Wu Shijing

The time and cost prediction of tunnel boring machine in tunnelling

Making use of microsoft visual studio, net platform, the assistant decision-making system of tunnel boring machine in tunnelling has been built to predict the time and cost. Computation methods of the performance parameters have been discussed. New time and cost prediction models have been depicted. The multivariate linear regression has been used to make the parameters more precise, which are the key factor to affect the prediction near to the reality.

Dynamic modeling and simulation on automatic transmission of tracked vehicle using fuzzy control

Tracked vehicle runs under dynamic condition frequently. Due to the inner complex physical and chemical changes in the course of engine operation, its system model are highly non-linear, so it is difficult to obtain the precision of model by means of mechanism modeling. To meet the requirement of making automatic shift schedule, the best power shift schedules of a tracked vehicle are deduced in this paper. The dynamic simulation model of drivetrain of tracked vehicle is created in Matlab/Simulink, and the fuzzy shift controller is designed using fuzzy logic. Then it simulates dynamic performance and shift of vehicle. The results of simulation truly and exactly show the stable processing without shift loop; they also improve efficiency of torque converter and dynamic performance of vehicle.

Application and realization of hierarchical network planning based on Web

Making use of Microsoft Visual Studio. NET platform, hierarchical network planning is realized in working procedure time-optimization of the construction by TBM, and hierarchical network graph of the construction by TBM is drawn based on browser. Then the theory of system realization is discussed, six components of system that can be reused are explained emphatically. The realization of hierarchical network panning in Internet provides available guarantee for controlling rate of progress in large-scale or middle-sized projects.

Simulation and stability analysis of spring operating mechanism with clearance for high voltage circuit breakers

Spring Operating Mechanism (SOM) is a dynamic mechanical system to open and close high voltage circuit breaker in electric power controlling system. The dynamic characteristics of SOM are short operating time and high instantaneous speed in the process of working, which present strong nonlinear features. In order to save time and money for a new design and analysis of SOM, the dynamic model with clearance considering the contact and collision under ADAMS program is established. The result indicated that the existence of the clearance joints causes hysteresis and impact effects on velocity and acceleration of the mechanism compared to the mechanism without clearance.

Study of PSO-BP neural networks application in high-voltage circuit breakers mechanical fault diagnosis

High voltage circuit breakers is an important switchgear of the power system, and 80 percent of fault of high voltage circuit breakers is caused by mechanical failure. Considering a circuit breaker with VS1 type spring actuator as the subject, and the vibration signal under typical mechanical fault is collected. Then the wavelet packet and energy entropy are used to extract the characteristic value. A diagnosis method is proposed based on particle swarm optimization Hopfield neural network. This method to diagnosis fault mode for high voltage circuit breakers is established by analyzing vibration signals of the mechanism. The results show that the accuracy of the method to diagnosis fault mode based on PSO-BP neural network for high voltage circuit breakers is higher than the method of traditional BP neural network model, and the local minimum problem of traditional BP neural network model is prevented by using PSO-BP neural network model. The method of diagnosis fault based on PSO-BP neural network for high voltage circuit breakers is more accurate and feasible compared with traditional BP neural network.

Research on improving unit thermal efficiency based on absorption heat pump by reducing the circulating water temperature

The system of regenerator cycle based on absorption heat pump, through heating up the feed water by the heat from the circulating cooling water by the absorption of the steam driving absorption heat pump, can reduce the temperature of the circulating water and exhaust steam pressure, thus to improve the thermal efficiency of the unit eventually. In this paper, based on the 30MW absorption heat pump which is successfully used in the market, calculation model is presented. Whats more, by studying on supercritical 600MW units, the influence on the unit efficiency based on absorption heat pump by reducing the temperature of circulating cooling water with waste heat utilization is analyzed.

Road characteristic identification based on wavelet neural network

This paper presents a road characteristic identification method derived from wheel vibration. Firstly, analyses the friction principle between tires and road, road characteristic restrict road adhesion coefficient; Secondly, the wheel vibration model shows that wheel vibration mappings road characteristic; Thirdly, wheel vibration signal is decomposed by wavelet transform, using FFT get the high frequency spectrum vectors of wheel vibration; Finally, built and trained the RBF neural network classifier with the frequency spectrum vectors. For fine blacktop and mattess, the high frequency spectrum of wheel vibration displays obvious difference, the road type identification accuracy reaches 100%.