Noise Adaptive Solid-State LIDAR System

Abstract

A light detection and ranging (LIDAR) system includes an optical transmitter comprising a plurality of lasers, where each of the plurality of lasers illuminates a field-of-view. A transmitter controller is configured to pulse desired ones of the plurality of lasers so that the plurality of lasers generate light in a desired illumination region. An optical receiver comprises a plurality of detectors positioned to detect light over the desired illumination region. The plurality of detectors generates an electrical detection signal. A time-of-flight measurement circuit measures the time-of-flight of light from the plurality of lasers to the plurality of detectors. The optical receiver calculates range information from the time-of-flight measurements. A receiver controller is electrically connected to the transmitter controller and is configured to bias at least some of the plurality of detectors at a bias point that achieves a desired detection signal noise level.

1 - 40 . (canceled) 
     
     
         41 . A light detection and ranging (LIDAR) system comprising:
 a) an optical transmitter comprising a plurality of lasers, each of the plurality of lasers illuminating a field-of-view;   b) a transmitter controller having a plurality of electrical outputs, a respective one of the plurality of electrical outputs being connected to a respective electrical input of each of the plurality of lasers, the transmitter controller being configured to pulse desired ones of the plurality of lasers so that the plurality of lasers generate light in a desired illumination region;   c) an optical receiver comprising a plurality of detectors positioned to detect light over the desired illumination region, where there is a correspondence established between the desired illumination region and particular detectors, at least some of the plurality of detectors configured as a sub-array with a common output that generates an electrical detection signal, and a time-of-flight measurement circuit that measures a time-of-flight of light from the plurality of lasers to the plurality of detectors, the optical receiver calculating range information from the time-of-flight measurements; and   d) an optical receiver controller being electrically connected to the transmitter controller and having a plurality of electrical outputs, at least one of the plurality of electrical outputs being connected to an input of at least one of the at least some of the plurality of detectors configured as the sub-array, the optical receiver controller being configured to bias the connected one of the at least one of the at least some of the plurality of detectors configured as the sub-array at a bias point that depends upon the established correspondence between the desired illumination region and the particular detectors.   
     
     
         42 . The LIDAR system of  claim 41  wherein at least two of the plurality of detectors are positioned to detect light in overlapping fields-of-view illuminated by at least two of the plurality of lasers. 
     
     
         43 . The LIDAR system of  claim 41  wherein the time-of-flight measurement circuit comprises a time-to-digital circuit. 
     
     
         44 . The LIDAR system of  claim 41  wherein the time-of-flight measurement circuit comprises an analog to digital convertor circuit. 
     
     
         45 . The LIDAR system of  claim 41  wherein at least one of the plurality of detectors in the optical receiver is selected from the group consisting of a PIN detector, a linear avalanche photodetector (APD), a Geiger-Mode APD, a silicon photomultiplier (SiPM), and a multi-pixel photon counter (MPPC). 
     
     
         46 . The LIDAR system of  claim 41  wherein at least one of the plurality of detectors comprises an array of detectors having at least some common electrical connections. 
     
     
         47 . The LIDAR system of  claim 41  wherein at least one of the plurality of detectors comprises an input filter that reduces an intensity of solar background light to an input of the detector. 
     
     
         48 . The LIDAR system of  claim 41  wherein at least one of the plurality of detectors is configured to have a restricted detection area field-of-view. 
     
     
         49 . The LIDAR system of  claim 41  wherein the transmitter controller is configured to pulse desired ones of the plurality of lasers with a number of pulses per duty cycle that achieves a detected light signal with a desired signal-to-noise ratio. 
     
     
         50 . The LIDAR system of  claim 49  wherein the transmitter controller is configured to pulse desired ones of the plurality of lasers with four or more pulses per duty cycle. 
     
     
         51 . The LIDAR system of  claim 49  wherein the transmitter controller is configured to pulse desired ones of the plurality of lasers with ten or more pulses per duty cycle. 
     
     
         52 . The LIDAR system of  claim 49  wherein the transmitter controller is configured to pulse desired ones of the plurality of lasers with twenty-five or more pulses per duty cycle. 
     
     
         53 . The LIDAR system of  claim 41  wherein at least two of the plurality of lasers emit a different wavelength.