In order to measure the geometry of workpiece, many contour measuring instruments have been used, such as coordinate machines and cylindrometers, which are essentially in form offline inspection cannot fulfill needs situ measurement. For workpieces with complex structures, hemispherical resonators, measurement capabilities limited. this paper, a contact probe based on multi-focus spectral confocal method is proposed for shape position errors surface workpieces. The stylus’s ruby sphere space...

Fluororubber sealing products are widely used in nuclear power equipment, and the degree of degradation their mechanical properties directly affects performance, which turn overall safety units. In order to quantitatively evaluate fluororubber, theory ultrasonic propagation fluororubber was studied. A second-order generalized Maxwell viscoelastic model constructed a small strain scenario high-frequency harmonic vibration describe correlation between acoustic parameters. nondestructive...

In this paper, the width and depth of rectangular surface-breaking defects were successfully gauged using an all-optical laser-ultrasonic system. The finite element method was used to simulate propagating paths defect-induced reflected transmitted Rayleigh waves. It is observed that most waves with wavelengths less than defect are by defect. A small part greater directly transmits through bottom edge without acting on left Based simulation results, a three-step detection gauging proposed....

A scanning tunneling microscope-based multi-axis measuring system is specially developed for the on-machine measurement of three-dimensional (3D) microstructures, to address quality control difficulty with traditional off-line process. typical 3D microstructure curved compound eye was diamond-machined by slow slide servo technique, and then whole surface scanned three-dimensionally based on tip-tracking strategy utilizing a spindle, two linear motion stages, an additional rotary stage. The...

In this study, the widths of subsurface lateral rectangular defects were successfully gauged using laser-generated Rayleigh waves. Finite element analysis was used to simulate interaction between waves and defects. The results simulation show that diffracted bulk modes resulting from may interact with free surface. Modes are converted into propagate along arrival time reflected mode-converted remains constant, even when height increases. However, as depth increases, changes due mode...

Simultaneous determination of the multiple local acoustic and geometrical properties thin layer with a high lateral resolution is great interest in ultrasonic non-destructive evaluation. In this paper, we propose technique based on V(z, t) data to simultaneously determine four layer, namely, thickness, sound velocity, impedance, density. First, are collected from both reference material. Then velocity thickness calculated by focusing point-focusing transducer front back surfaces confocal...

This paper presents a novel nondestructive ultrasonic technique for measuring the sound speed and acoustic impedance of articular cartilage using pulsed Vz,t technique. data include series echoes collected different distances between transducer specimen. The 2D Fourier transform is applied to reconstruct reflection spectrum Rθ,ω. To obtain coefficient cartilage, from reference specimen with well-known are obtained eliminate dependence on general system transfer function. ultrasound-derived...

To accurately characterize the geometric form of key components in industrial products, many profile measuring instruments have been developed to date. However, there are some special components, such as hemispherical resonators featuring thin curved transparent surfaces, which difficult be measured using general instruments. The chromatic confocal technology was introduced this paper conduct bilateral characterization type surfaces. Based on assumption tilted plate approximation, a modified...

A new prototype non-contact profiler based on surface tracking has been specially developed. Surface is carried out by a designed dual stage probe system with the aid of four-Degree Of Freedom high-precision motion platform. The keeps short-range optical constantly self-developed voice coil motor servo, which wide measuring range up to 10 mm realized. performance evaluation including resolution, repeatability, and scanning speed proved good capability profiler. To realize full area covered...

Spiral scanning is a high-efficiency mode for surface profile measurement systems. The most important priority to realize the spiral accurately align measuring probe with rotational centre of spindle. This paper proposes novel alignment method probe, which considered be suitable any type proposed method, only needs tilted flat mirror as artefact, makes time-consuming process become much easier and faster. operational steps are presented. Experiments have also been carried out based on...

A noise-resistant linearization model that reveals the true nonlinearity of sensor is essential for retrieving accurate physical displacement from signals captured by sensing electronics. In this paper, we propose a novel information-driven smoothing spline method, which innovatively integrates one new and three standard information criterions into high-precision sensors' linearization. Using theoretical analysis Monte Carlo simulation, proposed method demonstrated to outperform traditional...

Detection of surface defects is critical in quality control reflective optics. In this note, we propose a new defect detection method for optics using the normalized reflectivity, which calculated from signal intensity chromatic confocal profiler. This first scans to acquire data and then models calculate local reflectivity map. The map further processed by threshold segmentation extract normal areas. Measurement experiments on an Al-coated concave reflector with artificial were carried out...

Guided-wave echoes from weak reflective pipe defects are usually interfered by coherent noise and difficult to interpret. In this paper, a deconvolution imaging method is proposed reconstruct defect images synthetically focused guided-wave signals, with enhanced axial resolution. A compact transducer, circumferentially scanning around the pipe, used receive discontinuities at distance. This achieves higher circumferential sampling density than arrayed transducers—up 72 spots per lap for...