LiDAR sensor system including dual-polarization transmitting and receiving optical antennas

Abstract

A light detection and ranging (LIDAR) sensor system includes a dual-polarization optical antenna, a single-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna is configured to (i) transmit a transmitted beam having a first polarization orientation, and (ii) detect a returned beam having a second polarization orientation. The single-polarization optical antenna is configured to detect the returned beam having a second polarization orientation.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. non-provisional application No. 17 / 848,167, filed June 23, 2022, which is incorporated herein by reference.

[0003] Background Information

[0004] Frequency-modulated continuous wave (FMCW) optical detection and ranging (LIDAR) directly measures the range and velocity of an object by emitting a frequency-modulated beam of light and detecting the returned signal. The automotive industry is currently developing autonomous functions for controlling vehicles under specific conditions. According to SAE international standard J3016, autonomy is divided into six levels, from level 0 (no autonomy) to level 5 (the vehicle can operate without operator input under any conditions). Vehicles with autonomous features utilize sensors to perceive the environment through which they navigate. Acquiring and processing data from sensors allows the vehicle to navigate its environment. Summary of the Invention

[0005] Embodiments of this disclosure include a light detection and ranging (LIDAR) sensor system comprising one or more LIDAR pixels. At least one of the one or more LIDAR pixels may include a dual-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna may be configured to (i) transmit a transmitted light beam having a first polarization orientation, and (ii) detect a returned light beam having a second polarization orientation. The first receiver may be configured to generate a first signal in response to receiving the second polarization orientation of the returned light beam and in response to a first local oscillator signal. The second receiver may be configured to generate a second signal in response to receiving the second polarization orientation of the returned light beam from the dual-polarization optical antenna and in response to a second local oscillator signal.

[0006] In one embodiment, the dual-polarization optical antenna includes a two-dimensional (2D) polarization-separating grating coupler, which includes a first port and a second port. The 2D polarization-separating grating can be configured to receive a transmitted signal at the first port and can be configured to provide a return beam with a second polarization to the second port coupled to a second receiver.

[0007] In one implementation, the LIDAR sensor system also includes a single-polarization optical antenna configured to detect a returning beam having a second polarization orientation. The single-polarization optical antenna is coupled to a first receiver to provide the first receiver with the second polarization orientation of the returning beam.

[0008] In this implementation, the single-polarization optical antenna is a one-dimensional (1D) polarization grating coupler.

[0009] In this implementation, the dual-polarization optical antenna is offset from the single-polarization optical antenna by a specific distance.

[0010] In this implementation, the first polarization orientation is orthogonal to the second polarization orientation.

[0011] In one implementation, the LIDAR sensor system also includes a single-polarization optical antenna configured to detect a returning beam with a second polarization orientation.

[0012] In one implementation, the first local oscillator signal is polarized with a third polarization orientation, the second local oscillator signal is polarized with a third polarization orientation, and the transmitted signal is polarized with a third polarization before transmission. The dual-polarization optical antenna can be configured to couple the transmitted signal into free space as a transmitted beam.

[0013] In one implementation, the dual-polarization optical antenna is configured to couple the returned beam into at least one of one or more LiDAR pixels as a returned signal. The returned signal can be polarized with a third polarization orientation.

[0014] In an implementation, the third polarization orientation is either the first polarization orientation or the second polarization orientation.

[0015] In one embodiment, the first receiver includes a first optical mixer and the second receiver includes a second optical mixer. The first receiver may include a first diode pair coupled to the first optical mixer and configured to provide a first electrical signal. The first electrical signal may be a first signal. The second receiver may include a second diode pair coupled to the second optical mixer and configured to provide a second electrical signal. The second electrical signal may be a second signal.

[0016] In this implementation, the transmitted beam and the returned beam are narrowband near-infrared wavelengths.

[0017] In this implementation, the returned beam is the transmitted beam reflected from the object.

[0018] Embodiments of this disclosure include an autonomous vehicle control system for an autonomous vehicle. The autonomous vehicle control system may include a light detection and ranging (LIDAR) device and one or more processors. The LIDAR device may include one or more LIDAR pixels. At least one of the one or more LIDAR pixels may include a dual-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna may be configured to (i) transmit a transmitted light beam having a first polarization orientation, and (ii) detect a returned light beam having a second polarization orientation. The first receiver may be configured to generate a first electrical signal in response to receiving the second polarization orientation of the returned light beam and in response to a first local oscillator signal. The second receiver may be configured to generate a second electrical signal in response to receiving the second polarization orientation of the returned light beam from the dual-polarization optical antenna and in response to a second local oscillator signal. One or more processors may be configured to control the autonomous vehicle in response to the first and second electrical signals.

[0019] In one embodiment, the dual-polarization optical antenna includes a two-dimensional (2D) polarization-separating grating coupler having a first port and a second port. The 2D polarization-separating grating can be configured to receive a transmitted signal at the first port and to provide a return beam with a second polarization to the second port coupled to a second receiver.

[0020] In one embodiment, at least one of the one or more LIDAR pixels further includes a single-polarization optical antenna configured to detect a returning beam having a second polarization orientation. The single-polarization optical antenna is capable of being coupled to a first receiver to provide the first receiver with the second polarization orientation of the returning beam.

[0021] In this implementation, the single-polarization optical antenna is a one-dimensional (1D) polarization grating coupler.

[0022] In this implementation, the dual-polarization optical antenna is offset from the single-polarization optical antenna by a specific distance.

[0023] In one implementation, the autonomous vehicle control system further includes a rotating mirror and a birefringent plate. The rotating mirror can be configured to guide a transmitted beam into the LIDAR environment and to guide a returned beam onto at least one of one or more LIDAR pixels. The birefringent plate can be located between the rotating mirror and at least one of the one or more LIDAR pixels. The birefringent plate can be configured to guide a returned beam with a second polarization orientation onto a single-polarization optical antenna or a dual-polarization optical antenna.

[0024] Embodiments of this disclosure include autonomous vehicles. The autonomous vehicle may include a light detection and ranging (LIDAR) device and one or more processors. The LIDAR device may include one or more LIDAR pixels. At least one of the one or more LIDAR pixels may include a dual-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna may be configured to (i) transmit a transmitted light beam having a first polarization orientation, and (ii) detect a returned light beam having a second polarization orientation. The first receiver may be configured to generate a first electrical signal in response to receiving the second polarization orientation of the returned light beam and in response to a first local oscillator signal. The second receiver may be configured to generate a second electrical signal in response to receiving the second polarization orientation of the returned light beam from the dual-polarization optical antenna and in response to a second local oscillator signal. One or more processors may be configured to control the autonomous vehicle in response to the first and second signals.

[0025] Embodiments of this disclosure include a light detection and ranging (LIDAR) sensor system comprising one or more LIDAR pixels. At least one of the one or more LIDAR pixels may include a dual-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna may be configured to (i) transmit a transmitted light beam having a first polarization orientation, and (ii) detect a returned light beam having a second polarization orientation. The first receiver may be configured to generate a first signal in response to receiving the second polarization orientation of the returned light beam and in response to a first local oscillator signal. The second receiver may be configured to generate a second signal in response to receiving the second polarization orientation of the returned light beam from the dual-polarization optical antenna and in response to a second local oscillator signal.

[0026] In one embodiment, the dual-polarization optical antenna includes a two-dimensional (2D) polarization-separating grating coupler, which includes a first port and a second port. The 2D polarization-separating grating can be configured to receive a transmitted signal at the first port and can be configured to provide a return beam with a second polarization to the second port coupled to a second receiver.

[0027] In one implementation, the LIDAR sensor system also includes a single-polarization optical antenna configured to detect a returning beam having a second polarization orientation. The single-polarization optical antenna can be coupled to a first receiver to provide the first receiver with the second polarization orientation of the returning beam.

[0028] In this implementation, the single-polarization optical antenna is a one-dimensional (1D) polarization grating coupler.

[0029] In this implementation, the dual-polarization optical antenna is offset from the single-polarization optical antenna by a specific distance.

[0030] In this implementation, the first polarization orientation is orthogonal to the second polarization orientation.

[0031] In one implementation, the LIDAR sensor system also includes a single-polarization optical antenna configured to detect a returning beam with a second polarization orientation.

[0032] In one implementation, the first local oscillator signal is polarized with a third polarization orientation, the second local oscillator signal is polarized with a third polarization orientation, and the transmitted signal is polarized with a third polarization before transmission. The dual-polarization optical antenna can be configured to couple the transmitted signal into free space as a transmitted beam.

[0033] In one implementation, the dual-polarization optical antenna is configured to couple the returned beam into at least one of one or more LiDAR pixels as a return signal. The return signal may be polarized with a third polarization orientation.

[0034] In an implementation, the third polarization orientation is either the first polarization orientation or the second polarization orientation.

[0035] In one embodiment, the first receiver includes a first optical mixer and the second receiver includes a second optical mixer. The first receiver may include a first diode pair coupled to the first optical mixer and configured to provide a first electrical signal. The first electrical signal may be a first signal. The second receiver may include a second diode pair coupled to the second optical mixer and configured to provide a second electrical signal. The second electrical signal may be a second signal.

[0036] In this implementation, the transmitted beam and the returned beam are narrowband near-infrared wavelengths.

[0037] In this implementation, the returned beam is the transmitted beam reflected from the object.

[0038] Embodiments of this disclosure include an autonomous vehicle control system for an autonomous vehicle. The autonomous vehicle control system may include a light detection and ranging (LIDAR) device and one or more processors. The LIDAR device may include one or more LIDAR pixels. At least one of the one or more LIDAR pixels may include a dual-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna may be configured to (i) transmit a transmitted light beam having a first polarization orientation, and (ii) detect a returned light beam having a second polarization orientation. The first receiver may be configured to generate a first electrical signal in response to receiving the second polarization orientation of the returned light beam and in response to a first local oscillator signal. The second receiver may be configured to generate a second electrical signal in response to receiving the second polarization orientation of the returned light beam from the dual-polarization optical antenna and in response to a second local oscillator signal. One or more processors may be configured to control the autonomous vehicle in response to the first and second electrical signals.

[0039] In one embodiment, the dual-polarization optical antenna includes a two-dimensional (2D) polarization-separating grating coupler having a first port and a second port. The 2D polarization-separating grating can be configured to receive a transmitted signal at the first port and to provide a return beam with a second polarization to the second port coupled to a second receiver.

[0040] In one embodiment, at least one of the one or more LIDAR pixels further includes a single-polarization optical antenna configured to detect a returning beam having a second polarization orientation. The single-polarization optical antenna is capable of being coupled to a first receiver to provide the first receiver with the second polarization orientation of the returning beam.

[0041] In this implementation, the single-polarization optical antenna is a one-dimensional (1D) polarization grating coupler.

[0042] In this implementation, the dual-polarization optical antenna is offset from the single-polarization optical antenna by a specific distance.

[0043] In one implementation, the autonomous vehicle control system further includes a rotating mirror and a birefringent plate. The rotating mirror can be configured to guide a transmitted beam into the LIDAR environment and to guide a returned beam onto at least one of one or more LIDAR pixels. The birefringent plate can be located between the rotating mirror and at least one of the one or more LIDAR pixels. The birefringent plate can be configured to guide a returned beam with a second polarization orientation onto a single-polarization optical antenna or a dual-polarization optical antenna.

[0044] Embodiments of this disclosure include autonomous vehicles. The autonomous vehicle may include a light detection and ranging (LIDAR) device and one or more processors. The LIDAR device may include one or more LIDAR pixels. At least one of the one or more LIDAR pixels may include a dual-polarization optical antenna, a first receiver, and a second receiver. The dual-polarization optical antenna may be configured to (i) transmit a transmitted light beam having a first polarization orientation, and (ii) detect a returned light beam having a second polarization orientation. The first receiver may be configured to generate a first electrical signal in response to receiving the second polarization orientation of the returned light beam and in response to a first local oscillator signal. The second receiver may be configured to generate a second electrical signal in response to receiving the second polarization orientation of the returned light beam from the dual-polarization optical antenna and in response to a second local oscillator signal. One or more processors may be configured to control the autonomous vehicle in response to the first and second signals. Attached Figure Description

[0045] Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following drawings, wherein, unless otherwise stated, the same reference numerals refer to the same parts in the various views.

[0046] Figure 1 A LiDAR system including LiDAR pixels according to an embodiment of the present disclosure is shown.

[0047] Figure 2A and Figure 2B An example of a coherent receiver according to an embodiment of the present disclosure is shown.

[0048] Figure 3 A LiDAR system including LiDAR pixels, a birefringent plate, and a rotating mirror according to an embodiment of the present disclosure is shown.

[0049] Figure 4A A block diagram illustrating an example of a system environment for an autonomous vehicle according to an embodiment of the present disclosure is shown.

[0050] Figure 4B A block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure is shown.

[0051] Figure 4C A block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure is shown.

[0052] Figure 4D A block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure is shown. Detailed Implementation

[0053] This document describes an implementation of a LIDAR pixel with dual-polarization transmit / receive optical antennas. The LIDAR pixel can include one or more modules, one or more integrated chips, or one or more circuits. Furthermore, the LIDAR pixel can be implemented as a single packaged chip or as a modular design, such that the LIDAR pixel includes multiple packaged chips. In the following description, numerous specific details are set forth to provide a thorough understanding of the implementation. However, those skilled in the art will recognize that the techniques described herein can be practiced without one or more of these specific details or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring certain aspects.

[0054] The references to "one embodiment" or "implementation" in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0055] Several technical terms are used in this specification. These terms should be used in their ordinary sense in the field of their respective domains, unless otherwise expressly defined herein or the context of their use clearly implies otherwise. For the purposes of this specification, the term "autonomous vehicle" includes vehicles that possess autonomous characteristics of any level of autonomy as defined in SAE International Standard J3016.

[0056] In various aspects of this disclosure, visible light can be defined as having a wavelength range of about 380 nm to 700 nm. Non-visible light can be defined as light with wavelengths outside the visible light range, such as ultraviolet light and infrared light. Infrared light with a wavelength range of about 700 nm to 1 mm includes near-infrared light. In various aspects of this disclosure, near-infrared light can be defined as having a wavelength range of about 700 nm to 1600 nm.

[0057] Frequency-modulated continuous wave (FMCW) LiDAR directly measures the range and velocity of an object or target by sending a frequency-modulated beam of light. The light reflected from the object / target can be combined with a tapped version of the beam. Once the Doppler shift required for the second measurement is corrected, the frequency of the resulting beat signal is proportional to the distance between the object and the LiDAR system. The two measurements, which can be performed simultaneously or separately, provide both range and velocity information.

[0058] Embodiments of this disclosure include a LIDAR device comprising a LIDAR pixel having an optical antenna, a receiving optical antenna, a first receiver, and a second receiver. The optical antenna is a dual-polarization optical antenna that transmits a beam of light with a first polarization orientation and detects a returning beam with a second polarization orientation. The receiving optical antenna may be coupled to the first receiver to provide a returning beam with a second polarization orientation. The dual-polarization optical antenna may be coupled to the second receiver to provide a returning beam with a second polarization orientation. The first receiver generates a first signal in response to receiving the second polarization orientation of the returning beam detected by the receiving optical antenna, and the second receiver generates a second signal in response to receiving the second polarization orientation of the returning beam detected by the dual-polarization optical antenna. Detecting the returning beam at an offset from the transmitting antenna can increase the signal-to-noise ratio (SNR) of the detected returning beam and thus increase the imaging quality of the LIDAR system. Additionally, detecting the returning beam at two different locations can allow the LIDAR system to detect additional information about the external environment, such as objects located over a larger area within the external environment of the LIDAR system. Figures 1 to 4D These and other implementation methods will be described in more detail.

[0059] Figure 1A LiDAR system 100 including LiDAR pixels 102 according to an embodiment of the present disclosure is shown. According to the embodiment, the LiDAR pixel 102 includes an optical antenna 104, a receiving optical antenna 106, a first coherent receiver 121, and a second coherent receiver 126. However, the present invention is not limited to this. Figure 1 The specific LIDAR pixel architecture shown is applicable. LIDAR pixels can be implemented using any suitable chip design architecture. For example, the transmitting and receiving optical antennas can be implemented as a single module or a single integrated chip, or as separate modules or chips. As another example, the first and second coherent receivers can be implemented as a single module or a single integrated chip, or as separate modules or chips. Optical antenna 104 can be configured to transmit a beam with a first polarization orientation and can be configured to detect a return beam with a second polarization orientation. Receiving optical antenna 106 can be positioned at a distance D from optical antenna 104 to account for or compensate for beam drift caused by the LIDAR system's rotating mirrors. The transmitting beam can be an infrared transmitting beam. The transmitting beam can be a near-infrared transmitting beam. The transmitting beam can be transmitted as a single, defined polarization orientation. Figure 1 In this embodiment, the optical antenna 104 is shown as a dual-polarization optical coupler and can transmit a transmission beam in response to receiving a transmission signal 108 through the waveguide 109. The transmission signal 108 can be generated by a laser, and the transmission beam emitted by the optical antenna 104 can have a very narrow linewidth (e.g., 1 nm or less).

[0060] In some embodiments, the optical antenna 104 may include a dual-polarization transmit / receive optical antenna, which can be configured to transmit a signal having a first polarization orientation and can be configured to (e.g., simultaneously) detect a return beam having a second polarization orientation. The return beam may be a reflection of the transmitted beam reflected from an object in the external environment of the LIDAR system 100. The first polarization orientation may be orthogonal to the second polarization orientation. In some embodiments, the orthogonality can have a margin greater than 0 to 10%. For example, if the first polarization orientation has an angle between 80 and 100 degrees relative to the second polarization orientation, it can be defined as orthogonal. The optical antenna 104 may be implemented as a two-dimensional (2D) polarization-separating grating coupler with two ports. The first port of the optical antenna 104 may be coupled to transmit a signal 108 using waveguide 109 so that the optical antenna 104 can transmit a transmitted beam having the first polarization orientation. The second port of the optical antenna 104 may be coupled to a second coherent receiver 126 using waveguide 110 so that the optical antenna 104 can provide the second polarization orientation of the return signal to the second coherent receiver 126. Optical antenna 104 can be configured to couple a return beam from free space into waveguide 110 as a return signal propagating through waveguide 110 to coherent receiver 126. When in LIDAR pixel 102 (e.g., when on-chip), the return signal can have the same polarization orientation as the transmit signal TX and local oscillator signal LO2. According to embodiments, the polarization orientations of the return signal, transmit signal TX, local oscillator signal LO1, and local oscillator signal LO2 can be the same as a first polarization orientation or a second polarization orientation, or they can be completely different polarization orientations. According to embodiments, the first polarization orientation can be positive 45 degrees, and the second polarization orientation can be negative 45 degrees (e.g., linear TE or TM polarization).

[0061] The receiving optical antenna 106 can be implemented as a single-polarization grating coupler. The receiving optical antenna 106 can be rotated to receive and detect (e.g., coupled into a waveguide) the second polarization orientation of the returning beam. The receiving optical antenna 106 can be rotated to receive light polarized at a negative 45 degrees. The receiving optical antenna 106 can be offset by a distance D from the position of the optical antenna 104, so that the receiving optical antenna 106 can compensate for beam drift, for example, as... Figure 3 As shown. The receiving optical antenna 106 can be coupled to the first coherent receiver 121 via waveguide 112 to provide a second polarization orientation of the returned beam to the first coherent receiver 121.

[0062] In some embodiments, the first coherent receiver 121 may be configured to generate a first signal 123 in response to receiving a second polarization orientation of the returned beam and a first local oscillator signal (LO1) 131. The first local oscillator signal 131 may be an optical signal having a second polarization orientation. Figure 1 In this embodiment, the first coherent receiver 121 receives the second polarization orientation of the returned beam from the receiving optical antenna 106 via waveguide 112, and the first coherent receiver 121 receives the first local oscillator signal 131 via waveguide 132. The first signal 123 may be an electrical signal provided to the processing logic 150 via communication channel 122.

[0063] In some embodiments, the second coherent receiver 126 may be configured to generate a second signal 128 in response to receiving a second polarization orientation and a second local oscillator signal (LO2) 136 of the returned beam. The second local oscillator signal 136 may be an optical signal having a second polarization orientation. Figure 1 In this embodiment, the second coherent receiver 126 receives the second polarization orientation of the returned beam from the optical antenna 104 via the waveguide 110, and the second coherent receiver 126 receives the second local oscillator signal 136 via the waveguide 137. The second signal 128 may be an electrical signal provided to the processing logic 150 via the communication channel 127.

[0064] In some embodiments, processing logic 150 may be configured to generate image 155 in response to receiving a first signal 123 and a second signal 128 from a first coherent receiver 121 and a second coherent receiver 126, respectively. The LIDAR system 100 may include an array of LIDAR pixels 102 configured to provide the processing logic 150 with the first signal (e.g., signal 123) and the second signal (e.g., signal 128). In this case, processing logic 150 may generate image 155 in response to the first and second signals received by the processing logic 150 from a plurality of LIDAR pixels 102 in the LIDAR pixel array.

[0065] In the operational example, the transmit signal 108 can be emitted into free space by the optical antenna 104 as a transmit beam. The transmit beam can propagate through one or more lenses and be deflected by a rotating mirror, then propagate through the external environment until it encounters an object. A portion of the transmit beam that encounters the object can be reflected back towards the LIDAR system 100 and LIDAR pixels 102 as a return beam. The return beam can be reflected from the rotating mirror and propagate through one or more lenses, but is offset relative to the optical antenna 104 due to the time difference of the mirror rotation. To compensate for this offset, the receiving optical antenna 106 can be offset by a distance D from the optical antenna 104.

[0066] Figure 2A and Figure 2B Coherent receivers 121 and 126 according to embodiments of the present disclosure are shown. Figure 1 (See the example shown).

[0067] Figure 2A A coherent receiver 200 is shown. The coherent receiver 200 may include an optical mixer 202, a return beam port 204, a local oscillator port 208, and an output port 212. According to one embodiment, the optical mixer 202 is configured to combine the return beam signal RB with the local oscillator signal LO to generate an output signal OUT. The optical mixer 202 may be configured to receive two or more optical signals. The optical mixer 202 may be coupled to receive the return beam signal RB from the return beam port 204 via waveguide 206. According to one embodiment, the optical mixer 202 may be coupled to receive the local oscillator signal LO from the local oscillator port 208 via waveguide 210. The optical mixer 202 may combine input signals to generate multiple combined output signals OUT1 and OUT2. The number of output signals from the optical mixer can be any suitable number, and is not limited to a specific number. According to one embodiment, output signals OUT1 and OUT2 are provided to a pair of photodiodes (including photodiodes PD1 and PD2) to convert the return beam signal RB and the local oscillator signal LO into the output signal OUT. The output signal OUT can be an electrical signal. The output signal OUT can also be a beat frequency signal representing the range and / or velocity of one or more objects in the environment of the LIDAR system. Each of these variations in the output signal OUT can provide information about the object's characteristics (e.g., distance, reflectivity) in the environment from which the beam of light is reflected back. For example, object characteristics (e.g., distance, reflectivity) can enable an autonomous vehicle (e.g., a truck) to perform vehicle operations (e.g., stop, steer, ignore) based on these object characteristics. Each output signal can be provided to a corresponding receiver among multiple receivers to enable concurrent reception and processing of multiple output signals.

[0068] Figure 2BAn example of a coherent receiver 230 with an optical mixer 232 according to an embodiment is shown. The optical mixer 232 is configured to provide multiple output signals OUT3, OUT4, OUT5, and OUT6 based on a return beam signal RB and a local oscillator signal LO. However, the number of output signals from the optical mixer can be any suitable number, and is not limited to a specific number. According to an embodiment, the optical mixer 232 provides signals OUT3, OUT4, OUT5, and OUT6 to a photodiode configuration that converts the mixed signals into an in-phase output signal OUT_I and a quadrature output signal OUT_Q. The in-phase output signal OUT_I can be provided to output port 234, and the quadrature output signal OUT_Q can be provided to output port 236. The photodiode configuration may include photodiodes PD3, PD4, PD5, and PD6.

[0069] Figure 3 An example of a LIDAR system 300 according to an embodiment of the present disclosure is shown, illustrating how LIDAR pixels 102 can be used to compensate for beam drift and support beam scanning.

[0070] In an operational example, optical antenna 104 can emit light as a transmitted beam 302 with a first polarization orientation (e.g., linearly polarized at 45 degrees). The transmitted beam 302 can propagate through birefringent plate 304, which introduces a small offset 306 in the position of the transmitted beam 302 relative to optical antenna 104. The transmitted beam 302 can be collimated by lens 308 and guided to mirror 310. Lens 308 can be positioned between birefringent plate 304 and mirror 310. Mirror 310 can be selectively rotated or configured to rotate continuously to scan the LIDAR environment. The transmitted beam 302 can be reflected by mirror 310 and guided into the LIDAR environment as a free-space beam. The transmitted beam 302 can propagate to object 312 and can be reflected back as a return beam 314. Object 312 can be a reflective surface, a diffuse surface, or a partially reflective and partially diffuse surface. Object 312 can change the polarization orientation / characteristics of the return beam 314 to be different from the polarization orientation of the transmitted beam 302. For example, the polarization of the return beam 314 can be randomized. The return beam 314 may include several polarization orientation components (e.g., circular, elliptical, linear). As an example, the return beam 314 may include a light component with a second polarization orientation (e.g., linear polarization -45°) that is, for example, orthogonal to the first polarization orientation (e.g., linear polarization +45°) of the transmitted beam 302. Upon reflection, the return beam 314 propagates back to mirror 310.

[0071] During the transmission time of the transmitted beam 302 and the returned beam 314 to the object 312 and back to the mirror 310, the mirror 310 may have rotated slightly. The amount of rotation will vary based on the distance traveled by the transmitted beam 302 and the returned beam 314. Due to the rotation of the mirror 310, the returned beam 314 may be incident on the lens 308 at a different angle than the transmitted beam 302. This change in position of the returned beam 314 on the mirror 310 may cause the returned beam 314 to drift away from or miss the optical antenna 104. However, the LIDAR pixel 102 includes a receiving optical antenna 106, so if the returned beam 314 returns with an offset away from the optical antenna 104 and becomes incident on the receiving optical antenna 106, the LIDAR pixel 102 can receive the returned beam 314 with a second polarization orientation.

[0072] According to one embodiment, upon returning to the LIDAR pixel 102, the birefringent plate 304 can guide the return beam 314 towards different positions on the LIDAR pixel 102 based on the polarization characteristics of the return beam 314. The return beam 314 can be guided through the birefringent plate 304, which horizontally offsets the return beam 314 in space. If the polarization of the return beam 314 differs from the polarization of the transmitted beam 302, the offset introduced by the birefringent material can be different. According to one embodiment, the birefringent plate 304 can be configured to guide the return beam 314 to a position on the LIDAR pixel 102 based on the polarization orientation or characteristics of the return beam 314. According to one embodiment, the birefringent plate 304 can be configured to guide the return beam 314 along an optical path different from the transmitted beam 302 based on the polarization of the two signals to reduce signal interference.

[0073] In some embodiments, by selecting a specific birefringent material and controlling the thickness 322 and angle 324 of the birefringent plate 304, the relative offset of the transmitted and returned beams can be controlled. Figure 3 In the illustration, the birefringent material is angled relative to the transmitted light beam 302 incident on the birefringent plate 304, and the birefringent plate 304 is tilted relative to the returned light beam 314 incident on the birefringent material. In an embodiment, the tilt angle 324 and the thickness 322 of the birefringent plate 304 are configured to detect objects at a detection distance of 50 meters or greater.

[0074] In some embodiments, the birefringent plate 304 may include LiNO3 (lithium nitrate). In some embodiments, the birefringent plate 304 may include YVO4 (yttrium orthovanadate). However, the material used for the birefringent plate is not limited to the above-mentioned materials. Any suitable material can be used for the birefringent plate to optimally correct for drift introduced by the rotating mirror over a wide range of object distances. For example, optimizing for longer range targets may include selecting a birefringent material that exhibits a large horizontal offset due to the long round-trip time of the beam reflecting from the target and propagating back to the receiving optical antennas 104, 106.

[0075] The tilting element of the birefringent plate 304 can be part of a lens assembly or a chip package assembly. It can be integrated onto the same photonic chip as the coherent pixel array. Multiple coherent pixels and tilted birefringent elements can be used together to achieve more complex operation of the FMCW LIDAR. In some embodiments, the birefringent element can be motorized to change the tilt angle 324. In some embodiments of the LIDAR system 300, the birefringent plate 304 is omitted between the LIDAR pixel 102 and the lens 308. In some embodiments, one or more optical elements are located between the mirror 310 and the LIDAR pixel 102 to manipulate the polarization characteristics of the transmitted beam 302 and the returned beam 314. For example, one or more half-wave plates or quarter-wave plates can be included to change the polarization from linear to circular (or vice versa) and to orthogonally shift the orientation.

[0076] 1. System environment for autonomous vehicles

[0077] Figure 4A This is a block diagram illustrating an example of the system environment of an autonomous vehicle according to some implementation methods.

[0078] See Figure 4A An example autonomous vehicle 410A may be implemented, incorporating various technologies disclosed herein. For example, vehicle 410A may include: a powertrain 492 comprising a prime mover 94 driven by energy source 496 and capable of supplying power to transmission system 498; and a control system 80 comprising steering control 482, powertrain control 84, and braking control 486. Vehicle 410A can be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or goods and capable of operating in a variety of environments, and it should be understood that the aforementioned components 480-498 can vary widely depending on the type of vehicle in which these components are used.

[0079] For simplicity, the embodiments discussed below will focus on wheeled land vehicles, such as cars, vans, trucks, buses, etc. In such embodiments, the prime mover 494 may include one or more electric motors and / or internal combustion engines (etc.). Energy sources may include, for example, fuel systems (e.g., providing gasoline, diesel, hydrogen, etc.), battery systems, solar panels or other renewable energy sources, and / or fuel cell cell systems. The drivetrain 498 may include wheels and / or tires, as well as a transmission and / or any other mechanical drive components to convert the output of the prime mover 494 into vehicle motion, and one or more brakes configured to controllably stop or slow down the vehicle 410A, and directional or steering components suitable for controlling the trajectory of the vehicle 410A (e.g., rack and pinion steering linkages that enable one or more wheels of the vehicle 410A to pivot about a generally vertical axis to change the angle of the wheel's plane of rotation relative to the vehicle's longitudinal axis). In some embodiments, a combination of powertrain and energy source may be used (e.g., in the case of an electric / gas hybrid vehicle), and in some cases, multiple electric motors (e.g., dedicated to individual wheels or axles) may be used as prime movers.

[0080] The steering controller 482 may include one or more actuators and / or sensors for controlling and receiving feedback from the steering or directional components to enable the vehicle 410A to follow a desired trajectory. The powertrain control 484 may be configured to control the output of the powertrain 492, for example, controlling the output power of the prime mover 494 to control the gear position of the transmission in the drivetrain 498, thereby controlling the speed and / or direction of the vehicle 410A. The braking control 486 may be configured to control one or more brakes that slow down or stop the vehicle 410A, such as disc brakes or drum brakes coupled to the wheels of the vehicle.

[0081] Other vehicle types (including but not limited to off-road vehicles, all-terrain or tracked vehicles, construction equipment, etc.) will inevitably use different powertrains, drivetrains, energy sources, steering control, powertrain control, and braking control. Furthermore, in some embodiments, certain components can be combined; for example, vehicle steering control is primarily handled by altering the output of one or more prime movers. Therefore, the embodiments disclosed herein are not limited to the specific applications of the techniques described herein in autonomous wheeled land vehicles.

[0082] Various levels of autonomous control of the vehicle 410A can be achieved in the vehicle control system 420, which may include one or more processors 422 and one or more memories 424, each processor 422 being configured to execute program code instructions 426 stored in the memory 424. The processor may include, for example, a graphics processing unit (“GPU”) and / or a central processing unit (“CPU”).

[0083] Sensor 430 may include various sensors suitable for collecting information from the vehicle's surrounding environment for controlling the vehicle's operation. For example, sensor 430 may include a radar sensor 434, a LiDAR (Light Detection and Ranging) sensor 436, a 3D positioning sensor 438, such as an accelerometer, gyroscope, magnetometer, or any of a satellite navigation system (such as GPS, GLONASS, BeiDou Navigation Satellite System, Galileo, compass, etc.). The 3D positioning sensor 438 can be used to determine the vehicle's position on Earth using satellite signals. Sensor 430 may include a camera 440 and / or an IMU (Inertial Measurement Unit) 442. The camera 440 may be a single-frame or stereo camera and capable of recording still and / or video images. The IMU 442 may include multiple gyroscopes and accelerometers capable of detecting the vehicle's linear and rotational motion 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 vehicle 410A. Each sensor 430 is capable of outputting sensor data at various data rates, which may differ from the data rates of other sensors 430.

[0084] The output of sensor 430 can be provided to a set of control subsystems 450, including a positioning subsystem 452, a planning subsystem 456, a perception subsystem 454, and a control subsystem 458. The positioning subsystem 452 is capable of functions such as accurately determining the position and orientation (sometimes referred to as "pose") of vehicle 410A in its surrounding environment, typically within a reference frame. As part of generating labeled autonomous vehicle data, the position of the autonomous vehicle can be compared with the positions of additional vehicles in the same environment. The perception subsystem 454 is capable of functions such as detecting, tracking, identifying, and / or recognizing objects in the environment surrounding vehicle 410A. Machine learning models can be used to track objects. The planning subsystem 456 is capable of functions such as planning a trajectory for vehicle 410A within a time frame, given a desired destination and static and moving objects within the environment. Machine learning can be used to plan vehicle trajectories. The control subsystem 458 is capable of functions such as generating appropriate control signals to control various controls in the vehicle control system 420 to achieve the planned trajectory of vehicle 410A. It can use machine learning models to generate one or more signals to control autonomous vehicles to implement planned trajectories.

[0085] It should be understood that Figure 4AThe assembly of components of the vehicle control system 420 shown is merely exemplary in nature. In some embodiments, individual sensors may be omitted. Additionally or alternatively, in some embodiments, sensors may be used... Figure 4A Multiple sensors of the type shown are used to achieve redundancy and / or coverage of different areas around the vehicle, and other types of sensors can be used. Similarly, different types and / or combinations of control subsystems can be used in other embodiments. Furthermore, although subsystems 452-458 are shown as separate from processor 422 and memory 424, it should be understood that in some embodiments, some or all of the functionality of subsystems 452-458 can be implemented using program code instructions 426 residing in one or more memories 424 and executed by one or more processors 422, and these subsystems 452-458 may, in some cases, be implemented using the same processor and / or memory. Subsystems can be implemented, at least in part, using various application-specific circuit logics, various processors, various field-programmable gate arrays (“FPGAs”), various application-specific integrated circuits (“ASICs”), various real-time controllers, etc., and as mentioned above, multiple subsystems can utilize circuit systems, processors, sensors, and / or other components. Furthermore, the various components in the vehicle control system 420 can be networked in various ways.

[0086] In some embodiments, vehicle 410A may further include an auxiliary vehicle control system (not shown), which can serve as a redundancy or backup control system for vehicle 410A. The auxiliary vehicle control system is capable of fully operating the autonomous vehicle 410A in the event of an adverse event in vehicle control system 420. In other embodiments, the auxiliary vehicle control system may have only limited functionality, such as controlled stopping of vehicle 410A in response to an adverse event detected in primary vehicle control system 420. In other embodiments, the auxiliary vehicle control system may be omitted.

[0087] Generally speaking, countless different architectures can be used to implement this. Figure 4A The various components shown represent numerous different architectures, including various combinations of software, hardware, circuit logic, sensors, networks, etc. For example, each processor can be implemented as a microprocessor, and each memory can represent a random access memory (“RAM”) device, including main memory and any supplementary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), read-only memory, etc. Furthermore, each memory can be considered to include memory storage physically located elsewhere in the vehicle 410A, such as any cache memory within the processor, and any storage capacity used as virtual memory, such as storage on a mass storage device or another computer controller. Figure 4AOne or more processors, or completely independent processors, shown can be used in vehicle 410A to implement additional functionality beyond autonomous control purposes, such as controlling the entertainment system, operating doors, lights, convenience features, etc.

[0088] In addition, for additional storage, the vehicle 410A may include one or more mass storage devices, such as removable disk drives, hard disk drives, direct access storage devices (“DASD”), optical disc drives (e.g., CD drives, DVD drives, etc.), solid-state storage drives (“SSD”), network attached storage, storage area networks, and / or tape drives, etc.

[0089] Furthermore, vehicle 410A may include a user interface 464 to enable vehicle 410A to receive multiple inputs from a user or operator and generate outputs for the user or operator, such as one or more displays, touchscreens, voice and / or gesture interfaces, buttons, and other tactile controls. Alternatively, user input may be received via another computer or electronic device, such as via an application on a mobile device or via a web interface.

[0090] Furthermore, vehicle 410A may include one or more network interfaces, such as network interface 462, which is adapted to communicate with one or more networks 470 (e.g., local area network (“LAN”), wide area network (“WAN”), wireless network, and / or the Internet, etc.) to allow communication of information with other computers and electronic devices, including, for example, a central service such as a cloud service, from which vehicle 410A receives environmental and other data for its autonomous control. Data collected by one or more sensors 430 can be uploaded via network 470 to computing system 472 for ancillary processing. A timestamp can be added to each instance of vehicle data before uploading.

[0091] Figure 4A Each processor shown, as well as the various additional controllers and subsystems disclosed herein, typically operates under the control of an operating system and executes or otherwise depends on various computer software applications, components, programs, objects, modules, data structures, etc., as will be described in more detail below. Furthermore, the various applications, components, programs, objects, modules, etc., can also execute on one or more processors in another computer coupled to vehicle 410A via network 470, for example, in a distributed, cloud-based, or client-server computing environment, thereby distributing the processing required to implement the functions of the computer program to multiple computers and / or services on the network.

[0092] Generally, routines executed to implement the various embodiments described herein, whether as part of an operating system or as a particular application, component, program, object, module, or sequence of instructions, or even a subset thereof, are referred to herein as "program code." Program code can include one or more instructions that reside at different times in various memories and storage devices, and when read and executed by one or more processors, perform the steps or elements necessary to embody the aspects of this disclosure. Furthermore, while embodiments have been described and will be described below in the context of fully functional computer and systems, it should be understood that the various embodiments described herein can be distributed as program products in various forms, and can be implemented regardless of the specific type of computer-readable medium used for actual distribution.

[0093] Examples of computer-readable media include tangible, non-transitory media—such as volatile and non-volatile memory devices, floppy disks and other removable disks, solid-state drives, hard disk drives, magnetic tapes and optical discs (e.g., CD-ROMs, DVDs, etc.), and so on.

[0094] Furthermore, the various program codes described below can be identified according to their application in a particular implementation. However, it should be understood that any particular program nomenclature used below is for convenience only, and therefore this disclosure should not be limited to use only in any particular application identified and / or implied by that nomenclature. Moreover, given the virtually endless ways in which computer programs can be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functionality can be distributed across various software layers (e.g., operating systems, libraries, APIs, applications, applets, etc.) residing in a typical computer, it should be understood that this disclosure is not limited to the specific organization and distribution of program functionality described herein.

[0095] Figure 4A The environments shown are not intended to limit the implementations disclosed herein. In practice, other alternative hardware and / or software environments can be used without departing from the scope of the implementations disclosed herein.

[0096] 2. FM LIDAR for automotive applications

[0097] Trucks can include LIDAR systems (e.g., vehicle control system 420 and / or LIDAR system 100 and / or 300, etc.). In some embodiments, the LIDAR system can use frequency modulation to encode an optical signal and use optics to scatter the encoded optical signal into free space. By detecting the frequency difference between the encoded optical signal and the reflected signal from the object, a frequency-modulated (FM) LIDAR system can determine the position of the object and / or accurately measure the velocity of the object using the Doppler effect. FM LIDAR systems can use continuous waves (referred to as "FMCW LIDAR" or "coherent FMCW LIDAR") or quasi-continuous waves (referred to as "FMQW LIDAR"). LIDAR systems can use phase modulation (PM) to encode an optical signal and use optics to scatter the encoded optical signal into free space.

[0098] FM or phase-modulated (PM) LiDAR systems may offer significant advantages over traditional LiDAR systems in automotive and / or commercial truck applications. Firstly, in some cases, objects (e.g., pedestrians wearing dark clothing) may have low reflectivity, reflecting only a small amount of light (e.g., 10% or less) back to the sensors of an FM or PM LiDAR system. Figure 4A (Sensor 430 in the system). In other cases, an object (e.g., a flashing road sign) may have a high reflectivity (e.g., above 10%) because it reflects a large amount of light that hits the object back to the sensor of the FM LIDAR system.

[0099] Regardless of an object's reflectivity, FM LIDAR systems are able to detect (e.g., classify, identify, discover) objects at much greater distances (e.g., twice as far) than traditional LIDAR systems. For example, an FM LIDAR system can detect low-reflectivity objects at distances of more than 300 meters and high-reflectivity objects at distances of more than 400 meters.

[0100] To achieve this improvement in detection capability, FM LIDAR systems can use sensors (e.g., Figure 4A(Sensor 430 in the example). In some implementations, these sensors can be single-photon sensitive, meaning they can detect the smallest possible amount of light. While FM LIDAR systems can use infrared wavelengths (e.g., 950 nm, 1550 nm, etc.) in some applications, they are not limited to the infrared wavelength range (e.g., near-infrared: 800 nm–1500 nm; mid-infrared: 1500 nm–5600 nm; and far-infrared: 5600 nm–1,000,000 nm). By operating FM or PM LIDAR systems at infrared wavelengths, they can broadcast stronger light pulses or beams while meeting eye safety standards. Conventional LIDAR systems are typically insensitive to single photons and / or operate only at near-infrared wavelengths, thus requiring them to limit their light output (and distance detection capabilities) for eye safety reasons.

[0101] Therefore, by detecting objects at greater distances, FM LIDAR systems can have more time to react to unexpected obstacles. In fact, even a few extra milliseconds can improve safety and comfort, especially for heavy vehicles (e.g., commercial trucks) driven at highway speeds.

[0102] Another advantage of FM LIDAR systems is their ability to provide accurate velocity for each data point in real time. In some implementations, velocity measurement is achieved using the Doppler effect, which offsets the frequency of light received from an object based on at least one of radial velocity (e.g., the direction vector between the detected object and the sensor) or the frequency of the laser signal. For example, for a velocity encountered on a road condition with a speed less than 100 m / s, such an offset at a wavelength of 1550 nanometers (nm) corresponds to a frequency offset of less than 130 MHz. This frequency offset is so small that it is difficult to detect directly in the optical domain. However, by using coherent detection in FMCW, PMCW, or FMQW LIDAR systems, the signal can be converted to the RF domain, allowing the frequency offset to be calculated using various signal processing techniques. This enables autonomous vehicle control systems to process incoming data much faster.

[0103] Instantaneous velocity calculations also make it easier for FM LIDAR systems to identify distant or sparse data points as objects and / or track how these objects move over time. For example, FM LIDAR sensors (e.g., Figure 4A The sensor 430 in the system may only receive a few returns (e.g., hits) from objects at a distance of 300 meters, but if these returns give a velocity value of interest (e.g., moving toward the vehicle at a speed >70 mph), the FM LIDAR system and / or the autonomous vehicle control system can determine the appropriate weights of the probabilities associated with the object.

[0104] The faster the FM LIDAR system identifies and / or tracks an object, the more time the autonomous vehicle control system has to maneuver the vehicle. A better understanding of the object's speed also allows the autonomous vehicle control system to plan better responses.

[0105] Another advantage of FM LIDAR systems is that they experience less electrostatic interference compared to traditional LIDAR systems. That is, traditional LIDAR systems, designed to be more sensitive to light, typically perform poorly in bright sunlight. These systems are also susceptible to crosstalk (e.g., when sensors are confused by each other's light pulses or beams) and self-interference (e.g., when a sensor is confused by its own preceding light pulse or beam). To overcome these drawbacks, vehicles using traditional LIDAR systems typically require additional hardware, complex software, and / or more computing power to manage this "noise."

[0106] In contrast, FM LIDAR systems do not suffer from such problems because each sensor is specifically designed to respond only to its own optical characteristics (e.g., beams, waves, pulses). If the returned light does not match the time, frequency, and / or wavelength of the original transmission, the FM sensor can filter (e.g., delete, ignore, etc.) that data point. Therefore, FM LIDAR systems produce (e.g., generate, export, etc.) more accurate data and have lower hardware or software requirements, resulting in safer and smoother driving.

[0107] Finally, FM LIDAR systems are more scalable than traditional LIDAR systems. As more autonomous vehicles (e.g., cars, commercial trucks, etc.) appear on the road, vehicles powered by FM LIDAR systems may not have to deal with interference problems caused by sensor crosstalk. Furthermore, FM LIDAR systems use lower peak optical power than traditional LIDAR sensors. Therefore, some or all of the optical components of an FM LIDAR can be manufactured on a single chip, which has its own advantages, as described in this article.

[0108] 3. Commercial trucks

[0109] Figure 4BThis is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some embodiments. Environment 400B includes a commercial truck 402B for hauling cargo 406B. In some embodiments, the commercial truck 402B may include a vehicle configured for long-haul freight, regional freight, intermodal freight (i.e., where a road-based vehicle is used as one of a variety of modes of transport to move cargo), and / or any other road-based freight application. The commercial truck 402B may be a flatbed truck, a refrigerated truck (e.g., a refrigerated box truck), a ventilated van (e.g., a dry van), a mobile truck, etc. Cargo 406B may be goods and / or products. The commercial truck 402B may include trailers for carrying cargo 406B, such as flatbed trailers, low-floor trailers, ladder trailers, retractable flatbed trailers, side trailers, etc.

[0110] Environment 400B includes object 410B (in Figure 4B (The vehicle shown in the image is another vehicle), and its distance from the truck is equal to or less than 30 meters.

[0111] Commercial truck 402B may include LIDAR system 404B (e.g., FM LIDAR system, Figure 4A The vehicle control system 420 in Figure 1 The LIDAR system 100 in China Figure 3 The LIDAR system 300, etc., is used to determine the distance to object 410B and / or measure the velocity of object 410B. Although Figure 4B A LiDAR system 404B is shown mounted on the front of a commercial truck 402B, but the number of LiDAR systems and the mounting areas of the LiDAR systems on the commercial truck are not limited to a specific number or specific area. The commercial truck 402B may include any number of LiDAR systems 404B (or components thereof, such as sensors, modulators, coherent signal generators, etc.) mounted in any area of ​​the commercial truck 402B (e.g., front, rear, side, top, bottom, under, and / or bottom) to facilitate the detection of objects in any free space relative to the commercial truck 402B.

[0112] As shown in the figure, the LIDAR system 404B in environment 400B can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at close range (e.g., 30 meters or less) to the commercial truck 402B.

[0113] Figure 4C This is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some embodiments. Environment 400C includes the same components contained in environment 400B (e.g., commercial truck 402B, cargo 406B, LIDAR system 404B, etc.).

[0114] Environment 400C includes object 410C (in) Figure 4C The object 410C is located within a distance range of (i) greater than 30 meters and (ii) equal to or less than 150 meters from the commercial truck 402B. As shown in the figure, the LIDAR system 404B in environment 400C can be configured to detect objects (e.g., another vehicle, bicycle, tree, road sign, pothole, etc.) at a certain distance (e.g., 100 meters) from the commercial truck 402B.

[0115] Figure 4D This is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some embodiments. Environment 400D includes the same components contained in environment 400B (e.g., commercial truck 402B, cargo 406B, LIDAR system 404B, etc.).

[0116] Environment 400D includes objects 410D (in Figure 4D As shown in the figure, the object 410D is located at a distance greater than 150 meters from the commercial truck 402B. The LIDAR system 404B in the environment 400D can be configured to detect objects (e.g., another vehicle, bicycle, tree, road sign, pothole, etc.) at a certain distance (e.g., 300 meters) from the commercial truck 402B.

[0117] In commercial truck applications, due to increased weight and the resulting need for longer stopping distances, effective detection of objects across the entire range is crucial. Because of these advantages, FM LIDAR systems (e.g., FMCW and / or FMQW systems) or PM LIDAR systems are well-suited for commercial truck applications. Therefore, commercial trucks equipped with such systems can enhance their ability to safely transport people and goods over short or long distances, thereby improving not only the safety of the commercial truck itself but also the safety of surrounding vehicles. In various implementations, such FM or PM LIDAR systems can be used in semi-autonomous applications where the commercial truck has a driver and some functions of the commercial truck are operated autonomously using the FM or PM LIDAR system, or in fully autonomous applications where the commercial truck is operated entirely by the FM or LIDAR system alone or in combination with other vehicle systems.

[0118] 4. Continuous wave modulation and quasi-continuous wave modulation

[0119] In a LiDAR system using CW modulation, the modulator continuously modulates the laser. For example, if the modulation period is 10 seconds, the input signal is modulated throughout the entire 10 seconds. Conversely, in a LiDAR system using quasi-CW modulation, the modulator modulates the laser to have both an active and an inactive portion. For example, for a 10-second period, the modulator modulates the laser for only 8 seconds (sometimes called the "active portion"), but not for 2 seconds (sometimes called the "inactive portion"). By doing so, the LiDAR system can reduce power consumption by 2 seconds because the modulator does not have to provide a continuous signal.

[0120] In frequency modulated continuous wave (FMCW) LiDARs used in automotive applications, it can be advantageous to operate the LiDAR system using quasi-continuous wave modulation, where FMCW measurement and signal processing methods are employed, but the optical signal is not always on (e.g., enabled, powered on, transmitted, etc.). In some implementations, the duty cycle of the quasi-continuous wave modulation can be equal to or greater than 1% and can be as high as 50%. If the energy that is in a closed state (e.g., disabled, powered off, etc.) can be consumed during the actual measurement time, the signal-to-noise ratio (SNR) may be improved and / or the signal processing requirements reduced, allowing for the coherent integration of all energy over longer timescales.

[0121] The term "processing logic" as used in this disclosure may include one or more processors, microprocessors, multi-core processors, application-specific integrated circuits (ASICs), and / or field-programmable gate arrays (FPGAs) to perform the 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 to perform operations according to embodiments of this disclosure.

[0122] The term "memory" or "multiple memories" described in this disclosure may include one or more volatile or non-volatile memory architectures. "Memory" or "multiple memories" may be removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Example memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile optical disc (DVD), high-definition multimedia / data storage disc, or other optical storage, magnetic tape cassette, magnetic tape, disk storage, or other magnetic storage devices, or any other non-transfer medium capable of storing information for access by a computing device.

[0123] A network may include any network or network system, such as, but not limited to, the following: peer-to-peer networks; local area networks (LANs); wide area networks (WANs); public networks, such as the Internet; private networks; cellular networks; wireless networks; wired networks; wireless and wired combined networks; and satellite networks.

[0124] Communication channels may include or be routed using one or more of the following wired or wireless communications: IEEE 802.11 protocol, Bluetooth, SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit), USB (Universal Serial Port), CAN (Controller Area Network), cellular data protocols (e.g., 3G, 4G, LTE, 5G), optical communication networks, Internet Service Providers (ISPs), peer-to-peer networks, local area networks (LANs), wide area networks (WANs), public networks (e.g., the "Internet"), private networks, satellite networks, or other means.

[0125] Computing devices may include desktop computers, laptop computers, tablet computers, phablets, smartphones, feature phones, server computers, or other devices. Server computers may be located in remote data centers or stored locally.

[0126] The above processes are described in the form of computer software and hardware. The techniques may constitute machine-executable instructions contained in a tangible or non-transitory machine-readable storage medium, which, when executed by a machine, will cause the machine to perform the described operations. Additionally, the processes may be contained within hardware, such as application-specific integrated circuits (“ASICs”) or other hardware.

[0127] Tangible, non-transitory machine-readable storage media include any mechanism that provides (i.e., stores) information in a form accessible to a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device having one or more processors, etc.). For example, machine-readable storage media include recordable / non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, etc.).

[0128] The foregoing description of embodiments of the invention (including the description in the abstract) is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments and examples of the invention have been described herein for illustrative purposes, those skilled in the art will recognize that various modifications can be made within the scope of the invention.

[0129] These modifications to the invention are possible in light of the above detailed description. The terminology used in the following claims should not be construed as limiting the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is fully defined by the following claims, which should be interpreted in accordance with established principles of claim interpretation.

Claims

1. A light detection and ranging (LIDAR) sensor system, comprising: One or more LIDAR pixels, wherein at least one of the one or more LIDAR pixels includes: A dual-polarization optical antenna, configured to: (i) transmit a transmitted beam having a first polarization orientation, and (ii) detect a returned beam having a second polarization orientation; A first receiver, configured to generate a first signal in response to receiving the second polarization orientation of the returned beam and in response to a first local oscillator signal; and The second receiver is configured to generate a second signal in response to receiving the second polarization orientation of the returned beam from the dual-polarization optical antenna and in response to a second local oscillator signal.

2. The optical detection and ranging (LIDAR) sensor system according to claim 1, wherein, The dual-polarization optical antenna includes a two-dimensional (2D) polarization-separating grating coupler having a first port and a second port, wherein... The 2D polarization-separating grating is configured to receive a transmitted signal at the first port and to provide the return beam with a second polarization orientation to the second port coupled to the second receiver.

3. The optical detection and ranging (LIDAR) sensor system according to claim 1 further includes: A single-polarization optical antenna, configured to detect the returning beam having the second polarization orientation, wherein... The single-polarization optical antenna is coupled to the first receiver to provide the second polarization orientation of the returned beam to the first receiver.

4. The optical detection and ranging (LIDAR) sensor system according to claim 3, wherein, The single-polarization optical antenna is a one-dimensional (1D) polarization grating coupler.

5. The optical detection and ranging (LIDAR) sensor system according to claim 3, wherein, The dual-polarization optical antenna is offset by a specific distance relative to the single-polarization optical antenna.

6. The optical detection and ranging (LIDAR) sensor system according to claim 1, wherein, The first polarization orientation is orthogonal to the second polarization orientation.

7. The optical detection and ranging (LIDAR) sensor system according to claim 6, further comprising: A single-polarization optical antenna configured to detect the returning beam having the second polarization orientation.

8. The optical detection and ranging (LIDAR) sensor system according to claim 1, wherein, The first local oscillator signal is polarized with a third polarization orientation. The second local oscillator signal is polarized with the third polarization orientation, and The transmitted signal is polarized with the third polarization orientation before transmission. The dual-polarization optical antenna is configured to couple the transmitted signal as the transmitted beam into free space.

9. The optical detection and ranging (LIDAR) sensor system according to claim 8, wherein, The dual-polarization optical antenna is configured to couple the returned beam as a returned signal to at least one of the one or more LIDAR pixels. The returned signal is polarized with the third polarization orientation.

10. The optical detection and ranging (LIDAR) sensor system according to claim 9, wherein, The third polarization orientation is either the first polarization orientation or the second polarization orientation.

11. The optical detection and ranging (LIDAR) sensor system according to claim 1, wherein, The first receiver includes a first optical mixer, and the second receiver includes a second optical mixer. The first receiver includes a first diode pair coupled to the first optical mixer and configured to provide a first electrical signal. Wherein, the first electrical signal is the first signal. The second receiver includes a second diode pair coupled to the second optical mixer and configured to provide a second electrical signal. Wherein, the second electrical signal is the second signal.

12. The optical detection and ranging (LIDAR) sensor system according to claim 1, wherein, The transmitted beam and the returned beam are narrowband near-infrared wavelengths.

13. The optical detection and ranging (LIDAR) sensor system according to claim 1, wherein, The returned beam is the transmitted beam reflected from the object.

14. An autonomous vehicle control system for an autonomous vehicle, the autonomous vehicle control system comprising: A light detection and ranging (LIDAR) device and one or more processors, wherein the light detection and ranging (LIDAR) device includes one or more LIDAR pixels, wherein at least one of the one or more LIDAR pixels includes: A dual-polarization optical antenna, configured to (i) transmit a transmitted beam having a first polarization orientation, and (ii) detect a returned beam having a second polarization orientation; A first receiver, configured to generate a first electrical signal in response to receiving the second polarization orientation of the returned beam and in response to a first local oscillator signal; and A second receiver, configured to generate a second electrical signal in response to receiving a second polarization orientation of the returned beam from the dual-polarization optical antenna and in response to a second local oscillator signal; and The one or more processors are configured to control the autonomous vehicle in response to the first electrical signal and the second electrical signal.

15. The autonomous vehicle control system according to claim 14, wherein, The dual-polarization optical antenna includes a two-dimensional (2D) polarization-separating grating coupler having a first port and a second port, wherein... The 2D polarization-separating grating is configured to receive a transmitted signal at the first port and to provide the return beam having the second polarization orientation to the second port coupled to the second receiver.

16. The autonomous vehicle control system according to claim 14, wherein, At least one of the one or more LIDAR pixels further includes: A single-polarization optical antenna, configured to detect the returning beam having the second polarization orientation, wherein... The single-polarization optical antenna is coupled to the first receiver to provide the first receiver with the second polarization orientation of the returned beam.

17. The autonomous vehicle control system according to claim 16, wherein, The single-polarization optical antenna is a one-dimensional (1D) polarization grating coupler.

18. The autonomous vehicle control system according to claim 16, wherein, The dual-polarization optical antenna is offset by a specific distance relative to the single-polarization optical antenna.

19. The autonomous vehicle control system according to claim 18, further comprising: A rotating mirror configured to direct the transmitted beam into the LIDAR environment and configured to direct the returned beam onto at least one of the one or more LIDAR pixels; as well as A birefringent plate, the birefringent plate being located between the rotating mirror and at least one of the one or more LiDAR pixels, The birefringent plate is configured to guide the returning beam with the second polarization orientation onto the single-polarization optical antenna or the dual-polarization optical antenna.

20. An autonomous vehicle, comprising: A light detection and ranging (LIDAR) device and one or more processors, wherein the light detection and ranging (LIDAR) device includes one or more LIDAR pixels, wherein at least one of the one or more LIDAR pixels includes: A dual-polarization optical antenna, configured to (i) transmit a transmitted beam having a first polarization orientation, and (ii) detect a returned beam having a second polarization orientation; A first receiver, configured to generate a first electrical signal in response to receiving the second polarization orientation of the returned beam and in response to a first local oscillator signal; and A second receiver, configured to generate a second electrical signal in response to receiving a second polarization orientation of the returned beam from the dual-polarization optical antenna and in response to a second local oscillator signal; and The one or more processors are configured to control the autonomous vehicle in response to the first electrical signal and the second electrical signal.

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