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Partial discharge (PD) online monitoring is considered as one of the most effective means to prevent sudden accidents of hydro-generator. In this paper, a set of high reliable hydro-generator PD online monitoring system was developed, which made use of PDA technique to obtain PD signal and adopted PD integrated monitoring method to make sure the credibility of PD analysis results. Three aspects of...
Wireless Sensor Network (WSN) used under the coalmine tunnel is an emerging area of research that promises to provide reliable and flexible communication. This paper first discussed the best working frequency about the WSN in coalmine. Then, according to the actual circumstances of coal mine, the network structure should adopt cluster-tree topology. We also develop a multifunction communication wireless...
According to the statistics, roof and side fall accidents often occur and jeopardize greatly in coal mines. The variation of the strain and stress in the surrounding rocks of the mine roadway can predict the accident. How to obtain the strain and stress is the key point of the prediction. This paper provides a method on the case. Firstly the principle of monitoring stress in surrounding rocks of mine...
This paper designs the diagnosis strategy for OBD system oxygen sensor degradation and the relevant test on engine bench is made by oxygen signal generator. The engine emission influence due to oxygen sensor degradation is analysed. Based on the structure and sensing principle of zirconia type oxygen sensor, the mechanism of oxygen sensor deterioration is analysed, and some proposals are put forward...
As we known, to evaluate and diagnosis the insulation faults of large-size power transformers, partial discharges (PDs) can be detected via ultra high frequency (UHF) technique. In this paper, an UHF PD online monitoring system was developed for large-size step-up transformers. The principle of UHF PD monitoring method was introduced., and the hardware structure and software key techniques in the...
As we known, to evaluate and diagnosis the insulation faults of large-size power transformers, partial discharges (PDs) can be detected via ultra high frequency (UHF) technique. In this paper, an UHF PD online monitoring system was developed for large-size step-up transformers. The principle of UHF PD monitoring method was introduced., and the hardware structure and software key techniques in the...
The optimal placement method of sensors is carried out based on improved genetic algorithm for solving the sensors optimal placement problem of the health monitoring system for long-span railway bridge. Dual structure coding method is introduced to improve the individual encoding method in the Genetic Algorithm. Adaptive partial matching crossover and inversus mutation method is adopted in the optimal...
Errors model of 6-PTRT parallel robot is proposed by setting up the relation of pose errors and structural parameters based on the closed-vectors differential. Errors sensitivity index are defined by using of singular value of the matrix and are given to physical meanings. Errors synthetical sensitivity, direction sensitivity and maximum sensitivity are quantitatively analyzed through simulation,...
With the development of low-voltage electrical apparatus toward intelligent, network, communication-capable, and its special application, it is necessary to realize remote supervisory for it. This paper designs a remote supervisory system for intelligent motor control protection device based on virtual instrument technology. The system realizes the communication of monitoring PC with lots-dot of motor...
The Article focuses on a monitoring system for high-speed wire running consisting of process volume system and vibration monitoring system based on precision of fault diagnosis and demands of energy lowering for high-speed wire mill, and the System will ensure stable running of equipment and lower the energy consumption. The Article shows composition, functions and purposes of the System and illustrates...
Vehicle intelligent terminal system for engineering equipment could realize condition monitoring, fault diagnosis, time based maintenance intelligent management and long-distance operation management synthetically. Adopting computer technique, sensor technique, fault diagnosis technique and wireless communication technique, vehicle intelligent terminal system for engineering equipment is researched...
The paper took the reclaimed water plant in one economic zone of Tianjin for an example, and set up six source water quality indexes, pH, SS, CODCr, TN, NH3-N and TP, on the basis of analysis on primary pollutions' variation regularity of the source and the treatment process's characteristic of the reclaimed water plant, and built source water quality forecast system on grey system theory. The study...
The function and structure and the architecture of sensor network based on ZigBee/802.15.4 standard for forest monitoring are designed in this paper. According to the features of forest monitoring, the sensor nodes based on CC2520 and low power consumption chip MSP430F5437 and the coordinator Combing with ARM are designed which realize the energy control in physical layer. With the wireless sensor...
This paper describes two methods of Fiber Bragg Grating (FBG) embedded in the three-dimensional (3D) braided composite materials and acoustic emission health monitor for 3D braided composite materials condition. The paper mainly analyses the relations of FBG change and the inner straining under the stretching on materials. It is provided that the way of signal collection and processing. The experimental...
An integrated automatic system of pig feeding is presented. It includes the mechanical structure and control module. In the mechanical structure, the system is composed of supplying-screws, sending-screw, feed-tanks, buffer-tank, medicine-tank, water pump, medicine pump, feeding pumps, motors, ring distribution and control valves et al. In the control module, PLC is applied to implement centralized...
It's very important to monitor the mechanical condition of portal crane for the device safety management. According to the characters of portal crane, a wireless monitoring system of the mechanical condition has been designed in the paper, including the status of metal structure, slewing bearing and speed reducer. The system has solved the temperature drift, zero point setting and other problems of...
The method of monitoring the wear of piston ring with a magneto-resistive sensor for a marine diesel engine is presented in the paper. The magnetic field intensity variations caused by both the wear and the motion of piston ring are analyzed by simulation. The theoretical basis for monitoring the wear of piston ring with the magneto-resistive sensor for the marine diesel engine is provided.
The highway is the inevitable outcome of the social and economic development. In recent years, with the rapid development of our economy, the growth of highway is becoming faster and faster. But the followed is a series of highway management issues. In view of the issues of poor vehicle control, the traditional parking charge as well as traffic jam brought by this, road toll in confusion, low level...
The selection of monitoring parameters is the principal condition for condition monitoring and fault diagnosis of hydraulic system of excavator, a new method of selecting monitoring parameters based on AHP is proposed by analyzing faults of hydraulic system. And to take example for the main pump, the hierarchical model of its monitoring parameters is constructed and four correlative rules are confirmed...
This article analysis the tunnel water leakage characteristics of the Trial operation of Shanghai Metro on the 7th line. Pointed out that the causes of disease, there are four main areas - engineering design, construction, project supervision, operations environment. Depth analysis of the key of the operations of leakage is segment structural cracks, surface subsidence, segment shrink, protected area...
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