Accurate photo detector measurements for lidar

Abstract

A light ranging system can include a laser device and an imaging device having photosensors. The laser device illuminates a scene with laser pulse radiation that reflects off of objects in the scene.The reflections can vary greatly depending on the reflecting surface shape and reflectivity. The signal measured by photosensors can be filtered with a number of matched filter designed according to profiles of different reflected signals. A best matched filter can be identified, and hence information about the reflecting surface and accurate ranging information can be obtained. The laser pulse radiation can be emitted in coded pulses by allowing weights to different detection intervals. Other enhancements include staggering laser pulses and changing an operational status of photodetectors ofa pixel sensor, as well as efficient signal processing using a sensor chip that includes processing circuits and photosensors.

Description

[0001] Cross References to Related Applications [0002] This application claims U.S. Provisional Application No. 62 / 465,310, filed March 1, 2017, entitled "System And Method Of Object Detection Using Coded Optical Pulses" priority to U.S. Provisional Application No. 62 / 596,002, filed December 7, 2017, entitled "Accurate Photo Detector Measurements For Lidar" and is a non-provisional application of the above case, which is hereby incorporated by reference in its entirety for all purposes. Background technique [0003] Light Detection And Ranging (LIDAR) systems are used for object detection and ranging, for example, for vehicles such as cars, trucks, boats and the like. LIDAR systems are also used in mobile applications (eg, for facial recognition), home entertainment (eg, capturing gesture capture for video game input), and augmented reality. A LIDAR system measures distance to an object by illuminating a landscape with pulses from a laser, and then measuring the time for a...

AI Technical Summary

Problems solved by technology

[0004] Can be difficult to provide robust range accuracy up to a few centimeters under all conditions, especially at the economic cost of LIDAR systems

Promising new detector technologies such as single photon avalanche diodes (SPADs) are attractive but have significant drawbacks when used to measure time-of-flight and other signal properties, especially over a wide range of environmental conditions Significant drawbacks in terms of distance and target due to their limited dynamic range

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