Abstract: Described herein are systems and methods for improving detection of a return signal in a light ranging and detection system. The system comprises a transmitter and a receiver. A first sequence of pulses may be encoded with an anti-spoof signature and transmitted in a laser beam. A return signal, comprising a second sequence of pulses, may be received by the receiver and the anti-spoof signature extracted from the second sequence of pulses. If based on the extraction, the first and second sequences of pulses match, the receiver outputs return signal data. If based on the extraction, the first and second sequence of pulses do not match, the return signal is disregarded. The system may dynamically change the anti-spoofing signature for subsequent sequences of pulses. Additionally, the first sequence of pulses may be randomized relative to a prior sequence of pulses.

Abstract: Described herein are systems and methods that may efficiently detect multi-return light signals. A light detection and ranging system, such as a LiDAR system, may fire a laser beam that may hit multiple objects with a different distance in one line, causing multi-return light signals to be received by the system. Multi-return detectors may be able to analyze the peak magnitude of a plurality of peaks in the return signals and determine a multitude of peaks, such as the first peak, the last peak and the maximum peak. One embodiment to detect the multi-return light signals may be a multi-return recursive matched filter detector. This detector comprises a matched filter, peak detector, centroid calculation and a zeroing out function. Other embodiments may be based on a maximum finder that algorithmically selects the highest magnitude peaks from samples of the return signal and buffers for regions of interests peaks.

Abstract: Ultrasonic sensing systems and associated methods provide side-lobe reduction to improve the acoustic detection of small objects, the signature envelope peaks of which can otherwise be obscured by subsidiary envelope peaks in side lobes that result from residual correlation between a signal received by an ultrasonic transducer and a template signal corresponding to a burst signal emitted by the ultrasonic transducer. A shaping signal by which the amplitude of the burst signal can be varied with respect to time is taken into account in the template signal, and correlator circuitry correlates a signal derived from the ultrasonic transducer with the template signal to produce a correlated output exhibiting the desired side-lobe reduction. The distance from the transducer to the detected object can thereby be determined with enhanced accuracy and responsiveness.

Abstract: Methods and systems for combining return signals from multiple channels of a LIDAR measurement system are described herein. In one aspect, the outputs of multiple receive channels are electrically coupled before input to a single channel of an analog to digital converter. In another aspect, a DC offset voltage is provided at the output of each transimpedance amplifier of each receive channel to improve measured signal quality. In another aspect, a bias voltage supplied to each photodetector of each receive channel is adjusted based on measured temperature to save power and improve measurement consistency. In another aspect, a bias voltage supplied to each illumination source of each transmit channel is adjusted based on measured temperature. In another aspect, a multiplexer is employed to multiplex multiple sets of output signals of corresponding sets of receive channels before analog to digital conversion.

Abstract: Ultrasonic ranging systems and methods that use coding to distinguish emitted bursts from multiple transducers temporally stagger the bursts emitted from the transducers. The stagger delay between bursts from different transducers in a sensing frame can be randomized between different sensing frames to prevent blind zones. The stagger delay can be relatively small (e.g., between 3 ms and 10 ms) as compared to delays required between bursts in a single-tone ranging system (which would need to be more on the order of between 30 ms and 40 ms, depending on the maximum detecting range of the ranging system). The coding of bursts can be selected to utilize the entire bandwidth of the bursting transducer so as to preserve short-range sensitivity over transducer ringing. Schemes in which some transducers in a system only listen for bursts from other transducers but do not themselves burst within a sensing frame are also described.

Abstract: Described herein are systems and methods that implement a dual axis resonant scanning mirror to support a sensor system such as a LIDAR system. The scanning mirror may comprise: 1) a small dual axis mirror, in which each axis is moving by similar electromagnetic mechanisms can generate crosstalk between each of these electromagnetic mechanisms causing perturbations in the motion; 2) a primary axis that may need to be driven independently of the motion of a secondary axis and vice versa; 3) an optical position sensor; 4) a scanning mirror assembly that may be mounted to a scanner base via the secondary axis. The scanning mirror assembly may comprise resonant spring, resonant spring assembly, the rocking chair (with electromagnetic drive coils), the scanner base with a set of two secondary axis propulsion magnets, the mirror with a spacer and primary axis propulsion magnets, and the optical sense board.

Abstract: The present disclosure relates generally to systems and methods for generating, processing and correlating data from multiple sensors in an autonomous navigation system, and more particularly to the utilization of configurable and dynamic sensor modules within light detection and ranging systems that enable an improved correlation between sensor data as well as configurability and responsiveness of the system to its surrounding environment.

Abstract: The present disclosure relates generally to systems and methods for generating, processing and correlating data from multiple sensors in an autonomous navigation system, and more particularly to the utilization of configurable and dynamic sensor modules within light detection and ranging systems that enable an improved correlation between sensor data as well as configurability and responsiveness of the system to its surrounding environment.

Abstract: The present disclosure relates generally to systems and methods for configuring architectures for a sensor, and more particularly for light detection and ranging (hereinafter, “LIDAR”) systems based on ASIC sensor architectures supporting autonomous navigation systems. Effective ASIC sensor architecture can enable an improved correlation between sensor data as well as configurability and responsiveness of the system to its surrounding environment and avoid any unnecessary delay within the decision-making process that may result in a failure of the autonomous driving system. It may be essential to integrated multiple functions within an electronic module and implement the functionality with one or more ASICs.

Abstract: Described herein are systems and methods that may efficiently detect multi-return light signals. A light detection and ranging system, such as a LIDAR system, may fire a laser beam that may hit multiple objects with a different distance in one line, causing multi-return light signals to be received by the system. Multi-return detectors may be able to analyze the peak magnitude of a plurality of peaks in the return signals and determine a multitude of peaks, such as the first peak, the last peak and the maximum peak. One embodiment to detect the multi-return light signals may be a multi-return recursive matched filter detector. This detector comprises a matched filter, peak detector, centroid calculation and a zeroing out function. Other embodiments may be based on a maximum finder that algorithmically selects the highest magnitude peaks from samples of the return signal and buffers for regions of interests peaks.

Abstract: Methods and systems for performing three dimensional LIDAR measurements with an integrated LIDAR measurement device are described herein. In one aspect, a return signal receiver generates a pulse trigger signal that triggers the generation of a pulse of illumination light and data acquisition of a return signal, and also triggers the time of flight calculation by time to digital conversion. In addition, the return signal receiver also estimates the width and peak amplitude of each return pulse, and samples each return pulse waveform individually over a sampling window that includes the peak amplitude of each return pulse waveform. In a further aspect, the time of flight associated with each return pulse is estimated based on a coarse timing estimate and a fine timing estimate. In another aspect, the time of flight is measured from the measured pulse due to internal optical crosstalk and a valid return pulse.

Abstract: Described herein are systems and methods for improving detection of a return signal in a light ranging and detection system (LiDAR). The method includes the following steps at the LiDAR system: encoding and transmitting a sequence of pulses based on a user signature. Then, receiving a multi-return signal based on a reflection off objects of the sequences of pulses. The multi-return signal may be decoded based on the user signature, and then authenticated the via a correlation calculation. The user signature may determine an amplitude of a first pulse in the sequence of pulses, an amplitude of a second pulse of the sequence of pulses, and an interval between the first pulse and the second pulse. A bit representation of the user signature is orthogonal to a bit representation of another user signature of another LiDAR system. The user signature may be dynamically adjusted by the LiDAR system.

Abstract: In an ultrasonic detection system that uses frequency-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses dynamic thresholding to discriminate valid echoes from system and environmental noise in multiple envelope signals produced by multiple correlators. The time-varying dynamic thresholds are generated from the mean of noise in a respective envelope derived from the output of a respective correlator. Multiple thresholds can be combined together such that a single time-varying threshold is applied to all correlators' envelopes. Such thresholding has the benefits of a constant false-alarm rate with regard to detection of echoes (as opposed to false triggering from noise), and, owing to finer-resolution and adaptive thresholds, can detect targets or obstacles as further distances and with greater time responsiveness.

Abstract: Methods and systems for performing three dimensional LIDAR measurements with an integrated LIDAR measurement device are described herein. In one aspect, a return signal receiver generates a pulse trigger signal that triggers the generation of a pulse of illumination light and data acquisition of a return signal, and also triggers the time of flight calculation by time to digital conversion. In addition, the return signal receiver also estimates the width and peak amplitude of each return pulse, and samples each return pulse waveform individually over a sampling window that includes the peak amplitude of each return pulse waveform. In a further aspect, the time of flight associated with each return pulse is estimated based on a coarse timing estimate and a fine timing estimate. In another aspect, the time of flight is measured from the measured pulse due to internal optical crosstalk and a valid return pulse.

Abstract: In an ultrasonic detection system that uses frequency-modulation or phase-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses peak search, peak buffer, and peak rank stages in one or more receiver signal processing paths to identify valid received ultrasonic signal envelope peaks in correlator outputs. The peak rank stage can support different modes respectively designed to handle one code, two or more codes, or two or more codes with support for Doppler frequency shift detection. Valid peak information (e.g., amplitude and time) can be reported to a central controller and/or stored locally in a fusion stage to generate more intelligent information for targets or obstacles using peaks from multiple bursts.

Abstract: A voltage regulator and a gate control circuit for an aid transistor coupled to assist a pass element for the voltage regulator during line transients having a given slope are disclosed. The gate control circuit includes a first circuit coupled to receive an output voltage of the voltage regulator on a first node and to provide a gate control voltage that mirrors the output voltage on a second node. A low pass filter is coupled to receive the gate control voltage and to provide a filtered gate control voltage to the gate of the aid transistor.

Abstract: Described herein are systems and methods for improving detection of a return signal in a light ranging and detection system. The system comprises a transmitter and a receiver. A first sequence of pulses may be encoded with an anti-spoof signature and transmitted in a laser beam. A return signal, comprising a second sequence of pulses, may be received by the receiver and the anti-spoof signature extracted from the second sequence of pulses. If based on the extraction, the first and second sequences of pulses match, the receiver outputs return signal data. If based on the extraction, the first and second sequence of pulses do not match, the return signal is disregarded. The system may dynamically change the anti-spoofing signature for subsequent sequences of pulses. Additionally, the first sequence of pulses may be randomized relative to a prior sequence of pulses.

Abstract: Methods and systems for combining return signals from multiple channels of a LIDAR measurement system are described herein. In one aspect, the outputs of multiple receive channels are electrically coupled before input to a single channel of an analog to digital converter. In another aspect, a DC offset voltage is provided at the output of each transimpedance amplifier of each receive channel to improve measured signal quality. In another aspect, a bias voltage supplied to each photodetector of each receive channel is adjusted based on measured temperature to save power and improve measurement consistency. In another aspect, a bias voltage supplied to each illumination source of each transmit channel is adjusted based on measured temperature. In another aspect, a multiplexer is employed to multiplex multiple sets of output signals of corresponding sets of receive channels before analog to digital conversion.

Abstract: Described herein are systems and methods that may efficiently detect multi-return light signals. A light detection and ranging system, such as a LIDAR system, may fire a laser beam that may hit multiple objects with a different distance in one line, causing multi-return light signals to be received by the system. Multi-return detectors may be able to analyze the peak magnitude of a plurality of peaks in the return signals and determine a multitude of peaks, such as the first peak, the last peak and the maximum peak. One embodiment to detect the multi-return light signals may be a multi-return recursive matched filter detector. This detector comprises a matched filter, peak detector, centroid calculation and a zeroing out function. Other embodiments may be based on a maximum finder that algorithmically selects the highest magnitude peaks from samples of the return signal and buffers for regions of interests peaks.

Abstract: A voltage regulator and a gate control circuit for an aid transistor coupled to assist a pass element for the voltage regulator during line transients having a given slope are disclosed. The gate control circuit includes a first circuit coupled to receive an output voltage of the voltage regulator on a first node and to provide a gate control voltage that mirrors the output voltage on a second node. A low pass filter is coupled to receive the gate control voltage and to provide a filtered gate control voltage to the gate of the aid transistor.