成型机微机控制系统的研究和应用

简要介绍了旋压封头一次成型冷旋压机的结构及工作过程，着重阐述了该旋压机的数控系统的结构和工作原理。     

Experimental force response of a grooved squeeze film damper

The effects of a circumferential feeding groove on the dynamic force response of a squeeze film damper are determined experimentally. Open end and sealed damper configurations are tested for different groove depths, Journal orbit radii, whirl frequency and fluid viscosity conditions. Significant levels of dynamic pressures are measured at the groove in dampers with groove depth-to-clearance ratios equal to 5 and 10. These pressures affect considerably the dynamic forces of the dampers tested. Large tangential (damping) forces are produced at the circumferential groove which contribute significantly to the damping characteristics of the test articles. For uncavitated lubricant conditions, radial forces of substantial magnitude are determined at the groove and at the thin film land where the squeeze film Reynolds numbers are typically less than 1.     

数控技术在普通机床改造中的应用

介绍了采用开环控制系统对传统CA6140车床改造的原理和改造中硬件电路及控制软件的设计、选用,以及如何采用微机对数据进行传递、反馈,从而提高了机床运行的可靠性。     

音圈电机与电感组合传感器的系统辨识与数字控制

介绍了音圈电机与电感组合传感器的结构与工作原理；提出直接采用阶跃响应法对系统动态特性参数进行辨识的方法，并给出了实验辨识结果；通过对传感器测量噪声的频谱分析，应用数字滤波的方法消除了工频噪声的干扰；测量结果表明具有较好的动态性能指标。     

Effect of surface roughness on the hydrodynamic lubrication of porous step-slider bearings with couple stress fluids

This paper presents the theoretical study of the effect of surface roughness on the hydrodynamic lubrication of porous step-slider bearings. A more general form of surface roughness is mathematically modeled by a stochastic random variable with non-zero mean, variance and skewness. The generalized average Reynolds-type equation is derived for the rough porous step-slider bearing lubricated with Stokes couple stress fluid. The closed-form expressions for the mean load carrying capacity, frictional force and the coefficient of friction are obtained. The performance of the rough porous step-slider bearing is compared with a corresponding smooth porous step-slider bearing. The numerical computations of the results show that the negatively skewed surface roughness pattern increases the load carrying capacity and decreases the coefficient of friction whereas the adverse effects were found for the positively skewed surface roughness pattern.     

基于Internet的旋转变压器实验系统

介绍了浙江大学网络实验室基于Internet的旋转变压器实验系统的框架,给出了系统硬件设计、控制端和客户端软件设计及实现方法,并对系统的控制功能、方案设计给予了详细的说明.该系统融合了网络、计算机实时控制、面向对象编程、电气电子等技术,将真实的物理设备与网络相结合,为局域网和Internet用户提供了一个开放的实验平台,使学生可以通过因特网远程登录该系统后进行旋转变压器等相关实验.     

Experimental study on integration of laser-based additive/subtractive processes for meso/micro solid freeform fabrication

Solid freeform fabrication has attracted considerable attention lately because of its ability to build a 3D structure with a complex and arbitrary shape. This work presents initial studies to adapt this technology for the fabrication of meso-/micro-3D structures. A pulsed Nd:YAG laser was used for laser microdeposition (additive) and micromachining (subtractive) processes. An ultrasonic-based micropowder feeding system was developed to generate precise patterns of micropowders on a substrate without any pre-processing. Laser microdeposition of copper and stainless steel micropowders was accomplished. The characterization of micromachining was performed on stainless steel and copper plates with a laser beam of wavelengths of 355 nm and 266 nm. The integration of laser microdeposition and micromachining processes improved the resolution and edge quality of the meso-/micropatterns.     

Novel precision piezoelectric step rotary actuator

A novel piezoelectric (PZT) precision step rotary actuator was developed on the basis of PZT technology. It adopts the principle of bionics and works with an inside anchoring/loosening of the stator and a distortion structure of the uniformly distributed thin flexible hinge to solve problems such as ineffective anchoring/loosening, low step rotary frequency, small travel, poor resolution, low speed and unsteady output. The developed actuator is characterized by high frequency (30 Hz), high speed (380 μrad/s), large travel (>270°), high resolution (1 μrad/step), and work stability. It greatly improves the ability to drive the existing PZT step rotary actuator. The new actuator can be applied in the field of micromanipulation and precision engineering, including precision driving and positioning and optics engineering. __________ Translated From Journal of Jilin University (Engineering and Technology Edition), 2006, 36(5): 673–677 [译自: 吉林大学学报 (工学版)]     

机械式疲劳试验机的机电自动加载系统设计

介绍了由单片机AT89C2051控制的步进电机和曲柄——滑决机构组成的机电自动加载系统，包括机械结构组成、控制系统的工作原理、硬件设计和软件的实现方法。     

适用于保护控制的同步相量测量方法

近年来,电力系统电力电子化特征导致输配电网动态特性耦合紧密,系统性故障频发。同步相量测量单元(PMU)在动态安全控制中作用愈发重要。适用于智能配电网的同步相量测量装置的研究也得到广泛开展。如何在当前复杂电气信号条件下保证相量测量精度的同时,缩短其阶跃条件下的响应时间对保护控制应用至关重要。文中提出一种适用于保护控制的同步相量测量方法。该方法揭示了阶跃信号对相量测量的影响机理,分析了相量模型参数在阶跃信号条件下的行为规律,提出了信号阶跃识别方法。进一步,揭示了阶跃量大小与动态相量模型参数突变量的线性关系,提出了阶跃过程中相量修正方法,减少了相量计算的响应时间。仿真与实际录波数据测试验证了所提方法可有效减少响应时间,为智能配电网保护控制提供快速准确的测量数据。