Wyniki wyszukiwania - BazTech

1

Stretchable optical fibre sensor for soft surgical robot shape reconstruction

He Yanlin, Gao Likun, Bai Yuchen, Zhu Hangwei, Sun Guangkai, Zhu Lianqing, Xu Haidong

Optica Applicata

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2021

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Vol. 51, nr 4

589--604

EN

Soft robotics presents several advantages in the field of minimally invasive surgery. However, existing methods have not fully addressed problems related to soft robot shape sensing due to the complex motion of soft robots and the stretchable nature of the soft materials employed. This study demonstrates the shape sensing of a soft robot with a helically embedded stretchable fibre Bragg grating (FBG)-based optical fibre sensor. Unlike straight FBG embedding configurations, this unique helical configuration prevents sensor dislocation, supports material stretchability, and facilitates shape detection for various soft-robot movements. The proposed soft-robot design principle and FBG sensor are analysed and their fabrication process, which includes an FBG-written optical fibre sensor, is described. Bending experiments are conducted with the soft robot, the wavelengths of FBG sensors at different bending and telescopic movement states are obtained, and the soft-robot shape is reconstructed. Experimental results demonstrate that the maximum error between FBG sensing and the actual bending state is less than 2.5%, validating the feasibility and effectiveness of the proposed helical stretchable FBG sensing method for the shape measurement of soft robots. These results indicate the potential and applicability of this shape-sensing approach in biomedical research.

2

Comparative analysis of numerical models of arch-shaped steel sheet sections

Piekarczuk A., Malowany K.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 4

645--658

EN

The modern construction industry makes use of innovative production and assembly technologies, whose purpose is to implement reliable and simple structures. One product of such technologies is an arch-shaped steel sheet section that might be used as a self-supporting covering for general construction and industrial building construction. Considering complex geometry and boundary conditions, the FEM model of this structure is sophisticated and may contain errors. This paper presents numerical approaches for the calculation of sheet metal section elements of such coverings, namely two numerical approaches that differ in detailing of the properties of considered physical object. The first approach is based on a model that is characterized by simplified geometry and boundary conditions. The second scenario concerns a detailed FEM model with actual geometry captured by a laser triangulation method, experimentally determined material stress–strain relationship, and load conditions measured on an experimental stand. The results obtained with the use of computer simulations based on both approaches described above and experimental results are compared. The errors caused by simplification of the first numerical model are discussed. Finally, an acceptable reduction of FEM model complexity is proposed for the analyzed structure.

3

Neural network model for phase-height relationship of each image pixel in 3D shape measurement by machine vision

Chung B

Optica Applicata

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2014

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Vol. 44, nr 4

587--599

EN

In a three-dimensional measurement system based on a digital light processing projector and a camera, a height estimating function is very important. Sinusoidal fringe patterns of the projector are projected onto the object, and the phase of the measuring point is calculated from the camera image. Then, the height of the measuring point is inferred by the phase. The phase-to-height relationship is unique at each image point. However it is nonlinearly different according to the image coordinates. It is also difficult to obtain the geometrical model because of lens distortion. Even though some studies have been performed on neural network models to find the height from the phase and the related coordinates, the results are not good because of the complex relationship. Therefore, this paper proposes a hybrid method that combines a geometric analysis and a neural network model. The proposed method first finds the phase-to-height relationship from a geometric analysis for each image pixel, and then uses a neural network model to find the related parameters for the relationship. The experimental results show that the proposed method is superior to previous neural network methods.

4

Wear estimation of current collector contact strips by analysis of a 3D scanning results

Jarzębowicz L., Judek S.

Computer Applications in Electrical Engineering

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2013

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Vol. 11

336--344

EN

The technical condition of current collector contact strips is very important when operational reliability of railway transportation is considered. The authors proposed a novel measurement system based on a 3D camera to register the shape and dimensions of the current collector contact strips surface. The system was installed above the railway track for tests in target ambient. During the trial operation a few dozen of contact strips 3D-profiles were recorded for the locomotives which passed the test point. The collected results vary widely, particularly with regard to the position and tilt of the obtained profiles. This variety makes the surface analysis more complex. Therefore, an automatic method for normalization of the registered profiles was introduced. Standardized profiles are compared with the pattern of a new contact strip in order to estimate their wear. Summary of scanning and analysis results confirm the possibility of commercial use of the introduced system.

5

3D-scanning system for railway current collector contact strips

Judek S., Jarzębowicz L.

Computer Applications in Electrical Engineering

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2013

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Vol. 11

328--335

EN

Undisturbed collection of current from a contact wire of the catenary constitutes one of the basic elements in reliable operation of electrified rail transport, particularly when vehicles move at high speed. Quality of current collection is influenced by the construction of catenary and current collectors, as well as by the technical condition and regulation of these two elements. Total contact force of a current collector head on contact line and the condition of contact strip surface determine the quality of the contact between a current collector and contact line. This paper presents an innovative stand for diagnosing contact strips on current collectors with the use of 3D imaging technique. The stand has been tested in laboratory and during trial exploitation on a railway line. Implementation potential of the proposed method has been confirmed.

6

Stanowisko dydaktyczne do wyznaczania kształtu obiektów

Michalak S.

Pomiary Automatyka Robotyka

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2008

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R. 12, nr 6

55-57

PL

W pracy przedstawiono koncepcję sterowania silnikiem krokowym zastosowanym w projektowanym dydaktycznym stanowisku do pozyskiwania sekwencji obrazów i wyznaczania kształtu obiektów. Przedstawiono schemat blokowy systemu pomiarowego z kartą akwizycji obrazu i sterownikiem wymuszającym zadany tryb pracy silnika krokowego. Omówiono zrealizowany w środowisku LabView program nadzorujący pracę systemu oraz komunikację sterownika silnika z komputerem.

EN

In this paper the conception of step motor controlling in designed educational shape measurement system was described. The main idea of this system is collecting images sequence with controlled rotate of the object, next the images are used to build three-dimensional model. Block diagram of computer based system with image acquisition card and step motor mode controller was presented. An example of control application made in LabView environment also was shown.

7

Geometrical identification of form of biobearings working surfaces and defect of joint cartilage.

Ryniewicz A.

Advances in Manufacturing Science and Technology

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2005

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Vol. 29, nr 4

45-57

EN

In the paper there is presented the own method identification of form of biobearings working surfaces and of geometrical estimation of the articulation cartilage defects imaged using magnetic nuclear resonance. There were examined three animal and three human specimen knees using computer tomography (CD, magnetic resonance (MR) and coordinate control machine (CCM). The joint cartilage was artificial destroyed and the loss was measured. Visualization of working surfaces and assessment of geometry and size of cartilage damages using MR were performed. Then, measurements of shape joint surfaces and damages were conducted using CCM, followed by damage modelling using finite elements method in Ansys, FEMAP and NE Nastran packages. Research into CT was carried out to identify form and position of bone structures and to verify bone defects.

PL

W pracy przedstawiono własną metodę identyfikacji kształtu powierzchni roboczych biołożysk i geometrycznego szacowania rozległości uszkodzeń chrząstki stawowej obrazowanej metodą magnetycznego rezonansu jądrowego. Badaniu poddano trzy preparaty stawowe zwierzęce i trzy preparaty ludzkie stawów kolanowych, w których uszkodzono chrząstkę stawową. Preparaty zbadano z użyciem spiralnej tomografii komputerowej (TK), magnetycznego rezonansu jądrowego (MR) i współrzędnościowej maszyny pomiarowej (WMP). Przeprowadzono wizualizację powierzchni roboczych oraz oceniono geometrię i rozmiar uszkodzenia chrząstki, stosując MR. Następnie wykonano pomiary kształtu powierzchni stawowych i uszkodzenia z zastosowaniem WMP. Ubytki modelowano metodą elementów skończonych w pakietach Ansys, FEMAP i NE Nastran. Badanie TK przeprowadzono celem identyfikacji kształtu i położenia struktur kostnych oraz zweryfikowania rozmiarów ubytków kostnych.

8

Photonics virtual laboratory: concept and exemplary implementation

Bączyk R., Sitnik R.

Elektronika : konstrukcje, technologie, zastosowania

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2004

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Vol. 45, nr 8-9

265-268

EN

General concept of photonics collaboralive laboratory with remote access via Internet or local network and using PC is proposed. The client/server model and server service are presented. The communication protocol permits the management with any device available in the laboratory. Exemplary of implementation of the project by creating ready for use 3D Shape Measurement Laboratory is presented.

PL

Zaproponowano koncepcję udostępnienia laboratorium fotonicznego ze zdalnym dostępem, bazując na Internecie lub sieci lokalnej oraz komputerów PC. Przedstawiono strukturę klient/serwer i dostępne usługi serwera. Opracowany protokół komunikacji pozwala na zarządzanie sprzętem znajdującym się w laboratorium. Zaprezentowano też przykładowe rozwiązanie bazujące na laboratorium pomiaru kształtu 3D.