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Straightness uncertainty in dimensional metrology is an important parameter in precision engineering. Optimization in straightness measurement using soft algorithm techniques is widely encountered solution in coordinate metrology. In this work, we report on the uncertainty in the CMM measurement of straightness feature for a slab surface. Straightness points have been measured precisely in 3D using CMM at NIS. The straightness has been analyzed using a Particle Swarm Optimization (PSO) algorithm. The probability density distribution of the measured spatial straightness was developed using a Sequential Monte Carlo (SMC) technique; forming probability density histogram with 95% confidence level representing an uncertainty in the straightness measurement. Comparison with relevant reports showed and approved that our results are more accurate since we used a computationally efficient modified SMC technique and PSO algorithm.

Due to the accidents of the motor vehicles and the osteoporosis, many people enface a lot of troubles and sometimes necessities for replacement of their knee joints. Practically, mechanical properties and surface characteristics of Total Knee Replacement (TKR) are very important parameters for improving the performance response in human. The meniscus is a small element and an essential part of the TKR. The knee meniscus has special feature allows the easy dynamic loading and motion of leg and foot with high accuracy and good balance. Therefore design and analysis of the geometrical shape for the meniscus replacement is worthy to be studied. In this paper, a proposed design using a computer software package has been presented. 3D simulation analyses of a variety of meniscus thickness and different materials under different loads are investigated. The compression stresses and surfaces deformations are determined numerically through the Finite Element Analysis (FEA) technique.

The main aim of this work is to develop an identification method to demonstrate the crucial surfaces of automotive braking system. Two brand new brake discs manufactured by two different manufacturers are tested. A typical disc to the one of them was put under working condition in actual braking system. Dimensional and geometrical deviations are investigated using advanced engineering metrological technique. Mechanical properties, tribological characteristics and chemical analyses are investigated. A coordinate measuring machine, universal hardness tester, mass comparator and XRF spectrometer are used in these diagnoses. Measurements of dimensional and geometrical deviations such as disc thickness variations, thickness deviations, straightness, parallelism, runout of disc surfaces are conducted. A comparison between form deviations in disc surfaces have been carried out and analyzed.