Conventional displacement sensors have limitations in practical applications. This paper develops a vision sensor system for remote measurement of structural displacements. An advanced template matching algorithm, referred to as the upsampled cross correlation, is adopted and further developed into a software package for real-time displacement extraction from video images. By simply adjusting t...

This paper describes a new angular displacement interferometer based on the internal-reflection effect. In order to make use of the internal-reflection effect, a novel prism assembly is designed, which yields a very compact optical configuration. As a result, the linearity of the angular displacement interferometer is greatly improved. Both the linearization of the measurement equation and the ...

Many applications in industry require non-contact, fast and accurate measurement of both surface profile and deformation field for manufacturing quality control and structural testing purposes. The fringe projection technique has been widely used due to its high accuracy and spatial resolution in measuring shape and out-of-plane displacement fields, but it cannot identify in-plane displacements...

Displacement of a civil structure contains important information about structural behavior that helps confirm safety and serviceability. Displacement measurement by conventional devices such as LVDT is still challenging due to issues in the cost-effectiveness and accessibility to measurement locations. This paper presents a monocular vision-based displacement measurement system (VDMS) that is c...

Optical methods that give displacement or strain fields are now emerging significantly in the mechanical sciences. In the Material Research laboratory at École des Mines d'Albi, we have developed a binocular stereovision system that can be used a) to measure the 3D shape of a static object or b) to measure the deformations of an object undergoing some 3D mechanical or thermal stress. In this pa...

We propose to use a Nomarski imaging interferometer to measure the out-of-plane displacement field of MEMS. It is shown that the measured optical phase arises both from height and slope gradients. Using four integrating buckets a more efficient approach to unwrap the measured phase is presented, thus making the method well suited for highly curved objects. Slope and height effects are then deco...

A universal digital holographic microscope to measure shape and displacement of microelement and MEMS (MicroElectroMechnacalSystems) is presented. This device is designed to exploit a measurement for MEMS with either a smooth or a rough surface. The method is based on digital laser interferometry and digital laser speckle interferometry (TV holography) incorporated with optoelectronic devices i...

This paper presents a two-probe implementation of microwave interferometry for displacement measurement at an unknown reflection coefficient. Theoretically, the proposed technique gives the exact value of the displacement for reflection coefficients (at the location of the probes) no greater than 1/ √ 2 and in the general case determines it to a worst-case accuracy of about 4.4% of the operatin...