Genetic-based fuzzy control for half-car active suspension systems

In this paper, a fuzzy controller is designed for automotive active suspension systems. A half-car model is used in order to consider the pitch angle of the body and the coupling dynamics of front and rear wheels. It is assumed that the three measurements of body acceleration, front suspension deflection and rear suspension deflection are available. The fuzzy control rules are separately designed for each measurement. After the fuzzy control rules are determined, a genetic algorithm is applied to tune the membership functions of these control rules. To measure the performance of the designed genetic-based fuzzy active suspension system, three road disturbance models are designed to simulate actual road conditions. The performance of the designed system is evaluated with respect to these disturbance models, and it is shown that the designed active suspension system provides good performance in improving ride quality and maintaining vehicle maneuvrability. It is also shown that the designed active suspension system shows robust performance with system model uncertainties.     

Effect of carbon on microstructure of CrAlC_xN_(1-x) coatings by hybrid coating system

A systematic investigation of the microstructure of CrAlCxN1-x coatings as a function of carbon contents was conducted. Quaternary CrAlCxN1-x coatings were deposited on Si wafers by a hybrid coating system combining an arc-ion plating technique and a DC reactive magnetron sputtering technique using Cr and Al targets in the Ar/N2/CH4 gaseous mixture. The effect of carbon content on microstructure of CrAlCxN1-x coatings was investigated with instrumental analyses of X-ray diffraction, X-ray photoelectron, and high-resolution transmission electron microscopy. The results show that the carbon content of CrAlCxN1-x coatings linearly increases with increasing CH4/(CH4/N2) gas flow rate ratio. The surface roughness of the CrAlCxN1-x coating layer decreases with the increase of carbon content.     

Silver-palladium alloy deposited by DC magnetron sputtering method as lubricant for high temperature application

The silver-palladium(Ag-Pd) alloy coating as a solid lubricant was investigated for its application to the high temperature stud bolts used in nuclear power plants. A hex bolt sample was prepared in the following steps: 1) bolt surface treatment using alumina grit blasting for cleaning and increasing the surface area; 2) nickel(Ni) film coating as a glue layer on the surface of the bolt; and 3) Ag-Pd alloy coating on the Ni film. The films were deposited by using a direct current(DC) magnetron sputtering system. The thickness and composition of the Ag-Pd alloy film have effect on the friction coefficient, which was determined using axial force measurement. A 500 nm-thick Ag-Pd (80:20, molar ratio) alloy film has the lowest friction coefficient of 0.109. A cyclic test was conducted to evaluate the durability of bolts coated with either the Ag-Pd (80:20) alloy film or N-5000 oil. In a cycle, the bolts were inserted into a block using a torque wrench, which was followed by heating and disassembling. After only one cycle, it was not possible to remove the bolts coated with the N-5000 oil from the block. However, the bolts coated with the Ag-Pd (80:20) alloy could be easily removed up until 15 cycles.     

轴流转浆式水轮机数字调速器的仿真以及PID参数优化

本文用离散系统理论,建立轴流转浆式水轮机微机调速器的数学模型,并且通过脉冲传递函数和它的z反变换,得到微机调节器的每个采样周期的离散控制量,同时解决了过渡过程计算中不同的采样周期与计算时步协调的问题。然后与原有的过渡过程计算程序结合计算轴流转浆式微机调节系统的小波动工况,且对仿真结果进行了分析。在此基础上用单纯型加速法进行PID参数优化,分析了目标函数形式对过渡过程的影响。     

Dielectrophoretic assembly of semiconducting single-walled carbon nanotube transistor

A novel burning technique for making a semiconducting single-walled carbon nanotubes (SWNTs) transistor assembled by the dielectrophoretic force was suggested. The fabrication process consisted of two steps. First, to align and attach a bundle of SWNTs between the source and drain, the alternating (AC) voltage was applied to the electrodes. When a bundle of SWNTs was connected between two electrodes, some of metallic nanotubes and semi-conducing nanotubes existed together. The second step is to burn the metallic SWNTS by applying the voltage between two electrodes. With increasing the voltage, more current flowed through the metallic SWNTs, thus, the metallic SWNTs burnt earlier than the semiconducting one. This technique enables to obtain only semi-conducting SWNTs connection in the transistor. Through the I-V characteristic graph, the moment of metallic SWNTs burning and the characteristic of semi-conducing nanotubes were verified.     

Graphical interface for motion editing using procedure visualization

In this paper, we introduce an interface for motion editing that visualizes editing procedures. For intuitive understanding and construction of motion editing procedures, our system represents an editing element that produces modified motion from a given input motion as a graphical node, and enables user to construct a whole motion editing procedure by connecting the nodes with a few mouse interactions. The system provides both the 3D transform manipulator and the time-line slider for intuitive controlling ...     

Lubrication properties of silver-palladium alloy prepared by ion plating method for high temperature stud bolt

As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature stud bolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and then Ag-Pd alloy coating was performed on it using ion plating method. The friction coefficient of Ag-Pd alloy film coated bolt was lower than that of N-5000 oil coated bolt by the result of axial force measurement. The cyclic test of heat treatment was conducted to evaluate the durability of Ag-Pd alloy film coated bolt. In a cycle, sample was assembled into the block using torque wrench, followed by heating and disassembling. It was not successful to disassemble the N-5000 oil coated bolt from the block after only one cycle. However, the Ag-Pd alloy film coated bolt was able to be disassembled softly till 12 cycles.