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EN
The study presents the finite element (FE) model update of the existing simple-spans steel-concrete composite bridge structure using a particle swarm optimisation (PSO) and genetic algorithm (GA) approaches. The Wireless Structural Testing System (STS-WiFi) of Bridge Diagnostic, Inc. from the USA, implemented various types of sensors including: LVDT displacement sensors, intelligent strain transducers, and accelerometers that the static and dynamic historical behaviors of the bridge structure have been recorded in the field testing. One part of all field data sets has been used to calibrate the cross-sectional stiffness properties of steel girders and material of steel beams and concrete deck in the structural members including 16 master and slave variables, and that the PSO and GA optimisation methods in the MATLAB software have been developed with the new innovative tools to interface with the analytical results of the FE model in the ANSYS APDL software automatically. The vibration analysis from the dynamic responses of the structure have been conducted to extract four natural frequencies from experimental data that have been compared with the numerical natural frequencies in the FE model of the bridge through the minimum objective function of percent error to be less than 10%. In order to identify the experimental mode shapes of the structure more accurately and reliably, the discrete-time state-space model using the subspace method (N4SID) and fast Fourier transform (FFT) in MATLAB software have been applied to determine the experimental natural frequencies in which were compared with the computed natural frequencies. The main goal of the innovative approach is to determine the representative FE model of the actual bridge in which it is applied to various truck load configurations according to bridge design codes and standards. The improved methods in this document have been successfully applied to the Vietnamese steel-concrete composite bridge in which the load rating factors (RF) of the AASHTO design standards have been calculated to predict load limits, so the final updated FE model of the existing bridge is well rated with all RF values greater than 1.0. The presented approaches show great performance and the potential to implement them in industrial conditions.
EN
Typically, an inertial navigation system (INS) is used to determine the position, speed, and orientation of an object moving relative to the earth's surface. The navigation information (position, speed and orientation) of an unmanned aerial vehicle (UAV) is needed to control its flight. Since the resistance of INS to interferences is very high, it is possible to ensure reliable flights in conditions of high-intensity noise. This article explores the principles of constructing inertial measurement units (IMU) that are part of the INS and indicates perspective directions for their development. Micro-electromechanical inertial measurement units were studied in this work, and functional and principal electrical circuits for connecting units of inertial measurements to the microcontroller were developed. The results of practical measurements of units without calibration and after calibration were obtained using the created laboratory device. Based on the obtained results, the necessity of sensor calibration was revealed, and accuracy was improved by performing calibration with the Kalman filter algorithm. The Kalman filter is the heart of the navigation system. In a low-cost system, IMU errors like bias, scale factor error and random walk noise dominate the INS error growth.
EN
This paper presents the concept of diagnosing the technical condition of mechanical devices. The test is based on a non-invasive vibration analysis technique combined with the use of artificial intelligence method. The object of the research is an electric motor for which vibrations were recorded by a vibration sensor based on four 3-axis digital accelerometers and MPU-6050 gyroscopes. The effectiveness of classification methods using the two-class and one-class classification was compared. It has been shown that the use of an incomplete pattern of the vibration model and a single-class classifier allows for effective detection of anomalies in the operation of an induction motor. Satisfactory classification efficiency was achieved, despite the limitation of the teaching set only to the information obtained during the correct operation of the device. The described method is universal and can be used to diagnose the technical condition of many different types of technical devices.
4
Content available remote Zastosowanie efektu tunelowego w akcelerometrach o wysokiej czułości
PL
We wstępie artykułu opisano kwantowo-mechaniczny efekt tunelowy. Wykonano obliczenia strzałki ugięcia mikrobelki krzemowej pod wpływem przyspieszenia. Obliczono też natężenie prądu tunelowego, płynącego przez złącze utworzone między końcem igły o atomowej grubości ostrza zamocowanej na mikrobelce i powierzchnią Przedstawiono projekt czujnika przyspieszenia o wysokiej czułości, w którym zastosowano układy takich złącz połączone szeregowo i równolegle. Przedyskutowano otrzymane wyniki oraz możliwości zastosowania takich czujników przyspieszenia w szczególności jako precyzyjnych grawimetrów.
EN
The quantum-mechanical tunneling effect is described in introduction of the article. Computation of the bending arrow of the microcantilever undergo acceleration are conducted. A tunneling current intensity flowing in the junction between tip of the needle witch atomic size thickness connected with the microcantilever made of silicone and surface are also executed. The project of the high sensitivity accelerometer based on systems of the junction connected parallel and in series is presented. Obtained results and feasibility of the application of the considered system in accelerometers, especially in precision gravimeters are discussed.
PL
W artykule przedstawiono algorytm opracowany do przetwarzania sygnałów pomiarowych z 3-osiowego akcelerometru, które przyjęto do opisu ruchu pióra podczas odręcznego pisania cyfr. Do rozpoznawania wspomnianych symboli zastosowano metodę DTW z uwzględnieniem różnych kryteriów detekcji. W artykule zaprezentowano wyniki oceny dokładności rozpoznawania cyfr arabskich. Wykazano, że dokładność rozpoznawania cyfr arabskich metodą DTW zależy od przyjętego kryterium detekcji.
EN
The article presents an algorithm developed for processing measurement signals from a 3-axis accelerometer, which was adopted to describe the movement of the pen when writing digits by hand. The DTW method was used to recognize these symbols, taking into account different detection criteria. The article presents the results of the assessment of the accuracy of digits recognition. It has been shown that the accuracy of digits recognition using the DTW method depends on the adopted detection criterion.
EN
When driving on a road with an uneven surface, the tractor receives shocks and oscillates. The main components that protect the tractor from the dynamic action of the road and reduce fluctuarions and vibrations to an acceptable level are the steered axle and tires. A serviceable steered axle of a wheeled tractor provides optimal controllability, traffic safety, durability and reliability of work. The work with faulty components of the steered axle impairs the controllability and stability of the tractor, reduces the safety of its movement, impairs ergonomic indications. A faulty steered axle contributes to the vibration of the tractor frame, as a result of which riveted and threaded connections are weakened, the alignment of the engine and gearbox is disturbed, and additional loads occur in the body parts. Vibration of the whole tractor accelerates wear and causes breakage of many parts. Therefore, monitoring the technical condition of the steered axle of a wheeled tractor is an actual task in the field of exploitation and repair of equipments. The article presents a method for determining the location of accelerometers for vibration diagnostics of steered axles of wheeled tractors.
PL
Podczas jazdy po drodze o nierównej nawierzchni ciągnik ulega wstrząsom i drganiom. Głównymi elementami, które chronią ciągnik przed dynamicznym działaniem drogi i redukują do akceptowalnego poziomu wahania i wibracje, są oś kierowana i opony. Sprawna oś skrętna ciągnika kołowego zapewnia optymalną sterowność, bezpieczeństwo ruchu, trwałość i niezawodność pracy. Praca z wadliwymi elementami osi pogarsza sterowność i stabilność ciągnika, zmniejsza bezpieczeństwo jego poruszania się, pogarsza ergonomię wskazań. Wadliwa oś przyczynia się do wibracji ramy ciągnika, w wyniku czego osłabione są połączenia nitowane i gwintowane, zaburzone jest osiowanie silnika i skrzyni biegów, a w częściach nadwozia występują dodatkowe obciążenia. Dlatego monitorowanie stanu technicznego osi ciągnika kołowego jest rzeczywistym zadaniem w zakresie eksploatacji i naprawy urządzeń. W artykule przedstawiono metodę wyznaczania położenia akcelerometrów do diagnostyki drganiowej osi k ciągników.
7
Content available remote Steering structure for a single wheeled vehicle
EN
Nowadays, there is a need to reduce emissions in the world and use electricity to drive vehicles. There is an increasing interest in small passenger vehicles suitable for crowded cities. In this paper it was designed a universal control structure for a single-wheeled vehicle with a tilt sensor. In this structure is possible to apply a vehicle with parallel wheel arrangement. The paper describes a current and position loop with PI and PD controllers suitable for a single wheeled vehicle. It was designed a simple complementary filter for data processing. A complementary filter evaluate the data from accelerometer and gyroscope, which includes all signal processing requirements for control. Additionally, a program block diagram was also designed to be used in any microprocessor. The results and recommendations of the adjustment for further work with the proposed structure are evaluated in the end of the paper.
PL
W artykule zaprezentowano system sterowania jednokołowym pojazdem elektrycznym stosowanym do poruszania się w zatłoczonym mieście. Do kontroli prądu i pozycji pojazdu zastosowano sterowniki PI i PD. Do kontroli ruchu zastosowano czujniki przyśpieszenia oraz pochyelnia ora żyroskop.
EN
A measurement system includes all components in a chain of hardware and software that leads from a measured variable to processed data. In that context, the type and quality of the sensors or measuring devices are critical to any measurement system. MEMS/IMU sensors lag behind leading technologies in this respect, but the MEMS/IMU performance rapidly changes while is relatively inexpensive. For this reason, the paper proposes some investigations of currently available MEMS/IMUs, but in an array configuration. The article presents the results of research undertaken on this type of IMU sensor configuration under quasi-stationary and dynamic conditions and answers the question of whether the precision of current MEMS technologies for acceleration and angular velocity sensors is still improved using this kind of approach.
9
Content available Crowdsourced Driving Comfort Monitoring
EN
In this paper, the authors are showing a calculation of the road quality index called Simple Road Quality Index (SRQI) using the weight provided by the amateur drivers to best possibly rate their comfort on driving on that road. The index is calculated from acceleration data acquired by the smartphone application and is aggregated in a crowdsourcing system for the classification of road quality using the fuzzy membership function. The paper shows that the proposed index correctly shows road quality changes over time and may be used as a way to mark roads to be avoided or needs to be repaired. The numerical experiment was based on the same street in Lublin, Poland, in 2015-2021 and is correctly showing that the quality of analyzed roads deteriorated over time, especially in the winter season.
PL
Artykuł przedstawia zastosowanie metody Monte Carlo do parametrycznej identyfikacji akcelerometrów w dziedzinie częstotliwości. Omówione zostały dwie metody identyfikacji: intuicyjna, realizowana wyłącznie w oparciu o punkty pomiarowe charakterystyki amplitudowo-częstotliwościowej i bazująca na klasycznej metodzie najmniejszych kwadratów oraz procedura oparta na punktach pomiarowych obu charakterystyk częstotliwościowych (amplitudowej i fazowej), realizowana przy wykorzystaniu uogólnionej metody najmniejszych kwadratów. Przedstawiono wyniki identyfikacji dla wybranego akcelerometru typu Althen 731-207, a dla potrzeb realizacji obu metod identyfikacji zastosowano oprogramowanie Mathcad 14.
EN
The paper presents an application of the Monte Carlo method for parametric identification of accelerometers in the frequency domain. Two identification methods are discussed here. The first one is intuitive and implemented only based on measuring points of amplitude-frequency response and employs the classical least squares method. The second one is the procedure based on measuring points of both frequency responses (amplitude and phase) and implemented by using the generalized least squares methods. Identification results for the selected accelerometer of type Althen 731-207 are presented and discussed. Mathcad 14 software was used for the needs of both identification methods.
11
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.
EN
The aim of this study was to analyse absolute and relative reliability of a number of postural static stability measures obtained from a GYKO inertial sensor system in young adults. Methods: The study examined 29 healthy non-athlete young adults. A test was performed for 30 s while standing on one foot, without moving, with eyes open and arms relaxed along the sides of the body. The examinations were performed twice, with a one-week interval. Relative reliability was measured using the intraclass correlation coefficient (ICC) and the 95% confidence interval (95% CI), whereas the absolute reliability was evaluated based on the standard error of measurement (SEM) and the minimal detectable change (MDC). Results: The results of this study showed moderate to good relative reliability scores for all the postural stability measures, with ICC values ranging from 0.62 to 0.70. For most of the analysed variables, SEM% ranged from ca. 10 to 14%. Relatively high SEM% values were obtained only for two variables (Area, Convex Hull Area). Conclusions: The low costs of GYKO inertial sensor systems, the fast and easy installation, the mobility and high reliability of the measurement of postural stability show that it can be effective alternative to stabilographic platforms.
PL
Artykuł prezentuje autorską metodę monitorowania przemieszczeń mostowych konstrukcji kolejowych. Wykorzystuje ona inklinometry i akcelerometr do pośredniego pomiaru przemieszczeń pionowych pod obciążeniem dynamicznym. Opracowany system monitorowania ciągłego jest wspomagany przez okresowe pomiary tachimetryczne, które służą do weryfikacji przemieszczeń statycznych. Przedstawiono opis działania systemu pomiarowego oraz przykład testowego monitoringu konstrukcji, którą wybrano pod kątem praktycznej weryfikacji działania systemu w różnych trudnych warunkach pracy. Wybrano wiadukt łukowy na Centralnej Magistrali Kolejowej (CMK), gdzie występują duże prędkości przejazdu oraz złożona linia ugięcia pomostu. Uzyskane wyniki pomiarów pod krótkotrwałym obciążeniem statycznym i dynamicznym wykazują możliwość określenia przemieszczeń z odchyleniem w stosunku do metody odniesienia poniżej 1,2 mm.
EN
The article presents the railway bridge structures monitoring system. The elaborated method uses inclinometers together with accelerometer for indirect displacement measurement under the dynamic load. The continuous monitoring system is supported by periodic measurements with the use of Total Station. A description of the measurement system operation and example of test monitoring of bridge were presented. The test bridge was selected to test the developed methods under different operating conditions. The arch railway bridge at Central Railway Line (CMK) was selected due to high train speeds and complex deflection line of bridge deck. The obtained results of measurements under short-time static and dynamic load show the possibility of determining displacements with the deviation to the references method below 1.2 mm.
14
Content available remote Badanie modułu przyspieszenia na potrzeby diagnostyki czujników inercyjnych
PL
W artykule przedstawione zostały wyniki badań stabilności modułu przyspieszenia grawitacyjnego czujników inercyjnych wykonanych w technologii MEMS (Micro Electro Mechanical Systems). Tego typu pomiary analizowane są w szczególności na potrzeby tzw. nawigacji inercyjnej. W referacie zaprezentowano badania porównawcze dwóch czujników wykonanych w technologii MEMS, na podstawie których wybrano najlepsze rozwiązanie pod względem stabilności modułu przyspieszenia grawitacyjnego.
EN
The article presents the results of the stability study of the gravitational acceleration module of inertial sensors performed in MEMS (Micro Electro Mechanical Systems) technology. Such measurements are analysed in particular for the needs of inertial navigation. The paper presents comparative studies of two sensors made in MEMS technology, based on which the best solution in relation to stability of the gravitational acceleration module has been selected.
PL
Artykuł dotyczy dokładności pomiaru kątów z wykorzystaniem czujników inercyjnych w trójwymiarowym układzie współrzędnych. Jako system odniesienia wykorzystano system akwizycji ruchu firmy Vicon. W artykule opisano przebieg badania, aplikację, która posłużyła do zbierania danych ze smartfona. W artykule zawarto także metody, wzory oraz algorytm, których użyto, aby porównać uzyskane dane.
EN
This article discusses angle measurement accuracy assessment using inertial sensors in three-dimensional coordinate system. Vicon's acquisition system was used as a reference system. The article describes conduct of the study and application that was used for collecting data from the smartphone. The article also contains methods, formulas and algorithms that were used to compare obtained data.
PL
W ramach pracy przedstawiono układ pomiarowy umożliwiający zbieranie oraz zapis parametrów ruchu pojazdu. Do budowy układu, wykorzystano moduł nawigacji inercyjnej składający się z trójosiowych akcelerometrów oraz żyroskopów wykonanych w technologii MEMS. Wykonano badania oraz opracowano metody obliczeniowe pozwalające na odniesienie zebranych danych, do punktu w przestrzeni trójwymiarowej, w celu wyznaczenia trajektorii ruchu pojazdu. Zbudowany układ pomiarowy wykorzystuje trzy rodzaje czujników: akcelerometr, żyroskop, magnetometr. Każdy z tych czujników pozwala na pomiar wielkości fizycznej, w trzech prostopadłych osiach kartezjańskiego układu współrzędnych. Dodatkowo w pracy wykorzystano moduł nawigacji satelitarnej (GPS), jako odniesienie w skali „makro” (układ współrzędnych związany ze środkiem kuli ziemskiej o promieniu wynoszącym ok. 6371 km) dla modułu nawigacji inercyjnej (INS/IMU), umożliwiającej dokładny pomiar w skali „mikro” (układ współrzędnych związany z punktem początkowym ruchu dla trasy, której długość nie przekracza kilkuset metrów). W artykule przedstawiono przegląd dostępnych czujników pomiarowych ze szczególnym uwzględnieniem parametrów wybranych sensorów oraz błędów wprowadzanych do układu pomiarowego.
EN
As part of the work, a measuring system is presented that allows collecting and recording vehicle motion parameters. To build the system, an inertial navigation module was used, consisting of two-axis accelerometers and gyroscopes made in MEMS technology. The tests were carried out and calculation methods were developed to allow the collected data to be referenced, to a point in the three-dimensional space, in order to determine the trajectory of the vehicle's movement. The built-in measuring system uses three types of sensors: accelerometer, gyroscope, magnetometer. Each of these sensors allows the measurement of the physical size in three orthogonal axes of the Cartesian coordinate system. In addition, the work uses a satellite navigation module (GPS), as a reference on the "macro" scale (coordinate system related to the center of the globe with a radius of about 6371 km) for the inertial updating module (INS / IMU), enabling accurate measurement in the "micro" scale (the coordinate system associated with the starting point of the traffic for the route, the length of which does not exceed several hundred meters). The article presents an overview of available measuring sensors with special consideration of the parameters of selected sensors and errors introduced into the measurement system.
EN
It is well known that postural stability is influenced by visual stimuli. The influence of saccadic eye movement on postural control has been described, however, a specific response of different body segments has not been studied yet. Therefore, the aim of this study was to assess the effect of horizontal and vertical saccadic eye movements on postural stability with specific focus on upper trunk, lower trunk and lower limbs movement variability and complexity. Methods: Eighteen elderly participants (aged 70.3 ± 7.7 years) stood in bipedal stance in three visual conditions – horizontal saccades, vertical saccades and fixation. Accelerometers were attached to their lower back, sternum and shanks. Movement variability of each body segment was described by root-mean-square and sample entropy of acceleration. Results: The results of the present study revealed significant influence of saccadic eye movements on anterior-posterior and vertical shanks, and vertical lower trunk movement variability described by root-mean-square. Conclusions: The correlations between results of the observed segments showed segment-specific variability patterns but generalised complexity pattern.
PL
W artykule przedstawiono charakterystykę porównawczą akcelerometrów lotniczych. Omówiono przeznaczenie czujników przyspieszeń stosowanych w lotnictwie oraz dokonano przeglądu ich konstrukcji ze względu na rodzaj zastosowanego przetwornika rodzaju sygnału. Zdefiniowano błędy mające wpływ na niepewność pomiaru. Analizie poddano przyrządy kilku producentów, reprezentujące różne metody pomiarowe spośród akcelerometrów klasycznych, jak i wykonanych w technologii MEMS. Wskazano sensory cechujące się najmniejszymi błędami.
EN
The article presents the comparative characteristics of aviation accelerometers. There were discussed several issues like the purpose of acceleration sensors in aviation or their design with respect to the type of signal transducer used. Errors affecting the accuracy of measurement have been defined. Instruments from several manufacturers, representing various measurement methods used in classical accelerometers as well as those with MEMS technology applied have been analysed. The sensors with the smallest errors were indicated.
PL
W pracy przedstawiono prototyp zdigitalizowanego systemu pomiarowego do diagnostyki biomechaniki ludzkiego ciała. System pomiarowy zostanie zbudowany w ramach projektu dofinansowanego ze środków Unii Europejskiej, pod tytułem „Mobilne urządzenie do ortopedycznej diagnostyki biomechaniki i motoryki ludzkiego ciała”. W pracy przedstawiono dwie metody obliczania orientacji obiektu w przestrzeni 3D: metodę Madgwicka i filtr Kalmana. Zaprezentowano również stanowisko laboratoryjne do testowania zaproponowanych algorytmów oraz uzyskane wyniki badań.
EN
This paper presents assumptions and a prototype of a digitized measurement system for the diagnosis of human body biomechanics. The measurement system will be built as part of a project subsidized by the European Union, titled "Mobile device for orthopedic diagnostics of biomechanics and motility of the human body". The paper presents two methods for calculating the orientation of an object in 3D space: the Madgwick method and the Kalman filter. A laboratory stand for testing the proposed algorithms and obtained test results were also presented.
EN
MEMS are one of the fastest developing branch in microelectronics. Many integrated sensors are widely used in smart devices i.e. smartphones, and specialized systems like medical equipment. In the paper we present the main parts of a system for measuring human movement which can be used in human balance disorder diagnosis. We describe our design of capacitive accelerometers and dedicated switched capacitor readout circuit. Both will be manufactured as separate chips in different technological processes. The principle of operation, schematics and layouts of all parts of the system are presented. Preliminary simulations show that the proposed designs are applicable for the considered medical device.
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