Coordinating optimization-based sliding mode variable structure control for electro-hydraulic servo system

A sliding mode variable structure control (SMVSC) based on a coordinating optimization algorithm has been developed. Steady state error and control switching frequency are used to constitute the system performance indexes in the coordinating optimization, while the tuning rate of boundary layer width (BLW) is employed as the optimization parameter. Based on the mathematical relationship between the BLW and steady-state error, an optimized BLW tuning rate is added to the nonlinear control term of SMVSC. Simulation experiment results applied to the positioning control of an electro-hydraulic servo system show the comprehensive superiority in dynamical and static state performance by using the proposed controller is better than that by using SMVSC without optimized BLW tuning rate. This succeeds in coordinately considering both chattering reduction and high-precision control realization in SMVSC.     

网络故障分析及排除方法

本文笔者从实际工作经验出发,阐述了如何对网络故障进行分析及排除方法。希望对广大网络管理员有借鉴作用。     

混合注入式电力滤波器系统硬件研究及工程应用

有源滤波是电力系统谐波治理的主要趋势，根据工程实际应用的需要，研究一种基于TMS320LF2407DSP控制的混合注入式的有源电力滤波器（Hybrid Active Power Filter，HAPF）的系统结构，重点阐述DSP控制系统构成，智能型的IPM模块的应用。该装置在某冶炼厂成功应用，起到了改善电能质量的作用。     

PI control based on fuzzy set-point weighting tracking for hydraulic crane boom system

A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportional feedforward controller based on fuzzy set-point weighting following and a limited semi-integrator（LSI）, are designed respectively. LSI is used to limit output signal and to prevent wind up at the low frequency of the spectrum. By using a range camera and an electronic feedback control, the tip damping on the HCBS can be adjusted artificially. A collaborative control simulation technique of HOPSAN and MATLAB/SIMULINK is applied to the controller design. Simulation results show that the proposed PI control system has less overshoot as well as faster response. The tip damping on the HCBS during operation is improved.     

Accumulation of 2-Keto-L-Gulonate at 33℃ by a Thermotolerant Gluconobacter Oxydans Mutant Obtained by Ion Beam Implantation

To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a mutation source. Gluconobacter oxydans GO and Bacillus megaterium B0 were used in this study. The original strain Gluconobacter oxydans GO was mutated by the heavy ion implantation facility at the Institute of Plasma Physics, Chinese Academy of Sciences. Several mutants including Gluconobacter oxydans GI13 were isolated and cocultured with Bacillus megaterium B0 at 33℃ in shaking flasks. The average transformation rate of the new mixed strain GI13-B0 in per gram-molecule reached 94.4% after seven passages in shaking flasks, which was increased by 7% when compared with the original mixed strain G0-B0 （Gluconobacter oxydans GO and Bacillus megaterium B0）. Moreover, the transformation rate of I13B0 was stable at 94% at temperatures ranging from 25℃ to 33℃, which would be of much value in reducing energy consumption in the manufacture of L-ascorbic acid, especially in the season of summer. To clarify some mechanism of the mutation, the specific activities of L-sorbose dehydrogenase in both GO and GI13 were estimated.     

Ge nano-layer fabricated by high-fluence low-energy ion implantation

A Ge nano-layer embedded in the surface layer of an amorphous SiO₂ film was fabricated by high-fluence low-energy ion implantation. The component, phase, nano-structure and luminescence properties of the nano-layer were studied by means of Rutherford backscattering, glancing incident X-ray diffraction, laser Raman scattering, transmission electron microscopy and photoluminescence. The relation between nano-particle characteristics and ion fluence was also studied. The results indicate that nano-crystalline Ge and nano-amorphous Ge particles coexist in the nano-layer and the ratio of nano-crystalline Ge to nano-particle Ge increases with increasing ion fluence. The intensity of photoluminescence from the nano-layer increases with increasing ion fluence also. Prepared with certain ion fluences, high-density nano-layers composed of uniform-sized nano-particles can be observed.     

基于PCI卡的DSP系统在线加载方法的研究

概述了以DSP为核心的一般逻辑系统。结合实例详细介绍了基于PCI卡的DSP系统在线加栽电路的硬件设计和程序在线加栽技术，该技术具有较大的可扩展性，可广泛应用于基于网络的，以DSP作为核心处理器的各种电子设备中。     

通用串行数据产生器的研制

在研究多个机载设备的基础上．依据设备输出数据的通信协议，研制了通用数据产生器。介绍产生器的硬件电路的组成、原理、工作过程及软件流程。     

便携式飞机电缆智能检测系统

本文介绍了一种基于PC104的智能型飞机电缆性能检测系统。阐述了该系统的功能及工作原理,并给出了硬件电路的设计及软件流程。     

基于上下位机的油箱气密性检测系统

本文介绍了以PLC和工控机为基础的汽车油箱气密性检测系统的设计．在检测中引入了二次充气法来减少检测时间，详细介绍了二次充气法的原理；上位机使用OPC技术与工厂信息管理系统进行数据交换，实现汽车生产线信息管理的自动化。