Range estimation for light detecting and ranging (lidar) systems

Abstract

Example range estimation apparatus disclosed herein are to estimate a signal power parameter and a noise power parameter of a light detecting and ranging (LIDAR) system based on first data to be output from a light capturing device of the LIDAR system. Disclosed example range estimation apparatus are also to estimate a propagation delay associated with second data output from the light capturing device, the second data associated with a modulated light beam projected by the LIDAR system, the propagation delay estimated based on templates corresponding to different possible propagation delays, the templates based on the signal power parameter and the noise power parameter.

What is claimed is: 
     
         1 . A range estimation apparatus comprising:
 at least one memory;   computer readable instructions; and   processor circuitry to execute the computer readable instructions to at least:
 estimate a signal power parameter and a noise power parameter of a light detecting and ranging (LIDAR) system based on first data to be output from a light capturing device of the LIDAR system; and 
 estimate a propagation delay associated with second data output from the light capturing device, the second data associated with a modulated light beam projected by the LIDAR system, the propagation delay estimated based on templates corresponding to different possible propagation delays, the templates based on the signal power parameter and the noise power parameter. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the second data is to have a higher sampling rate and a lower quantization resolution than the first data. 
     
     
         3 . The apparatus of  claim 1 , wherein the processor circuitry is to convert the propagation delay to an estimated range to an object that reflected the modulated light beam. 
     
     
         4 . The apparatus of  claim 3 , wherein processor circuitry is to render the estimated range as a pixel value of a three-dimensional image of the object, the pixel value corresponding to a scan position of the modulated light beam associated with the second data. 
     
     
         5 . The apparatus of  claim 1 , wherein the templates include a first one of the templates corresponding to a first one of the possible propagation delays, and the processor circuitry is to:
 determine input values corresponding to respective samples of the second data, the input values based on the samples of the second data, the first one of the possible propagation delays and the signal and noise power parameters;   evaluate a cumulative distribution function based on the input values to determine probability values corresponding to the respective samples of the second data; and   determine the first one of the templates based on the probability values.   
     
     
         6 . The apparatus of  claim 1 , wherein the processor circuitry is to estimate the signal power parameter and the noise power parameter by:
 determine a first measurement based on a first portion of the first data, the first portion to be output from the light capturing device while the modulated light beam is off;   determine a second measurement based on a second portion of the first data, the second portion to be output from the light capturing device while the modulated light beam is on;   estimate the noise power parameter based on the first measurement; and   estimate the signal power parameter based on the second measurement and the noise power parameter.   
     
     
         7 . The apparatus of  claim 1 , wherein the processor circuitry is to cross-correlate the second data with the templates to estimate the propagation delay associated with the second data. 
     
     
         8 . At least one non-transitory computer readable medium comprising computer readable instructions which, when executed, cause one or more processors to at least:
 estimate a signal power parameter and a noise power parameter of a light detecting and ranging (LIDAR) system based on first data to be output from a light capturing device of the LIDAR system; and   estimate a propagation delay associated with second data output from the light capturing device, the second data associated with a modulated light beam projected by the LIDAR system, the propagation delay estimated based on templates corresponding to different possible propagation delays, the templates based on the signal power parameter and the noise power parameter.   
     
     
         9 . The at least one non-transitory computer readable medium of  claim 8 , wherein the second data is to have a higher sampling rate and a lower quantization resolution than the first data. 
     
     
         10 . The at least one non-transitory computer readable medium of  claim 8 , wherein the instructions are to cause the one or more processors to convert the propagation delay to an estimated range to an object that reflected the modulated light beam. 
     
     
         11 . The least one non-transitory computer readable medium of  claim 10 , wherein the instructions are to cause the one or more processors to render the estimated range as a pixel value of a three-dimensional image of the object, the pixel value corresponding to a scan position of the modulated light beam associated with the second data. 
     
     
         12 . The least one non-transitory computer readable medium of  claim 8 , wherein the templates include a first one of the templates corresponding to a first one of the possible propagation delays, and the instructions are to cause the one or more processors to:
 determine input values corresponding to respective samples of the second data, the input values based on the samples of the second data, the first one of the possible propagation delays and the signal and noise power parameters;   evaluate a cumulative distribution function based on the input values to determine probability values corresponding to the respective samples of the second data; and   determine the first one of the templates based on the probability values.   
     
     
         13 . The least one non-transitory computer readable medium of  claim 8 , wherein, to estimate the signal power parameter and the noise power parameter, the instructions are to cause the one or more processors to:
 determine a first measurement based on a first portion of the first data, the first portion to be output from the light capturing device while the modulated light beam is off;   determine a second measurement based on a second portion of the first data, the second portion to be output from the light capturing device while the modulated light beam was on;   estimate the noise power parameter based on the first measurement; and   estimate the signal power parameter based on the second measurement and the noise power parameter.   
     
     
         14 . The least one non-transitory computer readable medium of  claim 8 , wherein the instructions cause the one or more processors to cross-correlate the templates with the second data to estimate the propagation delay associated with the second data. 
     
     
         15 . A range estimation method for a light detecting and ranging (LIDAR) system, the method comprising:
 estimating, by executing an instructions with at least one processor, a signal power parameter and a noise power parameter of a light detecting and ranging (LIDAR) system based on first data to be output from a light capturing device of the LIDAR system; and   estimating, by executing an instruction with the at least one processor, a propagation delay associated with second data output from the light capturing device, the second data associated with a modulated light beam projected by the LIDAR system, the propagation delay estimated based on templates corresponding to different possible propagation delays, the templates based on the signal power parameter and the noise power parameter.   
     
     
         16 . The method of  claim 15 , wherein the second data is to have a higher sampling rate and a lower quantization resolution than the first data. 
     
     
         17 . The method of  claim 15 , further including converting the propagation delay to an estimated range to an object that reflected the modulated light beam. 
     
     
         18 . The method of  claim 15 , furthering including generating a first one of the templates corresponding to a first one of the possible propagation delays by:
 determining input values corresponding to respective samples of the second data, the input values being determined based on the samples of the second data, the first one of the possible propagation delays and the signal and noise power parameters;   evaluating a cumulative distribution function based on the input values to determine probability values corresponding to the respective samples of the second data; and   determining the first one of the templates based on the probability values.   
     
     
         19 . The method of  claim 15 , wherein the estimating of the signal power parameter and the noise power parameter include:
 determining a first measurement based on a first portion of the first data, the first portion to be output from the light capturing device while the modulated light beam is off;   determining a second measurement based on a second portion of the first data, the second portion to be output from the light capturing device while the modulated light beam was on;   estimating the noise power parameter based on the first measurement; and   estimating the signal power parameter based on the second measurement and the noise power parameter.   
     
     
         20 . The method of  claim 15 , wherein the estimating of the propagation delay associated with second data includes cross-correlating the templates with the second data to estimate the propagation delay associated with the second data.