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The active vibration control of SFSF (Simply Supported-Free-Simply Supported-Free) smart plate by using linear quadratic Gaussian (LQG) controller is described in the paper. In order to design proper optimal control law two pairs of PZT actuators and sensors oriented in two perpendicular directions X and Y are glued to the plate. The aforementioned locations and orientations of PZT elements allow...
This paper examines a filtering and control algorithm for stabilizing the electronic display contents under external shocks and vibrations to reduce eye strain and discomfort. A cascade of a first order high-pass filter and a stable second order double-integrator-like filter is used to generate a stable position estimate from the real-time accelerometer data. The estimated position signal is then...
In this work, a real-time method for characterization and analysis of vibration that can be applied in the transport of sensitive loads was proposed, developed and tested. For that, sensors nodes from a wireless sensor network were employed, performing data acquisition and calculating the power spectral density of vibrations. Transmitting only the result of the two most significant points of the PSD...
In this paper a stick guide model represented for visually impaired persons to guide in their way, which consist of a Global Positioning System (GPS) and a Global System for Mobile communication (GSM) modules along with sensors like Ultrasonic and Infrared sensors. This is a smart stick that will make the visually impaired persons guiding their way. GPS module is used in this to get the current location...
This paper proposes a sound source separation method for vibration-derived sound signals such as sounds derived from mechanical vibrations by using vibration sensors. The proposed method is based on two assumptions. First, a vibration signal and the sound derived from the vibration are assumed to have a linear correlation. This assumption enables us to model the vibration-derived sound as a linear...
In order to solve the problem of operation reliability estimation of a single NC turning tool, a method based on support vector space is proposed. In the method, the relative distance between the sample points and the hyper-sphere is calculated by establishing the high dimension hyper-sphere space of the similar data. The semi normal function is introduced to describe the reliability of cutting tool...
This paper utilizes cross recurrence quantification analysis (CRQA) as a quantitative tool for gear damage severity assessment, and proposes a new approach to simplify the procedure of embedding parameters selection. In principle, the CRQA derives quantitative measures from the cross recurrence plot (CRP) between two different systems to quantitatively describe their dependencies. In the present study,...
In this research, the vibration of a rotating functionally graded carbon nanotube reinforced composite (FG-CNTRC) blade is studied and an active controller scheme is applied to damp these vibrations. The composite blade has been reinforce by single walled carbon nanotubes. The material properties of the FG-CNTRC blade are assumed to be graded in the thickness direction of the beam. These properties...
Blade Tip Timing (BTT) is considered a promising technique for characterizing blade vibration in which non-contact timing sensors are used to measure the arrival time of the blade passing each sensor. For vibration features extraction from BTT measurement, rotational speed is a key factor. In current researches, the vibration parameters are usually identified on the assumption of steady rotational...
Our cold-atom gyroscope is based on a four-pulse configuration with a very large Sagnac area. Its short-term stability is limited by aliasing effects of the inertial forces (acceleration and rotation). We will show how continuous measurements and real-time compensation of the vibration during the interferometer sequence overcome this limit.
Blade tip-timing (BTT) is a promising method to monitor blade vibrations of aero engines. Since blade tip-timing signals are typically under-sampled, how to reconstruct vibration characteristics from under-sampled signals is a big challenge. Existing signal reconstruction methods are mainly based on the assumption of constant rotation speeds and equally mounted sensors. However, fluctuation of blade...
For the first time, this paper demonstrates the cancellation of nonlinear response in weakly coupled resonators. It has been observed that by working in the region where the mechanical nonlinearity of the resonators and the electrical nonlinearity of the electrostatic coupling cancel, the output current amplitudes are increased by 4x while the trend of vibration amplitude variation upon stiffness...
Long cantilever stings that support aerodynamic models in wind tunnels are a potential source of vibration problems which would damage test data quality, many documents use the methods of setting acceleration sensors on model to measure vibration of model-sting system, but setting sensors on little scale model is hard to realize, and sensors could interfere with flow field around the model. For purpose...
This study proposes a concept for multithread active vision sensing that can measure dynamically changing displacement and vibration at multiple points on civil engineering structures. In multithread active vision sensing, a high-speed camera can function virtually as multiple tracking cameras by accelerating its measurement, computation, and actuation with ultrafast viewpoint switching at millisecond...
Sensing bed vibrations caused by heartbeats has shown great potentials in detecting and monitoring a person's heartbeats during sleep, without requiring special mattress or sheets, or assuming certain sleeping position/posture. Earlier work has studied how to use this method to detect heartbeats when a single subject is on the bed, and in this study, we aim to separate the heartbeats when multiple...
Touch surfaces are intuitive interfaces for computing devices. Most of the traditional touch interfaces (vision, IR, capacitive, etc.) have mounting requirements, resulting in specialized touch surfaces limited by their size, cost, and mobility. More recent work has shown that vibration-based touch sensing techniques can localize taps/knocks, which provides a low-cost flexible alternative. These surfaces...
Quartz tuning forks (QTFs) have been successfully employed as piezoelectric optoacoustic transducers in a quartz enhanced photoacoustic spectroscopic sensor (QEPAS) for sensitive and selective gas sensing applications. Stainless tubes are acoustically coupled with the QTF and act as an acoustic micro-resonator (AmR) to confine the acoustic waves and enhance the QEPAS signal [1]. Very recently, we...
Open Platform Communication (OPC) also known as Object Linking and Embedding (OLE) for Process Control (OPC) is the platform for communication in automation and manufacturing fields among the group of networked devices. OPC standard supports the group of specifications known as OPC-Data Access (OPC-DA), OPC-Historical Data Access (OPC-HDA) and OPC-Unified Architecture (OPC-UA). In this paper, the...
Blade tip timing (BTT) measurement systems enable the measurement of blade vibrations by means of contactless sensors mounted in the engine casing. Despite this sophisticated and expensive instrumentation is commercially available since years, there is no simple and standard laboratory procedure to calibrate a tip timing system. Performance of BTT measurement systems sensors and processing methods...
The aging issue has become an important issue of the world, mostly because the aging body makes elderly people in high risk. Since falling is a common accident when getting off bed and bed activities can help estimate sleeping quality, it is desirable to monitor bed activities for elderly people sleeping on beds. In addition, the deployment should be simple for the practicability. In this work, a...
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