This paper presents a ball-bar based self-calibration technique for a five-axis point laser optical measurement system.
The system is composed of a high accuracy laser point sensor and five motion stages X, Y, Z, B, C. A kinematical
system model of the 5-axis measurement system is presented to map the stages and sensor readouts to the target position
of the work piece to be measured. With an assumption that each stages’ linearity error, straightness errors, angular
errors and sensor linearity error have been calibrated or omitted due to high performance hardware selection, the three
squareness angles, laser beam direction and rotary axis position and direction of the two rotary stages are well addressed
as the model parameters in the system model. Heuristic methods are introduced to separately calibrate the system
squareness, beam direction and rotary axis by using different data acquisition approaches over the ball bar. Parameter
estimation methods are applied to obtain the system model parameters via the data set of the ball bar. Experimental
studies using a cylinder bar and ball bar demonstrate that the system achieved an accuracy of better than 5 micron.