作者:
Cheng ChangJiyang ZhangMingfei HanJie MaSongfeng WuWei ZhangHongwei XieFuchu HeYunping ZhuInstitutes of Biomedical Sciences and Department of Chemistry
130 DongAn RoadFudan UniversityShanghai 200032P.R.China State Key Laboratory of Proteomics
Beijing Proteome Research CenterNational Engineering Research Center for Protein DrugsNational Center for Protein Sciences BeijingInstitute of Radiation MedicineBeijing 102206P.R.China Department of Automatic ControlCollege of Mechatronics and AutomationNational University of Defense TechnologyChangshaHunan 410073China State Key Laboratory of ProteomicsBeijing Proteome Research CenterNational Engineering Research Center for Protein DrugsNational Center for Protein Sciences BeijingInstitute of Radiation MedicineBeijing 102206P.R.China
The interest in the propagation of ultrasound waves in pipe-like solid waveguides arises out of several areas of the structural health monitoring (SHM) community for the detection, localization and assessment of defec...
详细信息
ISBN:
(纸本)9783940283412
The interest in the propagation of ultrasound waves in pipe-like solid waveguides arises out of several areas of the structural health monitoring (SHM) community for the detection, localization and assessment of defects as well as the prediction of remaining life in civil, mechanical, aeronautic and aerospace structures. SHM premise offers a continuous observation of the structural integrity of operational systems. This is particularly convenient, therefore, for the reduction of time and cost for maintenance without decreasing the level of safety. Some practical applications are the monitoring of pipework in gas and oil industries, suspension bridge cables, nuclear fuel cladding tubes, etc. This paper describes an approach for SHM using guided waves in pipe-like structures in terms of a pattern recognition problem. The formalism is based on a distributed piezoelectric sensor network for the detection of structural dynamic responses. Several methods for signal filtration, feature selection and extraction, and data compression of the recorded time histories are discussed and evaluated. Principal Component Analysis (PCA), Non-Linear PCA (NLPCA) and Wavelet Transform are among them. Additionally, the different clusters, corresponding to each damage level are visualized with the help of Self Organizing Maps (SOM). Tests were performed on a piping system where the properties of the proposed methods are compared and appraised with experimental pitch-catch signals between the pristine and the damaged structure.
An effective identification method and an informative signal are two inseparable aspects for precise estimation of power systems' electromechanical modes. Informative signal is conventionally selected by power spe...
详细信息
ISBN:
(纸本)9781467327275
An effective identification method and an informative signal are two inseparable aspects for precise estimation of power systems' electromechanical modes. Informative signal is conventionally selected by power spectrum density (PSD) analysis from numerous amounts of ambient data. However, directly comparing PSD plots of different signals is casual and imprecise, especially for those non-obvious modes which could be overlooked in the PSD plots. In this paper, a signal selection approach based on PSD analysis is proposed to accurately evaluate whether a signal is informative to a mode. Simulation is carried out in an 8-generator 36-node benchmark system;mode estimation is employed to validate its effectiveness.
In this paper, we focus on cooperative adaptive cruise control of ground vehicles and platoon stability in daily traffic. The general adaptive cruise control (ACC) structure and different cooperative adaptive cruise c...
详细信息
In this paper, we focus on cooperative adaptive cruise control of ground vehicles and platoon stability in daily traffic. The general adaptive cruise control (ACC) structure and different cooperative adaptive cruise control (CACC) approaches are discussed for highway platooning, considering case studies for a Grand Cooperative Driving Challenge (GCDC) program the authors involved in. The hardware design and the low level control strategy for braking, throttle and gearshift actuators for these case studies are presented. Finally, the performance of a PD based CACC algorithm used in GCDC is analyzed.
When a video surveillance system tracks a specific object, it is very important to get quickly the information of the object through fast image processing. Usually one camera surveillance system for tracking the objec...
详细信息
When a video surveillance system tracks a specific object, it is very important to get quickly the information of the object through fast image processing. Usually one camera surveillance system for tracking the object made results in various problems such like occlusion, image noise during the tracking process. It makes difficulties on image based moving object tracking. Therefore, to overcome the difficulties the multi video surveillance system which installed several camera within interested area and looking the same object from multi angles of view could be considered as a solution. If multi cameras are used for tracking object, it is capable of making a decision having high accuracy in more wide space. This paper proposes a method of recognizing and tracking a specific object like a car using the homography in which multi cameras are installed at the crossroad.
This paper proposes an online training method for the parameters of a fuzzy neural network (FNN) using sliding mode systems theory with an adaptive learning rate. The implemented control structure consists of a conven...
详细信息
This paper proposes an online training method for the parameters of a fuzzy neural network (FNN) using sliding mode systems theory with an adaptive learning rate. The implemented control structure consists of a conventional controller in parallel with a FNN. The former is provided both to guarantee global asymptotic stability in compact space and acts as a sliding surface to guide the states of the system towards zero. The output of the conventional controller is used to update the parameters of the FNN. The output of the FNN gradually replaces the conventional controller. The adaptive learning rate makes it possible to control the system without priori knowledge about the upper bound of the states of the system and their derivatives. An appropriate Lyapunov function approach is used to analyze the stability of the adaptation law of parameters of FNN. Sufficient conditions to guarantee the boundedness of the parameters are derived. The proposed approach is tested on the velocity control of an electro hydraulic servo system in presence of flow nonlinearities and internal friction.
This paper mainly proposes a timing scheme of a digitally controlled DC-DC converter, which is described in hardware description language (HDL) at the functional level. FPGA is adopted for the optimization of computat...
详细信息
ISBN:
(纸本)9781467301596
This paper mainly proposes a timing scheme of a digitally controlled DC-DC converter, which is described in hardware description language (HDL) at the functional level. FPGA is adopted for the optimization of computation, sampling and modulation to get precise and fast dynamic response of DC-DC converters. The concept of this timing scheme is broad and includes DPWM scheme, sampling scheme and computation scheme. Computational accuracy of the scheme is guaranteed by floating-point arithmetic. At the same time, fast integer-float and float-integer converters are developed based on look-up tables and real-time computation which can greatly reduce the duty pulse width computation clock cycles. A specific sampling and PWM scheme are designed to eliminate compensator delay caused by sampling and hold and the computation process. High precision digital pulse-width modulator based on second-order sigma-delta concept (Σ-ΔDPWM) and dual-mode compensator method are implemented to eliminate steady Limit-Cycle and to maintain fast dynamic response as well. This design is made for IC design verification to practically used digital DC-DC converters.
Postharvest handling of table grape is commonly carried out using multi-scale packages comprised of the main container, inner liner film and pouches holding individual bunch of berries. Total pressure drop through dif...
详细信息
In order to improve the quality of power supplied by medium and small-sized diesel generator which was applied an islanded load, a digital electronic speed control system was designed in this paper. For adapting the b...
详细信息
In order to improve the quality of power supplied by medium and small-sized diesel generator which was applied an islanded load, a digital electronic speed control system was designed in this paper. For adapting the broad load characteristics, the structure of Variable-Speed-Integrated-Generator (VSIG) was adopted by the diesel generating set. The proposed governor used a fuzzy self-tuning proportion-integral-derivative structure controller that can provide variable gain strategies to account for nonlinearities in the system. The results of test were obtained by a 3kW naturally aspirated diesel generator which was applied islanded load. The test results showed that the system designed had integrated functions of speed regulating and good speed characteristics.
暂无评论