Grating displacement measurement technique is an important means to achieve precise displacement measurement of nanometer scale. Moiré fringe phase difference measurement is the basis of grating displacement measurement technique. Traditional Moiré fringe subdivision method based on DFT algorithm has low frequency resolution relatively when extracting Moiré fringe fundamental frequency spectral...

the zagros fold-and-thrust belt is tectonically active and often has active faults with insensible and slow motions. determining the rate of movement and displacement in these faults requires very precise measurements. one of the measurement methods of fault movements is using geodetic and micro-geodetic studies. this research is focused on one of the active faults in the north of shiraz city, ...

The rotor displacement measurement plays an important role in an active bearing system, however, in practice this measurement might be quite noisy, so that the control performance might be seriously degraded. In this paper, a soft sensing method for magnetic bearing-rotor system based on Support Vector Regression (SVR) and Extended Kalman Filter (EKF) is proposed. In the proposed method, SVR te...

− The article discusses the measurement of surface displacement of an electrically conductive solid material. Deflection is excited by electro-magneto-acoustic transducer (hereinafter referred to as EMAT). Measurement is realized by laser interferometer. In our research the precise surface displacement measurement is necessary for two reasons. First is EMAT transducer numerical model convergenc...

This paper introduces a kind of measurement method of the displacement for the liquid level by the use of the laser triangulation and the angular displacement tracking. Based on the principle of the laser reflection and the principle of the source synchronous tracking, according to the triangulation method and the optoelectronic matrix imaging technology, it realize the corresponding relationsh...

INTRODUCTION Displacement measurement is an essential technique in the field of precision metrology and precision manufacturing. The linear encoder is the most popular displacement sensor for measurement of the position of a moving stage along the axis of motion. Many commercially available linear encoders, whose principles are based on interference and diffraction, can achieve nanometer-level ...

This paper presents the design and realization of a three degrees of freedom (DOFs) displacement measurement system composed of Hall sensors, which is built for the XYθz displacement measurement of the short stroke stage of the reticle stage of lithography. The measurement system consists of three pairs of permanent magnets mounted on the same plane on the short stroke stage along the Y, Y, X d...

Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indi...

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...