Robotic vision system to locate Z-forms

Abstract

A Z-form position detector useful for ascertaining the position of Z-forms with respect to underlying composite structure. The device comprises an oscillating laser that generates a line projected onto the Z-form and composite structure at an angle. The line appears discontinuous due to the topography of the Z-form and composite structure. For example, the line is discontinuous at the edges of the Z-form. The device further comprises a sensor sensitive to the frequency of the laser. The sensor scans along the line until a discontinuity (i.e., a break in the line) is detected. Since the discontinuity corresponds to the edge of the Z-form, detection of the discontinuity allows the device to ascertain precise coordinates of a point on the edge of the Z-form. The device thus allows Z-pins to be driven into composite structure automatically for savings on time and cost.

1 - 17 . (canceled)  
   
   
       18 . An edge detector for detecting an edge of a surface, the surface defining a surface plane, the detector comprising: 
 a) a light beam generator for generating a light beam along a generator axis, the light beam generator being disposed at a first location and operative to direct the light beam along the generator axis toward a first position on the surface plane wherein the generator axis defines a first angle relative to the surface plane;    b) a sensor for detecting a reflection of the light beam off the surface in the surface plane, the sensor being disposed at a second location and having a sensor axis aligned to the first position on the surface plane wherein the optical axis defines a second angle relative to the surface plane, the sensor having a first detected state when the light beam and sensor axis substantially intersect the surface at the first position and a second detected state when the light beam and sensor optical axis do not substantially intersect the surface at the first position;    c) wherein the edge is detected when the sensor transitions between the first and second detected states.    
   
   
       19 . The detector of  claim 20  wherein the light beam generator is a laser beam generator for generating a laser beam.  
   
   
       20 . The detector of  claim 20  wherein the first angle is about 30 degrees normal to the surface plane.  
   
   
       21 . The detector of  claim 22  wherein the second angle is about zero degrees normal to the surface plane.  
   
   
       22 . The detector of  claim 20  wherein the edge is detected when the sensor transitions from the first detected state to the second detected state.  
   
   
       23 . The detector of  claim 20  wherein the light beam generator directs the light beam toward the surface plane such that a laser line is formed on the surface.  
   
   
       24 . The detector of  claim 20  wherein in the first detected state the sensor detects the light beam reflected from the surface first position.  
   
   
       25 . The detector of  claim 20  wherein in the second detected state the sensor does not detect the light beam reflected from the surface first position.  
   
   
       26 . The detector of  claim 20  wherein the sensor detects the reflection of the light beam off the surface in the surface plane when the detected frequency of the reflected light beam is above or equal to a first threshold level.  
   
   
       27 . The detector of  claim 28  wherein the first threshold level is equal to the frequency at which a light line generated by the light generator oscillates.  
   
   
       28 . The detector of  claim 28  wherein the sensor does not detect the reflection of the light beam off the surface in the surface plane when the detected frequency of the reflected light beam is below or equal to a second threshold level.  
   
   
       29 . The detector of  claim 30  wherein the second threshold level is equal to zero.  
   
   
       30 . The detector of  claim 20  wherein the first position is in the surface plane and traverses across the surface upon movement thereof.