The measurement of small displacements on the nanometric scale demands metrological systems of high accuracy and precision. In this context, interferometer-based displacement measurements have become the main tools used for traceable dimensional metrology. The different industrial applications in which small displacement measurements are employed requires the use of online measurements, high sp...

In this paper, an effective numerical method is introduced for the treatment of nonlinear two-dimensional Volterra-Fredholm integro-differential equations. Here, we use the so-called two-dimensional block-pulse functions.First, the two-dimensional block-pulse operational matrix of integration and differentiation has been presented. Then, by using this matrices, the nonlinear two-dimensional Vol...

In this paper, we propose a three-dimensional (3-D) measurement method of objects in liquid with a laser range finder. When applying vision sensors to measuring objects in liquid, we meet the problem of an image distortion. It is caused by the refraction of the light on the boundary between the air and the liquid, and the distorted image brings errors in a triangulation for the range measuremen...

Phase unwrapping is one of important task in synthesizes aperture radar (SAR) interferometric measurement data processing procedure. Accuracy of it will directly affects precision of the interferometric measurement result. Through the experimental study, this paper analyzes principle and the characteristic of two kind of main current phases unwrapping algorithm, then conbines respective merit a...

Measurement of weld pool surface is an important research area in the welding community. In recent years, many vision-based approaches have been proposed that have achieved certain successes in this area. However, the accuracy of the measurement results in these systems deserves further consideration since the shape information of small weld pool surface may be used to validate welding models a...

in this paper, reduced order proper orthogonal decomposition method has been used for simulation of unsteady incompressible flow fields. after projection of the governing equations along pod modes, a low-dimensional dynamical system is achieved. normally, standard low-dimensional models, due to some reasons, do not predict time variations of flow field accurately. accuracy of dynamical system h...

a r t i c l e i n f o Keywords: Dimensional metrology Interoperability Standard development STEP DMIS Dimensional metrology is an important part of any manufacturing system. It consists of distinct components and requires a large, diverse, and interconnected knowledge base. How to pass information seamlessly with minimal cost and minimal data loss between different components of a dimensional m...

Introduction In vivo three-dimensional (3D) kinematics of the ankle joint is essential for a better understanding of its biomechanics and for many clinical applications. Several measurement techniques are available for this data, but few allow non-invasive measurements with sub-millimetre accuracy. The purposes of the study were to develop further a voxel-based 2D to 3D registration method [1] ...