Light detection and ranging (lidar) technology is capable of using light to measure the distance to objects in a field of view. A lidar system typically comprises a lidar transmitter, a lidar receiver, and a clock. The lidar transmitter transmits light into the field of view, and the light is reflected back to the lidar receiver after striking objects in the field of view. Techniques are described herein for encoding channel information into light transmissions so that the lidar receiver can use the encoded channel information to reduce the out-of-channel noise in channel-specific photodetection signals.
G01S 7/481 - Constructional features, e.g. arrangements of optical elements
G01S 7/4863 - Detector arrays, e.g. charge-transfer gates
G01S 7/4865 - Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G01S 17/32 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
H04B 10/508 - Pulse generation, e.g. generation of solitons
Systems and methods are disclosed that employ a photodetector having a field of view. The photodetector generates signals indicative of photon detections in response to incident light over time. A circuit generates first histogram data and second histogram data in a memory based on the generated signals during first and second collection subframes of a frame respectively using first and second mappings of time to bins respectively, wherein the second mapping of time to bins for the second collection subframe exhibits shorter bin widths than the first mapping of time to bins for the first collection subframe. A range to a target in in the field of view is resolvable in the event of a pile-up condition for the photodetector based on (1) data indicative of a coarse range estimate derived from the first histogram data and (2) data indicative of a range adjustment derived from the second histogram data.
Systems and methods can employ an emitter with adaptive active illumination in combination with a receiver that images a field of view illuminated by the emitter. An example active illumination camera system may comprise a light source that generates light output for sequentially illuminating a scene, a scanner that scannably steers the light output to targeted regions in the scene, a photodetector array comprising a photodetector array having a plurality of photodetector pixels that sense incident light from the scene and generate signals representative of the sensed incident light via integration of photo-generated charge for the pixels over time, and a circuit that generates image frames of the scene based on the generated signals, identifies regions of interest in the scene, and dynamically controls the light source and the scanner so that the steered light output exhibits a pattern that targets the identified regions with an increase in light energy
Techniques for resolving a range to an object using histograms are disclosed. A frame collection time for a depth-image frame is divided into a plurality of different collection subframes, where each collection subframe encompasses a plurality of light pulse cycles. Counts of accumulated photon detections by a pixel during the different collection subframes are allocated to histogram bins using different bin maps for the collection subframes. Each bin map defines a different mapping of time to bins for the light pulse cycles within its applicable collection subframe, and each mapping defines a bin width for its bins so that its bin map covers a maximum detection range for the depth-image frame. A range to an object in the pixel's field of view (within the maximum detection range) can be resolved according to a combination of peak bin positions in the histogram data with respect to the different collection subframes.
Techniques for imaging such as lidar imaging are described where a plurality of light steering optical elements are moved (such as rotated) to align different light steering optical elements with an optical path of emitted optical signals at different times and/or an optical path of optical returns from the optical signals to an optical sensor at different times. Each light steering optical element corresponds to a zone within the field of view and provides steering of the emitted optical signals incident thereon into its corresponding zone and/or steering of the optical returns from its corresponding zone to the optical sensor so that movement of the light steering optical elements causes the imaging system to step through the zones on a zone-by-zone basis.
G01S 17/02 - Systems using the reflection of electromagnetic waves other than radio waves
G01S 17/88 - Lidar systems, specially adapted for specific applications
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
6.
SYSTEMS AND METHODS OF REAL-TIME DETECTION OF AND GEOMETRY GENERATION FOR PHYSICAL GROUND PLANES
Example implementations can include a method of real-time detection of and geometry generation for physical ground planes, the method including generating a point cloud based on one or more detected points, the detected points being reflected from one or more projected points of focused light projected onto an environment, slicing, in accordance with at least one coordinate space threshold, one or more threshold points from the point cloud to generate a first sliced point cloud excluding the threshold points, slicing, in accordance with at least one residual threshold, one or more residual points from the first sliced point cloud to generate a second sliced point cloud excluding the residual points, generating a ground plane aligned with one or more points of the second point cloud in the coordinate space, and calculating a geometric characteristic of the second ground plane.
G01S 17/89 - Lidar systems, specially adapted for specific applications for mapping or imaging
G06V 20/58 - Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
7.
SYSTEMS AND METHODS OF CALIBRATION OF LOW FILL-FACTOR SENSOR DEVICES AND OBJECT DETECTION THEREWITH
The present disclosure relates to calibration of actively illuminated low fill-factor sensor devices and object detection, including capturing one or more returns in a first scan direction, assigning first timestamps corresponding to one or more of the returns in the first scan direction, identifying one or more peaks corresponding to intensity of one or more of the returns, correlating peak timestamps with one or more time intervals, the peak timestamps being associated with the peaks, generating a scan timing interval based on the peak timestamps, and calibrating one or more input devices or output devices based on the scan timing interval.
A lidar system comprises a lidar receiver that includes a first lens and a second lens. The first lens has a first field of view (FOV). The second lens has a second FOV, wherein the second FOV is encompassed by and narrower than the first FOV. A switch can control which of the first and second lenses are used for detecting returns from laser pulse shots based on where the laser pulse shots are targeted in a FOV that encompasses the first and second FOVs. The lidar receiver can include multiple readout channels for reading out signals from a photodetector array that senses light passed by the first and/or second lenses. Furthermore, the first and/or second lenses can be adjustable so that their respective FOVs are adjustable. Furthermore, shot scheduling for the lidar system can take into consideration potential changes in tilt amplitude of a variable amplitude scan mirror.
A lidar system comprises a photodetector circuit and a signal processing circuit. The photodetector circuit comprises an array of pixels for sensing incident light. The signal processing circuit processes a signal representative of the sensed incident light to detect a reflection of a laser pulse from a target within a field of view. The signal processing circuit can comprise a plurality of matched filters that are tuned to different reflected pulse shapes for detecting pulse reflections within the incident light, and wherein the signal processing circuit applies the signal to the matched filters to determine an obliquity and/or brightness (e.g., retro-reflectivity) for the target based how the matched filters respond to the applied signal. Furthermore, the determined target obliquity can be used for orienting the lidar system to a frame of reference (such as the horizon) in response to movements (such as tilting) of the lidar system.
G01S 7/48 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group
G01S 17/89 - Lidar systems, specially adapted for specific applications for mapping or imaging
10.
HYPER TEMPORAL LIDAR WITH CONTROLLABLE PULSE BURSTS
A lidar system can include a lidar transmitter and a lidar receiver, where the lidar transmitter controllably transmits a pulse burst toward a target in a field of view. This pulse burst transmission can be performed in response to a detection of the target, and the lidar receiver can resolve an angle to the target based on returns from the pulse burst. The pulse burst can include a first pulse fired at a first shot angle and a second pulse fired at a second shot angle. Predictive laser energy modeling can be used to schedule the pulse burst, and this modeling can take into account a variable laser seed energy if applicable. Furthermore, the lidar system can controllably switch between a baseline scan mode and a pulse burst mode in response to target detections or other conditions.
A lidar receiver that includes a photodetector circuit can be controlled so that the detection intervals used by the lidar receiver to detect returns from fired laser pulse shots are closely controlled. Such control over the detection intervals used by the lidar receiver allows for close coordination between a lidar transmitter and the lidar receiver where the lidar receiver is able to adapt to variable shot intervals of the lidar transmitter (including periods of high rate firing as well as periods of low rate firing). The detection intervals can vary across different shots, and at least some of the detection intervals can be controlled to be of different durations than the shot intervals that correspond to such detection intervals.
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G01S 7/483 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group - Details of pulse systems
A lidar system that includes a laser source and transmits laser pulses produced by the laser source toward range points in a field of view can use a laser energy model to model the available energy in the laser source over time. The timing schedule for laser pulses fired by the lidar system can then be determined using energies that are predicted for the different scheduled laser pulse shots based on the laser energy model. This permits the lidar system to reliably ensure at a highly granular level that each laser pulse shot has sufficient energy to meet operational needs, including when operating during periods of high density/high resolution laser pulse firing.
G01S 7/28 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group - Details of pulse systems
G01S 7/523 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group - Details of pulse systems
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G01S 17/89 - Lidar systems, specially adapted for specific applications for mapping or imaging
13.
INTELLIGENT LADAR SYSTEM WITH LOW LATENCY MOTION PLANNING UPDATES
Systems and methods are disclosed for vehicle motion planning where a sensor, such as a ladar system, is used to detect threatening or anomalous conditions within the sensor's field of view so that priority warning data about such conditions can be inserted at low latency into the motion planning loop of a motion planning computer system for the vehicle. Also disclosed herein is a ladar system that includes ladar transmitter, ladar receiver, and camera, where the camera that is co-bore sited with the ladar receiver, the camera configured to generate image data corresponding to a field of view for the ladar receiver. Also disclosed are techniques where a ladar system can estimate intra-frame motion for an object within a field of view of the ladar system using a tight cluster of ladar pulses.
G01S 7/481 - Constructional features, e.g. arrangements of optical elements
G01S 17/02 - Systems using the reflection of electromagnetic waves other than radio waves
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
Disclosed herein are a number of example embodiments that employ controllable delays between successive ladar pulses in order to discriminate between "own" ladar pulse reflections and "interfering" ladar pulses reflections by a receiver. Example embodiments include designs where a sparse delay sum circuit is used at the receiver and where a funnel filter is used at the receiver. Also, disclosed are techniques for selecting codes to use for the controllable delays as well as techniques for identifying and tracking interfering ladar pulses and their corresponding delay codes. The use of a ladar system with pulse deconfliction is also disclosed as part of an optical data communication system.
G01S 7/483 - RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - Details of systems according to groups , , of systems according to group - Details of pulse systems
Disclosed herein is a scanning ladar transmitter that employs an optical field splitter/inverter to improve the gaze characteristics of the ladar transmitter on desirable portions of a scan area. Also disclosed is the use of scan patterns such as Lissajous scan patterns for a scanning ladar transmitter where a phase drift is induced into the scanning to improve the gaze characteristics of the ladar transmitter on desirable portions of the scan area.
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
Disclosed herein are various embodiment of an adaptive ladar receiver and associated method whereby the active pixels in a photodetector array used for reception of ladar pulse returns can be adaptively controlled based at least in part on where the ladar pulses were targeted. Additional embodiments disclose improved imaging optics for use by the receiver and further adaptive control techniques for selecting which pixels of the photodetector array are used for sensing incident light.
Various embodiments are disclosed for improved ladar transmission, including but not limited to example embodiments where closed loop feedback control is used to finely control mirror scan positions, example embodiments where range point down selection is used to improve scanning, and others.
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G02B 26/12 - Scanning systems using multifaceted mirrors
G01P 3/68 - Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
patents
