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Page 354 of 977 Results 3531 - 3540 of 9762

Igor Ostrowski, Piotr Szulewski
THE INITIAL ANALYSIS OF WIFI COMMUNICATION (DATA INTERCHANGE) FOR AGV ON THE FACTORY SHOP FLOOR

The AGV (AGV-automated guided vehicle) platforms make simply transport tasks which can be easy automated and give big benefits on human work in production environment. One of problems in AGV evolution is the easy and efficient communication with base station. Such a link is most often built by WLAN using 802.11 standard. This is very important for AGV to keep communication with base station (supervising computer) on some minimal quality level because of needing continuous stream of control data. It is the crucial when the cloud computing is established and permanent synchronization is realized. In our opinion this crucial problem is not deeply analyzed as required. This issue joins the interesting subjects of wide technical areas from robotics to communication. This paper tries to shed new light for it.

Joonas Melin, Risto Ritala
NOVEL METHOD FOR ONLINE STEREO SELF-CALIBRATION

We present a novel method for correcting for the most critical errors in stereo camera calibration. Online self-calibration is often required as small errors in the vertical direction render many stereo vision algorithms useless. The method presented here is suitable for online self-calibration and does not require any external information. The results indicate that the developed algorithm is able to correct vertical errors to a sufficient degree.

Andrzej Masłowski, Janusz Będkowski, Paweł Musialik, Karol Majek
3D LASER MAPPING FOR ADVANCED ROBOTICS APPLICATIONS

This paper presents the gathering, processing and presenting 3D data for use in Advanced Robotics Applications like Search and Rescue operations. The data are gathered by unmanned ground platforms, in the form of 3D point clouds via laser scanning systems. The clouds are matched and transformed into a consistent, highly accurate 3D model. The paper describes the pipeline for such matching based on Iterative Closest Point algorithm supported by loop closing done with LUM method. The pipeline was implemented for parallel computation with NVIDIA CUDA, which leads to higher matching accuracy and lower computation time.

Giuseppe Dinardo, Laura Fabbiano, Gaetano Vacca
AN INNOVATIVE ALGORITHM FOR FIBER BRAGG GRATING SENSORS INTERROGATION

The aim of the paper is to introduce an innovative algorithm able to determine the shift of the Bragg wavelength of a Fiber Bragg Grating (FBG) as it experiences a perturbation due to an applied strain. An accurate and precise evaluation of the FBG spectrum displacement is crucial for determining the amount of strain inducing such perturbations. The proposed method, very fast and simple to implement, is compared with the usually employed FBG demodulation techniques.

Leonard Klaus
COMPARISON OF HILBERT TRANSFORM AND SINE FIT APPROACHES FOR THE DETERMINATION OF DAMPING PARAMETERS

For the analysis of rotational damping measurements in the time domain, two different identification procedures are compared. The first procedure investigated incorporates a Hilbert transform of the data, which enables an analysis by a linear regression calculation. The second approach is a direct nonlinear regression calculation of a damped sine function. The two approaches are compared using both simulated data and measurement data. The results of the comparison are presented.

I. Ibanez, M. Hodnett, B. Zeqiri, M. N. Frota
MEASUREMENTS OF INERTIAL ACOUSTIC CAVITATION EMISSIONS AND THEIR CORRELATION WITH EROSION RESISTANCE OF STAINLESS STEEL 304

This work describes a ASTM G32-10 compliant technique for measuring ultrasonic cavitation used to induce erosion in engineering materials. The hydrodynamic cavitation erosion resistance of coupons of stainless steel 304 was investigated by exposure of the material to acoustic cavitation generated by an ultrasound transducer. A 65 mm diameter variant of a cavitation sensor developed by the National Metrology Institute of the UK (NPL) proved to detect broadband acoustic emissions and logs acoustic signals produced in the MHz frequency range. The readings of cavitation were made during the exposure duration at discrete intervals (900 to 7200 s) enabling periodic mass measurements (evaluation of erosion) under a strict protocol. Cavitation measurements were carried out for different positions of the ultrasound transducer horn confronting the material exposed to erosion. For a transducer displacement amplitude of 43.5 µm, maximum variation in measurements of cavitation level was found to be between 2.6% and 3.8% when the separation (λ) between the transducer horn and the specimen amplified from 0.5 to 1.0 mm, respectively. Mass loss of the specimen —a measure of erosion— was 7.5 mg (λ = 0.5 mm) and 6.8 mg (λ = 1.0 mm) for experiments carried out at the same transducer displacement amplitude.

Ondřej Berka, Martin Dub, František Lopot, Vojtěch Dynybyl
MESH QUALITY MONITORING IN EVOLVENTN TEETH IN GEARBOXES UNDER OPERATION – SIGNAL IDENTIFICATION

The work deals with the design and implementation of autonomy tensometric apparatus for measuring of gear mesh of wheels in large industrial gearboxes and with possibilities of processing and evaluation of the recorded data and results interpretation. The method is demonstrated on case studies showing development of loading distribution across the width of the teeth, limited stiffness of the tooth rim, repetitive artifact, and ovality of the paired wheel.

Marta Wiśniewska, Sabina Żebrowska-Łucyk
DETERMINATION OF FORM MEASURING MACHINE DISPLACEMENT SENSOR CHARACTERISTICS WITH A USE OF FLICK STANDARD

A new approach towards calibration of FMM displacement sensor with a use of a flick standard is presented. The main drawback of the prevailing procedure is the fact that instrument’s probe could have been calibrated only for a single value, whereas following a novel method removes this limitation. Therefore, FMM probe linearity deviations may be determined within a full range of sensor. In the paper, the core idea and sample results presenting performance of the proposed method are outlined.

Marta Wiśniewska, Sabina Żebrowska-Łucyk
CALIBRATION OF A WHITE-LIGHT INTERFEROMETER WITH A USE OF MATERIAL MEASURES RECOMMENDED BY ISO 25178 SERIES: RELIABILITY AND UNCERTAINTY

There is a discrepancy between rapid pace of introducing more and more sophisticated white-light interferometers and a tardy tempo of developing proper calibration procedures applicable to these machines. Therefore, the authors evaluated both repeatability and credibility of calibration results obtained with a use of PGR and PPT calibration standards recommended by ISO 25178 series. The outcomes of the research, as well as limitations of the calibration artefacts usefulness, are presented in the paper.

Kosuke Uchiyama, Hiroshi Murakami, Akio Katsuki, Takao Sajima, Zhu Guangyu
MONITORING OF MACHINING PROCESSES AND ERROR MOTIONS FOR A HIGH-SPEED AIR TURBINE MICROSPINDLE

We develop a high-speed air turbine microspindle with a built-in microphone and pressure sensor to detect the breakage and wear of a micro-tool and to detect anomalies in the bearing and other spindle components. The results show that the spindle can detect variations in the microtorque (0.1 N·cm) and the frequency components of the rotation of the balls of the ball bearing. In addition, the effect of the external torque variation on the radial error motions of an air turbine microspindle is investigated. The results show that it is possible to measure the microtorque by measuring the change in the rotational speed of the spindle and that the radial error motions in the X and Y directions increase as the torque increases. In the case of the radial error motion in the X direction, the radial error motion is increased to approximately 0.007 µm per torque variation of 0.001 N·cm.

Page 354 of 977 Results 3531 - 3540 of 9762