Patent ID: 9395180
Filing Date: 2016-07-19
CPC Classification: G01B

Claim Text:
1. A method for producing a surface shape map of at least one surface of an object and independent of relative motion of the object, the method comprising: (a) arranging at least four opposed sets of distance sensors to measure changes in surface height on at least two surfaces of the object, the sets of distance sensors positioned to avoid sole equally spaced parallel lines directed at the object; (b) moving the object or the sets of distance sensors a distance relative to -one another in a selected direction; (c) taking sensor readings of the distance moved by the object in the selected direction at measured increments of relative movement of the object to the sets of distance sensors, wherein the sensor readings include measured positions of a plurality of points on the surface of the object from different sensors of the sets of distance sensors, the measured positions of the plurality of the points on the surface of the object producing point measurements that comprise surface shape quantities and relative motion, wherein the relative motion is translation, pitch, roll and combinations thereof; (d) comparing the point measurements of the plurality of points on the surface of the object at different times by excluding the surface shape quantities from relative motion for the plurality of points on the surface of the object, so that only the relative motion of translation, pitch and roll of the plurality of points on the surface of the object are involved in the comparison, thereby determining the relative motions of the plurality of points on the surface of the object; and (e) subtracting the relative motions of the plurality of points on the surface of the object from sensor readings to obtain the surface shape map; wherein the distance sensors are multi-point line sensors and wherein the object is a cylindrical object including surface slopes.