Kinematic SAMI : a new real-time multi-sensor data assimilation strategy for nonlinear modal identification

2020 ◽  
Vol 21 (4) ◽  
pp. 413
Author(s):  
Adrien Goeller ◽  
Jean-Luc Dion ◽  
Ronan Le Breton ◽  
Thierry Soriano
Keyword(s):  
Real Time ◽  
High Speed ◽  
Natural Frequencies ◽  
Modal Identification ◽  
Modal Testing ◽  
Sensor Data ◽  
Contactless Measurement ◽  
Vibration Level ◽  
Set Up ◽  
Real Time Identification

In many engineering applications, the vibration analysis of a structure requires the set up of a large number of sensors. These studies are mostly performed in post processing and based on linear modal analysis. However, many studied devices highlight that modal parameters depend on the vibration level non linearities and are performed with sensors as accelerometers that modify the dynamics of the device. This work proposes a significant evolution of modal testing based on the real time identification of non linear parameters (natural frequencies and damping) tracked with a linear modal basis. This method, called Kinematic-SAMI (for multiSensors Assimilation Modal Identification) is assessed firstly on a numerical case with known non linearities and secondly in the framework of a classical cantilever beam with contactless measurement technique (high speed and high resolution cameras). Finally, the efficiency and the limits of the method are discussed.

Interaction Between Wind Loading and Japanese Slates: Effect on Vibration and Scattering

2008 ◽  
Author(s):  
Satoru Okamoto
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Natural Frequencies ◽  
Basic Mechanism ◽  
Video Camera ◽  
Flow Speed ◽  
Test Method ◽  
Wind Loading ◽  
Natural Mode ◽  
Set Up

A series of wind tunnel tests was conducted on the vibration and scattering behavior of full-sized model of roof tiles, which were used widely for roofings of Japanese wooden dwellings. This study has investigated the nature and source of the vibrating and scattering behavior of roof tiles with the aim of providing a better insight to the mechanism. The roof tiles were set up on the pitched roof in the downstream of the flow from the wind tunnel. The vibrations for the roof tiles were measured by the Laser Doppler Vibrometry and the accelerometer, and the practical natural frequencies of the roof tiles were analyzed by the impulse force hammer test method. The motions of the vibration and scattering were observed by the high-speed video camera. Based on the consideration on the results of the measurements, there is a basic mechanism which can lead to flow-induced vibrations of the roof tiles. This mechanism is similar to that of the so-called fluttering instability, which appears as the self-excited oscillation in the natural mode of the structure at the certain critical flow speed. The values of the frequencies for the oscillating relate to the values of natural frequencies of the vibration.

Online Real-Time Quality Monitoring in Additive Manufacturing Processes Using Heterogeneous Sensors

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Prahalad K. Rao ◽  
Jia (Peter) Liu ◽  
David Roberson ◽  
Zhenyu (James) Kong ◽  
Christopher Williams
Keyword(s):  
Additive Manufacturing ◽  
Real Time ◽  
Dirichlet Process ◽  
Failure Modes ◽  
Evidence Theory ◽  
Sensor Data ◽  
Support Vector ◽  
Fused Filament Fabrication ◽  
Detection Approach ◽  
Real Time Identification

The objective of this work is to identify failure modes and detect the onset of process anomalies in additive manufacturing (AM) processes, specifically focusing on fused filament fabrication (FFF). We accomplish this objective using advanced Bayesian nonparametric analysis of in situ heterogeneous sensor data. Experiments are conducted on a desktop FFF machine instrumented with a heterogeneous sensor array including thermocouples, accelerometers, an infrared (IR) temperature sensor, and a real-time miniature video borescope. FFF process failures are detected online using the nonparametric Bayesian Dirichlet process (DP) mixture model and evidence theory (ET) based on the experimentally acquired sensor data. This sensor data-driven defect detection approach facilitates real-time identification and correction of FFF process drifts with an accuracy and precision approaching 85% (average F-score). In comparison, the F-score from existing approaches, such as probabilistic neural networks (PNN), naïve Bayesian clustering, support vector machines (SVM), and quadratic discriminant analysis (QDA), was in the range of 55–75%.

Real Time Identification for Natural Input Modal Testing

2008 ◽  
Author(s):  
Alain Girard ◽  
Etienne Cavro ◽  
Alain Launay
Keyword(s):  
Real Time ◽  
Modal Testing ◽  
Real Time Identification

Experimental Modal Analysis of a Half-Scale Model Twin-Engine Aircraft Rear Fuselage Engine Mount Support Frame

2017 ◽  
Author(s):  
Diego A. Chamberlain ◽  
Chris K. Mechefske
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Testing Procedure ◽  
Modal Testing ◽  
Scale Model ◽  
Mode Shapes ◽  
Component Testing ◽  
Fitting Procedures ◽  
Engine Mount ◽  
Set Up

Experimental modal testing using an impact hammer is a commonly used method for obtaining the modal parameters of any structure for which the vibrational behavior is of interest. Natural frequencies and associated mode shapes of the structure can be extracted directly from measured FRFs (Frequency Response Functions) through various curve fitting procedures. This paper provides an overview of the modal testing conducted on an aerospace component. Testing set-up, experimental equipment and the methodology employed are all described in detail. Further validation of the testing procedure was done by ensuring that the experimental results satisfy the requirements of repeatability, reciprocity and linearity. The relevant ISO standard has been referenced and important concepts to modal analysis are expanded upon. Recorded natural frequencies, coherence and a description of the observed mode shapes are presented along with notable trends.

scholarly journals Real Time Measurement for Spring-Mass System: The Graphical and Mathematical Representations

2021 ◽  
Vol 7 (1) ◽  
pp. 74
Author(s):  
Nurul Hidayat ◽  
Erni Yulianti
Keyword(s):  
Real Time ◽  
Physical Phenomenon ◽  
Sensor Data ◽  
Mass Motion ◽  
Mass System ◽  
Mathematical Representations ◽  
Harmonic Motion ◽  
Simple Harmonic Motion ◽  
Spring Force ◽  
Set Up

Mathematics is the language of physics. The best way to describe a physical phenomenon is by describing its mathematical representations. In addition, viewing the graphical diagram of the corresponding mathematical expression is crucial to deeply understand the physical events. Therefore, setting simple experiments in real time to (1) observe the phenomena, (2) view the related diagrams, and (3) extract the mathematical representations is required. In this study, the real time and simple experimental set-up (consisting of ultrasonic sensor HC-SR04 connected to an Arduino Uno board) was designed to perceive the motion of a spring-mass system. The spring force, which is equal to the object’s weight, and displacement or spring elongation data were recorded for the object (with varying mass) attached to the spring. A small external downward force was given to stimulate the simple harmonic motion of the vertical spring-mass system. The displacement as the function of time of the spring-mass motion was recorded. With those measurements, the sinusoidal patterns, representing the simple harmonic motion characteristics, were also observed. The spring constants were 6.35(2) N/m and 6.26(1) N/m for the displacements measured by sensor and ruler, respectively. The periods form the angular frequency of the displacement function and from the spring constant (acquired from sensor data fitting) showed consistent results with very high accuracy. This simple experimental set-up is believed to fulfill the technological-based learning demand.

Effect on Slates by Wind Over Roof of Japanese Residence

2009 ◽  
Author(s):  
Satoru Okamoto
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Natural Frequencies ◽  
Basic Mechanism ◽  
Video Camera ◽  
Flow Speed ◽  
Test Method ◽  
Natural Mode ◽  
Excited Oscillation ◽  
Set Up

A series of wind tunnel tests was conducted on the vibration and scattering behavior of full-sized model of roof tiles, which were used widely for roofings of Japanese wooden dwellings. This study has investigated the nature and source of the vibrating and scattering behavior of roof tiles with the aim of providing a better insight to the mechanism. The roof tiles were set up on the pitched roof in the downstream of the flow from the wind tunnel. The vibrations for the roof tiles were measured by the Laser Doppler Vibrometry and the accelerometer, and the practical natural frequencies of the roof tiles were analyzed by the impulse force hammer test method. The motions of the vibration and scattering were observed by the high-speed video camera. Based on the consideration on the results of the measurements, there is a basic mechanism which can lead to flow-induced vibrations of the roof tiles. This mechanism is similar to that of the so-called fluttering instability, which appears as the self-excited oscillation in the natural mode of the structure at the certain critical flow speed. The values of the frequencies for the oscillating relate to the values of natural frequencies of the vibration.

scholarly journals A Methodology for Heterogeneous Sensor Data Organization and Near Real-Time Data Sharing by Adopting OGC SWE Standards

2019 ◽  
Vol 8 (4) ◽  
pp. 167 ◽  
Author(s):  
Bartolomeo Ventura ◽  
Andrea Vianello ◽  
Daniel Frisinghelli ◽  
Mattia Rossi ◽  
Roberto Monsorno ◽  
...  
Keyword(s):  
Real Time ◽  
Sensor Data ◽  
Weather Data ◽  
Time Data ◽  
Heterogeneous Sensors ◽  
Heterogeneous Datasets ◽  
Real Time Data ◽  
Sensor Registration ◽  
Set Up ◽  
Minimum Interaction

Finding a solution to collect, analyze, and share, in near real-time, data acquired by heterogeneous sensors, such as traffic, air pollution, soil moisture, or weather data, represents a great challenge. This paper describes the solution developed at Eurac Research to automatically upload data, in near real-time, by adopting Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) standards to guarantee interoperability. We set up a methodology capable of ingesting heterogeneous datasets to automatize observation uploading and sensor registration, with minimum interaction required of the user. This solution has been successfully tested and applied in the Long Term (Socio-)Ecological Research (LT(S)ER) Matsch-Mazia initiative, and the code is accessible under the CC BY 4.0 license.

Automatic Traffic Queue-End Identification using Location-Based Waze User Reports

2021 ◽  
pp. 036119812110133
Author(s):  
Yuandong Liu ◽  
Zhihua Zhang ◽  
Lee D. Han ◽  
Candace Brakewood
Keyword(s):  
Real Time ◽  
High Speed ◽  
Recurrent Events ◽  
Clustering Algorithm ◽  
Selection Procedure ◽  
The United States ◽  
Streaming Data ◽  
Data Sources ◽  
Sensor Data ◽  
Temporal Extent

Traffic queues, especially queues caused by non-recurrent events such as incidents, are unexpected to high-speed drivers approaching the end of queue (EOQ) and become safety concerns. Though the topic has been extensively studied, the identification of EOQ has been limited by the spatial-temporal resolution of traditional data sources. This study explores the potential of location-based crowdsourced data, specifically Waze user reports. It presents a dynamic clustering algorithm that can group the location-based reports in real time and identify the spatial-temporal extent of congestion as well as the EOQ. The algorithm is a spatial-temporal extension of the density-based spatial clustering of applications with noise (DBSCAN) algorithm for real-time streaming data with an adaptive threshold selection procedure. The proposed method was tested with 34 traffic congestion cases in the Knoxville,Tennessee area of the United States. It is demonstrated that the algorithm can effectively detect spatial-temporal extent of congestion based on Waze report clusters and identify EOQ in real-time. The Waze report-based detection are compared to the detection based on roadside sensor data. The results are promising: The EOQ identification time of Waze is similar to the EOQ detection time of traffic sensor data, with only 1.1 min difference on average. In addition, Waze generates 1.9 EOQ detection points every mile, compared to 1.8 detection points generated by traffic sensor data, suggesting the two data sources are comparable in respect of reporting frequency. The results indicate that Waze is a valuable complementary source for EOQ detection where no traffic sensors are installed.

The Design of Flexible Manufacturing System Design Based on Fieldbus

2013 ◽  
Vol 850-851 ◽  
pp. 628-631
Author(s):  
Fang He
Keyword(s):  
Real Time ◽  
Time Management ◽  
Flexible Manufacturing ◽  
High Speed ◽  
Manufacturing System ◽  
Flexible Manufacturing System ◽  
High Efficiency ◽  
Manufacturing System Design ◽  
Multi Level ◽  
Set Up

Control system is a very important part of flexible manufacturing system, But the disadvantages of traditional FMS communication network is getting more and more can't meet the need of the high-speed development of flexible manufacturing system technology, the real-time and the high efficiency of the communication system, this paper puts forward the fieldbus network used in flexible manufacturing system. By means of field bus communication technology to realize flexible manufacturing system, set up the master station and slave station in the system, multi-level real-time management, the reliability of the system has been greatly improved.

CMOS Real-Time Image Acquisition and Display System Design Based on FPGA

2014 ◽  
Vol 644-650 ◽  
pp. 4403-4406
Author(s):  
Jian Wei Leng ◽  
Ying Hui Wu
Keyword(s):  
Data Acquisition ◽  
System Design ◽  
Real Time ◽  
High Speed ◽  
Image Acquisition ◽  
Control Unit ◽  
Image Sensor ◽  
Acquisition System ◽  
Sensor Data ◽  
Time Data

Based on characteristics of image acquisition system of high-speed and large-capacity, this paper presents a CMOS Image sensor data acquisition system that is using FPGA Chip as its core processing devices. Data acquisition logic control unit is designed by FPGA. The modular structure of the system design, FIFO, ping-pong and other technology are used in the design process to ensure real-time data acquisition and transmission. FPGA implementation of video acquisition can improve system performance. It also has a strong adaptability and flexibility, and it is easy to design, debug and so on. Through the experiment, we can get a clear image.

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