Panosense Inc.

Zoox, Inc.

Riley Andrews

Denis Nikitin

Ryan McMichael

Adam Berger

Brian Pilnick

Subasingha Shaminda Subasingha

Turhan Karadeniz

Brian Alexander Pesch

Ravi Sankar Mahankali

Arthur Benemann

Joshua Franz

A LIDAR system emits laser bursts, wherein each burst has at least a pair of pulses. The pulses of each pair are spaced by a time interval having a variable duration to reduce effects of cross-talk. For example, certain embodiments may have multiple emitter/sensor channels that are used sequentially, and each channel may use a different duration for inter-pulse spacing to reduce the effects of cross-talk between channels. The durations may also be varied over time. The emitters and sensors are physically arranged in a two-dimensional array to achieve a relatively fine vertical pitch. The array has staggered rows that are packed using a hexagonal packing arrangement. The channels are used in a sequential order that is selected to maximize spacing between consecutively used channels, further reducing possibilities for inter-channel cross-talk.

Lidar system

A time delay of arrival (TDOA) between a time that a light pulse was emitted to a time that a pulse reflected off an object was received at a light sensor may be determined for saturated signals by using an edge of the saturated signal, rather than a peak of the signal, for the TDOA calculation. The edge of the saturated signal may be accurately estimated by fitting a first polynomial curve to data points of the saturated signal, defining an intermediate magnitude threshold based on the polynomial curve, fitting a second polynomial curve to data points near an intersection of the first polynomial curve and the intermediate threshold, and identifying an intersection of the second polynomial curve and the intermediate threshold as the rising edge of the saturated signal.

Detecting a laser pulse edge for real time detection

A lidar photosensor amplification circuit may include light sensors; amplifiers corresponding respectively to the light sensors, in a powered-on state, to amplify output signals of the respective light sensors as amplified outputs; and switches corresponding respectively to the amplifiers, where individual switches may be controlled to pass a respective amplified output in a closed state or disconnect the amplified output in an open state. The lidar photosensor amplification circuit may be controlled by a controller according to timing rules that conserve power supplied to photosensor amplification circuit, reduce heat produced by the light sensor board, and do not aggravate cross-talk between sensors. The timing rules include staging an amplifier for a staging time before the corresponding light sensor is to be read, closing a switch after the staging time has passed, and powering down the amplifier and opening the switch after a reading time passes.

Lidar photosensor amplification circuit

A LIDAR system includes one or more LIDAR sensor assemblies, which may be mounted to a vehicle or other object. Each LIDAR sensor assembly includes a laser light source to emit laser light, and a light sensor to produce a light signal in response to sensing reflected light corresponding to reflection of the laser light emitted by the laser light source from a reference surface that is fixed in relation to the LIDAR sensor assembly. A controller of the LIDAR sensor assembly may calibrate the LIDAR sensor assembly based at least in part on a signal from the light sensor indicating detection of reflected light corresponding to reflection of a pulse of laser light reflected from the reference surface.

LIDAR sensor assembly calibration based on reference surface

A LIDAR system emits laser pulses, wherein each pulse is associated with a power level. A laser emitter is adjusted during operation of a LIDAR system using power profile data associated with the laser. The power profile data is obtained during a calibration procedure and includes information that associates charge duration for a laser power supply with the actual power output by laser. The power profiles can be used during operation of the LIDAR system. A laser pulse can be emitted, the reflected light from the pulse received and analyzed, and the power of the next pulse can be adjusted based on a lookup within the power profile for the laser. For instance, if the power returned from a pulse is too high (e.g., above some specified threshold), the power of the next pulse is reduced to a specific value based on the power profile.

Laser power cailibration and correction

A device can accurately discriminate an active pulse from noise by setting a dynamic noise floor that adjusts according to environmental conditions. For example, the device may discriminate, as the active pulse, a light pulse emitted by a light emitter of the system and reflected off an object to a light sensor, from noise such as sunlight glare by determining a dynamic noise floor and identifying, as an active pulse, at least a portion of the received signal that exceeds the dynamic noise floor for a threshold number of samples. The dynamic noise floor may be determined, for example, using a moving average of the received signal and/or shifting or scaling the noise floor based on other properties of the return signal.

Active signal detection using adaptive identification of a noise floor

LIDAR system

A LIDAR device can accurately calculate distances to objects in an environment by classifying a signal received from a sensor as being a particular type of signal (e.g., saturated or unsaturated) and selecting, based on the type of signal, a detector for processing the received signal from among multiple detectors. For example, the multiple detectors may include different programming and/or circuitry for determining a time delay of arrival (TDOA) between a time that a light pulse was emitted to a time that a pulse reflected off an object was received at a light sensor. The output of the selected detector may then be used to calculate a distance to the object from which the received signal was reflected.

Selecting LIDAR pulse detector depending on pulse type

Laser power calibration and correction

Lidar sensor assembly calibration based on reference surface

An interface for transferring data between a non-rotating body and a rotating body of a sensor assembly using a bidirectional communication link. For instance, the interface may include a first data transmitter coupled to the rotating body and configured to transmit first data signals representing sensor signals generated by the sensor assembly. A first data receiver is coupled to the non-rotating body and configured to receive the first data signals via a first wireless coupling. The interface further includes a second data transmitter coupled to the non-rotating body and configured to transmit second data signals. A second data receiver is coupled to the rotating body and configured to receive the second data signals via a second wireless coupling. In some instances, the first data signals may be transmitted using a first wavelength and the second data signals may be transmitted using a second, different wavelength.

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San Francisco, CA, United States of America

Riley Andrews