LIDAR sensor system including dual polarization transmit and receive 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return beam having a second polarization orientation. The single polarization optical antenna is configured to detect a return 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 on June 23, 2022, which is incorporated herein by reference.

[0003] Background Information

[0004] Frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) directly measures the range and speed of an object by emitting a frequency modulated light beam and detecting the return signal. The automotive industry is currently developing autonomous features for controlling vehicles in specific situations. According to SAE International Standard J3016, there are 6 levels of autonomy, ranging from Level 0 (no autonomy) to Level 5 (the vehicle is capable of operating without operator input under all conditions). Vehicles with autonomous features utilize sensors to perceive the environment through which the vehicle is navigating. Acquiring and processing data from the sensors allows the vehicle to navigate through its environment. Summary of the invention

[0005] Embodiments of the present disclosure include a light detection and ranging (LIDAR) sensor system including 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return 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 return 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 return beam from the dual polarization optical antenna and in response to a second local oscillator signal.

[0006] In an embodiment, a dual polarization optical antenna includes a two-dimensional (2D) polarization separation grating coupler including a first port and a second port. The 2D polarization separation grating can be configured to receive a transmit signal on the first port and can be configured to provide a return beam having a second polarization to a second port coupled to a second receiver.

[0007] In an embodiment, the LIDAR sensor system further comprises a single polarization optical antenna configured to detect a return light beam having a second polarization orientation. The single polarization optical antenna can be coupled to the first receiver to provide the second polarization orientation of the return light beam to the first receiver.

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

[0009] In an embodiment, the dual polarization optical antenna is offset from the single polarization optical antenna by a specific distance.

[0010] In an embodiment, the first polarization orientation is orthogonal to the second polarization orientation.

[0011] In an embodiment, the LIDAR sensor system further includes a single polarization optical antenna configured to detect a return light beam having a second polarization orientation.

[0012] In an embodiment, the first local oscillator signal is directionally polarized with a third polarization, the second local oscillator signal is directionally polarized with a third polarization, and the transmit signal is polarized with the third polarization prior to transmission.The dual polarization optical antenna can be configured to couple the transmit signal into free space as a transmit beam.

[0013] In an embodiment, the dual polarization optical antenna is configured to couple the return beam into at least one of the one or more LIDAR pixels as a return signal. The return signal can be polarized in a third polarization orientation.

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

[0015] In an 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 that is coupled to the first optical mixer and may be 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 that is coupled to the second optical mixer and may be configured to provide a second electrical signal. The second electrical signal may be a second signal.

[0016] In an embodiment, the transmit light beam and the return light beam are narrow-band near infrared wavelengths.

[0017] In an embodiment, the return beam is the transmitted beam reflected from the object.

[0018] Embodiments of the present 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return 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 return 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 return 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 electrical signal and the second electrical signal.

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

[0020] In an embodiment, at least one of the one or more LIDAR pixels further comprises a single polarization optical antenna configured to detect a return beam having a second polarization orientation. The single polarization optical antenna can be coupled to the first receiver to provide the second polarization orientation of the return beam to the first receiver.

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

[0022] In an embodiment, the dual polarization optical antenna is offset from the single polarization optical antenna by a specific distance.

[0023] In an embodiment, the autonomous vehicle control system further comprises a rotating mirror and a birefringent plate. The rotating mirror may be configured to direct the transmit beam into the LIDAR environment and to direct the return beam onto at least one of the one or more LIDAR pixels. The birefringent plate may be located between the rotating mirror and at least one of the one or more LIDAR pixels. The birefringent plate may be configured to direct the return beam having a second polarization orientation onto a single polarization optical antenna or onto a dual polarization optical antenna.

[0024] Embodiments of the present 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return 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 return 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 return 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 signal and the second signal.

[0025] Embodiments of the present disclosure include a light detection and ranging (LIDAR) sensor system including 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return 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 return 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 return beam from the dual polarization optical antenna and in response to a second local oscillator signal.

[0026] In an embodiment, a dual polarization optical antenna includes a two-dimensional (2D) polarization separation grating coupler including a first port and a second port. The 2D polarization separation grating can be configured to receive a transmit signal on the first port and can be configured to provide a return beam having a second polarization to a second port coupled to a second receiver.

[0027] In an embodiment, the LIDAR sensor system further includes a single polarization optical antenna configured to detect a return light beam having a second polarization orientation. The single polarization optical antenna may be coupled to the first receiver to provide the second polarization orientation of the return light beam to the first receiver.

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

[0029] In an embodiment, the dual polarization optical antenna is offset from the single polarization optical antenna by a specific distance.

[0030] In an embodiment, the first polarization orientation is orthogonal to the second polarization orientation.

[0031] In an embodiment, the LIDAR sensor system further includes a single polarization optical antenna configured to detect a return light beam having a second polarization orientation.

[0032] In an embodiment, the first local oscillator signal is directionally polarized with a third polarization, the second local oscillator signal is directionally polarized with a third polarization, and the transmit signal is polarized with the third polarization prior to transmission. The dual polarization optical antenna may be configured to couple the transmit signal into free space as a transmit beam.

[0033] In an embodiment, the dual polarization optical antenna is configured to couple the return beam into at least one of the one or more LIDAR pixels as a return signal. The return signal may be polarized in a third polarization direction.

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

[0035] In an 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 that is coupled to the first optical mixer and may be 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 that is coupled to the second optical mixer and may be configured to provide a second electrical signal. The second electrical signal may be a second signal.

[0036] In an embodiment, the transmit light beam and the return light beam are narrow-band near infrared wavelengths.

[0037] In an embodiment, the return beam is the transmitted beam reflected from the object.

[0038] Embodiments of the present 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return 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 return 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 return 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 electrical signal and the second electrical signal.

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

[0040] In an embodiment, at least one of the one or more LIDAR pixels further comprises a single polarization optical antenna configured to detect a return beam having a second polarization orientation. The single polarization optical antenna can be coupled to the first receiver to provide the second polarization orientation of the return beam to the first receiver.

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

[0042] In an embodiment, the dual polarization optical antenna is offset from the single polarization optical antenna by a specific distance.

[0043] In an embodiment, the autonomous vehicle control system further comprises a rotating mirror and a birefringent plate. The rotating mirror may be configured to direct the transmit beam into the LIDAR environment and to direct the return beam onto at least one of the one or more LIDAR pixels. The birefringent plate may be located between the rotating mirror and at least one of the one or more LIDAR pixels. The birefringent plate may be configured to direct the return beam having the second polarization orientation onto a single polarization optical antenna or onto a dual polarization optical antenna.

[0044] Embodiments of the present disclosure include an autonomous vehicle. 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) emit a transmit beam having a first polarization orientation, and (ii) detect a return 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 return 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 return 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 signal and the second signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[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 a LIDAR pixel, 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 is shown in accordance with an embodiment of the present disclosure.

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

[0052] Figure 4D A block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle is shown in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION

[0053] Embodiments of LIDAR pixels with dual polarization transmit / receive optical antennas are described herein. The LIDAR pixel can include one or more modules, one or more integrated chips, or one or more circuits. In addition, the LIDAR pixel can be implemented as a single packaged chip or as a modular design so that the LIDAR pixel includes multiple packaged chips. In the following description, many specific details are set forth to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the technology described herein can be practiced without one or more specific details or using other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid covering up certain aspects.

[0054] References in this specification to "one embodiment" or "an embodiment" mean that the particular features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places in 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.

[0055] In this specification, a number of specialized terms are used. These terms should be taken to have the ordinary meaning in the art to which they belong, unless otherwise explicitly defined herein or the context of their use clearly implies other meanings. For the purpose of this specification, the term "autonomous vehicle" includes vehicles with autonomous features of any autonomy level of SAE International Standard J3016.

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

[0057] Frequency modulated continuous wave (FMCW) LIDAR directly measures the range and velocity of an object / target by sending a frequency modulated beam of light to the object or target. The light reflected from the object / target can be combined with a tapped version of the beam. Once corrected for the Doppler shift that requires a second measurement, the frequency of the resulting beat signal is proportional to the distance of the object from the LIDAR system. The two measurements, which may or may not be taken simultaneously, provide both range and velocity information.

[0058] Embodiments of the present disclosure include a LIDAR device including 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 transmit beam with a first polarization orientation and detects a return beam with a second polarization orientation. The receiving optical antenna can be coupled to the first receiver to provide a return beam with a second polarization orientation. The dual polarization optical antenna can be coupled to the second receiver to provide a return beam with a second polarization orientation. The first receiver generates a first signal in response to receiving the second polarization orientation of the return 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 return beam detected by the dual polarization optical antenna. Detecting the return beam at an offset from the transmitting antenna can increase the signal-to-noise ratio (SNR) of the detected return beam and, therefore, increase the imaging quality of the LIDAR system. Additionally, detecting two different positions of the return beam can allow the LIDAR system to detect additional information about the external environment, such as objects located within a larger range in the external environment of the LIDAR system. In combination Figures 1 to 4D These and other embodiments are described in further detail.

[0059] Figure 1A LIDAR system 100 including a LIDAR pixel 102 according to an embodiment of the present disclosure is shown. According to an 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 Figure 1 The specific LIDAR pixel architecture shown. The LIDAR pixel can be implemented using any suitable chip design architecture. For example, the transmit and receive 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. The optical antenna 104 can be configured to emit a transmit beam having a first polarization orientation and can be configured to detect a return beam having a second polarization orientation. The receiving optical antenna 106 can be positioned at a distance D from the optical antenna 104 to account for or compensate for beam deviation caused by the rotating mirror of the LIDAR system. The transmit beam can be an infrared transmit beam. The transmit beam can be a near-infrared transmit beam. The transmit beam can be emitted as a single defined polarization orientation. In Figure 1 In the figure, according to an embodiment, the optical antenna 104 is shown as a dual polarization optical coupler, and can transmit a transmission light beam in response to receiving a transmission signal 108 through a waveguide 109. The transmission signal 108 can be generated by a laser, and the transmission light beam emitted by the optical antenna 104 can have a very narrow line width (e.g., 1 nm or less).

[0060] In some embodiments, the optical antenna 104 may include a dual polarization transmit / receive optical antenna, which may be configured to transmit a transmit signal having a first polarization orientation and may be configured to (e.g., simultaneously) detect a return beam having a second polarization orientation. The return beam may be a reflection of a transmit 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 may have a margin range higher 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 may be defined as orthogonal. The optical antenna 104 may be implemented as a two-dimensional (2D) polarization separation grating coupler having two ports. The first port of the optical antenna 104 may be coupled to transmit a signal 108 using a waveguide 109 so that the optical antenna 104 can transmit a transmit beam having a first polarization orientation. The second port of the optical antenna 104 may be coupled to a second coherent receiver 126 using a waveguide 110 so that the optical antenna 104 can provide the second polarization orientation of the return signal to the second coherent receiver 126. The optical antenna 104 can be configured to couple a return beam from free space into the waveguide 110 as a return signal that propagates through the waveguide 110 to the coherent receiver 126. When in the LIDAR pixel 102 (e.g., when on-chip), the return signal can have the same polarization orientation as the transmit signal TX and the local oscillator signal LO2. Depending on the embodiment, the polarization orientation of the return signal, the transmit signal TX, the local oscillator signal LO1, and the local oscillator signal LO2 can be the same as the first polarization orientation or the second polarization orientation, or can be completely different polarization orientations. According to the embodiment, 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 receive optical antenna 106 may be implemented as a single polarization grating coupler. The receive optical antenna 106 may be rotated to receive and detect (e.g., couple into a waveguide) a second polarization orientation of the return beam. The receive optical antenna 106 may be rotated to light that is polarized negative 45 degrees. The receive optical antenna 106 may be offset from the position of the optical antenna 104 by a distance D so that the receive optical antenna 106 can compensate for beam deviations, e.g., as Figure 3 The receiving optical antenna 106 can be coupled to the first coherent receiver 121 by using the waveguide 112 to provide the first coherent receiver 121 with a second polarization orientation of the returning light beam.

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

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

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

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

[0066] Figure 2A and Figure 2B 1 shows coherent receivers 121 and 126 according to an embodiment of the present disclosure ( Figure 1 ) as 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 an 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 through a waveguide 206. According to an embodiment, the optical mixer 202 may be coupled to receive the local oscillator signal LO from the local oscillator port 208 through a waveguide 210. The optical mixer 202 may combine input signals to generate a plurality of combined output signals OUT1 and OUT2. The number of output signals from the optical mixer can be any suitable number, not limited to a specific number. According to an embodiment, the output signals OUT1 and OUT2 are provided to a photodiode pair (including photodiodes PD1 and PD2) to convert the return beam signal RB and the local oscillator signal LO into output signals OUT. The output signal OUT may be an electrical signal. The output signal OUT may be a beat signal representing the range and / or velocity of one or more objects in the environment of the LIDAR system. Each of these output signal OUT variations may provide object characteristics (e.g., distance, reflectivity) of an object in the environment from which the return beam was reflected. For example, the object characteristics (e.g., distance, reflectivity) may enable an autonomous vehicle (e.g., a truck) to perform vehicle operations (e.g., stop, turn, ignore) based on the characteristics of the object. Each output signal may be provided to a corresponding receiver in a plurality of receivers to enable concurrent reception and processing of a plurality of output signals.

[0068] Figure 2BAn example of a coherent receiver 230 with an optical mixer 232 according to an embodiment is shown, and the optical mixer 232 is configured to provide multiple output signals OUT3, OUT4, OUT5 and OUT6 based on the return beam signal RB and the 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 the signals OUT3, OUT4, OUT5 and OUT6 to a photodiode configuration, which converts the mixed signals into an in-phase output signal OUT_I and an orthogonal output signal OUT_Q. The in-phase output signal OUT_I can be provided to an output port 234, and the orthogonal output signal OUT_Q can be provided to an output port 236. The photodiode configuration can include photodiodes PD3, PD4, PD5 and PD6.

[0069] Figure 3 An example of a LIDAR system 300 is shown that illustrates how LIDAR pixels 102 can be used to compensate for beam deviation and support beam scanning, in accordance with an embodiment of the present disclosure.

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

[0071] During the transit time of the transmit beam 302 and the return beam 314 to the object 312 and back to the mirror 310, the mirror 310 may have rotated a small amount. The amount of rotation will vary based on the distance traveled by the transmit beam 302 and the return beam 314. Due to the rotation of the mirror 310, the return beam 314 may be incident on the lens 308 at a different angle than the transmit beam 302. The changed position of the return beam 314 on the mirror 310 may cause the return beam 314 to deviate from or miss the optical antenna 104. However, the LIDAR pixel 102 includes a receiving optical antenna 106, so if the return 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 may receive the return beam 314 oriented at a second polarization.

[0072] According to an embodiment, upon returning to the LIDAR pixel 102, the birefringent plate 304 may direct the return beam 314 toward different locations of the LIDAR pixel 102 based on the polarization characteristics of the return beam 314. The return beam 314 may be directed through the birefringent plate 304, which horizontally offsets the return beam 314 in space. If the polarization of the return beam 314 is different from the polarization of the transmit beam 302, the offset introduced by the birefringent material may be different. According to an embodiment, the birefringent plate 304 may be configured to direct the return beam 314 to a location on the LIDAR pixel 102 based on the polarization orientation or characteristics of the return beam 314. According to an embodiment, the birefringent plate 304 may be configured to direct the return beam 314 along a different optical path from the transmit beam 302 based on the polarization of the two signals to reduce signal interference.

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

[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 materials used for the birefringent plate are not limited to the above materials. Any suitable material can be used for the birefringent plate to best correct the deviation introduced by the rotating mirror for a wide range of object distances. For example, optimizing for longer range targets may include selecting a birefringent material that has a larger horizontal offset due to a longer round trip time for the light beam to reflect from the target and propagate back to the receiving optical antenna 104, 106.

[0075] The tilted piece of the birefringent plate 304 can be part of a lens assembly or a chip packaging assembly. It can be integrated on the same photonic chip as the coherent pixel array. Multiple coherent pixels and tilted birefringent pieces can be used together to achieve more complex operations of FMCW LIDAR. In some embodiments, the birefringent piece 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 properties of the transmitted light beam 302 and the return light 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 shift the orientation by an orthogonal amount.

[0076] 1. System environment for autonomous vehicles

[0077] Figure 4A is a block diagram illustrating an example of a system environment for an autonomous vehicle, according to some implementations.

[0078] See also Figure 4A , an example autonomous vehicle 410A in which various techniques disclosed herein may be implemented. For example, vehicle 410A may include: a powertrain 492, which includes a prime mover 94 driven by an energy source 496 and capable of providing power to a drivetrain 498; and a control system 80, which includes a directional control 482, a powertrain control 84, and a brake control 486. Vehicle 410A may be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or cargo and capable of traveling in a variety of environments, and it should be understood that the above-described components 480-498 can vary widely based on the type of vehicle in which they 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, 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 monomer system. The transmission system 498 can include wheels and / or tires and a transmission and / or any other mechanical drive assembly to convert the output of the prime mover 494 into vehicle motion, as well as one or more brakes configured to controllably stop or slow down the vehicle 410A, and a direction or steering assembly suitable for controlling the trajectory of the vehicle 410A (e.g., a rack and pinion steering linkage that enables one or more wheels of the vehicle 410A to pivot about a substantially vertical axis to change the angle of the rotation plane of the wheel relative to the longitudinal axis of the vehicle). In some embodiments, a combination of a 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 each wheel or axle) may be used as prime movers.

[0080] The direction controller 482 may include one or more actuators and / or sensors for controlling and receiving feedback from the direction or steering 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, to control the output power of the prime mover 494, to control the gear of the transmission in the transmission 498, etc., thereby controlling the speed and / or direction of the vehicle 410A. The brake control 486 may be configured to control one or more brakes that slow or stop the vehicle 410A, for example, 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 necessarily use different powertrains, drivetrains, energy sources, directional controls, powertrain controls, and brake controls. In addition, in some embodiments, some components may be combined, for example, directional control of the vehicle is primarily handled by changing the output of one or more prime movers. Therefore, the embodiments disclosed herein are not limited to the specific application of the technology described herein in autonomous wheeled land vehicles.

[0082] Various levels of autonomous control of the vehicle 410A can be implemented in a vehicle control system 420, which can include one or more processors 422 and one or more memories 424, with each processor 422 configured to execute program code instructions 426 stored in the memory 424. The processor can 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 surrounding environment of the vehicle for controlling the operation of the vehicle. For example, sensor 430 may include radar sensor 434, LIDAR (light detection and ranging) sensor 436, 3D positioning sensor 438, for example, accelerometer, gyroscope, magnetometer or satellite navigation system (such as GPS (Global Positioning System), GLONASS (Globalnaya Navigazionnaya Sputnikovaya Sistema or Global Navigation Satellite System), Beidou Navigation Satellite System (BDS), Galileo, compass, etc.) Any one. 3D positioning sensor 438 can be used to determine the position of the vehicle on the earth using satellite signals. Sensor 430 can include camera 440 and / or IMU (Inertial Measurement Unit) 442. Camera 440 can be a single or stereo camera and can record static and / or video images. IMU 442 can include multiple gyroscopes and accelerometers that can detect linear and rotational motion of the vehicle 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 may be capable of outputting sensor data at various data rates, which may be different from the data rates of the other sensors 430 .

[0084] The output of the sensor 430 can be provided to a set 450 of control subsystems, which include a positioning subsystem 452, a planning subsystem 456, a perception subsystem 454, and a control subsystem 458. The positioning subsystem 452 can perform functions such as accurately determining the position and orientation (sometimes also referred to as "pose") of the vehicle 410A in its surroundings, and usually within a certain 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 can perform functions such as detecting, tracking, determining and / or identifying objects in the surrounding environment of the vehicle 410A. Machine learning models can be used to track objects. The planning subsystem 456 can perform functions such as planning a trajectory for the vehicle 410A within a certain time frame given a desired destination and static and moving objects in the environment. Machine learning can be used to plan vehicle trajectories. The control subsystem 458 can perform functions such as generating appropriate control signals for controlling various controls in the vehicle control system 420 to achieve the planned trajectory of the vehicle 410A. The machine learning model can be utilized to generate one or more signals to control the autonomous vehicle to implement the planned trajectory.

[0085] It should be understood that Figure 4AThe assembly of components of the vehicle control system 420 shown in FIG. 4 is merely exemplary in nature. In some embodiments, individual sensors may be omitted. Additionally or alternatively, in some embodiments, a Figure 4A Multiple sensors of the type shown in can be used to achieve redundancy and / or cover 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. In addition, although subsystems 452-458 are shown as being separated 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 with program code instructions 426 residing in one or more memories 424 and executed by one or more processors 422, and these subsystems 452-458 can be implemented using the same processor and / or memory in some cases. The subsystem can be implemented at least in part using various dedicated circuit logic, various processors, various field programmable gate arrays ("FPGA"), various application-specific integrated circuits ("ASIC"), various real-time controllers, etc., as described above, multiple subsystems can utilize circuit systems, processors, sensors and / or other components. In addition, the various components in the vehicle control system 420 can be networked in various ways.

[0086] In some embodiments, the vehicle 410A may also include an auxiliary vehicle control system (not shown) that may be used as a redundant or backup control system for the vehicle 410A. The auxiliary vehicle control system may be able to fully operate the autonomous vehicle 410A in the event of an adverse event in the vehicle control system 420, while in other embodiments, the auxiliary vehicle control system may have only limited functionality, such as a controlled stop of the vehicle 410A in response to an adverse event detected in the primary vehicle control system 420. In other embodiments, the auxiliary vehicle control system may be omitted.

[0087] In general, there are countless different architectures that can be used to implement Figure 4A The various components shown in the vehicle 410A, the myriad of different architectures include 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, which includes 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. In addition, each memory can be considered to include memory storage physically located elsewhere in the vehicle 410A, such as any cache memory in the processor, as well as any storage capacity used as virtual memory, such as stored on a mass storage device or another computer controller. Figure 4AOne or more of the processors shown in , or an entirely separate processor, may be used to implement additional functionality in the vehicle 410A beyond autonomous control purposes, such as controlling entertainment systems, 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 a removable disk drive, a hard drive, a direct access storage device ("DASD"), an optical disk drive (e.g., a CD drive, a DVD drive, etc.), a solid-state storage drive ("SSD"), a network attached storage, a storage area network, and / or a tape drive, etc.

[0089] Additionally, the vehicle 410A may include a user interface 464 to enable the vehicle 410A to receive a plurality of inputs from and generate outputs to a user or operator, such as one or more displays, touch screens, voice and / or gesture interfaces, buttons and other tactile controls, etc. Otherwise, the 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] In addition, the vehicle 410A may include one or more network interfaces, such as a network interface 462, which is suitable for communicating 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, 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 the vehicle 410A receives environmental and other data for its autonomous control. Data collected by one or more sensors 430 can be uploaded to a computing system 472 via the network 470 for additional processing. Prior to uploading, a timestamp can be added to each instance of vehicle data.

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

[0092] In general, routines executed to implement the various embodiments described herein, whether as part of an operating system or a specific 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 various times in various memories and storage devices, and when read and executed by one or more processors, perform the steps necessary to perform the steps or elements embodying various aspects of the present disclosure. Furthermore, while the embodiments have been and will be described below in the context of fully functional computers and systems, it should be understood that the various embodiments described herein can be distributed as program products in various forms, and that the embodiments can be implemented regardless of the specific type of computer-readable medium used to actually perform the 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 drives, magnetic tapes, and optical disks (e.g., CD-ROMs, DVDs, etc.), among others.

[0094] In addition, various program codes described hereinafter can be identified according to the application implemented in a specific embodiment. However, it should be understood that any specific program nomenclature hereinafter is only used for convenience, so the present disclosure should not be limited to use in any specific application that is only identified and / or implied by the nomenclature. In addition, in view of the fact that computer programs can be organized into routines, processes, methods, modules, objects, etc., the ways are usually endless, and the various ways in which program functionality can be distributed among the various software layers (e.g., operating systems, libraries, APIs, applications, applets, etc.) resident in typical computers, it should be understood that the present disclosure is not limited to the specific organization and distribution of the program functionality described herein.

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

[0096] 2. FM LIDAR for automotive applications

[0097] The truck can include a LIDAR system (e.g., vehicle control system 420 and / or LIDAR system 100 and / or 300, etc.). In some embodiments, the LIDAR system can encode a light signal using frequency modulation and scatter the coded light signal into free space using optics. By detecting the frequency difference between the coded light signal and the return signal reflected from the object, a frequency modulation (FM) LIDAR system can determine the position of an object and / or accurately measure the speed of an 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"). The LIDAR system can encode a light signal using phase modulation (PM) and scatter the coded light signal into free space using optics.

[0098] FM or phase modulation (PM) LIDAR systems may have significant advantages over traditional LIDAR systems for automotive and / or commercial truck applications. First, in some cases, an object (e.g., a pedestrian wearing dark clothing) may have low reflectivity, reflecting only a small amount of the light striking the object (e.g., 10% or less) back to the FM or PM LIDAR system's sensor (e.g., Figure 4A In other cases, an object (e.g., a shiny road sign) may have a high reflectivity (e.g., greater than 10%) because it reflects a large amount of light striking the object back to the sensor of the FM LIDAR system.

[0099] Regardless of the reflectivity of the object, the FM LIDAR system is able to detect (e.g., classify, identify, find, etc.) objects at a greater distance (e.g., 2 times) than a conventional LIDAR system. For example, the FM LIDAR system can detect low reflectivity objects at a distance of 300 meters, and high reflectivity objects at a distance of 400 meters.

[0100] To achieve this improvement in detection capabilities, FM LIDAR systems can use sensors (e.g. Figure 4ASensors 430 in. In some embodiments, these sensors can be single photon sensitive, meaning they are able to 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, it is 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 a FM or PM LIDAR system at infrared wavelengths, the FM or PM LIDAR system is able to broadcast more intense 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, 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) driving at highway speeds.

[0102] Another advantage of an FM LIDAR system is that it can provide accurate velocity for each data point instantly. In some embodiments, velocity measurement is achieved using the Doppler effect, which shifts 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 velocities encountered on road conditions with speeds less than 100 meters per second (m / s), this shift at a wavelength of 1550 nanometers (nm) equates to a frequency shift of less than 130 megahertz (MHz). This frequency shift is so small that it is difficult to detect directly in the optical domain. However, by using coherent detection in an FMCW, PMCW, or FMQW LIDAR system, the signal can be converted to the RF domain, enabling the frequency shift to be calculated using various signal processing techniques. This enables the autonomous vehicle control system to process incoming data more quickly.

[0103] Instantaneous velocity calculations also make it easier for FM LIDAR systems to identify distant or sparse data points as objects and / or to track how these objects move over time. For example, FM LIDAR sensors (e.g., Figure 4A Sensor 430 in the FM LIDAR system may receive only a few returns (e.g., hits) for an object that is 300 meters away, but if those returns give velocity values ​​of interest (e.g., moving toward the vehicle at >70 mph), the FM LIDAR system and / or autonomous vehicle control system can determine a corresponding weight for the probability of being associated with the object.

[0104] The faster the FM LIDAR system can identify and / or track an object, the more time the autonomous vehicle control system has to maneuver the vehicle. Better knowledge of how fast an object is moving also allows the autonomous vehicle control system to plan a better response.

[0105] Another advantage of FM LIDAR systems is that they are less susceptible to static interference than traditional LIDAR systems. That is, traditional LIDAR systems, which are designed to be more sensitive to light, generally do not perform well 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 previous light pulse or beam). To overcome these shortcomings, vehicles using traditional LIDAR systems generally require additional hardware, complex software, and / or more computing power to manage this "noise."

[0106] In contrast, FM LIDAR systems do not have such issues because each sensor is specifically designed to respond only to its own light characteristics (e.g., light beam, light wave, light pulse). If the returning light does not match the time, frequency, and / or wavelength originally sent, the FM sensor is able to filter (e.g., delete, ignore, etc.) that data point. As a result, FM LIDAR systems produce (e.g., generate, derive, etc.) more accurate data and have fewer hardware or software requirements, resulting in safer and smoother driving.

[0107] Finally, FM LIDAR systems are more scalable than traditional LIDAR systems. As more self-driving vehicles (e.g., cars, commercial trucks, etc.) appear on the road, cars driven by FM LIDAR systems may not have to face interference issues caused by sensor crosstalk. In addition, FM LIDAR systems use less peak power of light than traditional LIDAR sensors. Therefore, some or all of the optical components of FM LIDAR can be produced on a single chip, which has its own benefits, as described in this article.

[0108] 3. Commercial Trucks

[0109] Figure 4B400B includes a commercial truck 402B for hauling cargo 406B. In some embodiments, 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 plurality of modes of transport to move cargo), and / or any other road-based freight application. 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 moving truck, etc. Cargo 406B may be goods and / or products. Commercial truck 402B may include a trailer for carrying cargo 406B, such as a flatbed trailer, a low bed trailer, a step trailer, a retractable flatbed trailer, a side trailer, etc.

[0110] Environment 400B includes object 410B (in Figure 4B The distance range between the truck and the vehicle is equal to or less than 30 meters.

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

[0112] As shown, LIDAR system 404B in environment 400B may be configured to detect objects (eg, another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) at a close distance (eg, 30 meters or less) from commercial truck 402B.

[0113] Figure 4C 400B (eg, commercial truck 402B, cargo 406B, LIDAR system 404B, etc.).

[0114] Environment 400C includes object 410C (in Figure 4C As shown in the figure, LIDAR system 404B in environment 400C can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a road sign, a pothole, etc.) at a certain distance (e.g., 100 meters) from commercial truck 402B.

[0115] Figure 4D 400B (eg, commercial truck 402B, cargo 406B, LIDAR system 404B, etc.).

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

[0117] In commercial truck applications, due to the increased weight and therefore longer stopping distances required for such vehicles, it is very important to effectively detect objects in all ranges. Due to the above advantages, FM LIDAR systems (e.g., FMCW and / or FMQW systems) or PM LIDAR systems are very suitable for commercial truck applications. Therefore, commercial trucks equipped with such systems can enhance the ability to safely transport people and goods over short or long distances, thereby improving not only the safety of commercial trucks, but also the safety of surrounding vehicles. In various embodiments, such FM or PM LIDAR systems can be used for 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 fully autonomous applications, where the commercial truck is completely operated 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 that uses CW modulation, the modulator modulates the laser continuously. For example, if the modulation period is 10 seconds, the input signal is modulated for the entire 10 seconds. In contrast, in a LIDAR system that uses quasi-CW modulation, the modulator modulates the laser to have both an active portion and an inactive portion. For example, for a 10 second period, the modulator only modulates the laser for 8 seconds (sometimes called the "active portion"), but does not modulate the laser for 2 seconds (sometimes called the "inactive portion"). By doing this, the LIDAR system may be able to reduce power consumption for the 2 seconds because the modulator does not have to provide a continuous signal.

[0120] In frequency modulated continuous wave (FMCW) LIDAR for automotive applications, it may be beneficial to operate the LIDAR system using quasi-continuous wave modulation, where FMCW measurement and signal processing methods are used, but the optical signal is not always in the on state (e.g., enabled, powered, transmitting, etc.). In some embodiments, the duty cycle of the quasi-continuous wave modulation may be equal to or greater than 1% and may be as high as 50%. If the energy in the off 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 in order to coherently integrate all the energy over a longer time scale.

[0121] The term "processing logic" in the present 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, a 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 circuits to perform operations according to embodiments of the present disclosure.

[0122] The "memory" or "memories" described in this disclosure may include one or more volatile or non-volatile memory architectures. The "memory" or "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 disks (DVD), high-definition multimedia / data storage disks, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing device.

[0123] The network may include any network or network system, such as, 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 combination of wireless and wired networks; and a satellite network.

[0124] The communication channel may include or be routed through 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] The computing device may include a desktop computer, a laptop computer, a tablet computer, a phablet, a smartphone, a feature phone, a server computer, or other device. The server computer may be located in a remote data center 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 (e.g., computer) readable storage medium, which, when executed by a machine, causes the machine to perform the described operations. Additionally, the processes may be contained in hardware, such as an application specific integrated circuit ("ASIC") 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, a network device, a personal digital assistant, a 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), magnetic disk storage media, optical storage media, flash memory devices, etc.).

[0128] The above description of the embodiments of the present invention (including the description in the Abstract) is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Although specific embodiments and examples of the present invention are described herein for illustrative purposes, those skilled in the relevant art will recognize that various modifications are possible within the scope of the invention.

[0129] These modifications can be made to the invention 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 in the specification. Instead, the scope of the invention is to be determined entirely by the following claims, which should be interpreted in accordance with established doctrines of claim interpretation.

Claims

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

2. The LIDAR sensor system according to claim 1, wherein: The dual polarization optical antenna comprises a two-dimensional (2D) polarization separation grating coupler having a first port and a second port, wherein: The 2D polarization separation grating is configured to receive a transmit signal on the first port and to provide the return beam having a second polarization to the second port coupled to the second receiver.

3. The LIDAR sensor system of claim 1 , further comprising: a single polarization optical antenna configured to detect the return light 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 return light beam to the first receiver.

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

5. The 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 LIDAR sensor system of claim 1, wherein: The first polarization orientation is orthogonal to the second polarization orientation.

7. The LIDAR sensor system of claim 6, further comprising: A single polarization optical antenna is configured to detect the return light beam having the second polarization orientation.

8. The LIDAR sensor system of claim 1, wherein: the first local oscillator signal being polarized with a third polarization orientation, The second local oscillator signal is polarized with the third polarization orientation, and The transmit signal is polarized with said third polarization before transmission, Wherein, the dual-polarization optical antenna is configured to couple the transmission signal into free space as the transmission light beam.

9. The LIDAR sensor system of claim 8, wherein: The dual polarization optical antenna is configured to couple the return light beam into the at least one LIDAR pixel of the one or more LIDAR pixels as a return signal, Wherein, the return signal is polarized in the third polarization orientation.

10. The LIDAR sensor system of claim 9, wherein: The third polarization orientation is the first polarization orientation or the second polarization orientation.

11. The LIDAR sensor system of claim 1 , wherein: The first receiver includes a first optical mixer, and The second receiver comprises a second optical mixer, wherein the first receiver comprises a first diode pair, the first diode pair being coupled to the first optical mixer and configured to provide a first electrical signal, wherein the first electrical signal is the first signal, wherein the second receiver comprises 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 LIDAR sensor system of claim 1, wherein: The transmit light beam and the return light beam are narrow-band near infrared wavelengths.

13. The LIDAR sensor system of claim 1, wherein: The return beam is the transmitted beam reflected from the object.

14. An autonomous vehicle control system comprising the LIDAR sensor system according to any one of claims 1-13.

15. An autonomous vehicle comprising a LIDAR sensor system according to any one of claims 1-13.

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