Abstract: A method and system to provide timebase synchronization for multiple processors in a multi-processor sensor system, where each processor operates according to a respective reference clock, and where the processors' respective reference clocks are off sync from each other. An example method includes simultaneously injecting a synchronization pulse respectively into the multiple processors. Further, the method includes recording for each processor, according to the processor's respective reference clock, a respective synchronization-pulse timestamp of the simultaneously injected synchronization pulse, comparing the respective synchronization-pulse timestamps recorded for the processors, and, based on the comparing, computing for each processor a respective time offset. Additionally, the method includes using the per-processor computed time offsets as a basis to provide a synchronized timebase across the processors.

Abstract: One example system comprises a light source configured to emit light. The system also comprises a waveguide configured to guide the emitted light from a first end of the waveguide toward a second end of the waveguide. The waveguide has an output surface between the first end and the second end. The system also comprises a plurality of mirrors including a first mirror and a second mirror. The first mirror reflects a first portion of the light toward the output surface. The second mirror reflects a second portion of the light toward the output surface. The first portion propagates out of the output surface toward a scene as a first transmitted light beam. The second portion propagates out of the output surface toward the scene as a second transmitted light beam.

Abstract: One example device comprises a plurality of emitters including at least a first emitter and a second emitter. The first emitter emits light that illuminates a first portion of a field-of-view (FOV) of the device. The second emitter emits light that illuminates a second portion of the FOV. The device also comprises a controller that obtains a scan of the FOV. The controller causes each emitter of the plurality of emitters to emit a respective light pulse during an emission time period associated with the scan. The controller causes the first emitter to emit a first-emitter light pulse at a first-emitter time offset from a start time of the emission time period. The controller causes the second emitter to emit a second-emitter light pulse at a second-emitter time offset from the start time of the emission time period.

Abstract: Described herein is a LIDAR device that may include a transmitter, first and second receivers, and a rotating platform. The transmitter may be configured to emit light having a vertical beam width. The first receiver may be configured to detect light at a first resolution while scanning the environment with a first FOV and the second receiver may be configured to detect light at a second resolution while scanning the environment with a second FOV. In this arrangement, the first resolution may be higher than the second resolution, the first FOV may be at least partially different from the second FOV, and the vertical beam width may encompass at least a vertical extent of the first and second FOVs. Further, the rotating platform may be configured to rotate about an axis such that the transmitter and first and second receivers each move based on the rotation.

Abstract: One example system includes a light source that emits light. The system also includes a waveguide that guides the emitted light from a first side of the waveguide toward a second side of the waveguide opposite the first side. The waveguide has a third side extending between the first side and the second side. The system also includes a mirror that reflects the guided light toward the third side of the waveguide. At least a portion of the reflected light propagates out of the waveguide toward a scene. The system also includes a light detector, and a lens that focuses light from the scene toward the waveguide and the light detector.

Abstract: A rotatable LIDAR device including contactless electrical couplings is disclosed. An example rotatable LIDAR device includes a vehicle electrical coupling including (i) a first conductive ring, (ii) a second conductive ring, and (iii) a first coil. The example rotatable LIDAR device further includes a LIDAR electrical coupling including (i) a third conductive ring, (ii) a fourth conductive ring, and (iii) a second coil. The example rotatable LIDAR device still further includes a rotatable LIDAR electrically coupled to the LIDAR electrical coupling. The first conductive ring and the third conductive ring form a first capacitor configured to transmit communications to the rotatable LIDAR, the second conductive ring and the fourth conductive ring form a second capacitor configured to transmit communications from the rotatable LIDAR, and the first coil and the second coil form a transformer configured to provide power to the rotatable LIDAR.

Abstract: Example implementations are provided for an arrangement of co-aligned rotating sensors. One example device includes a light detection and ranging (LIDAR) transmitter that emits light pulses toward a scene according to a pointing direction of the device. The device also includes a LIDAR receiver that detects reflections of the emitted light pulses reflecting from the scene. The device also includes an image sensor that captures an image of the scene based on at least external light originating from one or more external light sources. The device also includes a platform that supports the LIDAR transmitter, the LIDAR receiver, and the image sensor in a particular relative arrangement. The device also includes an actuator that rotates the platform about an axis to adjust the pointing direction of the device.

Abstract: A method is provided that involves mounting a transmit block and a receive block in a LIDAR device to provide a relative position between the transmit block and the receive block. The method also involves locating a camera at a given position at which the camera can image light beams emitted by the transmit block and can image the receive block. The method also involves obtaining, using the camera, a first image indicative of light source positions of one or more light sources in the transmit block and a second image indicative of detector positions of one or more detectors in the receive block. The method also involves determining at least one offset based on the first image and the second image. The method also involves adjusting the relative position between the transmit block and the receive block based at least in part on the at least one offset.

Abstract: A method and system to provide timebase synchronization for multiple processors in a multi-processor sensor system, where each processor operates according to a respective reference clock, and where the processors' respective reference clocks are off sync from each other. An example method includes simultaneously injecting a synchronization pulse respectively into the multiple processors. Further, the method includes recording for each processor, according to the processor's respective reference clock, a respective synchronization-pulse timestamp of the simultaneously injected synchronization pulse, comparing the respective synchronization-pulse timestamps recorded for the processors, and, based on the comparing, computing for each processor a respective time offset. Additionally, the method includes using the per-processor computed time offsets as a basis to provide a synchronized timebase across the processors.

Abstract: The technology relates to enhancing or extending the field of view of sensors for vehicles configured to operate in an autonomous driving mode. One or more mirrors are used to reflect or redirect beams emitted from onboard sensors that would otherwise be wasted, for instance due to obstruction by a portion of the vehicle or because they are emitted at high pitch angles to the side. The mirrors are also used to redirect incoming beams from the external environment toward one or more of the onboard sensors. Using mirrors for such redirection can reduce or eliminate blind spots around the vehicle. A calibration system may be employed to account for mirror movement due to vibration or wind drag. Each mirror may be a front surface mirror. The mirrors may be positioned on the vehicle body, on a faring, or extending from a sensor housing on the vehicle.

Abstract: One example method involves a light detection and ranging (LIDAR) device focusing light from a target region in a scene for receipt by a detector. The method also involves emitting a primary light pulse. The method also involves directing, via one or more optical elements, the primary light pulse toward the target region. The primary light pulse illuminates the target region according to a primary light intensity of the primary light pulse. The method also involves emitting a secondary light pulse. At least a portion of the secondary light pulse illuminates the target region according to a secondary light intensity of the secondary light pulse. The secondary light intensity is less than the primary light intensity.

Abstract: One example system includes a light source that emits light. The system also includes a waveguide that guides the emitted light from a first side of the waveguide toward a second side of the waveguide opposite the first side. The waveguide has a third side extending between the first side and the second side. The system also includes a mirror that reflects the guided light toward the third side of the waveguide. At least a portion of the reflected light propagates out of the waveguide toward a scene. The system also includes a light detector, and a lens that focuses light from the scene toward the waveguide and the light detector.

Abstract: One example LIDAR device comprises a substrate and a waveguide disposed on the substrate. A first section of the waveguide extends lengthwise on the substrate in a first direction. A second section of the waveguide extends lengthwise on the substrate in a second direction different than the first direction. A third section of the waveguide extends lengthwise on the substrate in a third direction different than the second direction. The second section extends lengthwise between the first section and the second section. The LIDAR device also comprises a light emitter configured to emit light. The waveguide is configured to guide the light inside the first section toward the second section, inside the second section toward the third section, and inside the third section away from the second section.

Abstract: Example embodiments relate to pulse energy plans for light detection and ranging (lidar) devices based on areas of interest and thermal budgets. An example lidar device includes a plurality of light emitters configured to emit light pulses into an environment in a plurality of different emission directions. The lidar device also includes circuitry configured to power the plurality of light emitters. Further, the lidar device includes a plurality of detectors configured to detect reflections of light pulses emitted by the plurality of light emitters. In addition, the lidar device includes a controller configured to (i) determine a pulse energy plan based on one or more regions of interest in the environment and a thermal budget and (ii) control the circuitry based on the pulse energy plan. The pulse energy plan specifies a pulse energy level for each light pulse emitted by each light emitter in the plurality of light emitters.

Abstract: The present disclosure relates to limitation of noise on light detectors using an aperture. One example implementation includes a system. The system includes a lens that focuses light from a scene toward a focal plane. The system also includes an aperture defined within an opaque material. The system also includes a plurality of waveguides. A given waveguide of the plurality has an input end that receives a portion of light transmitted through the aperture, and guides the received portion toward an output end of the given waveguide. A cross-sectional area of the guided portion at the output end is greater than a cross-sectional area of the received portion at the input end. The system also includes an array of light detectors that detects the guided light transmitted through the output end.

Abstract: A rotatable LIDAR device including contactless electrical couplings is disclosed. An example rotatable LIDAR device includes a vehicle electrical coupling including (i) a first conductive ring, (ii) a second conductive ring, and (iii) a first coil. The example rotatable LIDAR device further includes a LIDAR electrical coupling including (i) a third conductive ring, (ii) a fourth conductive ring, and (iii) a second coil. The example rotatable LIDAR device still further includes a rotatable LIDAR electrically coupled to the LIDAR electrical coupling. The first conductive ring and the third conductive ring form a first capacitor configured to transmit communications to the rotatable LIDAR, the second conductive ring and the fourth conductive ring form a second capacitor configured to transmit communications from the rotatable LIDAR, and the first coil and the second coil form a transformer configured to provide power to the rotatable LIDAR.

Abstract: The present disclosure relates to methods and systems that improve the dynamic range of LIDAR systems. An example system includes a plurality of single-photon photodetectors and at least one additional photodetector monolithically integrated on a shared substrate. The plurality of single-photon photodetectors and the at least one additional photodetector are configured to detect light from a shared field of view. The system also includes a controller configured to carry out operations. The operations include: receiving respective photodetector signals from the plurality of single-photon photodetectors and the at least one additional photodetector; selecting a photodetector signal from at least two of: the two received photodetector signals and a combined photodetector signal formed by combining the two received photodetector signals; and determining an intensity of light in the field of view based on the selected photodetector signal.

Abstract: Example embodiments relate to range calibration of light detectors. An example method includes emitting a first light signal toward a first region of a calibration target having a first reflectivity and detecting a reflection of the first light signal. The detected reflection of the first light signal has a first intensity. The example method further includes emitting a second light signal toward a second region of the calibration target having a second reflectivity and detecting a reflection of the second light signal from the second region of the calibration target. The detected reflection of the second light signal has a second intensity. Still further, the example method includes determining a first apparent range based on the detected reflection of the first light signal, determining a second apparent range based on the detected reflection of the second light signal, and generating walk-error calibration data for the detector.

Abstract: The present disclosure relates to limitation of noise on light detectors using an aperture. One example implementation includes a system. The system includes a lens disposed relative to a scene. The lens focuses light from the scene. The system also includes an opaque material that defines an aperture. The system also includes a waveguide having a first side that receives light focused by the lens and transmitted through the aperture. The waveguide guides the received light toward a second side of the waveguide opposite to the first side. The waveguide has a third side extending between the first side and the second side. The system also includes a mirror that reflects the guided light toward the third side of the waveguide. The system also includes an array of light detectors that detects the reflected light propagating out of the third side.

Abstract: Example embodiments relate to calibration systems for light detection and ranging (lidar) devices. An example calibration system includes a calibration target that includes a surface having at least one characterized reflectivity. The surface is configured to receive one or more calibration signals emitted by a lidar device along one or more optical axes when the lidar device is separated from the calibration target by an adjustable distance. The calibration system also includes at least one lens that modifies the one or more calibration signals. In addition, the system includes an adjustable attenuator configured to attenuate each of the one or more calibration signals to simulate, in combination with the at least one lens, a distance that is greater than the adjustable distance. Further, the system includes a calibration controller configured to analyze data associated with detected reflections of the one or more calibration signals.