0034] References throughout this specification to "one embodiment" or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0035] Throughout this specification, several technical terms are used. These terms shall take their ordinary meaning in the art unless specifically defined herein or the context of their use clearly indicates otherwise. For purposes of this disclosure, the term "autonomous vehicle" includes vehicles having autonomous capabilities at any autonomy level of SAE International Standard J3016.

[0036] In an embodiment of the present disclosure, visible light can be defined as having a wavelength range of about 380 nm to 700 nm. Invisible light can be defined as light having a wavelength outside the range of visible light, such as ultraviolet light and infrared light. Infrared light having a wavelength range of about 700 nm to 1 mm includes near infrared light. In an embodiment of the present disclosure, near infrared light can be defined as having a wavelength range of about 700 nm to 1.6 μm.

[0037] In embodiments of the present disclosure, the term "transparent" can be defined as having greater than 90% light transmission. In some embodiments, the term "transparent" can be defined as a material having greater than 90% transmission of visible light.

[0038] Frequency Modulated Continuous Wave (FMCW) LIDAR directly measures the distance and velocity of an object by directing a frequency modulated, collimated beam of light at the object. Light reflected from the object is combined with a tapped version of the beam. The frequency of the resulting Beat Tone, once corrected for Doppler Shift, which requires a second measurement, is proportional to the object's distance relative to the LIDAR system. The two measurements, which may or may not be made simultaneously, provide both range and velocity information.

[0039] FMCW LIDAR may use integrated photonics for improved manufacturability and performance. Integrated photonic systems typically use micron-scale waveguide devices to operate a single optical mode.

[0040] Coherent light generated by an FMCW LIDAR reflected from a diffusive surface produces a speckle pattern characterized by random intensity and phase in the reflected optical field. This speckle field reduces the amount of power that can be recoupled into a single-mode optical system. As the FMCW LIDAR beam is scanned across a diffusive surface, the reflected speckle field has a time-varying behavior that leads to a broadened signal spectrum.

[0041] An embodiment of the present disclosure includes one or more coherent pixels with active polarization control. The light in a coherent pixel is split evenly into two "arms," ​​and then the amplitude and relative phase of the pixel's two arms can be arbitrarily manipulated. The light in the two arms can be transmitted to a dual-polarization optical coupler, which can couple the light into free space with two orthogonal polarizations.

[0042] By controlling the amplitude and phase of the two arms of the coherent pixel, the output polarization of light can be arbitrarily selected. Alternatively, by controlling the amplitude and phase of the two arms of the coherent pixel, it can be arbitrarily sensitive to receiving a particular polarization of light.

[0043] FIG 1a illustrates an exemplary LIDAR device 199 including a LIDAR pixel 150 with active polarization control according to an embodiment of the present disclosure. The LIDAR pixel 150 in FIG 1a includes a 1x2 splitter 152, an optical mixer 159, a grating coupler 161, and a polarization controller 180. The polarization controller 180 includes a 2x2 splitter 156 and a phase shifter 157. The polarization controller 180 includes an upper arm 162 and a lower arm 160.

[0044] The light 151 entering the LIDAR pixel 150 can be split by a splitter (e.g., 1×2 splitter 152). The light 151 can be infrared laser light generated by a laser (e.g., a continuous wave laser). In some embodiments, the laser light can be collimated. The split ratio of the splitter 152 can be selected as desired for the FMCW LIDAR system. A portion of this split light (e.g., 70%-99%) propagates to the 2×2 splitter 156 via the interconnect 153. The remaining light (e.g., 1%-30%) exiting the lower output port of the 1×2 splitter 152 propagates to the optical mixer 159 via the interconnect 154. In some embodiments, the input light 151 and the 1×2 splitter 152 can be replaced by two independent light sources.

[0045] In the transmit direction, the polarization controller 180 is configured to receive a first portion of the split light split by the 1×2 splitter 152. The first portion of the split light propagates to the polarization controller 180 via the interconnect 153. The light entering the 2×2 splitter 156 is split between the two output ports of the 2×2 splitter 156. The "upper arm" 162 of the polarization controller 180 begins at the upper output port of the 2×2 splitter 156, and the "lower arm" 160 of the polarization controller 180 begins at the lower port of the 2×2 splitter 156. In some embodiments, the split ratio between the upper and lower ports of the 2×2 splitter 156 is 50:50, although other split ratios may be selected as needed. The light in the upper arm 162 passes through a phase shifter 157 that can be controlled to arbitrarily set the phase of the light in the upper arm 162 relative to the lower arm 160. The light in the upper arm 162 passes through a phase shifter 157 which can be controlled to arbitrarily set the phase of the light in the upper arm 162 relative to the lower arm 160 .

[0046] Phase shifter 157 sets the phase of the upper light propagating in upper arm 162 relative to the lower light propagating in lower arm 160. In FIG. 1a, processing logic 190 is configured to control phase shifter 157. Light in upper arm 162 propagates to upper port 168 of grating coupler 161, while light in lower arm 160 propagates to lower port 169 of grating coupler 161. Grating coupler 161 may be a dual polarization grating coupler configured to outcouple light of a first polarization direction and light of a second polarization direction orthogonal to the first polarization direction. Grating coupler 161, in some embodiments, couples light from upper port 168 into a first polarization beam (e.g., a "TE" polarization beam) and couples light from lower port 169 into a second polarization beam (e.g., a "TM" polarization beam). These two orthogonal beams are superimposed to form an output light beam 193 having an arbitrary polarization determined by the state of phase shifter 157. Thus, grating coupler 161 is configured to output output light beam 193 by receiving upper light propagating in upper arm 162 and lower light propagating in lower arm 160.

[0047] In the illustrated embodiment, the diffraction grating coupler 161 is presented as an "antenna." However, equivalent, alternative, or similar systems can be implemented using a Polarization Rotator, Polarization Combiner, or Edge Emitter.

[0048] In the receiving direction, arbitrarily polarized light 194 enters the grating coupler 161. Light with a first polarization is coupled into the upper arm 162 and passes through the phase shifter 157. Light with a second polarization is coupled into the lower arm 160. The light in both arms then passes through the 2×2 splitter 156. The phase shifter 157 can be controlled so that the maximum amount of light is coupled into the lower port of the 2×2 splitter 156, which is connected to the interconnect 163. The light in the interconnect 163 is fed into the optical mixer 159, which combines it with the light in the interconnect 154. The light in the interconnect 154 is the remaining part of the light except for the first part of the light propagating in the interconnect 153. Thus, the optical mixer 159 is configured to output an output signal 164 by receiving the remaining portion of the split light and the reflected beam 194 (propagating through the lower arm 160 and the 2×2 splitter 156). The optical mixer 159 converts these mixed optical signals (the light in the interconnect 163 and the interconnect 154) into the electrical domain to generate one or more output signals 164. For example, the output signal 164 can be an electronic signal such as a “Beat Signal.”

[0049] As previously described, the phase shifter 157 sets the phase of the upper light propagating in the upper arm 162 relative to the lower light propagating in the lower arm 160. In the illustrated embodiment of FIG. 1a, the processing logic 190 is configured to control the phase shifter 157 by receiving the beat signal 164 from the LIDAR pixel 150. In some embodiments, the processing logic 190 drives the phase shifter 157 with different phase values, selects the phase value that produces the beat signal 164 with the highest amplitude, and drives the selected phase value on the phase shifter 157 to increase or maximize the signal level of the beat signal 164. Because different target surfaces reflect with different polarization directions, different polarizations of the light reflected by the different target surfaces can cause the processing logic 190 to drive the phase shifter 157 with different phase values ​​that increase the amplitude of the beat signal 164. In some embodiments, the processing logic 190 receives the beat signals 164 from multiple LIDAR pixels 150 and generates an image 191 from the multiple beat signals.

[0050] FIG. 1b illustrates an exemplary LIDAR pixel 149 including a first phase shifter 107 and a second phase shifter 109 for active polarization control according to an embodiment of the present disclosure. The light 101 entering the coherent pixel 149 can be split by a splitter (e.g., 1×2 splitter 102). The split ratio of this splitter can be selected as desired for the FMCW LIDAR system. A portion of this split light (e.g., 70%-99%) propagates through interconnect 103 to 2×2 splitter 105. The remaining light (e.g., 1%-30%) exiting the bottom output port of the 1×2 splitter propagates through interconnect 104 to optical mixer 106. In some embodiments, the input light 101 and the 1×2 splitter 102 can be replaced by two independent light sources.

[0051] In the transmit direction, light entering the 2x2 splitter 105 is split between the two output ports of the 2x2 splitter 105 (which constitutes the first stage of the polarization controller 130 having an "upper arm" and a "lower arm"). The first stage includes a first 2x2 splitter 105 and a first phase shifter 107. In one embodiment of the coherent pixel 149, the splitting ratio is 50:50, but other splitting ratios can be selected as required. The light in the upper arm passes through the first phase shifter 107, which can be controlled to arbitrarily set the phase of the light in the upper arm relative to the lower arm.

[0052] The light in the upper and lower arms enter a second 2×2 splitter 108 (second stage of the polarization controller 130). The second stage includes a second 2×2 splitter 108 and a second phase shifter 109. Depending on the phase shift of the two arms, the amplitude of the light exiting the upper and lower ports of the splitter 108 can be controlled. The light in the upper arm of this second stage passes through a second phase shifter 109 that can be controlled to set the relative phase of the upper and lower arms of the second stage at any desired value. The light in the upper arm propagates to the upper port 118 of a dual polarization grating coupler 111, while the light in the lower arm 110 propagates to the lower port 119 of the dual polarization grating coupler 111. The upper port 118 is optically coupled to the second phase shifter 109. The grating coupler 111 couples light from the top port 118 into a first polarized beam and light from the bottom port 119 into a second orthogonally polarized beam. These two orthogonal beams are superimposed to form a light beam 143 with an arbitrary polarization determined by the states of the two phase shifters 107, 109.

[0053] In the illustrated embodiment, a dual polarization grating coupler 111 is presented as an "antenna." However, equivalent, alternative, or similar systems can be implemented using a polarization rotator, a polarization coupler, or an edge emitter.

[0054] In the receive direction, arbitrarily polarized light 144 enters the dual polarization grating coupler 111. Light with a first polarization is coupled into the upper arm 112 of the second stage and passes through the second phase shifter 109. Light with a second polarization is coupled into the lower arm 110 of the second stage. The light in both arms then passes through the 2×2 splitter 108 into the first stage. The light in the upper arm of the first stage passes through the first phase shifter 107. The light in both arms of the first stage passes through the 2×2 splitter 105. The first phase shifter 107 and the second phase shifter 109 can be controlled such that the maximum amount of light is coupled into the lower port of the 2×2 splitter 105, which is connected to the interconnect 113. The light in interconnect 113 is fed into optical mixer 106, which combines it with the light in interconnect 104. Optical mixer 106 converts these mixed optical signals into the electrical domain to generate one or more output signals 114.

[0055] FIG. 2 illustrates how two or more coherent pixels with active polarization control according to embodiments of the present disclosure can be coupled to a focal plane array (FPA) 201. The coherent pixels 203 can be embodied in the design of the LIDAR pixel 149 and / or the LIDAR pixel 150. Multiple optical channels 202 enter the array. These can be separate parallel channels or can be switched between pixels using optical circuitry. In some embodiments, the same continuous wave (CW) infrared laser provides the laser light for each of the optical channels 202. Waveguides, optical fibers, micro-optical elements, optical amplifiers, and / or photonic circuits can be embodied such that each of the channels 202 receives a portion of the laser light from the CW infrared laser. The light enters each coherent pixel (e.g., 203), which manipulates, transmits, and receives light with any polarization 204, as previously described. The received light is converted into an array of output electrical signals 205. Image processing may be performed on the array of output electrical signals 205 to generate an image of the environment imaged by FPA 201.

[0056] FIG. 3 illustrates how a coherent pixel array with active polarization control according to an embodiment of the present disclosure can be used in an FMCW LIDAR system 399. In FIG. 3, a lens 300 receives an input from an active polarization controlled coherent pixel array 301, which may include an FPA 201 in some embodiments. The lens 300 also receives an output beam having various angles 306. The pixels in the active polarization controlled coherent pixel array 301 are controlled by an FPA driver module 304. Individual pixels in the array can be turned on to emit or receive light, or multiple simultaneous pixels in the array can be turned on to emit or receive light simultaneously. The light emitted by the active polarization controlled coherent pixel array 301 is generated by a laser array 303 with Q parallel channels. The laser array can be directly integrated with the active polarization controlled coherent pixel array 301 or can be a separate module packaged together with the active polarization controlled coherent pixel array 301. The laser array is controlled by a laser driver module 305 which receives control signals from the LIDAR processing engine 302 via a digital-to-analog converter (DAC) 307. The LIDAR processing engine 302 also controls an FPA driver 304 to receive and send data from the active polarization controlled coherent pixel array 301.

[0057] The LIDAR processing engine 302 includes a microcomputer 308. The microcomputer 308 can process data from the FPA system 330 and send control signals to the FPA system 330 via the FPA driver 304 and the laser controller 305. Signals are received by an N-channel receiver 309 of the LIDAR processing engine 302. These input signals are digitized using a set of M-channel analog-to-digital converters (ADCs) 310, and the microcomputer 308 is configured to receive the digitized versions of the signals.

[0058] FIG. 4a illustrates an example autonomous vehicle 400 that may include the LIDAR designs of FIGS. 1a-3 according to aspects of the present disclosure. The illustrated autonomous vehicle 400 includes a sensor array configured to capture one or more objects in an external environment of the autonomous vehicle and generate sensor data related to the captured one or more objects for purposes of controlling the operation of the autonomous vehicle 400. FIG. 4a illustrates sensors 433A, 433B, 433C, 433D, 433E. FIG. 4b illustrates a top view of the autonomous vehicle 400 that includes sensors 433A, 433B, 433C, 433D, 433E, as well as sensors 433F, 433G, 433H, 433I. Any of the sensors 433A, 433B, 433C, 433D, 433E, 433F, 433G, 433H, and / or 433I may include a LIDAR device that includes the designs of FIGS. 1a-3. 4c illustrates a block diagram of an example system 499 for an autonomous vehicle 400. For example, the autonomous vehicle 400 may include a powertrain 402 including a prime mover 404 that may be powered by an energy source 406 and provide power to a drivetrain 408. The autonomous vehicle 400 may further include a control system 410 including a directional control 412, a powertrain control 414, and a brake control 416. The autonomous vehicle 400 may be embodied as any number of different vehicles, including vehicles capable of transporting people and / or cargo and moving in a variety of different environments. It will be appreciated that the aforementioned components 402-416 may vary widely depending on the type of vehicle in which these components are utilized.

[0059] The embodiments described below focus on Wheeled Land Vehicles, such as, for example, cars, vans, trucks, or buses. In such embodiments, the prime mover 404 may include (among other things) one or more electric motors and / or an internal combustion engine. The energy source may include, for example, a fuel system (e.g., providing gasoline, diesel, hydrogen, etc.), a battery system, a solar panel, or other renewable energy source, and / or a fuel cell system. The drive train 408 may include wheels and / or tires along with a transmission and / or any other mechanical drive components suitable for converting the output of the prime mover 404 into vehicle motion, as well as one or more brakes configured to controllably stop or slow the autonomous vehicle 400 or directional or steering components suitable for controlling the trajectory of the autonomous vehicle 400 (e.g., a rack and pinion steering linkage that allows one or more wheels of the autonomous vehicle 400 to pivot about a substantially vertical axis to change the angle of the plane of rotation of the wheel relative to the longitudinal axis of the vehicle). In some embodiments (e.g., in the case of electric / gas hybrid vehicles), a combination of powertrains and energy sources can be used. In some embodiments, multiple electric motors (e.g., dedicated to individual wheels or axles) can be used as prime movers.

[0060] Directional control 412 may include one or more actuators and / or sensors for receiving and controlling feedback from directional or steering components to enable autonomous vehicle 400 to follow a desired trajectory. Powertrain control 414 may be configured to control the speed and / or direction of autonomous vehicle 400 by controlling the output of powertrain 402, such as by controlling the output power of prime mover 404 and controlling transmission gears in drivetrain 408. Brake control 416 may be configured to control one or more brakes, such as disc or drum brakes coupled to the wheels of the vehicle, to slow or stop autonomous vehicle 400.

[0061] As will be appreciated by one of ordinary skill in the art having the benefit of this disclosure, other vehicle types, including, but not limited to, off-road, all-terrain or tracked vehicles or construction equipment, will necessarily use different powertrains, drivetrains, energy sources, directional controls, powertrain controls and brake controls. Furthermore, in some embodiments, some of the components may be combined, for example, where the directional control of the vehicle is handled primarily by modifying the output of one or more prime movers. Thus, the embodiments disclosed herein are not limited to the specific application of the technology described herein in autonomous wheeled land vehicles.

[0062] In the illustrated embodiment, the autonomous control for the autonomous vehicle 400 may include one or more processors and one or more memories 424 in processing logic 422 embodied in a vehicle control system 420 configured to execute program code (e.g., instructions 426) stored in the memory 424. The processing logic 422 may include, for example, graphics processing units (GPU(s)) and / or central processing units (CPU(s)). The vehicle control system 420 may be configured to control the powertrain 402 of the autonomous vehicle 400 in response to an output of an optical mixer of a LIDAR pixel, such as LIDAR pixel 149 or 150. The vehicle control system 420 may be configured to control the powertrain 402 of the autonomous vehicle 400 in response to an output from a plurality of LIDAR pixels. The vehicle control system 420 may be configured to control the powertrain 402 of the autonomous vehicle 400 in response to an output from the microcomputer 308 generated based on a signal received from the FPA system 330.

[0063] The sensors 433A-433I may include various sensors suitable for collecting data from the autonomous vehicle's surrounding environment for use in controlling the operation of the autonomous vehicle. For example, the sensors 433A-433I may include a RADAR unit 434, a LIDAR unit 436, a 3D positioning sensor 438, e.g., a satellite navigation system such as GPS, GLONASS, BeiDou, Galileo, or Compass. The LIDAR design of FIGS. 1a-3 may be included in the LIDAR unit 436. The LIDAR unit 436 may include, for example, multiple LIDAR sensors distributed around the autonomous vehicle 400. In some embodiments, the 3D positioning sensor 438 may determine the vehicle's position on Earth using satellite signals. The sensors 433A-433I may optionally include one or more ultrasonic sensors, one or more cameras 440, and / or an Inertial Measurement Unit (IMU) 442. In some embodiments, camera 440 may be a monographic or stereographic camera and may record still and / or video images. Camera 440 may include a complementary metal-oxide-semiconductor (CMOS) image sensor configured to capture images of one or more objects in the environment external to autonomous vehicle 400. IMU 442 may include multiple gyroscopes and accelerometers capable of detecting linear and rotational motion of autonomous vehicle 400 in three directions. One or more encoders (not shown), such as wheel encoders, may be used to monitor the rotation of one or more wheels of autonomous vehicle 400.

[0064] The output of the sensors 433A-433I may be provided to a control subsystem 450, which includes a localization subsystem 452, a trajectory subsystem 456, a perception subsystem 454, and a control system interface 458. The localization subsystem 452 is configured to determine the location and orientation (or "pose") of the autonomous vehicle 400 within its surrounding environment, and generally within a particular geographic region. The location of the autonomous vehicle may be compared to the locations of additional vehicles within the same environment as part of the function of generating labeled autonomous vehicle data. The perception subsystem 454 may be configured to detect, track, classify, and / or determine objects within the environment surrounding the autonomous vehicle 400. The tracking subsystem 456 is configured to generate a trajectory for the autonomous vehicle 400 over a particular time frame when considering stationary and moving objects in the environment as well as a desired destination. Machine learning models according to some embodiments may be utilized to generate the vehicle trajectory. Control system interface 458 is configured to communicate with control system 410 to implement a trajectory for autonomous vehicle 400. In some embodiments, machine learning models can be utilized to control the autonomous vehicle to implement a planned trajectory.

[0065] It will be understood that the collection of components shown in FIG. 4c for vehicle control system 420 is merely exemplary in nature. Individual sensors may be omitted in some embodiments. In some embodiments, different types of sensors shown in FIG. 4c may be used for redundancy and / or to cover other areas in the environment surrounding the autonomous vehicle. In some embodiments, different types and / or combinations of control subsystems may be used. Also, although subsystems 452-458 are shown as separate from processing logic 422 and memory 424, it will be understood that in some embodiments, some or all of the functionality of subsystems 452-458 may be embodied in program code, such as instructions 426, resident in memory 424 and executed by processing logic 422, and such subsystems 452-458 may be embodied using the same processor and / or memory, in some cases. In some embodiments, the subsystems may be embodied at least in part using various dedicated circuit logic, various processors, various field programmable gate arrays (FPGAs), various application specific integrated circuits (ASICs), various real-time controllers, etc., and as discussed above, multiple subsystems may utilize circuits, processors, sensors, and / or other components. Additionally, the various components of vehicle control system 420 may be networked in various ways.

[0066] In some embodiments, autonomous vehicle 400 may also include a secondary vehicle control system (not shown) that may be used as a redundant or backup control system for autonomous vehicle 400. In some embodiments, the secondary vehicle control system may operate autonomous vehicle 400 in response to certain events. The secondary vehicle control system may only have limited functionality to respond to certain events detected by primary vehicle control system 420. In yet other embodiments, the secondary vehicle control system may be omitted.

[0067] In some embodiments, many different architectures including various combinations of software, hardware, circuit logic, sensors, and networks can be used to implement the various components shown in FIG. 4c. Each processor can be implemented, for example, as a microprocessor, and each memory can represent a random access memory (RAM) device including a main memory and any secondary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), and read-only memory. Each memory can also be considered to include memory storage devices physically located elsewhere in the autonomous vehicle 400, such as cache memory within the processor, and any storage capacity used as virtual memory (e.g., stored in a mass storage device or other computer controller). The processing logic 422 shown in FIG. 4c or entirely separate processing logic can be used to implement additional functions of the autonomous vehicle 400 other than those for autonomous driving control, such as controlling an entertainment system, operating doors, lights, or convenience functions, etc.

[0068] Additionally, for additional storage, autonomous vehicle 400 may also include one or more mass storage devices, such as a removable disk drive, a hard disk drive, a direct access storage device (DASD), an optical drive (e.g., CD drive, DVD drive, etc.), a solid state storage drive (SSD), a networked storage device, a storage area network, and / or a tape drive, among others. Additionally, autonomous vehicle 400 may include a user interface 464, such as, for example, one or more displays, touch screens, voice and / or gesture interfaces, buttons, and other tactile controls, that enables autonomous vehicle 400 to receive inputs from and generate outputs for the passenger. In some embodiments, inputs from the passenger may be received via an app or web interface of another computer or electronic device, such as a mobile device.

[0069] In some embodiments, the autonomous vehicle 400 may include one or more network interfaces, such as a network interface 462 adapted for communication with one or more networks 470 (e.g., a local area network (LAN), a wide area network (WAN), a wireless network, and / or the Internet, among others) to allow communication of information with other computers and electronic devices. The communication may include, for example, a central service, such as a cloud service, from which the autonomous vehicle 400 receives environmental and other data used to control the autonomous navigation of the vehicle. In some embodiments, data collected by one or more sensors 433A-433I may be uploaded via the network 470 to a computing system 472 for further processing. In such embodiments, a timestamp may be associated with each instance of vehicle data prior to upload.

[0070] 4c and various additional controllers and subsystems disclosed herein generally operate under the control of an operating system and execute or rely on various computer software applications, components, programs, objects, modules, or data structures, as described in more detail below. Additionally, the various applications, components, programs, objects, or modules may also execute on one or more processors of other computers coupled to the autonomous vehicle 400 via a network 470, such as in a distributed, cloud-based, or client-server computing environment, such that the processing required to implement the functionality of a computer program is allocated across multiple computers and / or services via the network.

[0071] The routines executed to implement the various embodiments described herein, whether embodied as part of an operating system, a particular application, component, program, object, module, or sequence of instructions, or a subset thereof, are referred to herein as "program code." Program code typically resides at various times in various memories and storage devices, and includes one or more instructions that, when read and executed by one or more processors, perform the steps necessary to carry out the steps or elements embodying various aspects of the present disclosure. Additionally, while the embodiments are described and discussed below in the context of fully functional computers and systems, it will be understood that the various embodiments described herein can be distributed as program products in a variety of forms, and that the embodiments can be embodied independently of the particular type of computer-readable medium used to actually effect such distribution. Examples of computer-readable media include tangible, non-transitory media, such as volatile and non-volatile memory devices, floppy and other removable disks, solid state drives, hard disk drives, magnetic tape, and optical disks (e.g., CD-ROM, DVD, etc.), among others.

[0072] Additionally, various program code described below may be identified based on the application for which it is embodied in a particular embodiment. However, it should be understood that any particular program nomenclature below is used merely for convenience, and thus the present invention should not be limited to use only with any particular application identified and / or implied by such nomenclature. Furthermore, when considering the typically infinite number of ways in which computer programs may be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functions are allocated among the various software layers (e.g., operating system, libraries, APIs, applications, applets, etc.) resident within a typical computer, it should be understood that the present invention is not limited to the specific organization and allocation of program functions described herein.

[0073] Those of ordinary skill in the art having the benefit of this disclosure will recognize that the exemplary environment illustrated in Figure 4c is not intended to limit the embodiments disclosed herein, and indeed, those of ordinary skill in the art will recognize that other alternative hardware and / or software environments may be used without departing from the scope of the embodiments disclosed herein.

[0074] The term "processing logic" in this disclosure (e.g., processing logic 190 or 422) may include one or more processors, microprocessors, multi-core processors, ASICs, and / or FPGAs to perform operations disclosed herein. In some embodiments, memory (not shown) is integrated into the processing logic to store instructions for performing operations and / or storing data. The processing logic may also include analog or digital circuitry for performing operations according to embodiments of the present disclosure.

[0075] A "memory" or "memories" as described in this disclosure may include one or more volatile or non-volatile memory architectures. A "memory" or "memories" may be a removable and non-removable medium embodied in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Exemplary memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, DVD (Digital Versatile Disk), high definition multimedia / data storage disks or other optical storage devices, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices or any other non-transmitting medium that can be used to store information for access by a computing device.

[0076] The network may include any network or network system, including, but not limited to, a peer-to-peer network, a local area network (LAN), a wide area network (WAN), a public network such as the Internet, a private network, a cellular network, a wireless network, a wired network, a combined wired and wireless network, and a satellite network.

[0077] The communication channel is IEEE802.11 protocol, SPI (Serial Peripheral Interface), I 2It may include or be routed by one or more wired or wireless communications utilizing an Inter-Integrated Circuit (C), Universal Serial Port (USB), Controller Area Network (CAN), cellular data protocols (e.g., 3G, 4G, LTE, 5G), optical communications networks, Internet Service Providers (ISPs), peer-to-peer networks, LANs, WANs, public networks (e.g., the “Internet”), private networks, satellite networks, and the like.

[0078] The computing device may include a desktop computer, a laptop computer, a tablet, a phablet, a smartphone, a feature phone, a server computer, or others. The server computer may be a server located remotely in a data center or stored locally.

[0079] The aforementioned processes are described in terms of computer software and hardware. The described techniques may be embodied in a tangible or non-transitory machine (e.g., computer) readable storage medium and constitute machine-executable instructions that, when executed by a machine, cause the machine to perform the described operations. Additionally, the processes may be embodied in hardware, such as ASICs.

[0080] A tangible, non-transitory, machine-readable storage medium includes any mechanism that provides (e.g., stores) information in a form accessible by a machine (e.g., a computer, a network device, a personal digital assistant, a manufacturing tool, any device having one or more processor sets, etc.). For example, machine-readable storage media include recordable / non-recordable media (e.g., ROM, RAM, magnetic disk storage media, optical storage media, flash memory devices, etc.).

[0081] The foregoing description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Although specific embodiments of, and examples for, the invention have been described herein for illustrative purposes, various modifications are possible within the scope of the invention, as one of ordinary skill in the relevant art will recognize.

[0082] Such modifications of the invention can be made in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed herein. Rather, the scope of the invention should be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.

Claims

1. a laser configured to generate light; one or more LIDAR pixels; The LIDAR pixel is a splitter configured to split the light into a first portion and a second portion; a dual polarization grating coupler configured to emit a transmit beam based on a combination of the first portion and the second portion; a first arm configured to provide the first portion from the splitter to the dual polarization grating coupler; a second arm configured to provide the second portion from the splitter to the dual polarization grating coupler; a phase shifter connected to the first arm and configured to change the phase of the first portion relative to the phase of the second portion; the transmit beams include a first transmit beam having a first polarization direction and a second transmit beam having a second polarization direction. LIDAR system.

2. an optical mixer configured to receive a third portion of the light; the dual polarization grating coupler is configured to couple reflected light having the first polarization direction into the first arm; the dual polarization grating coupler is configured to couple the reflected light having the second polarization direction into the second arm; the optical mixer is configured to output an output signal in response to the reflected light; the reflected light being a transmitted beam reflected from one or more objects within a LIDAR operating environment; 2. The LIDAR system of claim 1.

3. the splitter is coupled to the optical mixer and provides the reflected light to the optical mixer.

3. The LIDAR system of claim 2.

4. the splitter is a first 2×2 splitter; One or more of the LIDAR pixels further includes a second 2×2 splitter; the second 2×2 splitter is coupled between the first 2×2 splitter and the dual polarization grating coupler using the first arm and the second arm.

3. The LIDAR system of claim 2.

5. the polarization of the reflected light is based, at least in part, on one or more surfaces of the one or more objects; 3. The LIDAR system of claim 2.

6. the first arm is coupled between the splitter and the dual polarization grating coupler; the second arm is coupled between the splitter and the dual polarization grating coupler; the phase shifter is coupled to the first arm; 2. The LIDAR system of claim 1.

7. The first polarization direction is orthogonal to the second polarization direction.

2. The LIDAR system of claim 1.

8. a laser configured to generate light; a light detection and ranging (LIDAR) processing engine; one or more LIDAR pixels coupled to the LIDAR processing engine; The LIDAR pixel is a splitter configured to split the light into a first portion and a second portion; a dual polarization grating coupler configured to emit a transmit beam based on a combination of the first portion and the second portion; a first arm configured to provide the first portion from the splitter to the dual polarization grating coupler; a second arm configured to provide the second portion from the splitter to the dual polarization grating coupler; a phase shifter connected to the first arm and configured to change the phase of the first portion relative to the phase of the second portion; the transmit beams include a first transmit beam having a first polarization direction and a second transmit beam having a second polarization direction. Autonomous vehicle control system for autonomous vehicles.

9. an optical mixer configured to receive a third portion of the light; the dual polarization grating coupler is configured to couple reflected light having a first polarization direction into the first arm; the dual polarization grating coupler is configured to couple the reflected light having a second polarization direction into the second arm; the optical mixer is configured to output an output signal in response to the reflected light; the reflected light being a transmitted beam reflected from one or more objects within a LIDAR operating environment; 9. An autonomous vehicle control system for an autonomous vehicle according to claim 8.

10. the splitter is coupled to the optical mixer and provides the reflected light to the optical mixer.

10. An autonomous vehicle control system for an autonomous vehicle according to claim 9.

11. the splitter is a first 2×2 splitter; One or more of the LIDAR pixels further includes a second 2×2 splitter; the second 2×2 splitter is coupled between the first 2×2 splitter and the dual polarization grating coupler using the first arm and the second arm.

10. An autonomous vehicle control system for an autonomous vehicle according to claim 9.

12. the phase shifter is a first phase shifter coupled between the first 2×2 splitter and the second 2×2 splitter; At least one of the LIDAR pixels further includes a second phase shifter coupled to the first arm; the second phase shifter is coupled between the second 2×2 splitter and the dual polarization grating coupler.

12. An autonomous vehicle control system for an autonomous vehicle according to claim 11.

13. the polarization of the reflected light is based, at least in part, on one or more surfaces of the one or more objects; 10. An autonomous vehicle control system for an autonomous vehicle according to claim 9.

14. The first polarization direction is orthogonal to the second polarization direction.

9. An autonomous vehicle control system for an autonomous vehicle according to claim 8.

15. the LIDAR processing engine controls the phase shifter to increase a signal level of a beat signal based on reflected light coupled to one or more of the LIDAR pixels by the dual polarization grating coupler.

9. An autonomous vehicle control system for an autonomous vehicle according to claim 8.

16. the transmit beam is an infrared output beam; 9. An autonomous vehicle control system for an autonomous vehicle according to claim 8.

17. a laser configured to generate light; a light detection and ranging (LIDAR) processing engine; one or more LIDAR pixels coupled to the LIDAR processing engine; one or more processors; The LIDAR pixel is a splitter configured to split the light into a first portion and a second portion; a dual polarization grating coupler configured to emit a transmit beam based on a combination of the first portion and the second portion; a first arm configured to provide the first portion from the splitter to the dual polarization grating coupler; a second arm configured to provide the second portion from the splitter to the dual polarization grating coupler; a phase shifter connected to the first arm and configured to change the phase of the first portion relative to the phase of the second portion; The processor is configured to control an autonomous vehicle body based on output signals received by the LIDAR pixels; the transmit beams include a first transmit beam having a first polarization direction and a second transmit beam having a second polarization direction. Autonomous vehicles.

18. an optical mixer configured to receive a third portion of the light; the dual polarization grating coupler is configured to couple reflected light having a first polarization direction into the first arm; the dual polarization grating coupler is configured to couple the reflected light having a second polarization direction into the second arm; the optical mixer is configured to output the output signal in response to the reflected light; the reflected light being a transmitted beam reflected from one or more objects within a LIDAR operating environment; 20. The autonomous vehicle of claim 17.

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