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Analysis of thermal characteristics with multi-physicsc oupling for the feed system of a precision CNC machine tool

Zheng Junjian, Deng Xiaolei, Yang Junshou, Zhang Wanjun, Lin Xiaoliang, Jiang Shaofei, Yao Xinhua, Shen Hongchen

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 2

art. no. e148941

EN

The machining accuracy of CNC machine tools is significantly affected by the thermal deformation of the feed system. The ball screw feed system is extensively used as a transmission component in precise CNC machine tools, responsible for converting rotational motion into linear motion or converting torque into repetitive axial force. This study presents a multi-physical coupling analysis model for the ball screw feed system, considering internal thermal generation, intending to reduce the influence of screw-induced thermal deformation on machining accuracy. This model utilizes the Fourier thermal conduction law and the principle of energy conservation. By performing calculations, the thermal source and thermal transfer coefficient of the ball screw feed system are determined. Moreover, the thermal characteristics of the ball screw feed system are effectively analyzed through the utilization of finite element analysis. To validate the proposed analysis model for the ball screw feed system, a dedicated test platform is designed and constructed specifically to investigate the thermal characteristics of the ball screw feed system in CNC machine tools. By selecting specific CNC machine tools as the subjects of investigation, a comprehensive study is conducted on the thermal characteristics of the ball screw feed system. The analysis entails evaluating parameters like temperature field distribution, thermal deformation, thermal stress, and thermal equilibrium state of the ball screw feed system. By comparing the simulation results from the analysis model with the experimental test results, the study yields the following findings: The maximum absolute error between the simulated and experimental temperatures at each measuring point of the feed system components is 2.4◦C, with a maximum relative error of 8.7%. The maximum absolute error between the simulated and experimental temperatures at the measuring point on the lead screw is 2.0◦C, with a maximum relative error of 6.8%. The thermal characteristics obtained from the steady-state thermal analysis model of the feed system exhibit a prominent level of agreement with the experimental results. The research outcomes presented in this paper provide valuable insights for the development of ball screw feed systems and offer guidance for the thermal design of machine tools.

2

Implementation of contactless angular speed measurement based on photo sensor

Abu Al Aish Amir, Salah Wael, Ahmad Mohammad, Alrashdan Mohd, Alsawalmeh Wael

Przegląd Elektrotechniczny

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2021

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R. 97, nr 3

80--83

EN

The main aim of this research is to propose a new and low cost angular speed measurement based on optical imaging technique. A photo sensor available in computer mouse is implemented as a contactless speed measurement transducer device. The photo mouse sensor output is used to convert the rotating speed of motor shaft, revolutions per minute (RPM), to linear speed. A software program written in C-sharp language is employed to determine the speed and display it in RPM. A motor with maximum rated speed of 2850 RPM is tested at different speeds. Performance comparison is founded by using speed tachometer as a reference measurement. The maximum and minimum percentage error found is 0.099% and 0.05% respectively. Results validated the effectiveness of the proposed technique and its potential applications in electric drives and automation.

PL

Zaproponowano tani system do pomiaru prędkoścoi katowej z wykorzystaniem czujnika optycznego. Jako czujnik wykorzystano typowy fotodetektor stosowany w myszkach komputerowych. Prograam oblicza ilość obrotów na minutę RPM. Na podstawie bada© eksperymentalnych określono dokładność pomiaru na 0.1%.

3

Layer thickness measurement of technically anodised aluminium surfaces by using goniometric scattered light

Geisler Tobias, Manns Martin

Metrology and Measurement Systems

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2021

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Vol. 28, nr 2

371--382

EN

In recent years, scattered light measurement technology has developed into a common method for measuring roughness, form and waviness on precision machined surfaces. Meanwhile, the application for the material structure evaluation of electrolytically anodized surfaces has also been considered. In this context, we present a novel approach to layer thickness measurement of naturally anodised aluminium surfaces. Our approach is based on the reflection intensity of the light beam, which penetrates the oxide layer and is reflected back from the surface as well as from the layer base. In the approach, a model for estimating reflection intensity I from the absorption coefficient is employed. The methodology is tested by comparing results to a layer thickness evaluation using metallographic preparation. Based on the proposed approach, we are able to measure intervals of layer thicknesses on naturally anodized aluminium surfaces without contact.

4

Pose and Optical Flow Fusion (POFF) for accurate tremor detection and quantification

Alper Mehmet Akif, Goudreau John, Daniel Morris

Biocybernetics and Biomedical Engineering

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2020

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Vol. 40, no. 1

468--481

EN

Limb tremor measurements are one factor used to characterize and quantify the severity of neurodegenerative disorders. These tremor measurements can also provide dosage-response feedback to guide medication treatments. Here, we propose a system to automatically measure limb tremors in home or clinic settings. The key feature of proposed method is that it is contactless; not requiring a user to wear or hold a device or marker. Our sensor is a Kinect 2, which measures color and depth and estimates rough limb motion. We show that its pose accuracy is poor for small limb tremors below 10 mm amplitude, and so we propose an additional level of tremor tracking that recovers limb motion at a higher precision. Our method upgrades the sensitivity to achieve detection and analysis for tremors down to 2 mm amplitude. We include empirical experiments and measurements showing improved tremor amplitude and frequency estimation using our proposed Pose and Optical Flow Fusion (POFF) algorithm.

5

Influence and optimization of the setting of input parameters of laser profilometry by the surface measurement manufactured by the AWJ technology

Mitaľ Gerhard, Gajdoš Ivan, Ružbarsky Juraj, Jachowicz Tomasz, Majewski Łukasz

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 1

329--337

EN

The publication deals with the measurement and evaluation of roughness parameters by means of laser profiling, and its main task is to determine the effect of selecting the internal gain adjustment (Gain mode) on measured roughness values of the surface treated by the water beam technology. The publication details the software, hardware, and other parts of the device designed to measure the roughness of different types of surfaces. It further describes the behavior of individual parts of the apparatus as a whole and methods of measuring the roughness of the surface along a defined profile section by means of the triangulation principle of laser profiling. The measured sample was cut by a thick (rough) cut at pressure of 380 MPa. As an abrasive, the Australian Grenade with the grain Mesh 50 was used.The experiment was carried out at the Faculty of Production Technologies in the Laboratory of Roughness Measurement at the Department of technical systems design and monitoring in Prešov. Measurement of surface roughness parameters was performed on an optical measuring system to control surface parameters and the contact roughness meter Mitutyo SJ400.

6

Advanced Magnetic Materials for Aeronautics

Šmelko M., Praslička D., Blažek J.

Fatigue of Aircraft Structures

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2013

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Iss. 5

60--65

EN

In the field of magnetic sensors, magnetic microwires with positive magnetostriction are the materials of the future. Their mechanical and magnetic properties render them ideal materials for applications in aeronautics. A single microwire with a 40 μm diameter and a length of 10 mm is capable of capturing information about tensile stresses, magnetic fields, temperature and distance. This information is carried by a parameter called the Switching Field, HSW, which is specific for different types of microwire. Numerous physical qualities affect the HSW and through sensing of HSW, these qualities may be quantified. (A number of physical qualities affecting HSW can be sensed and quantified by means of a contactless induction method.) What distinguishes the system developed by the present authors from other measuring systems based on magnetic microwires is the positioning of a microwire outside the coil system. Thanks to this improvement it is possible to use microwires embedded directly in the construction material. Small dimensions microwires do not damage the structure of the construction material. The absence of a galvanic connection makes this technology even more interesting compared with traditional forge gauges. Offering the possibility of the simultaneous measuring of four parameters, this technology can be used in a wide range of aviation applications. Measurements of an external magnetic field can be used for the navigation and stabilization of an aerial vehicle. Tensile stress and distance measuring can be helpful to understand some processes occurring under the surface of the construction material and also to perform fatigue monitoring or structure load monitoring. Another big advantage of magnetic microwires is the low price. Just 1 gram of base material is sufficient to prepare about 40 km of microwire. All these features combine to offer us a material ideal for Smart Sensors, possibly available for use in the near future.

7

Contactless multipolar double-fed asynchronous generator for windmills

Levin M., Pugachov V., Ribickis L., Zhiravetska A.

Electrical Power Quality and Utilisation. Journal

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2006

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Vol. 12, nr 2

53-57

EN

A multipolar contactless doubly-fed asynchronous generator is considered where the primary and secondary generation windings are arranged on the teeth of the stator, while the rotor is tooth-like and without windings. Analytical treatment of such a generator has been performed and the basic equations that allow the parameters and performance of the machine to be calculated in generation mode of operation have been obtained. The results of experimental investigations are presented for the physical model of the generator and comparison with the calculation data is given.