New adaptive thresholds are designed for the fast fault detection and reduction of the false alarm rate. The feature of actuator fault is employed to reset the initial conditions based on the fault detection results. ...
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ISBN:
(纸本)9781509064151;9781509064144
New adaptive thresholds are designed for the fast fault detection and reduction of the false alarm rate. The feature of actuator fault is employed to reset the initial conditions based on the fault detection results. The limited memory least square method is developed to achieve a real-time estimation of mutation parameters, which is applied for fault isolation. Simulation results suggest that, for different cases of actuator faults, the identification method can accurately estimate the degree of damaging within 0.2 seconds after fault alarm.
With the rapid deterioration of the environment and the continuously food safety events, this paper takes the carbon emissions and green profits into considering to select the distribution path when distributing the f...
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ISBN:
(纸本)9781509064151;9781509064144
With the rapid deterioration of the environment and the continuously food safety events, this paper takes the carbon emissions and green profits into considering to select the distribution path when distributing the fresh fruits and vegetables, establish a multi-objective programming model which integrated the carbon emissions and the green profits. Finally, a case exemplifies the feasibility of the model, the best transport speed of the vehicle is obtained. Through sensitivity analysis, it reveals that transportation loss rate of fresh fruits and vegetables makes influence on the whole distribution process.
In view of the phenomenon of repeated development in data acquisition system, a universal data acquisition system was designed by using Lab VIEW software based on NI-6358 data acquisition card. Users could customize t...
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ISBN:
(纸本)9781509064151;9781509064144
In view of the phenomenon of repeated development in data acquisition system, a universal data acquisition system was designed by using Lab VIEW software based on NI-6358 data acquisition card. Users could customize the conversion of each channel and store the configuration information through files. A high-speed data acquisition and processing framework was proposed by combining state machine and production/consumer system, and it realized synchronous collection of 32 channels and display, convert, stored in real time. The test and operation results showed that the system had high sampling rate, stable and reliable operation, and could meet the requirement of generality.
This paper analyzed the mechanism of commutation failure in HVDC system, and summarized the factors affecting it. For the CIGRE HVDC benchmark model,possible commutation failures caused by faults in AC system are stud...
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ISBN:
(纸本)9781509064151;9781509064144
This paper analyzed the mechanism of commutation failure in HVDC system, and summarized the factors affecting it. For the CIGRE HVDC benchmark model,possible commutation failures caused by faults in AC system are studied, and the typical temporary state response of common faults are simulated with PSCAD/EMTDC. Some concludes are raised as the theoretical basis for practical projects.
The safety of the industrial control system directly affects the operation of the critical infrastructure, and the requirement of interconnection with external network puts the system at greater risk. However, due to ...
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ISBN:
(纸本)9781509064151;9781509064144
The safety of the industrial control system directly affects the operation of the critical infrastructure, and the requirement of interconnection with external network puts the system at greater risk. However, due to the particularity of the industrial control system, the traditional intrusion detection algorithm can't be used directly. In this paper, we propose a novel intrusion detection algorithm called OPSO-BPNN which is suitable for industrial control system. Our algorithm optimizes the particle swarm algorithm with nonlinear reduction inertia factor, then uses it to optimize the weight of BP neural network. Simulation results show that our OPSO-BPNN method proves to be feasible and has faster convergence rate, less iterations and higher accuracy.
In order to overcome the low efficiency and poor resolution of the one-frequency-one-time frequency-domain electromagnetic(FDEM) method, a well-organized multifrequency resonant network is presented to transmit a synt...
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ISBN:
(纸本)9781509064151;9781509064144
In order to overcome the low efficiency and poor resolution of the one-frequency-one-time frequency-domain electromagnetic(FDEM) method, a well-organized multifrequency resonant network is presented to transmit a synthetized current with two or more frequencies. A lowfrequency square pulse is used as the test signal to find the resonant frequencies, based on which the barcode driving signals are generated by the multi-frequency sinusoidal pulse width modulation(SPWM) method. The simulation results prove that the frequency leakage is reduced a lot and most of the energy is concentrated at the resonant frequencies. The resonant network and controltechnology is useful for obvious improvement of the sounding efficiency and resolution of FDEM method.
The goal of this work is to implement a multimedia communication system over IP network. The system supports the function of recording, encoding, transmitting, decoding and playing for audio and video. Our work includ...
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ISBN:
(纸本)9781509064151;9781509064144
The goal of this work is to implement a multimedia communication system over IP network. The system supports the function of recording, encoding, transmitting, decoding and playing for audio and video. Our work includes three parts: the design of relative algorithms and technologies, the procedure of system implementation and result display. In the system, RTP/RTCP is used for multimedia real-time transmission and an adaptive jitter buffering control algorithm is proposed to improve continuity for audio stream by adjusting the size of jitter buffer dynamically. Finally, the system is tested in a LAN environment, which shows that the system can work stably with little packets lost and the size of jitter buffer can adjust to network dynamically.
Fiber interferometry is an important means in sensing field. The phase shift affects the sensitivity of interferometry and high frequency signals are hardly detected by fiber itself. A feedback control system based on...
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ISBN:
(纸本)9781538662434
Fiber interferometry is an important means in sensing field. The phase shift affects the sensitivity of interferometry and high frequency signals are hardly detected by fiber itself. A feedback control system based on proportionalintegral-derivative algorithms was used to stabilize the phase. Meanwhile, a three ports circulator and two attenuators were added in the Michelson interferometry to improve the interference signal. Also, a self-built fiber focused head was employed to convert fiber light to space light in the end of detection path. With the presented approaches, we stabilized the phase and detected a high frequency vibration of 1.7 MHz.
with the development of power equipment manufacturing level and power grid scale, power grid equipment maintenance is in the continuous development and evolution from the regular maintenance to the condition based mai...
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ISBN:
(纸本)9781509064151;9781509064144
with the development of power equipment manufacturing level and power grid scale, power grid equipment maintenance is in the continuous development and evolution from the regular maintenance to the condition based maintenance. The foundation of condition based maintenance is the information collection, the premise is the state evaluation,and the key is the risk assessment. So most of the current risk assessment is based on theoretical research, it is difficult to promote the application. This paper establishes a new transformer risk assessment mode on the basis of the production information management system so as to provide the suggestions for the maintenance of 220 kV and above transformer in Shanxi power grid.
To study the dynamic characteristics of 3-DOF experimental teaching helicopter model , the mathematical model of small-sized 3-DOF helicopter system is set up. The movement of helicopter includes three parts of elevat...
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ISBN:
(纸本)9781538662434
To study the dynamic characteristics of 3-DOF experimental teaching helicopter model , the mathematical model of small-sized 3-DOF helicopter system is set up. The movement of helicopter includes three parts of elevation ax-is, pitch axis and travel axis, and their dynamic functions are set up. To solve the hovering control problem, a model-reference adaptive control system is designed based on Lyapunov stability theory. Simulation results show the designed control system can satisfy the dynamic and steady properties , and provide a reference for designing other control systems.
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