Advanced Materials Research Vols. 383-390

Abstract: Under the operating load, the fabrication hydraulic torque converter could be regarded as a rotating pressure vessel. It will dilate like a balloon as a result of the centrifugal force and fluid pressure. The magnitude of deformation affects the performance of fabrication hydraulic torque converter and its connection with adjacent parts. Based on the three dimensional measuring machine and platform UG and Gambit, the frame model of ballooning deformation is established and simplified. Based on modern computational fluid dynamics theory, the simulation software FLUENT, MSC.Partran and MSC.Nastran are employed to make simulation prediction for the ballooning deformation. The results of the simulation are checked out through the experiments. The experimental results show that the calculation and experiment results are coherent. The increase of axial displacement has a linear relation with the rise of fluid pressure. The largest stress occurs near the intersect of the shell and working face. The largest strain takes place at the outlet of the pump and inlet of the turbine.

Abstract: With high efficiency, simple structure and low cost, Automatic Mechanical Transmission (AMT) is suitable for the development and application of light vehicles. The control of clutch is emphasized on in the shifting process. It is necessary to study the control of engagement speed. In this paper, the electric-hydraulic clutch applied on light vehicles is modeled and the engagement process of clutch during vehicle starting simulated. After analyzing the operation quality of clutch with different engagement speeds, the speed variable control strategy is proposed. According to the strategy, engagement speed changes with the development of different operating stages. At last, the simulation is carried out to verify the feasibility and superiority of this kind of strategy.

Abstract: This paper describes an innovative systematic approach to factory automation. Northwestern Polytechnical University developed an Enterprise-level Digital fActory and its Simulation Platform, NPU-EDASP that adopted service-oriented architecture methodology to design and develop this software. In particular, it specifies the simulation technology within the NPU-EDASP platform to bridge the gape exits among products and production manufacturing process. In an advanced stage, simulation technology can be applied in the NPU-EDASP to enhance the operative production planning and control. Further, the combination of simulation and optimization techniques will improve and optimize material flow, resource utilization and logistics in production engineering processes. A case study of a model demonstrates that the NPU-EDASP digital factory offers an integrated approach to promote the ability of production engineering.

Abstract: This paper summarizes the defects of both OPA model and its improved models and then proposes a new model in order to simulate real power system roundly. There is an inner loop based on DC power flow optimization to minimize the change in generation or load shed and an outer loop based on the risk theory. In the outer loop, whether to improve the line capacity and how to improve are determined by risk index of line improvement (RILI) and line improvement degree function, respectively. A new prevention strategy against cascading failure is proposed by identifying the high-risk lines and determining optimal RILI which minimize line improvement cost and load loss. In the end, simulation based on 39-bus New England System reveals that new model is closer to real power system than the original one by comparing outage probability and load loss between the two models, and risk-based assessment interval and line improvement delay play important roles in prevention against power system outages, and improvement based on risk assessment can reduce outage probability to varying degrees, which illustrates the practical significance of optimal RILI.

Abstract: Human vision system exploits this fact by visual selective attention mechanisms towards important and informative regions. A computational model of combination both bottom-up and top-down simulating human vision system for machine vision inspection is proposed. In this model, top-down knowledge-based information is highlighted to integrate into bottom-up stimulus-based process of vision attention. The model is tested on inspecting contaminants in cotton images. Experiment result shows that the proposed model is feasible and effective in visual inspection. And it is available and quasi-equivalent to human vision attention.

Abstract: In this paper, a model predictive control (MPC) scheme is investigated for uncertain nonlinear system with time delay and input constraint. First, the Takagi-Sugeno (T-S) fuzzy model is used to approximate the dynamics of nonlinear processes and the parallel distributed compensation (PDC) controllers which are parameter dependent and mirror the structure of the T-S plant model are proposed. Then a novel feedback PDC predictive controller obtained from the linear matrix inequality (LMI) solutions which can guarantee the stability of the closed-loop overall fuzzy system is put forward. Finally, a numerical example is provided to demonstrate the effectiveness and feasibility of the proposed method.

Abstract: Reynolds averaged Navier-Stokes (RANS) equations, energy equation and V2f turbulence model equations governing the flow field of the rotor frame, magnetic yoke and the pole, the stator were solved with finite volume method(FVM) based on unstructured mesh. The MRF(multiple implicit rotating frame) method was used to simulated the rotating motion of the rotor frame, magnetic yoke and the pole. The flow characteristic of different parts was analyzed. The influence of the gap size between insulating layer of bar core, the gap size between insulating layer of pole and coil to the temperature distributions on the solid parts was studied. The results show that the temperature on the windward of the pole is lower than the temperature on the leeward. With the gap size between the insulating layer of bar and core varying from 0.0mm to 0.3mm,the temperature of insulating layer of bar rise increases 9.2 degrees, So the gap size is important for the life of insulating layer. With the gap size between the insulating layer of pole and the coil varying from 0.25mm to 0.75mm, the temperature of coil increases 16.5 degrees. The results provide a reference for the rational design of the gap size.

Abstract: In this paper, the adaptive maneuvering control based on output feedback is studied for uncertain nonlinear multi-input multi-output (MIMO) systems. The high frequency gain matrix of the systems only needs to be Hurwitz, which relaxes the positive definite limitation in the existing results. Based on the backstepping approach with vector form, an output feedback adaptive maneuvering control scheme is proposed. The geometric and the dynamic tasks are solved meanwhile the global stability of the closed-loop systems is guaranteed through the proposed control scheme.

Abstract: This article introduces the theory analysis and experimental study on the performance of special turbine in cooling tower. The author analyses the speed-flow characteristics of turbine-fan unit and the speed-flow characteristics of ultra-low specific speed turbine itself. At the same time the author points out the principles and methods to determine the best operating point of turbine-fan unit. So it is very important to determine whether the specific turbine is in the best condition.

Abstract: by the MSC Adams / Aircraft software features, setting pillar-type landing gear as the prototype, and using ADAMS software modules prior to the establishment of a certain type of aircraft landing gear model, then calculate the air buffer spring force oil, damping force and the structural constraints force curve based on dynamics model, At the end of paper we will analyze the model drop-test results. The results proved that we used this method was feasible.