Abstract: A system and method to receive radar returns from objects in response to a first radar scan, wherein the radar returns include Doppler shift, run a segmentation algorithm multiple times on the received radar returns, using a different preset estimated radar yaw angle for each iteration, wherein the estimated radar yaw angles are for estimated directions of transmission of the radar signals along a radar boresight from the transmitter of the radar system relative to a predetermined direction for each run of the segmentation algorithm, to determine which of the objects are static objects using the segmentation algorithm, and determine a first calibrated radar yaw angle as one of the preset estimated radar yaw angles which, among the different preset estimated radar yaw angles, has a highest number of adjusted radar returns for objects determined to be static objects by the segmentation algorithm.

Abstract: A system and method to receive radar returns from objects in response to radar scans from a moving radar system, wherein the radar returns include Doppler shift, to adjust velocity indicated in each of the radar returns based on an azimuth of each radar return to generate a set of adjusted radar returns, to group the adjusted radar returns into groups based on the velocity indicated in each of the adjusted radar returns, each group having a predetermined minimum velocity value Vmin, a predetermined maximum velocity value Vmax, and a predetermined threshold velocity difference value between Vmin and Vmax, and to determine which of the objects are static objects based on determining which group has the highest number of adjusted radar returns. Vehicle speed and speed of other moving objects can be determined based on determining which objects are static.

Abstract: Disclosed herein are systems and methods for radar networking for improved angular resolution. In an embodiment, a radar network includes a first radar and a second radar attached to a vehicular platform or another appropriate platform. Through coarse beamforming from each radar, a landmark is detected. The landmark's rough location in the first radar's coordinate and the landmark's rough location in the second radar coordinate are determined. The radar network is calibrated, by setting the first radar's location as the reference location and determining the second radar's location relative to it. Phase differences that may arise from relative positional or timing misalignment between the radars may be compensated. Fine beamforming is performed on the calibrated radars, and data from the fine beamforming is processed with the pre-detected target data to cancel out grating lobes.

Abstract: Disclosed herein are systems and methods for action potential-based object detection. Received signals corresponding to multiple chirps can be grouped based on temporal or spatial attributes. Within these groups, successful detections can be identified when at least one signal satisfies an action potential threshold. The presence of a valid object is confirmed when the number of groups with successful detections satisfies a predetermined detection threshold.

Abstract: Disclosed herein are systems and methods for filtering false targets from radar scans. A point in a current scan frame is associated with a doppler and point range from the radar. The point is validated and its doppler, point range, and scan time are used to determine an expected range of the point in a subsequent scan frame. A matching point is found within the expected range. The matching point is analyzed and validated over multiple consequent scans. Each successful detection of the point (e.g., validation of the matching point) in subsequent scan within its corresponding expected range is considered a positive identification. A positive identification count which exceeds a threshold relative to the total number of scans may indicate a valid target. Thus, a positive identification count for a point over multiple scans which is less than the threshold is classified as a false target.

Abstract: Disclosed herein are systems and methods for adaptive clustering of points from radar scans, utilizing feedback information to define appropriate clustering gate sizes, and optimizing overall radar system performance in various scenarios and environments. Various approaches enable separation of over-clustered targets into multiple clusters by removing points whose distance from a weighted center exceeds a disparity threshold, and uniting under-clustered targets into a single cluster. Outlier points can be removed based on their SNR and Doppler relative to a median SNR and median Doppler of all points in the cluster. The optimal cluster center is identified based on variable weighting techniques that consider at least one dimension beyond spatial dimensions, such as Doppler information, signal-to-noise ratio information, environmental conditions, or system constraints.

Abstract: Disclosed herein are systems and methods for adaptive CFAR detection and prioritization of objects in an environment. The system can select a cell under test (CUT) and an associated feature set of the cell. A CFAR detection threshold may be determined based on the feature set. The CUT is compared with its neighboring cells to determine whether an object is detected based on the CFAR detection threshold. The detected object is grouped by feature set and compared to a figure of merit (FOM) threshold to generate a priority score. Scored detected objects are sorted to generate a prioritized list of detected objects. The CFAR detection threshold and/or FOM threshold is dynamically updated based on the prioritized list of detected objects.

Abstract: A phased array frequency-modulated continuous-wave (FMCW) radar configured to operate to transmit, using at least one antenna, a calibration signal, to receive, using the antenna, a reflection of the at least one calibration signal from a calibration target, to determine, based on the at least one calibration signal, a phase shift factor, to estimate, based on the phase shift factor, a transmitter trace distance and a receiver trace distance, to transmit, using the antenna, at least one target signal, to receive, using the antenna, a reflection of the at least one target signal from a target, and to determine, based on the at least one target signal and the transmitter trace distance and the receiver trace distance, a range of the target.

Abstract: A phased array frequency-modulated continuous-wave (FMCW) radar system configured to transmit, using a plurality of antennas, a plurality of chirps, wherein each chirp within the plurality of chirps includes at least one temporal characteristic, and wherein the at least one temporal characteristic is pseudo-random for a portion of the plurality of chirps, to receive, using the plurality of antennas, a plurality of chirp reflections off one or more targets, to create, using a mixer, an intermediate frequency based on the plurality of chirps and the plurality of chirp reflections, and to determine, based on the intermediate frequency and the at least one temporal characteristic, a target attribute associated with the one or more targets.

Abstract: A multiple-input and multiple-output (MIMO) radar system, including a horizontal antenna array having horizontal elements to detect an azimuth angle estimation, the horizontal elements being arranged in a sparse and non-sparse distribution, a vertical antenna array having vertical elements to detect an elevation angle estimation, the vertical elements being arranged in a sparse and non-sparse distribution, and a two-dimensional antenna array including a portion of the horizontal antenna array and a portion of the vertical antenna array. The system is configured to estimate, using the horizontal antenna array, an azimuth angle, to estimate, using the vertical antenna array, an elevation angle, to identify, based on the azimuth angle and the elevation angle, one or more ambiguities, and to analyze, using a portion of the two-dimensional antenna array, the one or more ambiguities to determine a more accurate azimuth angle and elevation angle.

Abstract: In one embodiment, a method includes accessing a set of data points captured using a radar system of the vehicle. Each data point is associated with at least three measurements include a Doppler measurement, a range measurement, and an azimuth measurement in reference to the radar system. The method also includes clustering the set of data points into one or more first clusters based on a first pair of the three measurements associated with each of the data points; and clustering the set of data points into one or more second clusters based on a second pair of the three measurements associated with each of the data points. The second pair being different from the first pair of the three measurements.

Abstract: Systems, methods, and non-transitory computer-readable media provide an adaptive gating mechanism for radar tracking initialization. Specifically, the radar system obtains measurement data of target points, and then determines, based on the measured position and dopplers of points in the first few scans, whether the doppler and displacement parameters satisfy an initialization constraint. When the initialization constraint is not satisfied, the radar system flags the respective cluster with an initialization flag, and adaptively uses the measured position and doppler of scanned points to determine the gating size for the next scan, instead of using a fixed gate size. When the initialization flag of the same cluster across a few consecutive scans satisfies a combination logic, the radar system determines that the tracking enters into the association stage, e.g., the radar system formally generates a track for the target points along a series of scans.

Abstract: Systems, methods, and non-transitory computer-readable media provide a blind online calibration mechanism to calibrate the position of the radar unit while the self-driving vehicle is in motion without the use of any map data. Specifically, a calibration system associated with the self-driving vehicle is configured to adjust the boresight angle of the radar within a calibration range and monitor the convergence or divergence pattern of the resulting clutter locations. The boresight angle of the radar unit may be progressively adjusted in static or dynamic degree increments until the convergence of the clutter curves is observed. In this way, without using any map data or factory settings, radar calibration can be conducted as often as needed while the vehicle is moving. Radar sensing and measurement accuracy is thus improved.

Abstract: Various embodiments of the present technology can include systems, methods, and non-transitory computer readable media configured to adaptively identify clutter points representing static objects from a sensor data scan. A plurality of sensor data scans are captured, by a sensor unit placed on a vehicle, at a plurality of consecutive time instants while the vehicle is traveling along a route. A set of target points from each of the plurality of sensor data scans is identified. A characteristic indicative of a trajectory pattern relating to one or more respective sets of target points is obtained from one or more sensor data scans taken at consecutive time instants. In response to determining that the characteristic satisfies a pre-defined condition, an indicator with the respective sets of target points is adopted as relating to one or more static objects in an environment at which the vehicle is situated.

Abstract: Systems, methods, and non-transitory computer-readable media provide a blind online calibration mechanism to calibrate the position of the radar unit while the self-driving vehicle is in motion without the use of any map data. Specifically, a calibration system associated with the self-driving vehicle is configured to adjust the boresight angle of the radar within a calibration range and monitor the convergence or divergence pattern of the resulting clutter locations. The boresight angle of the radar unit may be progressively adjusted in static or dynamic degree increments until the convergence of the clutter curves is observed. In this way, without using any map data or factory settings, radar calibration can be conducted as often as needed while the vehicle is moving. Radar sensing and measurement accuracy is thus improved.

Abstract: In one embodiment, a method includes accessing a set of data points captured using a radar system of the vehicle. Each data point is associated with at least three measurements include a Doppler measurement, a range measurement, and an azimuth measurement in reference to the radar system. The method also includes clustering the set of data points into one or more first clusters based on a first pair of the three measurements associated with each of the data points; and clustering the set of data points into one or more second clusters based on a second pair of the three measurements associated with each of the data points. The second pair being different from the first pair of the three measurements.

Abstract: Systems, methods, and non-transitory computer-readable media provide an adaptive gating mechanism for radar tracking initialization. Specifically, the radar system obtains measurement data of target points, and then determines, based on the measured position and dopplers of points in the first few scans, whether the doppler and displacement parameters satisfy an initialization constraint. When the initialization constraint is not satisfied, the radar system flags the respective cluster with an initialization flag, and adaptively uses the measured position and doppler of scanned points to determine the gating size for the next scan, instead of using a fixed gate size. When the initialization flag of the same cluster across a few consecutive scans satisfies a combination logic, the radar system determines that the tracking enters into the association stage, e.g., the radar system formally generates a track for the target points along a series of scans.

Abstract: Various embodiments of the present technology can include systems, methods, and non-transitory computer readable media configured to adaptively identify clutter points representing static objects from a sensor data scan. A plurality of sensor data scans are captured, by a sensor unit placed on a vehicle, at a plurality of consecutive time instants while the vehicle is traveling along a route. A set of target points from each of the plurality of sensor data scans is identified. A characteristic indicative of a trajectory pattern relating to one or more respective sets of target points is obtained from one or more sensor data scans taken at consecutive time instants. In response to determining that the characteristic satisfies a pre-defined condition, an indicator with the respective sets of target points is adopted as relating to one or more static objects in an environment at which the vehicle is situated.

Abstract: An LO clock signal generator includes a fundamental mixer for mixing a source clock signal with a divided version of the source clock signal. The LO clock signal generator also includes a harmonic mixer for mixing the source clock signal with a third harmonic of a divided version of the source clock signal.

Abstract: An LO clock signal generator includes a fundamental mixer for mixing a source clock signal with a divided version of the source clock signal. The LO clock signal generator also includes a harmonic mixer for mixing the source clock signal with a third harmonic of a divided version of the source clock signal.