3D Displacement Measurement Using Ring-beam

IntroductionIntroduction

PhD Student: Shin Usuki

Parallel CMMIntroductionIntroduction3D Displacement (Position) Measurementwith High Accuracy and MeasurementFlexibility to Calibrate the End-effector ofthe Complicated 3D Mechanism

Ring-Beam System

dMeasurement PrincipleMeasurement Principle Light sourceBeam Expander

Sphere

l

Ring Slit

λ/4 Plate Image of reflected ray

lens

CCD

Beam Splitter

PC

Displacement of a ball

X X

Y Y

Z Z

Step Displacement Measurement & AnalysisStep Displacement Measurement & Analysis

Change of Reflected Light→ Sphere Displacement

Various Images of Reflected Light

Measurement of Target Sphere with 200nm Step

Ring Slit

CC

Source

Expander

Mirror

Lens

λ/4 200nm

Max Error: 50nm

X direction Displacement by PZT

D l d E i t

150mm

CCD

Height=100mm

Beam Splitter

polarizer

300mm

200nm

Standard deviation: 10nm

Measurement ResultDeveloped Equipment- Compact & Mobile -- Low Center of Gravity -- Easy to Assemble -

Ref.) S. Usuki, et. al., Improving the Accuracy of 3D Displacement Measurement using Ring-Shaped Laser Beam and High Resolution CCD, Proc. 4th International Conference of the European Society for Precision Engineering and Nanotechnology (euspen2004), pp328-329, 2004

Measurement Result(X direction repeatability: 10nm, accuracy: 50nm)(Y direction repeatability: 20nm)(Z direction repeatability : 100nm)Range (XD x YD x ZD: 0.1mm x 0.1mm x 0.5mm)