Spatial coordinates measurement system based on doublespots overlapped PSD
SUN Yu-xi，LU Yong-hua
（College of Mechanical and Electrical Engineering，Nanjing University of Aeronautics and Astronautics，
Nanjing 210016，China）
Abstract：Aiming at spatial coordinates measurement，a new spatial coordinates measurement system based on the double spotsoverlapped PSD was designed. The measurement and control platform of the spatial coordinate measurement system was constructed andphotoelectric sensor PSD was taken as the target on the measurement head to form the measuring triangle. A successive approximationalgorithm to make double spots alternately tracking on the PSD and realize the automatic tracking of the measurement system was used.
The principle of PSD acquisition spot center of gravity and judging double spots overlap was used by the measurement system to measurethe information of spatial coordinates. An 8th level turbine rotor blade of a certain type aircraft engine was taken as measuring object ofthe measurement system. The results indicate that measured by three coordinate measurement machine and by our measurement system，the deviation of our measurement system for target is at sub-millimeter level，and maintains at the range of +0.4 mm~-0.25 mm when thedistance varies in 1.5 m from the measurement system.
Key words：double spots；overlapped；PSD；spatial coordinates