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Yang Z.,Harbin Engineering University | Wang Y.,No703 Research Institute Of Csic | Liu Z.,Harbin Engineering University
Proceedings of the World Congress on Intelligent Control and Automation (WCICA) | Year: 2015

The paper studies the formation control problem for multiple underactuated surface vessels by utilizing leader-follower approach with parameter uncertainties and external disturbances, and the proposed formation control method that the follower tracks a reference trajectory based on the leader's position and the predetermined formation without the need for leader's velocity and dynamics. A virtual ship is constructed such that its trajectory converges to the reference trajectory of the follower in limited time. The Ships formation control model is established on the virtual ship under leader-follower mode. The robust controller can effectively deal with parameter uncertainties and external disturbances by combining backstepping with sliding-mode control method, which can make the follower move along the trajectory of the virtual ship, maintain the desired formation with leader and achieve the purpose of formation control. A Simulation of the formation control for the multiple underactuated surface vessels is performed by using three real Northern Clippers. Results validate the effectiveness of the proposed method. © 2014 IEEE. Source

Wang B.,Harbin Institute of Technology | Wang C.,Harbin Institute of Technology | Huang H.,China Aerospace Science and Technology Corporation | Huang H.,Harbin Institute of Technology | And 2 more authors.
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2013

Considering the effects of phase-change on the bubble interface, a new cavitation model based on Rayleigh-Plesset Equation is given and the secondary cavitation is successfully modeled. Using the new cavitation model on cavitation flow fields of the 2 d steady axisymmetrical hemispherical cylinder, the model surface is alternately distributed by a higher cavity pressure and lower collapse pressure due to the growth and collapse of the secondary cavity. With the decrease of cavitation number, the main cavity gradually becomes larger, and the secondary cavity zone is gradually moving to the tail of the model and falling off. Source

Yang Z.,Harbin Engineering University | Liu F.,Harbin Engineering University | Wang Y.,No703 Research Institute Of Csic
Ship Building of China | Year: 2015

In order to realize the path following control for underactuated surface vessels under parameter perturbation and external disturbances, a neural and sliding mode controller is presented based on visible distance. Desired position and current position are used to determine reference surge velocity and yawing angle, which are employed as virtual control laws in stabilizing position errors. Based on neural network and sliding modes, a new nonlinear feedback robust controller is designed, and then the tracking control of the laws of virtual control can be realized without determining upper bound of parameter perturbation and external disturbances. The problem of saturation and chattering of the controller are circumvented. Simulation experiments indicate that the controller is robust against parameter perturbation and external disturbances. Moreover, the path following control can be achieved with the proposed control method. ©, 2015, Editorial Office of Shipbuilding of China. All right reserved. Source

Wang W.-Y.,Harbin Engineering University | Li S.-Y.,Harbin Engineering University | Wang J.-F.,China National Offshore Oil Corporation | Cui B.,No703 Research Institute Of Csic
Reneng Dongli Gongcheng/Journal of Engineering for Thermal Energy and Power | Year: 2016

For the problems of compressor performance degradation and regular cleaning maintenance caused by compressor fouling in the actual operation process of gas turbine, the paper develops a prediction approach based on time series model for gas path performance degradation of gas turbine. On the basis of gas turbine thermal modeling and simulation, taking exhaust gas temperature of gas turbine as an example, the paper conducts the validity evaluation on the application of time series model in the prediction on gas path performance degradation of gas turbine. The study results indicate that by using the approach, the prediction on the changes of the gas path performance parameters of gas turbine can be transformed into the time series prediction problem. In this way, the prediction on gas path performance degradation of gas turbine can be realized effectively, and then cleaning maintenance as appropriate for compressor can also be implemented. The approach provides a new way to online condition monitoring and fault diagnosis for gas turbine, so it has a certain engineering application value. © 2016, Harbin Research Institute. All right reserved. Source

Qian T.,Harbin Engineering University | Li Y.,Harbin Engineering University | Zhang J.,No703 Research Institute Of Csic
Asia-Pacific Power and Energy Engineering Conference, APPEEC | Year: 2012

A 149 tubes simplified physical model is established by reasonable simplified assumed conditions. The basic differential equations of fluid flow and heat-transfer are obtained on the base of the thermodynamic process of superheater heat transfer. Spatial distribution of thermodynamic parameters under steady-state and dynamic working process is achieved directly by simulating the whole superheater system (gas, steam and wall). Therefore, the internal working principles of boiler system are revealed. © 2012 IEEE. Source

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