ROBUST METHOD FOR STRAIGHTNESS EVALUATION: COMBINED LS AND PSO METHODS
IHAB HAMDY NAEIM *
Faculty of Science, Taibah University, Preparatory Deanery, Yanbu, Saudi Arabia. and Precision Engineering Division, National Institute of Standards (NIS), Giza 12211, Egypt.
*Author to whom correspondence should be addressed.
Abstract
Uncertainty and metrological traceability are always an aim of metrology scientists to verify the true value of measuring process. This work reports on a reliable and robust method for estimating the CMM straightness by systematically employing a combination of the least-square LS and particle swarm-optimization PSO methods. Repetitive acquisition of the data points was performed along a straight line in a flat slab using advanced CMM measurement system. The least-square method gave rise to smaller straightness 7.22 μm with larger error ±0.20 μm as compared with the particle-swarm-optimization PSO method 9.08±0.13 μm. The combined average 8.15±0.11 μm of the results obtained by the two methods thus pertains to the better straightness from the LS method as well as the better accuracy from the PSO method.
Keywords: Straightness metrology combined LS, PSO computational methods