Calibration: What is Calibration?
Calibration is a process by which the location of the positioning system and vision cameras are determined in the mapped space of each machine. The ‘positioning system’ and vision cameras will be briefly described in a later section, under System Overview. Calibration process produces a large number of data that relate to the physical aspects of the machine. Typically, it produces a machine model file with data sets that:
a) locate PEC camera’s ( Position Error Correction or downward looking camera ) position , orientation as well as relate pixel values to Carriage Coordinates.
b) relate P2P (Part to Pad ) or ULC ( upward looking camera) camera pixel coordinates to machine Coordinates in microns and provide its location and orientation
c) map Theta encoder readings to spindle Theta
d) provide X, Y spindle locations when a spindle is down in Carriage Coordinates
e) indicate spindle X, Y and Theta runout , which are displacements in x, y and theta that may occur when the spindle moves up or down for part viewing and part pick / placement operations.. The spindle runout quantities need to be corrected for high precision placement of parts. A schematic diagram that explains spindle run out appears later in the document,
when the actual calculations are detailed.
