Advanced Materials Research Vols. 532-533

Abstract: Cables, distributed with diversity spatially angle, are rich in wind direction. Circular cross sectional shape is sensitive to the Reynolds number. This paper studed the aerodynamic performance of three-dimentional stayed cable under two-dimensional flow field in Chang'an University wind tunnel by Pitot tube, electronic pressure scanning valve, data conversion and collection systems. The following conclusions are obtained: (1)The stagnation point and the upper and lower airflow separation point clockwise goes on with the wind angle increases. Absolute value of pressure coefficient at stagnation point and separation point are biggest at 0°wind angle.(2)The absolute value of pressure coefficient at upper and lower separation point increase with the increase of wind speed.(3) Pressure stagnation point,and upper and lower airflow separation point don’t changed with the parameters of helix,while pressures near helix changed irregularlly. Drag coefficient decrease with the increase of helix distance and the deduce of helix height. Meaningful references are provided for the further refinement research on aerodynamic performance of cable-stayed with suppressing vibration measures.

Abstract: This paper conducts numerical simulation to a 15-stage civil axial flow compressor and obtains its main parameters distribution and performance curve by a full three-dimensional viscid flow computation software. The computation result indicates that, the developed axial flow compressor meets the anticipated design requirements, and satisfies the customers’ indicators. Under the designed compression ratio, the difference between the maximum air supply quantity in summer and the minimum air supply quantity in winter is 22%. By comparing the operating conditions and data analysis, obtained the change trend of axial velocity, static pressure and temperature, and Ma, and discovered that, under opening of 48° and outlet back pressure of 550KPa, flow separation occurred on the section of machine set close to hud, which indicated that operating condition was close to surging condition.

Abstract: The purpose of this paper is to briefly present important progresses of robots in the recent decade. A variety of fault tolerance processes are written for different robot categories, in which both minor and severe sensor and actuator failures as well as various combinations of failures are discussed. It is hopeful that these literatures may help researchers to have a glance of the fault tolerance autonomy in this area.

Abstract: The creation method of simulation model of manipulator grab the workpiece is studied based on PRO/E, and the steps how to do the simulation analysis of the manipulator grab the workpiece by PRO/E4.0 software are stated. The results of simulation analysis showed that, in the workpiece quality of 0.08 kg, normal force is about 54.11 N between 0.7 seconds to 7.5 seconds, tangential force is about 0.3924 N between 0.65 seconds to 7.7 seconds, the sum of tangential force of both sides is 0.784 N, it’s exactly equal to the workpiece weight, so that the manipulator can grab the workpiece quickly and accurately.

Abstract: Traditional parking management uses human staff and has high costs, low efficiency and low safety. We analyzed the deficiency of existing smart parking systems and proposed a management system for parking management with comprehensive application of RFID, video monitoring technology, sensing technology, image recognition technology and embedded technology. We propose to build a distributed, multilevel management architecture which is based on the SNMP protocol. This approach facilitates the automation of parking management.

Abstract: This paper proposed a fuzzy Linear Matrix Inequalities(LMI) control strategy for a rectangular thermosyphon. These thermo-fluid-dynamic systems are used to refrigerate heat sources by means of natural circulation of a fluid without mechanical pumping. Two different fuzzy LMI controllers have been designed in order to guarantee closed loop stability, on the basis of a suitable nonlinear T-S fuzzy model of the system. In particular the controllers are designed in order to prevent temperature oscillations, associated with the inversion of the flow direction, which compromise the heat removal from the thermal source. Two different strategies have been adopted to introduce suitable constraints on the control action.

Abstract: Applying neutral network-sliding model control design methods to large envelope flight control law of aircraft whose model parameter varies greatly with flight condition was studied in this paper. Neural network theory is used to approximately linearize the nonlinear system and cancel the errors brought with approximate inversion, and the residual error is solved by sliding model control. So it can approximate the nonlinear model accurately, and improve robustness and anti-jamming capability of the flight control system. Simulation results show the design neural network – sliding model large envelope flight controller has excellent control performance.

Abstract: Ball produce detection and control is an important aspect of ball mill control, however, contribute to the lack of effective and reliable ball detection means in the actual production process, so it is difficult to achieve optimal control. In this paper, secondary variable is selected with this mechanism analysis and information processing technology of choice, the establishment of the ball fast and accurate output of neural network soft sensor model can not only contribute to estimate the steady-state mill and ball mill on the dynamic process can effectively contribute to an online estimate, the soft-sensor model has a strong possibility. At the same time，it provides a reference for the soft measurement of power plant other parameters. This modeling method has portability.

Abstract: In the paper, the center of gravity fuzzy systems and probability representation theory based on two circle operators of the regular implications(Godel, Goguen) are studied. Firstly, based on CRI algorithm and the center of gravity defuzzification method, the joint probability density functions of two-dimensional random variables, the marginal probability density functions and numerical characteristics of these two circle operators are obtained. Then it is pointed out that the fuzzy systems based on these two circle operators are regression functions with the joint probability density function. Finally, we prove these two fuzzy systems not only have the universal approximation but possess the first-order approximation accuracy. By comparing with the center-average defuzzification method, it is found that the center of gravity defuzzification method is better than the center-average defuzzification method.

Abstract: The problem of robust fault-tolerant control for the uncertain time-delay system with state and control delays is studied.The considered system has sensor or actuator failures.Based on Lyapunov stability theory and linear matrix inequality(LMI),a method of robust fault-tolerant against sensor or actuator failures for uncertain system was proposed via memoryless feedback control law.The sufficient for the closed-loop system possessing integrity against sensor or actuator failures are given.At the same time,the controller design method is the linear matrix inequality(LMI).Finally,the numerical example and simulations demonstrate the validity of the proposed method.