Sensing system and method

Abstract

A sensing method, including: emitting a signal beam; sampling the reflected signal at a sensor with a field of view larger than the signal beam; and determining a surface parameter based on the bright and dark regions associated with the sampled signal.

We claim: 
     
         1 . An obstacle detection method, comprising:
 emitting source light;   shaping more than a threshold proportion of the source light into a narrow light beam having a minor dimension;   illuminating an ambient environment with the narrow light beam;   sampling, at an optical sensor with a field of view larger than the minor dimension, a reflection of the narrow light beam off the ambient environment, wherein the optical sensor is associated with an expected bright region corresponding to an expected reflection of the narrow light beam and an expected dark region corresponding to a non-illuminated region; and   determining an external obstacle parameter, for an external obstacle in the ambient environment, based on pixel parameters of a first bright pixel detected within sensor pixels associated with the expected bright region.   
     
     
         2 . The method of  claim 1 , wherein the minor dimension extends along an auxiliary axis, the method further comprising monitoring the auxiliary axis with an auxiliary light beam. 
     
     
         3 . The method of  claim 2 , wherein the minor dimension comprises a beam height of the narrow light beam, the method further comprising splitting the source light into the narrow light beam and the auxiliary light beam, the auxiliary light beam comprising a minority of the source light, wherein the main light beam and auxiliary light beam are associated with the expected bright region and an auxiliary expected bright region, respectively. 
     
     
         4 . The method of  claim 3 , wherein the source light comprises infrared light and is emitted with an average optical power of 2 W or less. 
     
     
         5 . The method of  claim 3 , further comprising detecting a second object based on aggregated parameter values of adjacent bright pixels detected within sensor pixels associated with the auxiliary expected bright region. 
     
     
         6 . The method of  claim 3 , wherein the auxiliary light beam is separated from the main light beam by an emission angle. 
     
     
         7 . The method of  claim 6 , further comprising splitting a second subset of the source light into a second auxiliary light beam, the second auxiliary light beam emitted at a second emission angle substantially equal to and opposite from the emission angle. 
     
     
         8 . The method of  claim 7 , wherein the auxiliary light beam and second auxiliary light beam are emitted at opposing emission angles defined along a vertical axis aligned along the minor dimension, wherein the auxiliary light beam is associated with a high vertical position, the main light beam is associated with a middle vertical position, and the second auxiliary light beam is associated with a low vertical position. 
     
     
         9 . The method of  claim 8 :
 wherein the main light beam is associated with a main pixel set, the auxiliary light beam is associated with an auxiliary pixel set, and the second auxiliary light beam is associated with a second auxiliary pixel set, wherein the main pixel set, the auxiliary pixel set are concurrently sampled by the optical sensor;   wherein the external obstacle parameter comprises an obstacle presence, wherein determining the external obstacle parameter comprises:
 detecting an object presence in response to an external surface distance, determined based on the pixel parameters of the first bright pixel, falling below a distance threshold; 
   the method further comprising:
 detecting a void in response to a second external surface distance, determined from a second bright pixel within the auxiliary pixel set, exceeding a second distance threshold; and 
 detecting presence of a second object in response to a third external surface distance, determined from a third bright pixel within the second auxiliary pixel set, exceeding a third distance threshold. 
   
     
     
         10 . The method of  claim 1 , wherein the obstacle parameter comprises an obstacle distance, wherein the light comprises phase-modulated light, wherein the obstacle distance is determined based on a phase shift in reflected light. 
     
     
         11 . The method of  claim 10 , further comprising determining an angular position of the object relative to the optical sensor based on a pixel position of the first bright pixel.