Advanced Materials Research Vols. 562-564

Abstract: The vacuum system control strategy based on event-driven approach is considered for monitoring startup status, stable operation status, shutdown status and failure processing of transmission electron microscope (TEM). Hierarchical structure is adopted so as to reasonably compartmentalize the vacuum control tasks. For startup operation, control logic flow of vacuum system is designed by event-based control mode. Finally, through the actual operation of the test results indicate that the vacuum control system fulfills design requirements and the event-based control mode is effective.

Abstract: In this study, moving mesh technique is used to construct an outside flow CFD model around H-vertical axis wind turbine with different types of airfoil. RNG turbulent models and the implicit Couple arithmetic based on pressure are selected to solve the transient equation. From the results of the calculation, the author obtains the velocity field, pressure field distribution of H-type vertical axis wind turbine airfoil at different moments and analyze the wind wheel blade torque variation. The conclusion provides the theoretical basis and a method to optimize aerodynamic performance for the further study of vertical axis wind turbine in the future.

Abstract: The elastoplastic phenomenon of the structures will be advent under the action of the strong earthquakes, the presented research on the vibration control of the ones is chiefly concentrated on fuzzy and neuro-controller with the expense of bigger energy. In the paper, the 3-storey benchmark building is used as research object, the control strategy of vibration system with fractional-order is studied. The control method based on acceleration responses output is emphatically concerned as it is usually adopted in most actual application of active vibration control techniques. The concrete courses include the following three steps: the integer-order approximation of fraction-order, the transfer function reduction in frequency-domain which base on Pade approximation, the controller design and simulation. In the last, an example is used to show the feasibility of proposed method.

Abstract: This paper introduces a microwave technology in measurement applications of textile moisture, and the humidity measurement principle is analyzed. This paper designs a non-contact textile material moisture content measurement system based on microwave. According to the result of the fitting line, the moisture content in this method for cotton cloth, denim and fine cotton cloth in the effective measurement range is 30~50% respectively, 30~55%, 35~70%.

Abstract: In order to improve the application effect of the NMR in Petroleum exploration and development, the quality of T2 spectrum inversion need to be controlled. Echo resolution matrix,T2 spectrum resolution matrix are deduced, the quality control index of T2 spectrum inversion is provided: the stretch coefficient, maximum, minimum, average and range of principal diagonal elements of resolution matrix. Calculating the inversion quality control index under different observation modes and choosing the observation mode of resolution matrix approximate to unit matrix for data acquisition can improve T2 spectrum inversion quality. Numerical experimentation indicate there is very good consistency between inversion quality and control index. Hence, it may direct the design before NMR data acquisition, control inversion quality of T2 spectrum

Abstract: A flow sensor for liquids, based on the principle of fluid-structure heat transfer is presented. The heater and thermistor are integrated and wrapped together as a detector and heat source, allowing heat exchange between the sensor and the fluid. Through numerical simulation, the temperature distribution of the sensor was investigated, under conditions of various flow velocities. The process of turbulent heat transfer in the flow pipe was simulated, the temperature distribution in the sensor was analyzed and compared under different temperature and velocity of the fluid, and the corresponding measuring ranges were determined. The flow detection circuit is designed and the results of water flow velocity tests in the range of (0.01–1)m/s are presented.

Abstract: Building energy research has been focused on the study of improving the efficiency of equipment operation and operating control mode, rather than the management of central air conditioning system terminal. In fact, large amounts of energy can be conserved through that study. And terminal temperature of the central air conditioning with automatic detection is necessary to fulfill the energy-saving with the management of central air conditioning system terminal. An automatic terminal temperature detection of central air conditioning system based on wireless communication mode has been designed. It can transfer data to the monitoring center to provide reference data to fulfill the energy-saving.

Abstract: According to the basic principle of measuring the magnetic aspect angle for the rotating body using the zero crossings exported by the two magnetic sensors, a measuring system based on the fluxgate sensors is put forward in this paper. The resolved approaches about the circuit design are analyzed. Then, an experimental system is established, and the measuring experiments are carried out for the certain conditions. The experiment results indicate that the system has higher measuring precision, which can ideally meet the demand of measuring the magnetic aspect angle. The study could be applied to navigational aids, attitude correction, and determination of angular motion histories of rotating bodies, and so on.

Abstract: This article describes a detection, tracking control method. The image sensor is the core components of the system. The microcontroller determine the position of the sun to track, store location information, and offer protection measures implemented on the system in inclement weather. The system has high accuracy, good adaptability and other characteristics.

Abstract: Aiming at wide variations in loads and moments of inertia, large disturbed moment of machine tool servo system, a parallel control structure is proposed, and sliding mode structure controller and PI Ziegler-Nichols controller of the position loop are designed. The sliding mode controller can restrain effects of parameter uncertainties and external disturbances and the PI Ziegler-Nichols can realize the parameter adjustments of the integral and proportion of the classical PI controller. Simulation results show that the designed parallel controller can guarantee high performance of tracking behavior and robustness.