| 摘要 |
A measurement method for thread parameters for a threaded object (3) having a coated thread surface , by means of a measurement device (1) defining a spatial reference system (X, Y, Z) incorporating an optical sensor (5) defining its spatial reference system (X', Y', Z'). A computer assembles a first matrix that describes the quadratic form representing the threaded object in the spatial reference system (X, Y, Z), thus providing the relationship between the two spatial reference systems. The method comprises the steps of:
a) before coating, predefining at least one trajectory of the at least one optical sensor (5) on the threaded object, along which measurement points are selected such that the matrix evaluated on these values satisfies the condition that it has maximum rank,
b) performing a first scanning operation by the at least one optical sensor (5) along said at least one trajectory and retrieving data of the predefined measurement points,
c) feeding these data to the first matrix and calculating an axes transformation matrix relating the first spatial reference system with the second spatial reference system for defining the relative position of the threaded object with respect to the second spatial reference system,
d) using the axes transformation matrix to convert all data retrieved from the second spatial reference system to the first spatial reference system.
e) coating the thread surface and performing the same measurement steps and determining the differences in measurement to verify coating quality. |
