LIDAR sensor system including an integrated transceiver

Abstract

A vehicle LIDAR sensor system may include: a light source configured to generate a beam; at least one optical amplifier configured to amplify the beam to generate an amplified beam; an optical power distribution network; a transmitter configured to receive the plurality of distributed beams; and one or more optical systems configured to emit the plurality of distributed beams. The optical power distribution network may include at least one input port configured to receive the amplified beam; one or more optical splitters configured to divide the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and one or more optical isolators configured to coherently interfere with the reflected signals from the plurality of output ports to attenuate the reflected signals.

Description

Technology Field

[0001] This application claims priority and interest to U.S. Application No. 18 / 484,930, filed October 11, 2023, and U.S. Application No. 18 / 599,602, filed March 8, 2024. Each of the above applications is incorporated herein by reference in its entirety. Background Technology

[0002] Light Detection and Ranging (LIDAR) systems use lasers to generate a three-dimensional representation of the surrounding environment. A LIDAR system includes at least one emitter paired with a receiver to form channels, but an array of channels may be used to extend the field of view of the LIDAR system. During operation, each channel emits a laser beam into the environment. The laser beam is reflected from objects within the surrounding environment, and the reflected laser beam is detected by the receiver. A single channel provides ranging information for a single point. Together, the channels are combined to generate a point cloud corresponding to a three-dimensional representation of the surrounding environment.

[0003] The aspects and advantages of the embodiments of the present disclosure may be partially presented in the following description, understood from the following description, or understood through the practice of the embodiments.

[0004] Exemplary embodiments of the present disclosure relate to LIDAR systems. As described in more detail herein, LIDAR systems are used by various devices and platforms (e.g., robot platforms, etc.) to enhance the ability of said devices and platforms to perceive their environment and, in response, perform functions (e.g., autonomously driving within the environment).

[0005] The present disclosure relates, for example, to a LIDAR system for use in a vehicle. A LIDAR system according to exemplary embodiments of the present disclosure includes a LIDAR module comprising an emitter configured to emit a light beam. The LIDAR module includes an optical device configured to split the light beam into a plurality of light beams. The LIDAR module includes an array of light amplifiers configured to amplify the plurality of light beams to generate a plurality of amplified light beams. For example, in some embodiments, the optical power of the amplified light beams may be in the range of 10 decibels greater than the optical power of the plurality of light beams to 30 decibels greater. The LIDAR module includes a transceiver configured to facilitate transmitting the plurality of amplified light beams to the surrounding environment. The transceiver is also configured to receive return light beams from the surrounding environment, and the return light beams may be combined to generate point cloud data representing objects within the surrounding environment.

[0006] An integrated LIDAR system generally consists of a complex circuit of photonic elements that may include multiple types of semiconductor materials. Optical signals (e.g., light signals) typically propagate in a single direction within the LIDAR system through one or more waveguides, such as from a light source to an optical system and / or from an optical system to a signal converter. However, the elements constituting these circuits, the interfaces between the semiconductor materials, and other components of the LIDAR system can reflect a portion of the optical signal back through the LIDAR system. Some active optical components that can be used in a LIDAR system, such as active optical amplifiers, may be sensitive to this back reflection. Therefore, reducing this back reflection can be beneficial for improving the operational characteristics of the LIDAR system.

[0007] The present disclosure provides an approach for implementing an optical isolator in an optical power distribution network, such as an optical power distribution network for an integrated LIDAR system. The optical power distribution network may be a 1×N splitter or may include such a splitter. The 1×N splitter may be formed from cascaded 1×2 splitters. One or more of the splitters may be optical isolators that are actively controlled to reduce the effect of optical signals back-reflected into the optical power distribution network. For example, the first splitter and / or the last row of splitters may be replaced with an optical isolator.

[0008] An optical power distribution network can be coupled to optical amplifiers within a LIDAR system. The optical power distribution network can distribute amplified optical signals to multiple devices (e.g., transmitters and / or optical systems of the LIDAR system). The use of optical isolators can reduce the occurrence of reflected signals returning from these amplified optical signals to the optical amplifier(s). The optical amplifier(s) may be sensitive to such reflections. For example, the optical amplifier(s) may be active nonlinear devices that behave unpredictably when exposed to reflected optical signals at their output ports. Therefore, utilizing optical isolators to reduce reflected optical signals can improve the operational characteristics of the LIDAR system, such as accuracy and reliability.

[0009] An optical isolator may be configured such that an optical signal passing forward through the optical isolator is not attenuated to a significant degree, and a portion of the optical signal back-reflected into the optical isolator coherently interferes with signals within the optical isolator, thereby at least significantly attenuating or removing the reflected signal at the input ports of the isolator. For example, in one embodiment, the optical isolator includes a two-way optical splitter equipped with phase shifters on each output arm of the optical splitter. An electrical signal is applied to at least one of the phase shifters to control the phase of the optical signal so that any reflected signals at the two output ports of the two-way optical splitter coherently interfere. Furthermore, to improve performance when the optical signal reflected from one output port of the splitter is not well balanced with the optical signal reflected from the other output port, the optical isolator may include attenuators on one or both output arms of the splitter, thereby attenuating the stronger of the two reflected signals so that the reflected signals from each output port can destructively interfere.

[0010] Reflected signals not removed by interference may be provided to a power dump port coupled to one or more light dissipation devices, such as, for example, a photoresistor or a photodiode. The light dissipation devices may dissipate the reflected light so that the reflected light is no longer reflected through the LIDAR system. Furthermore, in some embodiments, the power dump port and / or light dissipation devices may be coupled to and / or part of a feedback loop configured to tune an optical isolator (e.g., phase shifters and / or attenuators within each output arm of the isolator). The feedback loop may be configured to tune the optical isolator in response to changes in reflected light signals over time. For example, the feedback loop may generate one or more control signals for the optical isolator to tune the optical isolator based on the reflected signal at the power dump port.

[0011] Exemplary embodiments of the present disclosure may provide a number of technical effects and advantages. As an example, exemplary embodiments of the present disclosure may improve the robustness of a LIDAR system and / or components of a LIDAR system by utilizing one or more optical isolators configured to attenuate reflected signals by coherently interfering the reflected signals. Coherently interfering the reflected optical signals may reduce adverse performance effects of reflected optical signals in a LIDAR system, including but not limited to interference between the reflected optical signals and the optical amplifiers of the LIDAR system, and nonlinear behavior of the optical amplifiers caused by the reflected optical signals. For example, by incorporating optical isolators according to the present disclosure, the LIDAR system may have greater resistance to reflected optical signals. As another example, the present disclosure may improve the performance characteristics of a LIDAR system. For example, by reducing the influence of reflected optical signals on the optical amplifiers of the LIDAR system, the LIDAR system may output more accurate detection results as a result of reduced interference with the optical amplifiers.

[0012] For example, embodiments of the present disclosure provide a LIDAR sensor system for a vehicle. The LIDAR sensor system may include a light source configured to generate a beam. The LIDAR sensor system may include at least one optical amplifier configured to amplify the beam to generate an amplified beam. The LIDAR sensor system may include at least one input port configured to receive the amplified beam; one or more optical splitters configured to split the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and an optical power distribution network comprising one or more optical isolators configured to coherently interfere with the reflected signals at the plurality of output ports to attenuate the reflected signals. The LIDAR sensor system may include a transmitter configured to receive the plurality of distributed beams. The LIDAR sensor system may include one or more optics configured to emit the plurality of distributed beams.

[0013] In some embodiments, one or more optical splitters include a plurality of rows of cascaded two-way optical splitters.

[0014] In some embodiments, one or more optical isolators are configured in the first column of a plurality of columns.

[0015] In some embodiments, one or more optical isolators are configured in the last column of a plurality of columns.

[0016] In some embodiments, one or more optical isolators each comprise: an optical splitter having at least one input port and a plurality of output ports; and a phase shifter each coupled to a plurality of output ports of the optical splitter.

[0017] In some embodiments, the optical splitter of one or more optical isolators includes a two-way splitter having two output ports.

[0018] In some embodiments, one or more optical isolators include one or more attenuators coupled to a plurality of output ports of an optical splitter.

[0019] In some embodiments, a specific attenuator among one or more attenuators may include a Mach-Zehnder modulator. The Mach-Zehnder modulator may include a first optical splitter having two output ports; two phase shifters coupled to the two output ports of the first optical splitter; and a second optical splitter having two input ports each coupled to the two phase shifters. A control signal line may be coupled to a specific phase shifter among the two phase shifters.

[0020] In some embodiments, a specific optical isolator among one or more optical isolators may include a control signal line coupled to a phase shifter in one of the plurality of output ports of an optical splitter.

[0021] In some embodiments, a specific optical isolator among one or more optical isolators includes at least two input ports, and at least one of the at least two input ports is coupled to an optical dissipation device.

[0022] In some embodiments, a specific optical isolator among one or more optical isolators includes at least two input ports, and at least one of the at least two input ports is coupled to an optical dissipation device.

[0023] In some embodiments, at least one optical amplifier is active and nonlinear.

[0024] In some embodiments, one or more optical systems are configured to emit a plurality of distributed beams, and the LIDAR sensor system further includes a receiver configured to receive a reflected beam and determine object detection associated with an object that reflected the reflected beam.

[0025] For example, embodiments of the present disclosure provide an autonomous vehicle (AV) control system. The AV control system may include a LIDAR sensor system. The LIDAR sensor system may include a light source configured to generate a beam. The LIDAR sensor system may include at least one optical amplifier configured to amplify the beam to generate an amplified beam. The LIDAR sensor system may include an optical power distribution network comprising: at least one input port configured to receive the amplified beam; one or more optical splitters configured to divide the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and one or more optical isolators configured to coherently interfere the reflected signals at the plurality of output ports to attenuate the reflected signals. The LIDAR sensor system may include a transmitter configured to receive the plurality of distributed beams. The LIDAR sensor system may include one or more optical systems configured to emit the plurality of distributed beams. The LIDAR sensor system may include a receiver configured to receive a beam reflected from an object and to determine object detection associated with the object. The AV control system may further include one or more sub-control systems configured to control the autonomous vehicle based on object detection.

[0026] In some embodiments, one or more optical splitters include a plurality of rows of cascaded two-way optical splitters.

[0027] In some embodiments, a specific optical isolator among one or more optical isolators may include an optical splitter having at least one input port and a plurality of output ports; and a phase shifter coupled to each of the plurality of output ports of the optical splitter.

[0028] In some embodiments, a specific optical isolator among one or more optical isolators includes an attenuator each coupled to a plurality of output ports of an optical splitter.

[0029] In some embodiments, a specific attenuator among one or more attenuators may include a Mach-Zehnder modulator. The Mach-Zehnder modulator may include a first optical splitter having two output ports; two phase shifters coupled to the two output ports of the first optical splitter; and a second optical splitter having two input ports each coupled to the two phase shifters. A control signal line may be coupled to a specific phase shifter among the two phase shifters.

[0030] For example, embodiments of the present disclosure provide an autonomous vehicle. The autonomous vehicle may include a LIDAR sensor system. The LIDAR sensor system may include a light source configured to generate a beam. The LIDAR sensor system may include at least one optical amplifier configured to amplify the beam to generate an amplified beam. The LIDAR sensor system may include an optical power distribution network comprising: at least one input port configured to receive the amplified beam; one or more optical splitters configured to divide the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and one or more optical isolators configured to coherently interfere the reflected signals at the plurality of output ports to attenuate the reflected signals. The LIDAR sensor system may include a transmitter configured to receive the plurality of distributed beams. The LIDAR sensor system may include one or more optical systems configured to emit the plurality of distributed beams. The LIDAR sensor system may include a receiver configured to receive a beam reflected from an object and to determine object detection associated with the object. The autonomous vehicle may further include one or more sub-control systems configured to control the autonomous vehicle based on object detection.

[0031] In some embodiments, one or more optical isolators, a specific optical isolator comprises an optical splitter having at least one input port and a plurality of output ports, and phase shifters each coupled to the plurality of output ports of the optical splitter; and one or more optical isolators, a specific optical isolator comprises an attenuator each coupled to the plurality of output ports of the optical splitter. The attenuator may be a Mach-Zehnder modulator. The Mach-Zehnder modulator may comprise a first optical splitter having two output ports; two phase shifters coupled to the two output ports of the first optical splitter; and a second optical splitter having two input ports each coupled to the two phase shifters. A control signal line may be coupled to a specific phase shifter among the two phase shifters.

[0032] For example, embodiments of the present disclosure provide a LIDAR sensor system for a vehicle. The LIDAR sensor system may include a light source configured to generate a beam. The LIDAR sensor system may include an optical power distribution network. The optical power distribution network may include at least one input port configured to receive the beam. The optical power distribution network may include a plurality of output ports configured to output the beam. The optical power distribution network may include one or more optical isolators configured to coherently interfere with reflected signals received at the plurality of output ports to attenuate the reflected signals. The LIDAR sensor system may include a transmitter configured to transmit the beam.

[0033] In some embodiments, the LIDAR sensor system further includes at least one optical amplifier configured to amplify a beam.

[0034] In some embodiments, the optical power distribution network further includes one or more optical splitters configured to split a beam.

[0035] In some embodiments, one or more optical splitters comprise a plurality of rows of cascaded two-way optical splitters, and one or more optical isolators are configured in one of the first row or the last row of the plurality of rows.

[0036] In some embodiments, one or more optical isolators each include: an optical splitter comprising at least one input port and a plurality of output ports; and a phase shifter each coupled to a plurality of output ports of the optical splitter.

[0037] In some embodiments, the optical splitter of one or more optical isolators includes a two-way splitter having two output ports.

[0038] In some embodiments, one or more optical isolators include one or more attenuators coupled to a plurality of output ports of an optical splitter.

[0039] In some embodiments, a specific attenuator among one or more attenuators is or includes a Mach-Zehnder modulator, and the Mach-Zehnder modulator includes: a first optical splitter having two output ports; two phase shifters coupled to the two output ports of the first optical splitter; and a second optical splitter having two input ports each coupled to the two phase shifters. In some embodiments, a control signal line is coupled to a specific phase shifter among the two phase shifters.

[0040] In some embodiments, a specific optical isolator among one or more optical isolators includes a control signal line coupled to a phase shifter in one of the plurality of output ports of an optical splitter.

[0041] In some embodiments, a specific optical isolator among one or more optical isolators includes at least two input ports. In some embodiments, at least one of the at least two input ports is coupled to an optical dissipation device.

[0042] In some embodiments, a specific optical isolator among one or more optical isolators includes at least two input ports. In some embodiments, at least one of the at least two input ports is coupled to an optical dissipation device.

[0043] In some embodiments, at least one optical amplifier is active and nonlinear.

[0044] In some embodiments, the LIDAR sensor system further includes a receiver configured to receive a reflected beam and determine object detection associated with the object that reflected the reflected beam.

[0045] For example, embodiments of the present disclosure provide an AV control system. The AV control system may include a LIDAR sensor system. The LIDAR sensor system may include a light source configured to generate a beam. The LIDAR sensor system may include an optical power distribution network. The optical power distribution network may include at least one input port configured to receive a beam. The optical power distribution network may include a plurality of output ports configured to output a beam. The optical power distribution network may include one or more optical isolators configured to coherently interfere with reflected signals received at the plurality of output ports to attenuate the reflected signals. The LIDAR sensor system may include a transmitter configured to transmit a beam.

[0046] In some embodiments, a specific optical isolator among one or more optical isolators comprises: an optical splitter having at least one input port and a plurality of output ports; and a phase shifter each coupled to a plurality of output ports of the optical splitter.

[0047] In some embodiments, a specific optical isolator among one or more optical isolators includes an attenuator each coupled to a plurality of output ports of an optical splitter.

[0048] For example, embodiments of the present disclosure provide an optical power distribution network. The optical power distribution network may include at least one input port configured to receive a beam. The optical power distribution network may include one or more optical splitters configured to divide the beam into a plurality of distributed beams. The optical power distribution network may include a plurality of output ports configured to provide each of the distributed beams. The optical power distribution network may include one or more optical isolators configured to coherently interfere with reflected signals received at the plurality of output ports to attenuate the reflected signals.

[0049] In some embodiments, one or more optical splitters comprise a plurality of rows of cascaded two-way optical splitters, and one or more optical isolators are configured in the first row of the plurality of rows.

[0050] In some embodiments, a specific optical isolator among one or more optical isolators comprises: an optical splitter having at least one input port and a plurality of output ports; and a phase shifter each coupled to a plurality of output ports of the optical splitter.

[0051] In some embodiments, a specific optical isolator among one or more optical isolators includes an attenuator each coupled to a plurality of output ports of an optical splitter.

[0052] Other exemplary aspects of the present disclosure relate to other systems, methods, vehicles, apparatuses, tangible non-transient computer-readable media, and devices for operation and / or motion prediction of a device comprising a LIDAR system having a LIDAR module according to the exemplary aspects of the present disclosure.

[0053] These features and other features, aspects, and advantages of the various embodiments of the present disclosure will be better understood by referring to the following description and the appended claims. The appended drawings, incorporated herein and constituting a part thereof, illustrate embodiments of the present disclosure and serve to explain the relevant principles together with the description. Brief explanation of the drawing

[0054] FIG. 1 illustrates a block diagram of an exemplary system according to some embodiments of the present disclosure. FIG. 2 illustrates a block diagram of an exemplary LIDAR system according to some embodiments of the present disclosure. FIG. 3 illustrates a diagram of an exemplary power distribution network according to some embodiments of the present disclosure. FIG. 4 illustrates a diagram of an exemplary optical system according to some embodiments of the present disclosure. FIG. 5 illustrates a diagram of an exemplary optical isolator according to some embodiments of the present disclosure. FIG. 6 illustrates a diagram of an exemplary optical isolator according to some embodiments of the present disclosure. FIG. 7 illustrates a diagram of an exemplary optical isolator according to some embodiments of the present disclosure. FIG. 8 illustrates a diagram of an exemplary power distribution network according to some embodiments of the present disclosure. Specific details for implementing the invention

[0055] The following description explains the technology of the present disclosure in the context of autonomous vehicles for illustrative purposes only. As described herein, the technology is not limited to autonomous vehicles and may be implemented in various devices as well as other robots and computing systems. For example, the systems and methods disclosed herein may be implemented in various ways, including but not limited to computer-implemented methods, autonomous vehicle systems, autonomous vehicle control systems, robot platform systems, general robot device control systems, computing devices, etc.

[0056] With reference to FIGS. 1 through 8, exemplary embodiments of the present disclosure are described in more detail. FIG. 1 illustrates a block diagram of an exemplary autonomous vehicle control system (100) for an autonomous vehicle according to some embodiments of the present disclosure. The autonomous vehicle control system (100) may be implemented by a computing system of the autonomous vehicle. The autonomous vehicle control system (100) may include one or more sub-control systems (101) that operate to obtain input from sensor(s) (102) or other input devices of the autonomous vehicle control system (100). In some embodiments, the sub-control system(s) (101) may additionally obtain platform data (108) (e.g., map data (110)) from a local or remote storage. The sub-control system(s) (101) may generate control outputs for controlling the autonomous vehicle (e.g., via a platform control device (112), etc.) based on sensor data (104), map data (110), or other data. The sub-control system (101) may include different sub-systems for performing various autonomous driving operations. The sub-systems may include a position estimation system (130), a perception system (140), a planning system (150), and a control system (160). The position estimation system (130) may determine the position of the autonomous vehicle within an environment; the perception system (140) may detect, classify, and track objects and actors within an environment; the planning system (150) may determine a trajectory for the autonomous vehicle; and the control system (160) may convert the trajectory into vehicle controls for controlling the autonomous vehicle. The sub-control system(s) (101) may be implemented by one or more onboard computing system(s). The sub-systems may include one or more processors and one or more memory devices.One or more memory devices may store instructions executable by one or more processors to enable one or more processors to perform operations or functions related to subsystems. The computing resources of the sub-control system(s) (101) may be shared among the subsystems, or one subsystem may have a set of dedicated computing resources.

[0057] In some embodiments, the autonomous vehicle control system (100) may be implemented for or by an autonomous vehicle (e.g., a ground-based autonomous vehicle). The autonomous vehicle control system (100) may perform various processing techniques on inputs (e.g., sensor data (104), map data (110)) to recognize and understand the surrounding environment of the vehicle and to generate a set of appropriate control outputs for implementing a vehicle motion plan (e.g., including one or more trajectories) to pass through the surrounding environment of the vehicle. In some embodiments, the autonomous vehicle implementing the autonomous vehicle control system (100) may perform driving, navigating, operations, etc. with minimal or no interaction from a human operator (e.g., a driver, a pilot, etc.).

[0058] In some embodiments, the autonomous vehicle may be configured to operate in multiple modes of operation. For example, the autonomous vehicle may be configured to operate in a fully autonomous mode of operation (e.g., self-driving, etc.) in which the autonomous driving platform can be controlled without user input (e.g., driving and navigation can be performed without input from a human operator inside the autonomous vehicle or remotely). The autonomous vehicle may operate in a semi-autonomous mode of operation in which it can be operated through some input from a human operator inside the autonomous vehicle (or a human operator remotely from the autonomous driving platform). In some embodiments, the autonomous vehicle may enter a manual mode of operation in which it is fully controllable by a human operator (e.g., a human driver, etc.) and the performance of autonomous navigation (e.g., self-driving, etc.) may be prohibited or disabled (e.g., temporarily, permanently, etc.). The autonomous vehicle may be configured to operate in different modes, such as a parking or sleep mode (for use between tasks, such as waiting to provide trips / services, recharging, etc.). In some embodiments, the autonomous vehicle may implement vehicle driving assistance technologies (e.g., collision mitigation systems, power assist steering, etc.) to assist a human operator of the autonomous driving platform, for example, (e.g., while in manual mode).

[0059] The autonomous vehicle control system (100) may be mounted on an autonomous vehicle (e.g., on top or inside) and may be configured to operate the autonomous vehicle in various environments. The environment may be a real environment or a simulated environment. In some embodiments, one or more simulation computing devices may simulate one or more of sensors (102), sensor data (104), communication interface(s) (106), platform data (108), or platform control devices (112) to simulate the operation of the autonomous vehicle control system (100).

[0060] In some embodiments, the sub-control system(s) (101) may communicate with one or more networks or other systems through communication interface(s) (106). The communication interface(s) (106) may include suitable components for interfacing with one or more networks, such as transmitters, receivers, ports, controllers, antennas, or other suitable components that may help facilitate communication, and in some embodiments, the communication interface(s) (106) may include multiple components (e.g., antennas, transmitters, or receivers, etc.) that enable the implementation and utilization of various communication technologies (e.g., multiple-input, multiple-output (MIMO) technology, etc.).

[0061] In some embodiments, the sub-control system(s) (101) may communicate with one or more computing devices located remotely from the autonomous vehicle via one or more networks using communication interface(s) (106). For example, in some embodiments, one or more inputs, data, or functions of the sub-control system(s) (101) may be supplemented or replaced by a remote system communicating via the communication interface(s) (106). For example, in some embodiments, map data (110) may be downloaded to a remote system via a network using the communication interface(s) (106). In some embodiments, one or more of the position estimation system (130), perception system (140), planning system (150), or control system (160) may be updated, influenced, nudged, or communicated by the remote system for assistance, maintenance, situational response override, management, etc.

[0062] Sensor(s) (102) may be mounted on an autonomous driving platform. In some embodiments, the sensor(s) (102) may include one or more types of sensors. For example, one or more sensors may include image capture devices (e.g., visible light spectrum cameras, infrared cameras, etc.). Additionally or alternatively, the sensor(s) (102) may include one or more depth capture devices. For example, the sensor(s) (102) may include one or more LIDAR sensor(s) or Radio Detection and Ranging (RADAR) sensor(s). The sensor(s) (102) may be configured to generate point data representing at least a portion of a 360-degree view of the surrounding environment. The point data may be point cloud data (e.g., 3D LIDAR point cloud data, RADAR point cloud data). In some embodiments, one or more of the sensor(s) (102) for capturing depth information may be fixed to a rotating device to rotate the sensor(s) (102) around an axis. The sensor(s) (102) may be rotated around an axis while capturing data in interval sector packets representing different parts of a 360-degree view of the surrounding environment of the autonomous driving platform. In some embodiments, one or more of the sensor(s) (102) for capturing depth information may be in a solid state.

[0063] Sensor(s) (102) may be configured to represent at least a part of the environment of the autonomous vehicle or to capture sensor data (104) associated therewith. Sensor data (104) may include image data (e.g., 2D camera data, video data, etc.), RADAR data, LIDAR data (e.g., 3D point cloud data, etc.), audio data, or other types of data. In some embodiments, sub-control system(s) (101) may obtain input from additional types of sensors, such as an Inertial Measurement Unit (IMU), an altimeter, an inclinometer, an odometry device, a position or positioning device (e.g., GPS, a compass), a wheel encoder, or other types of sensors. In some embodiments, sub-control system(s) (101) may obtain sensor data (104) associated with specific component(s) or system(s) of the autonomous vehicle. This sensor data (104) may represent, for example, wheel speed, component temperature, steering angle, cargo or passenger status, etc. In some embodiments, the sub-control system(s) (101) may acquire sensor data (104) related to ambient conditions, such as environmental or weather conditions. In some embodiments, the sensor data (104) may include multi-modal sensor data. Multi-modal sensor data may be acquired by at least two different types of sensor(s) (e.g., sensors (102)) and may represent static and / or dynamic object(s) or actor(s) within the environment of the autonomous vehicle. Multi-modal sensor data may include at least two types of sensor data (e.g., camera and LIDAR data). In some embodiments, the autonomous vehicle may utilize sensor data (104) from sensors located remotely (e.g., offboard) from the autonomous vehicle.This may include, for example, sensor data (104) captured by another autonomous vehicle.

[0064] The sub-control system(s) (101) can acquire map data (110) related to the environment in which the autonomous vehicle has been, is, or will be located. The map data (110) may provide information about the environment or geographical area. For example, the map data (110) may include identification information and location of different passageways (e.g., roads, etc.), passageway sections (e.g., road sections, etc.), buildings, or other items or objects (e.g., streetlights, crosswalks, curbs, etc.); location and direction of boundaries or boundary markings (e.g., lanes, parking lanes, turning lanes, bicycle lanes, other lanes, etc.); traffic control data (e.g., location and instructions of signs, traffic lights, other traffic control devices, etc.); obstacle information (e.g., temporary or permanent blockages, etc.); event data (e.g., road closures / changes in traffic rules due to parades, concerts, sports events, etc.); and nominal vehicle route data (e.g., indicating an ideal vehicle route following the center of a specific lane). Alternatively, any other map data may be provided that provides information to help the autonomous vehicle understand its surrounding environment and its relationship with it. In some embodiments, the map data (110) may include high-definition map information. Additionally or alternatively, the map data (110) may include sparse map data (e.g., lane graphs, etc.). In some embodiments, sensor data (104) may be used to fuse with or update the map data (110) in real time.

[0065] The sub-control system(s) (101) may include a position estimation system (130), which can provide the autonomous vehicle with an understanding of its position and orientation within the environment. In some examples, the position estimation system (130) may support one or more other subsystems of the sub-control system(s) (101) by providing, for example, an integrated local reference frame for performing a recognition action, a planning action, or a control action.

[0066] In some embodiments, the position estimation system (130) can determine the current position of the autonomous vehicle. The current position may include a global position (e.g., relative to a georeferenced anchor, etc.) or a relative position (e.g., relative to an object in the environment, etc.). The position estimation system (130) may generally include or interface with any device or circuit for analyzing the position or position change of the autonomous vehicle. For example, the position estimation system (130) may determine the position using one or more of inertial sensors (e.g., inertial measurement unit(s), etc.), a satellite positioning system, radio receivers, networking devices (e.g., based on IP addresses, etc.), network access points or other network components (e.g., cellular towers, Wi-Fi access points, etc.), triangulation or proximity to, or other suitable techniques. The location of the autonomous vehicle can be used by various subsystems of the sub-control system(s) (101) or provided to a remote computing system (e.g., using communication interface(s) (106).

[0067] In some embodiments, the position estimation system (130) may register the relative positions of elements of the surrounding environment of the autonomous vehicle along with recorded positions in the map data (110). For example, the position estimation system (130) may determine the position of the autonomous vehicle within the corresponding environment by processing sensor data (104) (e.g., LIDAR data, RADAR data, camera data, etc.) to align or register them on a map of the surrounding environment (e.g., from the map data (110)). Thus, in some embodiments, the autonomous vehicle may identify its position within the surrounding environment (e.g., across six axes, etc.) based on a search of the map data (110). In some embodiments, given an initial position, the position estimation system (130) may update the position of the autonomous vehicle through gradual realignment based on deviations recorded or estimated from the initial position. In some embodiments, the position may be registered directly within the map data (110).

[0068] In some embodiments, the map data (110) may include large volume data subdivided into geographic tiles so that a desired area of ​​the map stored in the map data (110) can be reconstructed from one or more tiles. For example, a plurality of tiles selected from the map data (110) may be joined together by a sub-control system (101) based on a location obtained by a location estimation system (130) (e.g., a plurality of tiles selected near that location).

[0069] In some embodiments, the position estimation system (130) can determine the (e.g., relative or absolute) positions of attachments or accessories for an autonomous vehicle. For example, the autonomous vehicle may be associated with a cargo platform, and the position estimation system (130) may provide the positions of one or more points on the cargo platform. For example, the cargo platform may include a trailer or other device towed, attached to, or operated by the autonomous vehicle, and the position estimation system (130) may provide data describing the (e.g. absolute, relative) positions of the cargo platform as well as the autonomous vehicle. This information may be obtained by other autonomy systems to help operate the autonomous vehicle.

[0070] The sub-control system(s) (101) may include a perception system (140), which enables the autonomous driving platform to detect, classify, and track objects and actors within the environment. Environmental features or objects recognized within the environment may be those within the field of view of the sensor(s) (102) or those predicted to be obscured from the sensor(s) (102). This may include object(s) that are not moving or are not predicted to move (static objects) or object(s) that are moving or are predicted to move (dynamic objects / actors).

[0071] The perception system (140) can determine one or more states (e.g., current or past state(s), etc.) of one or more objects within the surrounding environment of the autonomous vehicle. For example, the state(s) may describe an estimate of the object's current or past position (e.g., for a given time, time period, etc.); current or past velocity / speed; current or past acceleration; current or past direction of travel; current or past direction; size / footprint (e.g., expressed as boundary shape, object highlighting, etc.); classification (e.g., pedestrian class vs. vehicle class vs. bicycle class, etc.); associated uncertainties; or other state information. In some embodiments, the perception system (140) may determine the state(s) using one or more algorithms or machine learning models configured to identify / classify objects based on inputs from the sensor(s) (102). The perception system may use different modalities of the sensor data (104) to generate a representation of the environment to be processed by one or more algorithms or machine learning models. In some embodiments, the state(s) of one or more identified or unidentified objects may be maintained and updated over time as the autonomous vehicle continues to recognize the objects or interact with them (e.g., maneuvering together or around, yielding, etc.). In this way, the perception system (140) may provide an understanding of the current state of the environment (e.g., including objects within it) based on a record of previous states of the environment (e.g., movement history of objects within it). This information may help the autonomous vehicle plan its motion in the environment.

[0072] The sub-control system(s) (101) may include a planning system (150), which may be configured to determine how the autonomous driving platform interacts and moves within an environment. The planning system (150) may determine one or more motion plans for the autonomous driving platform. A motion plan may include one or more trajectories (e.g., motion trajectories) representing a path that the autonomous vehicle must follow. A trajectory may have a specific length or time range. The length or time range may be defined by the computational planning horizon of the planning system (150). A motion trajectory may be defined by one or more waypoints (along with associated coordinates). The waypoint(s) may be future location(s) of the autonomous driving platform. Motion plans may be continuously generated, updated, and considered by the planning system (150).

[0073] The planning system (150) can determine a strategy for the autonomous driving platform. The strategy may be a set of individual decisions made by the autonomous driving platform (e.g., yielding to an actor, reverse yielding to an actor, merging, changing lanes). The strategy may be selected from among multiple potential strategies. The selected strategy may be the lowest cost strategy determined by one or more cost functions. The cost functions may evaluate, for example, the probability of collision with another actor or object.

[0074] The planning system (150) can determine a desired trajectory for executing a strategy. For example, the planning system (150) can obtain one or more trajectories for executing one or more strategies. The planning system (150) can evaluate and rank the trajectories or strategies (e.g., scores, costs, rewards, constraints, etc.). For example, the planning system (150) can use prediction output(s) representing interactions (e.g., proximity, intersection, etc.) between the trajectories of an autonomous driving platform and one or more objects to indicate the evaluation of candidate trajectories or strategies for an autonomous driving platform. In some embodiments, the planning system (150) can utilize static cost(s) (e.g., "lane boundary avoidance," "jerk minimization," etc.) to evaluate the trajectories of an autonomous driving platform. Additionally or alternatively, the planning system (150) may utilize dynamic cost(s) to evaluate the trajectories or strategies of the autonomous driving platform based on the predicted outcomes for the current motion scenario (e.g., predicted trajectories or strategies leading to interactions between actors, predicted trajectories or strategies leading to interactions between actors and the autonomous driving platform, etc.). The planning system (150) may rank the trajectories based on one or more static costs, one or more dynamic costs, or a combination thereof. The planning system (150) may select a motion plan (and a corresponding trajectory) based on the ranking of multiple candidate trajectories. In some embodiments, the planning system (150) may select the highest-ranked candidate or the highest-ranked feasible candidate.

[0075] After that, the planning system (150) can verify the selected trajectory against one or more constraints before the selected trajectory is executed by the autonomous driving platform.

[0076] To assist in motion planning decisions, the planning system (150) may be configured to perform a prediction function. The planning system (150) may predict future state(s) of the environment. This may include predicting future state(s) of other actors within the environment. In some embodiments, the planning system (150) may predict future state(s) based on current or past state(s) (e.g., formed or maintained by the perception system (140)). In some embodiments, the future state(s) may be or include predicted trajectories of objects within the environment, e.g., other actors (e.g., locations over time). In some embodiments, one or more of the future state(s) may include one or more associated probabilities (e.g., marginal probability, conditional probability). For example, one or more probabilities may include one or more probabilities conditioned on strategies or trajectory options available in the autonomous vehicle. Additionally or alternatively, the probabilities may include probabilities conditioned on trajectory options available to one or more other actors.

[0077] To implement selected motion plan(s), the sub-control system(s) (101) may include a control system (160) (e.g., a vehicle control system). Generally, the control system (160) may provide an interface between the sub-control system(s) (101) and the platform control devices (112) to implement strategies and motion plan(s) generated by the planning system (150). For example, the control system (160) may implement the selected motion plan / trajectory to control the movement of the autonomous driving platform through the environment by following a selected trajectory (e.g., waypoints included therein). The control system (160) may, for example, convert the motion plan into commands for appropriate platform control devices (112) (e.g., acceleration control, braking control, steering control, etc.). For example, the control system (160) can convert the selected motion plan into commands such as adjusting a steering component (e.g., steering angle) by a specific angle, applying a braking force of a specific magnitude, or increasing / decreasing speed. In some embodiments, the control system (160) can communicate with platform control units (112) through communication channels including, for example, one or more data buses (e.g., CAN (Controller Area Network), etc.), onboard diagnostic connectors (e.g., OBD-II), or a combination of wired or wireless communication links. The platform control units (112) can transmit or receive data, messages, signals, etc. to or from the sub-control system(s) (101) (or vice versa) through the communication channel(s).

[0078] The sub-control system(s) (101) can receive assistance signal(s) from the remote assistance system (170) via the communication interface(s) (106). The remote assistance system (170) can communicate with the sub-control system(s) (101) via a network. In some embodiments, the sub-control system(s) (101) can initiate a communication session with the remote assistance system (170). For example, the sub-control system(s) (101) can initiate a session based on or in response to a trigger. In some embodiments, the trigger may be an alarm, an error signal, a map feature, a request, a location, a traffic condition, a road condition, etc.

[0079] After starting a session, the sub-control system(s) (101) may provide context data to the remote support system (170). The context data may include sensor data (104) and state data of the autonomous vehicle. For example, the context data may include a live camera feed from the autonomous vehicle's camera and the autonomous vehicle's current speed. An operator of the remote support system (170) (e.g., a human operator) may select support signals using the context data. The support signal(s) may provide values ​​or adjustment values ​​for various operation parameters or characteristics of the sub-control system(s) (101). For example, the support signal(s) may include waypoint(s) (e.g., obstacle bypass path, lane change, etc.), speed or acceleration profiles (e.g., speed limit, etc.), relative motion commands (e.g., convoy formation, etc.), operation characteristics (e.g., use of assistance system, energy saving processing mode, etc.), or other signals to support the sub-control system(s) (101).

[0080] The sub-control system(s) (101) may use support signal(s) as inputs to one or more autonomous driving subsystems for performing autonomous driving functions. For example, the planning system (150) may receive support signal(s) as inputs for generating a motion plan. For example, the support signal(s) may include constraints for generating a motion plan. Additionally or alternatively, the support signal(s) may include cost or compensation adjustment values ​​to influence the motion plan by the planning system (150). Additionally or alternatively, the support signal(s) may be considered by the sub-control system(s) (101) as proposed inputs to be considered in addition to other received data (e.g., sensor inputs, etc.).

[0081] The sub-control system(s) (101) may not be platform-dependent, and the control system (160) may provide control commands to the platform control unit (112) for various platforms for autonomous movement (e.g., multiple different autonomous driving platforms equipped with autonomous control systems). This may include various types of autonomous vehicles from various manufacturers / developers that operate in various environments and perform one or more vehicle services in some embodiments (e.g., sedans, vans, SUVs, trucks, electric vehicles, internal combustion engine vehicles, etc.).

[0082] FIG. 2 is a block diagram illustrating an exemplary environment of a LIDAR sensor system for an autonomous vehicle according to some embodiments. The environment includes a LIDAR sensor system (200) comprising a transmit (Tx) path and a receive (Rx) path. The Tx path includes one or more Tx input / output ports, and the Rx path includes one or more Rx input / output ports. In some embodiments, a semiconductor substrate and / or a semiconductor package may include the Tx path and the Rx path. In some embodiments, the semiconductor substrate and / or the semiconductor package may include at least one of a silicon photonics circuit, a programmable logic controller (PLC), or a III-V semiconductor circuit.

[0083] In some embodiments, the first semiconductor substrate and / or the first semiconductor package may include a Tx path, and the second semiconductor substrate and / or the second semiconductor package may include an Rx path. In some configurations, Rx input / output ports and / or Tx input / output ports may exist (or be formed / placed / located) along one or more edges of one or more semiconductor substrates and / or semiconductor packages.

[0084] The LIDAR sensor system (200) includes one or more transmitters (220) and one or more receivers (222). The LIDAR sensor system (200) further includes one or more optical systems (210) (e.g., oscillatory scanner, unidirectional scanner, Risley prism, circulator optic, and / or beam collimator, etc.) coupled to the LIDAR sensor system (200) (e.g., transmitter (220) and / or receiver (222)). In some embodiments, one or more optical systems (210) may be coupled to a Tx path through one or more Tx input / output ports. In some embodiments, one or more optical systems (210) may be coupled to an Rx path through one or more Rx input / output ports.

[0085] The LIDAR sensor system (200) may be coupled to one or more sub-control system(s) (101) (e.g., the sub-control system(s) (101) of FIG. 1). In some embodiments, the sub-control system(s) (101) may be coupled to an Rx path through one or more Rx input / output ports. For example, the sub-control system(s) (101) may receive LIDAR outputs from the LIDAR sensor system (200). The sub-control system(s) (101) may control a vehicle (e.g., an autonomous vehicle) based on the LIDAR outputs.

[0086] The Tx path may include a light source (202), a modulator (204A), a modulator (204B), an amplifier (206), and one or more transmitters (220). The Rx path may include one or more receivers (222), a mixer (208), a detector (212), a transimpedance amplifier (TIA) (214), and one or more analog-to-digital converters (ADCs). Although FIG. 2 illustrates only a selected number of components, the LIDAR sensor system (200) may include any number of components and / or input / output channels (in any combination) interconnected in any arrangement to facilitate the combination of multiple functions of the LIDAR system to support the operation of a vehicle.

[0087] The light source (202) may be configured to generate an optical signal (or beam) derived from (or associated with) a local oscillator (LO) signal. In some cases, the light source (202) may be configured to output an optical signal having an operating wavelength. In some embodiments, the optical signal may have an operating wavelength equal to or substantially equal to 1550 nanometers. In some embodiments, the optical signal may have an operating wavelength between 1400 nanometers and 1440 nanometers. However, the wavelength of the optical signal is not limited to the specific wavelengths described in this paragraph. The optical signal may have any wavelength suitable for design purposes within the scope of the invention.

[0088] The light source (202) may be configured to provide an optical signal to a modulator (204A), and the modulator (204A) may be configured to modulate the phase and / or frequency of the optical signal based on a first radio frequency (RF) signal (e.g., "RF1" signal) to generate an optical signal modulated in a manner such as continuous wave (CW) modulation or quasi-continuous wave (quasi-CW) modulation. The modulator (204A) may be configured to transmit the modulated optical signal to an amplifier (206). The amplifier (206) may be configured to amplify the modulated optical signal to generate an amplified optical signal. The amplified optical signal may be provided to a power distribution network (215). The power distribution network (215) may divide the amplified optical signal into a plurality of beams provided to an optical system (210) through one or more transmitters (220). One or more transmitters (220) may include one or more optical waveguides or antennas. In some embodiments, the modulator (204A) and / or the modulator (204B) may have a bandwidth between 400 megahertz (MHz) and 1000 MHz. However, the bandwidths of the modulators are not limited to the specific bandwidths described in this paragraph. The modulators may have any bandwidth suitable for design purposes within the scope of the invention.

[0089] The optical system (210) may be configured to steer the amplified optical signal(s) received from the Tx path toward an object (218) in the environment within a given field of view, receive a return signal reflected back from the object (218), and provide the return signal to a mixer (208) in the Rx path through one or more receivers (222). One or more receivers (222) may include one or more optical waveguides or antennas. In some configurations, the transmitter (220) and the receiver (222) may collectively constitute one or more transceivers. In some configurations, one or more transceivers may include a monostatic transceiver or a bistatic transceiver.

[0090] The light source (202) may be configured to provide an LO signal to a modulator (204B), and the modulator (204B) may be configured to modulate the phase and / or frequency of the LO signal based on a second RF signal (e.g., "RF2" signal) to generate a modulated LO signal (e.g., using continuous wave (CW) modulation or quasi-continuous wave modulation), and to transmit the modulated LO signal to a mixer (208) in the Rx path. The mixer (208) may be configured to mix the modulated LO signal with a return signal (e.g., combine, multiply, etc.) to generate a down-converted signal, and to transmit the down-converted signal to a detector (212).

[0091] In some configurations, the mixer (208) may be configured to transmit the modulated LO signal to the detector (212). The detector (212) may be configured to generate an electrical signal based on the down-converted signal and transmit the generated electrical signal to the TIA (214). In some configurations, the detector (212) may be configured to generate an electrical signal based on the down-converted signal and the modulated signal. The TIA (214) may be configured to amplify the electrical signal and transmit the amplified electrical signal to the sub-control system(s) (101) through one or more ADCs (224). In some embodiments, the TIA (214) may be configured to 5 picowatts per square root Hertz (i.e., 5 × 10⁻¹⁰ per square root Hertz). -12 It may have a peak noise equivalent power (NEP) of less than watts. In some embodiments, the TIA (214) may have a gain between 4 kilohms and 25 kilohms. In some embodiments, the detector (212) and / or the TIA (214) may have a 3-decibel bandwidth between 80 kilohertz (kHz) and 450 megahertz (MHz).

[0092] The sub-control system(s) (101) may be configured to determine the distance to an object (218) and / or measure the speed of the object (218) based on one or more electrical signals received from the TIA through one or more ADCs (224).

[0093] FIG. 3 illustrates a diagram of an exemplary power distribution network (300) according to some embodiments of the present disclosure. The power distribution network (300) may include at least one input port (302) configured to receive a beam. The beam may be, for example, an amplified beam from an optical amplifier. The operating characteristics of some LIDAR systems incorporating the power distribution network (300) may be improved by mitigating the effect of reflected power at the input port (302).

[0094] The power distribution network (300) may include one or more optical splitters (310). The optical splitter (310) may be configured to split a beam (e.g., an amplified beam) from an input port (302) into a plurality of distributed beams. The power distribution network (300) may further include a plurality of output ports (304) configured to provide each of the plurality of distributed beams. For example, the output ports (304) may be coupled to one or more transmitters configured to provide the distributed beams to an optical system or other downstream components. In some embodiments, the splitter (310) may be a two-way splitter or a 1×2 splitter. A two-way splitter may have a single input port (312) and two output ports (314). An optical signal or beam received at the input port (312) may be split evenly between the two output ports (314). Any suitable splitter (310), such as a 2×2 splitter, a 1×4 splitter, etc., may be used according to exemplary embodiments of the present disclosure.

[0095] The power distribution network (300) may further include one or more optical isolators (320). The optical isolators (320) may be configured to coherently interfere with the reflected signals from a plurality of output ports (304) to attenuate the reflected signals. For example, some energy from the signals provided by the output ports (304) may be back-reflected toward the power distribution network (300). This reflected power may interfere with the operation of components coupled to the input ports (302) of the power distribution network (300), such as active optical amplifiers, for example.

[0096] The optical isolator (320) may include one or more tunable or active components, such as, for example, a phase modulator, a frequency modulator, etc. The optical isolator (320) may be controlled by one or more control signals (306) to modify signals propagating through the optical isolator (320). In particular, the optical isolator (320) may be controlled so that the reflected power interferes coherently with the beams from the optical splitter (310). The interference may reduce the reflected power (e.g., by destructive interference).

[0097] The optical isolator (320) may include two input ports (322, 323) and one or more output ports (324). The first input port (322) may be coupled to the output port (314) of the optical splitter (310). Additionally, the second input port (323) may be coupled to the power dump port (308). When power is reflected from the output port (324) of the optical isolator (320), the power may be split between the input ports (322, 323) of the optical isolator. Thus, most or all of the remaining reflected power may be directed to the power dump port(s) (308). The power dump port(s) (308) may be coupled to light dissipation devices, such as photoresistors, photodiodes, or other suitable devices configured to convert reflected power into a form that does not interfere with the rest of the system. For example, a photoresistor or photodiode may convert reflected power into light in free space. That light may be emitted from the system and dissipated into free space so as not to interfere with the system.

[0098] In some embodiments, the power distribution network (300) may include a plurality of rows of cascaded two-way optical splitters. The cascaded optical splitters used herein represent an arrangement of splitters (310) or other devices arranged in a progressive series of rows. Each row may have one splitter (310) (or other elements such as an isolator (320)) for each output port (314) of the splitters (310) of the previous row. For example, in the case of a two-way optical splitter having two output ports, the subsequent row may have two splitters (310) for each splitter (310) of the previous row. In the example of FIG. 3, the first column (342) may have one splitter (310), and the second column (344) may have two splitters (310). Furthermore, the third column (346) may have four isolators (320). In this way, the number of output ports (304) of the power distribution network (300) is 2 X-1 It can be expressed as, where X is the number of columns.

[0099] In the example of FIG. 3, the optical isolators (320) are configured in the last column (third column (346)) of the plurality of columns (342, 344, 346). However, the optical isolators(s) (320) may be configured in any suitable column. For example, in some embodiments, the optical isolators (320) may be configured in the first column (342). For example, the power distribution network (300) may include a single optical isolator (320) directly coupled to the input port (302). Furthermore, in some embodiments, a plurality of columns of optical isolators (320) (e.g., the first column (342) and / or the last column (346)) may be included in the power distribution network (300).

[0100] FIG. 4 illustrates a diagram of part of an exemplary system (400) according to some embodiments of the present disclosure. The system (400) includes an optical amplifier (410) coupled to a power distribution network (420). The optical amplifier (410) may be a semiconductor optical amplifier (SOA). The optical amplifier (410) may include an input port (412) configured to receive an input optical signal. The optical amplifier (410) may amplify the input optical signal and output the amplified signal at an output port (414). The optical amplifier (410) may be active and non-linear. For example, the optical amplifier (410) may inject additional power into the output signal in comparison to the input signal. However, the optical amplifier (410) may be sensitive to reflected power at the output port (414).

[0101] The output port (414) of the optical amplifier (410) may be coupled to at least one input port (422) of the power distribution network (420). The power distribution network (420) may divide a signal received at the input port (422) among a plurality of output ports (424). For example, the power distribution network (420) may divide the signal (e.g., input power) from the input port (422) evenly among the plurality of output ports (424). Additionally or alternatively, in some embodiments, the power distribution network (420) may distribute power unevenly among the plurality of output ports (424). Signals from the plurality of output ports (424) may be provided to downstream components of the LIDAR system, such as a transmitter, an optical system, and / or other suitable components.

[0102] The power distribution network (420) may include one or more optical isolators. The optical isolators may be configured to coherently interfere with reflected signals from a plurality of output ports (424) to attenuate the reflected signals. In particular, the power distribution network (420) may include one or more control signal lines (426) configured to provide control signals to the optical isolators. Additionally, the optical isolators may be configured to direct reflected power from the output ports (424) to one or more power dump ports (428). In some embodiments, the power dump ports (428) may be coupled to one or more optical dissipation devices configured to dissipate reflected power.

[0103] FIG. 5 illustrates a diagram of an exemplary optical isolator (500) according to some embodiments of the present disclosure. The optical isolator (500) may be included as an optical isolator for an optical power distribution network of a LIDAR system, for example, as the optical isolator(s) (320) of FIG. 3. The optical isolator (500) may include at least one input port (502) and one or more output ports, such as a first output port (504) and a second output port (505).

[0104] The optical isolator (500) may include an optical splitter (510). The optical splitter (510) may include at least two input ports, such as a first input port (512) and a second input port (513). Additionally or alternatively, the optical splitter (510) may include a plurality of output ports, such as a first output port (514) and a second output port (515). The first input port (512) of the optical splitter (510) may be coupled to the input port (502) of the optical isolator (500). For example, the optical splitter (510) may split an input optical signal from the input port (502) between the plurality of output ports (514, 515). The second input port (513) of the optical splitter (510) may be coupled to the optical dump port (508) of the optical isolator. The optical dump port (508) can be coupled to an optical dissipation device configured to dissipate reflected power from the second input port (513) of the optical splitter (510).

[0105] The optical isolator (500) may include phase shifters(s) each coupled to a plurality of output ports of the optical splitter (510). For example, the optical isolator (500) may include a first phase shifter (522) coupled to a first output port (514) of the optical splitter (510). Additionally or alternatively, the optical isolator (500) may include a second phase shifter (524) coupled to a second output port (515) of the optical splitter (510). In some embodiments, the second phase shifter (524) may be omitted. In some embodiments, the second phase shifter (524) may be included even if it is not controlled to balance losses at the two output ports (514, 515) of the optical splitter (510). Phase shifters (522, 524) can shift the phase of an optical signal passing through the phase shifters (522, 524). For example, the first phase shifter (522) and the second phase shifter (524) may be configured to balance the phases of reflected signals so that the reflected signals interfere coherently (e.g., constructively or destructively) at the second input port (513).

[0106] The optical isolator may further include a control signal line (506) coupled to a phase shifter(s) in one of the plurality of output ports (514, 515) of the optical splitter. In some embodiments, the phase control signal may be applied to only one of the phase shifters (522, 524) to compensate for phase drift of the reflected signals by changing the phase difference between two reflected signals. In some embodiments, a plurality of control signal lines may be provided so that a plurality of phase shifters (e.g., a second phase shifter (524)) may also be additionally controlled. The control signal line (506) may provide control signals to the first phase shifter (522) to control the amount by which the phase shifter (522) shifts the phase of the signal from the first output port (514) of the optical splitter (510) and the reflected signal from the first output port (504) of the optical isolator (500).

[0107] The control signal in the control signal line (506) can cause the phase shifter (522) to adjust the phase of the signals passing through the phase shifter (522), thereby controlling the phase difference between the reflected signals from the first output port (504) and the second output port (505) of the optical isolator (500). The phase shifters (522, 524) can shift the phase of the reflected signals from the output ports (504, 505) of the optical isolator (500) so that the reflected signals interfere coherently at the input ports (512, 513) of the optical splitter (510). For example, the reflected signals can interfere destructively at the first input port (512) and interfere constructively at the second input port (513), thereby allowing all reflected signals to be dumped to the optical dump port (508). Therefore, the reflected signals can coherently interfere when entering the optical splitter (510). After interference, if there are any remaining reflected signals, they can exit the optical isolator (500) through the optical dump port (508).

[0108] FIG. 6 illustrates a diagram of an exemplary optical isolator (600) according to some embodiments of the present disclosure. The optical isolator (600) may be included as an optical isolator for an optical power distribution network of a LIDAR system, for example, as the optical isolator(s) (320) of FIG. 3. The optical isolator (600) may include an optical splitter (610). The optical splitter (610) may include at least one input port, for example, at least two input ports such as a first input port (612) and a second input port (613). Additionally or alternatively, the optical splitter (610) may include a plurality of output ports such as a first output port (614) and a second output port (615). The first input port (612) of the optical splitter (610) may be coupled to an input port (602) of the optical isolator (600). For example, the optical splitter (610) can split an input optical signal from an input port (602) between a plurality of output ports (614, 615). The second input port (613) of the optical splitter (610) can be coupled to the optical dump port (608) of the optical isolator. The optical dump port (608) can be coupled to an optical dissipation device configured to dissipate reflected power from the second input port (613) of the optical splitter (610).

[0109] The optical isolator (600) may include phase shifter(s) each coupled to a plurality of output ports of the optical splitter (610). For example, the optical isolator (600) may include a first phase shifter (622) coupled to a first output port (614) of the optical splitter (610). Additionally or alternatively, the optical isolator (600) may include a second phase shifter (624) coupled to a second output port (615) of the optical splitter (610). In some embodiments, the second phase shifter (624) may be omitted. In some embodiments, the second phase shifter (624) may be included even if it is not controlled to balance losses at the two output ports (614, 615) of the optical splitter (610). Phase shifters (622, 624) can shift the phase of an optical signal passing through the phase shifters (622, 624). For example, the optical isolator may further include a control signal line (606) coupled to a phase shifter(s) in one of the plurality of output ports (614, 615) of the optical splitter (610). In some embodiments, a plurality of control signal lines may be provided so that a plurality of phase shifters (e.g., a second phase shifter (624)) can also be additionally controlled. The control signal line (606) may provide control signals to the first phase shifter (622) to control the amount by which the phase shifter (622) shifts the phase of the signal from the first output port (614) of the optical splitter (610) and the reflected signals from the first output port (604) of the optical isolator (600). The control signal in the control signal line (606) can cause the phase shifter (622) to adjust the phase of the signals passing through the phase shifter (622), thereby controlling the phase difference between the reflected signals from the first output port (604) and the second output port (605) of the optical isolator (600).Phase shifters (622, 624) can shift the phase of the reflected signals at the output ports (604, 605) of the optical isolator (600) so that the reflected signals can coherently interfere at the input ports (612, 613) of the optical splitter (610). For example, the reflected signals can destructively interfere at the first input port (612) and constructively interfere at the second input port (613), thereby allowing all reflected signals to be dumped to the optical dump port (608). For example, the reflected signals can interfere when entering the optical splitter (610). After interference, if there are any remaining reflected signals, they can exit the optical isolator (600) through the optical dump port (608).

[0110] In addition to the phase shifters (622, 624), the optical isolator (600) may further include attenuators each coupled to a plurality of output ports of the optical splitter (610). For example, a first attenuator (630) may be coupled to a first output port (614) of the optical splitter (610). The first attenuator (630) may be configured to attenuate reflected signals between the first output port (604) of the optical isolator (600) and the first output port (614) of the optical splitter (610). Additionally, or alternatively, a second attenuator (640) may be coupled to a second output port (615) of the optical splitter. The second attenuator (640) may be configured to attenuate reflected signals between the second output port (605) of the optical isolator (600) and the second output port (615) of the optical splitter (610). In this way, the reflected signals may be attenuated so that their amplitude or strength is reduced even before they coherently interfere at the optical splitter (610).

[0111] Any suitable attenuator may be used according to exemplary embodiments of the present disclosure. In the example of FIG. 6, the attenuators (630, 640) are Mach-Zehnder modulators. A Mach-Zehnder modulator is a device used to control the amplitude of a light wave. An input signal to a Mach-Zehnder modulator may be split into two signals, and a phase shift is induced in one of the split signals. The signals are then recombined, and the phase difference between the signals may induce amplitude modulation (e.g., attenuation) in the recombined signal. A Mach-Zehnder modulator may be a bidirectional attenuator. For example, a Mach-Zehnder modulator can attenuate both forward-passing signals (e.g., input signals from the input port (602) to the output ports (604, 605)) and reverse-passing signals (e.g., reflected signals from the output ports (604, 605) to the input port (602).

[0112] For example, in some embodiments, the attenuator (630) (e.g., a Mach-Zehnder modulator) may include a first optical splitter (632). In some embodiments, the first optical splitter (632) may include two input ports. The first input port may be coupled to a first phase shifter (622). Additionally or alternatively, in some embodiments, the second input port may be coupled to an optical dump port (631).

[0113] Furthermore, in some embodiments, the first optical splitter (632) may include two output ports (633). Two phase shifters (634, 635) may be coupled to the two output ports (633) of the first optical splitter (632). In some embodiments, the second phase shifter (635) may be omitted. A control signal line (636) may be coupled to one of the two phase shifters (634, 635). For example, the first phase shifter (634) and the second phase shifter (635) may be configured to balance the phases of reflected signals so that the reflected signals interfere coherently (e.g. constructively or destructively) in the first optical splitter (632). For example, the control signal line (636) may provide control signals to the first phase shifter (634) to cause the first phase shifter (634) to induce a phase shift in the signal passing through the first phase shifter (634). In some embodiments, the phase control signal may be applied to only one of the phase shifters (634, 635) to compensate for the phase drift of the reflected signals by changing the phase difference between the two reflected signals.

[0114] Furthermore, the attenuator (630) (e.g., a Mach-Zehnder modulator) may include a second optical splitter (637) having two input ports (639). The two input ports (639) may each be coupled to two phase shifters (634, 635). Additionally, in some embodiments, the second optical splitter (637) may include two output ports. The first output port of the optical splitter (637) may be coupled to the first output port (604) of the optical isolator (600). Additionally, or alternatively, the second output port of the optical splitter (637) may be coupled to an optical dump port (638).

[0115] FIG. 7 illustrates a diagram of an exemplary optical isolator (700) according to some embodiments of the present disclosure. The optical isolator (700) may be included as an optical isolator for an optical power distribution network of a LIDAR system, for example, as the optical isolator(s) (320) of FIG. 3. The optical isolator (700) may include at least one input port (702) and one or more output ports, such as a first output port (704) and a second output port (705).

[0116] The optical isolator (700) may include an optical splitter (710). The optical splitter (710) may include at least two input ports, such as a first input port (712) and a second input port (713). Additionally or alternatively, the optical splitter (710) may include a plurality of output ports, such as a first output port (714) and a second output port (715). The first input port (712) of the optical splitter (710) may be coupled to the input port (702) of the optical isolator (700). For example, the optical splitter (710) may split an input optical signal from the input port (702) between the plurality of output ports (714, 715). The second input port (713) of the optical splitter (710) may be coupled to the optical dump port (708) of the optical isolator.

[0117] The optical isolator (700) may include phase shifter(s) each coupled to a plurality of output ports of the optical splitter (710). For example, the optical isolator (700) may include a first phase shifter (722) coupled to a first output port (714) of the optical splitter (710). Additionally or alternatively, the optical isolator (700) may include a second phase shifter (724) coupled to a second output port (715) of the optical splitter (710). In some embodiments, the second phase shifter (724) may be omitted. In some embodiments, the second phase shifter (724) may be included even if it is not controlled to balance losses at the two output ports (714, 715) of the optical splitter (710). Phase shifters (722, 724) can shift the phase of an optical signal passing through the phase shifters (722, 724). For example, the first phase shifter (722) and the second phase shifter (724) may be configured to balance the phases of reflected signals so that the reflected signals interfere coherently (e.g. constructively or destructively) at the second input port (713).

[0118] The optical isolator may further include a control signal line (706) coupled to a phase shifter(s) in one of the plurality of output ports (714, 715) of the optical splitter. In some embodiments, the phase control signal may be applied to only one of the phase shifters (722, 724) to compensate for phase drift of the reflected signals by changing the phase difference between two reflected signals. In some embodiments, a plurality of control signal lines may be provided so that a plurality of phase shifters (e.g., a second phase shifter (724)) may also be additionally controlled. The control signal line (706) may provide control signals to the first phase shifter (722) to control the amount by which the first phase shifter (722) shifts the phase of the signal from the first output port (714) of the optical splitter (710) and the reflected signals from the first output port (704) of the optical isolator (700). The control signal in the control signal line (706) can cause the phase shifter (722) to adjust the phase of the signals passing through the phase shifter (722), thereby controlling the phase difference between the reflected signals from the first output port (704) and the second output port (705) of the optical isolator (700). The phase shifters (722, 724) can shift the phase of the reflected signals from the output ports (704, 705) of the optical isolator (700) so that the reflected signals interfere coherently at the input ports (712, 713) of the optical splitter (710). For example, the reflected signals can interfere destructively at the first input port (712) and interfere constructively at the second input port (713), thereby allowing all reflected signals to be dumped to the optical dump port (708). For example, reflected signals may interfere when entering the optical splitter (710). After interference, if there are any remaining reflected signals, they may exit the optical isolator (700) through the optical dump port (708).

[0119] The optical isolator (700) can be controlled by a feedback device (750). The feedback device (750) can generate control signals for a control signal line (706) based on the amount of power at the optical dump port (708). For example, the optical dump port (708) can be coupled to a photodiode (752). The photodiode (752) can emit a current proportional to the optical power at the optical dump port (708). The feedback device (750) may further include a voltage source (754) and a transimpedance amplifier (TIA) (758) configured to convert the current generated by the photodiode (752) into a voltage signal. The voltage source (754), photodiode (752), and TIA (758) collectively may be a reflected signal monitor configured to measure the power of the reflected signal at the optical dump port (708) and generate a voltage proportional to that power. The feedback device (750) may further include a servo (756) configured to generate a control signal for a control signal line (706) based on signals from the TIA (758). In this way, the phase shifter (722) can be controlled in response to the amount of reflected power entering the output ports (704, 705) of the optical isolator (700) and provided to the optical dump port (708).

[0120] FIG. 8 illustrates a diagram of an exemplary power distribution network (800) according to some embodiments of the present disclosure. The power distribution network (800) may include at least one input port (802) configured to receive a beam. The beam may be, for example, an amplified beam from an optical amplifier. The operating characteristics of some LIDAR systems incorporating the power distribution network (800) may be improved by mitigating the effect of reflected power at the input port (802).

[0121] The power distribution network (800) may include one or more optical splitters (810). The optical splitter (810) may be configured to split a beam (e.g., an amplified beam) from an input port (802) into a plurality of distributed beams. The power distribution network (800) may further include a plurality of output ports (804) configured to provide each of the plurality of distributed beams. For example, the output ports (804) may be coupled to one or more transmitters configured to provide the distributed beams to an optical system or other downstream components.

[0122] In some embodiments, the splitters (810) may each have at least two input ports, such as a first input port (812) and a second input port (813). For example, the splitters (810) may be 2×2 splitters. At least one of the at least two input ports may be coupled to an optical dissipation device. For example, in the example of FIG. 8, the optical splitters (810) include a second input port (813) coupled to a power dump port (853). The power dump port (853) may be coupled to an optical dissipation device such as a photoresistor. In this way, power reflected from the output ports (804) of the power distribution network (800) may be divided between the input ports (812, 813) of the splitters, and half of the reflected power may be dissipated at each splitter (810).

[0123] The power distribution network (800) may further include one or more optical isolators (820). The optical isolators (820) may be configured to coherently interfere with reflected signals from a plurality of output ports (804) to attenuate the reflected signals. For example, some energy from the signals provided by the output ports (804) may be back-reflected toward the power distribution network (800). This reflected power may interfere with the operation of components coupled to the input ports (802) of the power distribution network (800), such as active optical amplifiers, for example.

[0124] The optical isolator (820) may include one or more adjustable or active components, such as, for example, a phase modulator, a frequency modulator, etc. The optical isolator (820) may be controlled by one or more control signals (806) to modify signals propagating through the optical isolator (820). In particular, the optical isolator (820) may be controlled so that reflected power can coherently interfere within the optical splitter (810). The interference may reduce the reflected power (e.g., by destructive interference).

[0125] The optical isolator (820) may include two input ports (822, 823) and one or more output ports (824). The first input port (822) may be coupled to the output port (814) of the optical splitter (810). Additionally, the second input port (823) may be coupled to a power dump port (808). When power is reflected from the output port (824) of the optical isolator (820), the power may be split between the input ports (822, 823) of the optical isolators. Thus, most or all of the remaining reflected power may be directed to the power dump port(s) (808). The power dump port(s) (808) may be coupled to light dissipation devices, such as a photoresistor, a photodiode, or other suitable devices configured to convert the reflected power into a form that does not interfere with the rest of the system. For example, a photoresistor or photodiode can convert reflected power into electric current, which can cause light dissipation at the reflected port.

[0126] In some embodiments, the power distribution network (800) may include multiple rows of cascaded two-way optical splitters. The cascaded optical splitters used herein represent an array of splitters (810) or other devices arranged in a progressive series of rows. Each row may have one splitter (810) (or other elements such as an isolator (820)) for each output port (814) of the splitters (810) of the previous row. For example, in the case of a two-way optical splitter having two output ports, the subsequent row may have two splitters (810) for each splitter (810) of the previous row. In the example of FIG. 8, the first row (842) may have one splitter (810), and the second row (844) may have two splitters (810). Furthermore, the third column (846) may have four isolators (820). In this way, the number of output ports (804) of the power distribution network (800) is 2 X-1 It can be expressed as, where X is the number of columns.

[0127] In the example of FIG. 8, the optical isolators (820) are configured in the last column (third column (846)) of a plurality of columns (842, 844, 846). However, the optical isolators(s) (820) may be configured in any suitable column. For example, in some embodiments, the optical isolators (820) may be configured in the first column (842). For example, the power distribution network (800) may include a single optical isolator (820) directly coupled to the input port (802). Furthermore, in some embodiments, a plurality of columns of optical isolators (820) (e.g., the first column (842) and / or the last column (846)) may be included in the power distribution network (800).

[0128] The technology of the present disclosure is described below in the context of LIDAR systems and autonomous vehicles for exemplary purposes only. As described herein, the technology described herein is not limited to autonomous vehicles and may be implemented for or within other systems, autonomous driving platforms, and other computing systems.

Claims

Claim 1 A LIDAR sensor system for a vehicle comprises: a light source configured to generate a beam; at least one optical amplifier configured to amplify the beam to generate an amplified beam; an optical power distribution network comprising: at least one input port configured to receive the amplified beam; one or more optical splitters configured to divide the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and one or more optical isolators configured to coherently interfere with the reflected signals from the plurality of output ports to attenuate the reflected signals; a transmitter configured to receive the plurality of distributed beams; and one or more optical systems configured to emit the plurality of distributed beams. Claim 2 A LIDAR sensor system according to claim 1, wherein the one or more optical splitters comprise a plurality of rows of cascaded two-way optical splitters. Claim 3 In paragraph 2, the LIDAR sensor system wherein the one or more optical isolators are configured in the first column of the plurality of columns. Claim 4 In paragraph 2, the LIDAR sensor system wherein the one or more optical isolators are configured in the last column of the plurality of columns. Claim 5 A LIDAR sensor system according to claim 1, wherein each of the one or more optical isolators comprises: an optical splitter having at least one input port and a plurality of output ports; and a phase shifter each coupled to the plurality of output ports of the optical splitter. Claim 6 In claim 5, the optical splitter of the one or more optical isolators comprises a two-way splitter having two output ports, in a LIDAR sensor system. Claim 7 A LIDAR sensor system according to claim 5, wherein the one or more optical isolators comprise one or more attenuators coupled to the plurality of output ports of the optical splitter. Claim 8 A LIDAR sensor system according to claim 7, wherein a specific attenuator among the one or more attenuators comprises a Mach-Zehnder modulator, wherein the Mach-Zehnder modulator comprises: a first optical splitter comprising two output ports; two phase shifters coupled to the two output ports of the first optical splitter; and a second optical splitter comprising two input ports each coupled to the two phase shifters, wherein a control signal line is coupled to a specific phase shifter among the two phase shifters. Claim 9 A LIDAR sensor system according to claim 5, wherein a specific optical isolator among the one or more optical isolators comprises a control signal line coupled to a phase shifter located in one of the plurality of output ports of the optical splitter. Claim 10 A LIDAR sensor system according to claim 5, wherein a specific optical isolator among the one or more optical isolators comprises at least two input ports, and at least one of the at least two input ports is coupled to a light dissipation device. Claim 11 A LIDAR sensor system according to claim 1, wherein a specific optical isolator among the one or more optical isolators comprises at least two input ports, and at least one of the at least two input ports is coupled to an optical dissipation device. Claim 12 In claim 1, the LIDAR sensor system wherein at least one optical amplifier is active and non-linear. Claim 13 A LIDAR sensor system according to claim 1, wherein the one or more optical systems are configured to emit the plurality of distributed beams, and the LIDAR sensor system further comprises a receiver configured to receive a reflected beam and determine object detection related to an object that reflected the reflected beam. Claim 14 An autonomous vehicle control system comprising: a light source configured to generate a beam as a LIDAR sensor system; at least one optical amplifier configured to amplify the beam to generate an amplified beam; an optical power distribution network comprising at least one input port configured to receive the amplified beam; one or more optical splitters configured to divide the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and one or more optical isolators configured to coherently interfere with reflected signals from the plurality of output ports to attenuate the reflected signals; a transmitter configured to receive the plurality of distributed beams; one or more optical systems configured to emit the plurality of distributed beams toward an object; and a receiver configured to receive a beam reflected from the object and determine object detection associated with the object; an autonomous vehicle control system comprising: and one or more sub-control systems configured to control the autonomous vehicle based on the object detection. Claim 15 In claim 14, the autonomous vehicle control system wherein the one or more optical splitters comprise a plurality of rows of cascaded two-way optical splitters. Claim 16 In claim 14, a specific optical isolator among the one or more optical isolators comprises: an optical splitter having at least one input port and a plurality of output ports; and a phase shifter each coupled to the plurality of output ports of the optical splitter, in an autonomous driving vehicle control system. Claim 17 An autonomous vehicle control system according to claim 16, wherein a specific optical isolator among the one or more optical isolators comprises an attenuator each coupled to a plurality of output ports of the optical splitter. Claim 18 An autonomous vehicle control system according to claim 17, wherein the attenuator comprises a Mach-Zehnder modulator, and the Mach-Zehnder modulator comprises: a first optical splitter comprising two output ports; two phase shifters coupled to the two output ports of the first optical splitter; and a second optical splitter comprising two input ports coupled to the two phase shifters, wherein a control signal line is coupled to one of the two phase shifters. Claim 19 An autonomous vehicle comprising: a light source configured to generate a beam as a LIDAR sensor system as an autonomous vehicle; at least one optical amplifier configured to amplify the beam to generate an amplified beam; an optical power distribution network comprising at least one input port configured to receive the amplified beam; one or more optical splitters configured to divide the amplified beam into a plurality of distributed beams; a plurality of output ports configured to provide each of the plurality of distributed beams; and one or more optical isolators configured to coherently interfere with reflected signals from the plurality of output ports to attenuate the reflected signals; a transmitter configured to receive the plurality of distributed beams; one or more optical systems configured to emit the plurality of distributed beams toward a target; and a receiver configured to receive a beam reflected from the target and determine object detection associated with the target; and an autonomous vehicle controller configured to control the autonomous vehicle based on object detection associated with the target. Claim 20 In claim 19, a specific optical isolator among the one or more optical isolators comprises an optical splitter having at least one input port and a plurality of output ports and a phase shifter each coupled to the plurality of output ports of the optical splitter; a specific optical isolator among the one or more optical isolators comprises an attenuator each coupled to the plurality of output ports of the optical splitter, wherein the attenuator comprises a Mach-Zehnder modulator, and the Mach-Zehnder modulator comprises: a first optical splitter having two output ports; two phase shifters coupled to the two output ports of the first optical splitter, wherein a control signal line is coupled to one of the two phase shifters; and a second optical splitter having two input ports coupled to the two phase shifters, an autonomous vehicle.

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