Papers by Keyword: In-Process Metrology

Abstract: he article presents a measurement system designed for “on-line” high throughput simultaneous optical inspection of large set of geometrical parameters (more than 1000 points) defining geometry of some complex surface. The measurement system is based on the distributed network of optical distance sensors. Specialized optical sensor as basic system element was developed for this purpose. Among its features are the following: non-contact measurement, high optical and electromagnetic noise immunity, small footprint, and mass-production oriented. The system allows us to measure up to 1700 linear distance parameters simultaneously in the range of 40mm, with accuracy (3σ) of 0.1 mm and sampling rate of at least 103 Hz.

Abstract: Up to now, faults arc protection in electrical power system is passive by detecting electric current or arcing light. An active technique used to forecast faults arc is presented in this paper. By applying power spectrum density analysis, two signature bands of arc sound has been found before faults arc take place, one is inside of (5~10) kHz which is strong in intensity and variable in both bandwidth and center in different experimental conditions, the other one is situated on 19.25kHz which is weak in intensity but invariable in center. The proposed technique detects the arc sounds signature in the frequency of 19.25 kHz based on Duffing chaos oscillator. The arc sound is recorded using precision fiber microphone and imported into the chaos based detecting system. For the sensitivity to periodic signal, the chaos system appears either pure chaos or intermittent chaos. So arc sound can been identified by detecting the motion state of chaotic system, and the presently fault arc protection method can been improved into an active forecast and early warning one. Some experiment results and fault arc diagnosis and early warning scheme are also detailed in the paper.

Abstract: This paper presents an efficient computation method to evaluate scattered light intensity distributions, generated by a nanostructured surface which is illuminated with a monochromatic laser beam of several millimeters in diameter. The new simulation approach based on a modified Huygens-Fresnel approximation enables to improve measuring methods without expensive and time consuming experiments. The qualitative verification of the model results in a roughness measuring principle based on double scattering of coherent light.

Abstract: Based on an optical structured light method an opto-electronic system for automatic noncontact distant measurements of wear and defects detection for a contact wire electro-supply network is presented. The created industrial system prototype measures the main technological wire parameters, first of all, the remaining height with RMS error down to 0,15 mm and the wire cross-section area with RMS error of 1,5 mm2. Measurement results are sufficient for confident decision about the replacement of worn-out contact wires of electro-supply network. This method is also fit for automatic wire wear measurement and defects detection for trams, trolleybuses and other electro-supply vehicles.

Abstract: A non-contact on-machine measurement system has been developed since various precise machines are getting lighter and smaller; therefore, processing with nano-precision is demanded recently. This system makes possible to measure with high precision without any damages and it is unnecessary for workpieces to attach or detach from a machine tool. Moreover, this system achieves on-machine form error compensation with high precision. On the other hand, the details of the system performances are still unknown. This study focuses on evaluating the performances by the comparison of the results that measured by this system and an existing measurement instrument under various conditions. As a result, this system shows an equivalent capability of measurement with high precision as the existing measurement instrument.

Abstract: An optical-electronic measurement system for continuous monitoring of displacements and analysis of the friction pendulum bearings for the oil-drilling platforms is presented. Measuring principle of the system is based on target image formation by camera and digital image processing. The passive part of the system (optical target) is fixed on one part of construction while active part - a field measurement sensor (FMS) - is installed on another part of construction that moves relative to the first one. On the FMS output, after processing, the relative displacement between FMS and optical target is obtained with high degree of accuracy. The spatial resolution of a few micrometers can be achieved at cost of reduced measurement range.