Smart Grid is expected to provide a reliable power supply with fewer and briefer outages, cleaner power, and self-healing power systems, through advanced Power Quality (PQ) monitoring, analysis and diagnosis of the PQ...
详细信息
ISBN:
(纸本)9781612848570
Smart Grid is expected to provide a reliable power supply with fewer and briefer outages, cleaner power, and self-healing power systems, through advanced Power Quality (PQ) monitoring, analysis and diagnosis of the PQ measurements and identification of the root causes, and timely automated controls. It is important to understand that signalprocessing has been an integral part of advancing and expanding the horizons of this PQ research significantly. The capabilities and applications of signalprocessing for PQ are continually evolving due to the advanced PQ monitoring devices. Thus, this paper is to present a survey on the proven and emerging signal applications for enhancing PQ, focusing on algorithms for estimating system modal parameters because resonant frequencies and their damping information are critical signatures in evaluating the PQ. In particular, we discuss the need for investigating time-varying and nonlinear characteristics of the modal parameters due to dynamic changes in system operating conditions, and introduce promising signalprocessing techniques for this purpose.
Synchronization in wireless communications is an important problem. Good synchronization is critical to reliable signal detection and estimation. In this thesis, the concept of synchronization is presented as well as ...
详细信息
Synchronization in wireless communications is an important problem. Good synchronization is critical to reliable signal detection and estimation. In this thesis, the concept of synchronization is presented as well as several specific examples of wireless synchronization. An overview of the current state of the art in synchronization, including different techniques and implementations, is *** Time Offset Robust Modulation (STORM) is a waveform design technique involving the simultaneous transmission of a base waveform as well as a time-scaled and time- delayed copy of that waveform. For some applications this technique is attractive as a possible candidate to enhance synchronization performance, due to the different tradeoffs of its performance properties. This thesis presents background for the STORM technique. From there, a theoretical analysis of the performance of STORM as a possible timing synchronization mechanism is ***, this thesis performs a number of simulations showing the performance of STORM synchronization and timing under a variety of different channel conditions. The simulation results are compared to the theoretical analysis. Finally, conclusions from these STORM synchronization and timing simulations and the analyses are presented. Based on these conclusions, potential future work to develop STORM as a timing synchronization scheme is presented.
This paper presents a computational method for detecting vibrations related to eccentricity in ultra precision rotation devices used for nano-scale manufacturing. The vibration is indirectly measured via a frequency d...
详细信息
This paper presents a computational method for detecting vibrations related to eccentricity in ultra precision rotation devices used for nano-scale manufacturing. The vibration is indirectly measured via a frequency domain analysis of the signal from a piezoelectric sensor attached to the stationary component of the rotating device. The algorithm searches for particular harmonic sequences associated with the eccentricity of the device rotation axis. The detected sequence is quantified and serves as input to a regression model that estimates the eccentricity. A case study presents the application of the computational algorithm during precision manufacturing processes.
This paper presents real-time signal processing algorithm for detection of onsets and peaks in Photoplethysmogram (PPG) waveform. algorithm relies on the analysis of amplitude, slope and inter-beat intervals. The pres...
详细信息
ISBN:
(纸本)9781424441242
This paper presents real-time signal processing algorithm for detection of onsets and peaks in Photoplethysmogram (PPG) waveform. algorithm relies on the analysis of amplitude, slope and inter-beat intervals. The presented algorithm consists of four stages for characterizing PPG waveform. Preprocessing stage involves transformation of PPG since the original waveform is less impulsive and robust. In second stage, algorithm seeks for valid pulse detection in transformed signal complying with the amplitude threshold and inter-beat interval. On detection of valid pulses, algorithm then searches backward and forward in transformed signal for the detection of peaks and onsets. Further the detection parameters are made adaptive to comply with varying beat morphologies and fluctuations in baseline. All signalprocessing steps and decision logics are implemented with low computational complexity to make it applicable for compact ubiquitous health monitoring devices. On evaluation with our database, the algorithm achieved sensitivity of 96.89% and positive predictivity of 94.55% within an acceptance level of 12 ms.
Conventional AMB(active magnetic bearings) systems consist of electromagnetic coils, position sensors, power amplifiers and a feedback controller. This hardware configuration can lead to a structural complexity, probl...
详细信息
Conventional AMB(active magnetic bearings) systems consist of electromagnetic coils, position sensors, power amplifiers and a feedback controller. This hardware configuration can lead to a structural complexity, problems of space limitations for the installation, and position control difficulties due to the non-collocation of actuators and sensors. In this paper, a self-sensing mechanism is proposed to resolve Such limitations of the general AMB system. The proposed self-sensing scheme uses a phase difference of the injected current of two opposite electromagnetic actuators while an object is levitating between the actuators. The relationship between the phase difference of injected currents and the position of a levitated object was theoretically derived and linearized. In order to realize the proposed self-sensing scheme, a signal processing algorithm was developed. The frequency response of the estimator was measured to verify, the performance of the proposed self-sensing scheme. In addition, a magnetic levitation and a disturbance rejection response were experimentally obtained to verify the feasibility of the proposed self-sensing mechanism. Experimental results showed that the developed self-sensing technique has similar performance as a practical gap sensor.
Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement sy...
详细信息
Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.
A new algorithm for recognizing arousals related to breathing event that can be used on the micro-movement sensitive mattress monitoring system was presented. Firstly, the method included pre-processing the heart rate...
详细信息
A new algorithm for recognizing arousals related to breathing event that can be used on the micro-movement sensitive mattress monitoring system was presented. Firstly, the method included pre-processing the heart rate to get rid of the rapid-changing element and the slow-changing element in it. Following, the heart rate was processed using the wavelet analysis to make arousals more obvious. Finally, arousals were detected using the algorithm based on the characteristics of heart rate element that was related those. The contrast between our method and manual method on the polysomnography showed that the former can detect typical arousals and was consistent with the latter in most cases.
Optical triangulation displacement sensors are widely used for their non-contact measurement characteristic, sub-micrometre order resolution, simple structure and long operation range. However. errors originating from...
详细信息
Optical triangulation displacement sensors are widely used for their non-contact measurement characteristic, sub-micrometre order resolution, simple structure and long operation range. However. errors originating from surface inclination, speckle effect, light source fluctuation and detector noise restrict the wider use. In order to minimize these errors. a structure for an optical triangulation displacement sensor, which is composed of an incoherent source and a linear CCD (charge coupled device), has been proposed. However. using a linear CCD causes several problems in signalprocessing. Because CCDs consist of spatially discrete pixels, it is impossible to detect the peak position movement within a pixel. This is an inherently severe problem of CCDs. Therefore, a new approach is needed. In this paper, we propose an adequate signal processing algorithm to overcome the limited resolution problem of a CCD for the proposed sensor structure. The signal processing algorithm is composed of a pre-processingalgorithm and a modified cross correlation algorithm. With the help of the proposed algorithm, the limited resolution problem of the CCD can be solved.
Optical triangulation displacement sensors are widely used for their non-contact measurement characteristics, sub-micron order resolution, simple structure, and long operation range. However, errors originating from s...
详细信息
ISBN:
(纸本)0819439630
Optical triangulation displacement sensors are widely used for their non-contact measurement characteristics, sub-micron order resolution, simple structure, and long operation range. However, errors originating from surface inclination, speckle effect, light source fluctuation, and detector noise limit the wider use. In order to minimize these errors, the structure for optical triangulation displacement sensors, which is composed of an incoherent source and a linear CCD, has been proposed. But using a linear CCD causes several problems in signalprocessing. In this paper, we propose an adequate signalprocessing system for the proposed structure. With the help of the proposed algorithm, the limited resolution problem of CCD can be solved.
暂无评论