基于分布式网络的航天器真空热试验控制系统

传统的航天器真空热试验控制系统采用集中控制模式,系统精确度和可靠性较低,无法满足新型航天器的研制需求.为此设计了一套基于分布式网络、具备高可靠性和高控制精确度的控制系统.该控制系统所有终端均遵循以太网传输控制协议/因特网互联协议,以实现分布式的网络通信,并采用航天产品可靠性设计原则;同时在系统设计中采用增量式数字比例积分微分(PID)控制算法,运用模糊数学的基本理论和方法,设计了一种模糊自适应PID控制算法.控制系统中运用了数字信号处理技术,以保证控制能力的实现.经相关测试表明,该控制系统控制精确度高,动态特性良好,抗干扰能力强,可满足新型航天器研制需求.     

客车后置发动机舱热管理研究与改进

为了系统地研究客车发动机舱内空气的流动与传热,采用汽车外流场与发动机舱内流场耦合计算的方法,分析客车发动机舱内风速流动组织,并对比改进前后气体流线和高温区域分布。结果表明,增加挡板的设计使机舱内循环流动的区域变小,有效地隔阻发动机的热量传到散热器,改进后的机舱布置满足整车使用要求,为客车开发中的发动机舱热管理研究与改进提供了参考数据。     

An insulin infusion advisory system based on autotuning nonlinear model-predictive control

This paper aims at the development and evaluation of a personalized insulin infusion advisory system (IIAS), able to provide real-time estimations of the appropriate insulin infusion rate for type 1 diabetes mellitus (T1DM) patients using continuous glucose monitors and insulin pumps. The system is based on a nonlinear model-predictive controller (NMPC) that uses a personalized glucose-insulin metabolism model, consisting of two compartmental models and a recurrent neural network. The model takes as input patient's information regarding meal intake, glucose measurements, and insulin infusion rates, and provides glucose predictions. The predictions are fed to the NMPC, in order for the latter to estimate the optimum insulin infusion rates. An algorithm based on fuzzy logic has been developed for the on-line adaptation of the NMPC control parameters. The IIAS has been in silico evaluated using an appropriate simulation environment (UVa T1DM simulator). The IIAS was able to handle various meal profiles, fasting conditions, interpatient variability, intraday variation in physiological parameters, and errors in meal amount estimations.     

航空发动机转子故障特征提取方法研究

航空发动机的转子系统扮演着重要的角色,如果在运行过程中出现预期之外的故障会造成严重的后果。为了预防这类事件,采用转子的振动信号作为目标信号,对振动信号进行智能基函数分析,采用支持向量机分类器测试所提取的智能特征。实验表明,该方案的分类精度达到95.6%,是针对航空发动机转子系统故障诊断的一种有效的特征提取方法。     

An automotive engine calibration system using microcomputer

An automotive engine calibration system has been developed to aid in development and evaluation of a control algorithm for electronic spark advance. It consists of the programmer, controller, and measurement units. Given the spark advance and the dwell time in the form of function subroutines written in BASIC, the programmer unit makes the advance and dwell tables as a function of engine speed and load. Referring to these tables, the controller unit operates the engine under calibration. The measurement unit measures the resultant engine performance and anlayzes the control algorithm. This process is repeated until the optimum algorithm is reached. A few test examples are also presented to demonstrate the system capability. This system features an easy operation and an accurate calibration.     

发动机高能直接点火控制技术设计

针对发动机电子点火系统的性能要求,以MC9S12DP256微控制器为核心,通过分析点火时序控制方法,设计点火控制程序,结合外围硬件设备,设计了六缸发动机高能直接点火系统。结果表明,利用MC9S12DP256微控制器的逻辑运算能力和定时控制功能,六缸发动机高能直接点火系统获得了精确、可靠的点火时序控制性能,使发动机电子点火系统获得了新发展。     

Virtual world control system using sensed information and adaptation engine

The sensed information (e.g., temperature, humidity, light intensity, gas intensity) obtained from a user's vicinity plays an important role in the generation of environmental changes, the main character's reactions, and in storyline changes in the virtual world. In this paper, a method is proposed to transform sensed information from real world to standardized XML instances and to control virtual world objects. The sensed information from the real world is transformed into XML instances standardized by MPEG-V Part 5 (Data formats for Interaction Device) schemes and then delivered to a Real-to-Virtual (RV) adaptation engine. The engine generates another XML instance standardized by MPEG-V Part 4 (Virtual world object characteristics) that describes the control information of avatars and objects in the virtual world. The system is demonstrated by a real-world mock-up equipped with a sensor set and a virtual space realized in Second Life.     

热成像系统的NETD测试分析

总结了目前国内外热成像整机测试系统中常用的两种NETD测试方法.分析了NETD测试模型,比较了两种测试方法在处理非线性视频图像输出中的差异,选取测试精度、重复性更高的信号传递函数(SiTF)测试方法作为实验方法.对同一热成像系统在NETD测试中测试结果存在较大差异的现象进行了分析.重点针对自动增益亮度、图像增强、伽马矫正、高频滤波4种常见非线性处理方式对NETD测试结果的影响,提出了相应的测试说明及解决方案,为获得准确、可重复的NETD测试结果提供了有效的手段.     

纯电动汽车热管理系统的研究

随着世界各国对环境问题的日益重视,纯电动汽车已受到社会各界的广泛青睐,而电动汽车的发展,很大程度上受电池热管理系统、电机和电机驱动热管理系统、空调热管理系统三大系统技术成熟度的制约.本文将从结构布置和控制方式方面研究讨论,提供建议,以减少电池能耗,增加续航里程、提升整车可靠性和舒适性,希望能为EV热管理系统设计提供借鉴和参考.     

Human motor control: learning to control a time-varying, nonlinear,many-to-one system

Human motor control has always presented a great challenge to both scientists and engineers. It has presented most of the problems they have found difficult to handle and manipulate, which is a consequence of it being a distributed, nonlinear, time-varying system with multiple degrees of freedom that include redundancy on many levels. In recent years, the fast development of computers and the emergence of the new scientific field of neural computation have enabled consideration of complex, adaptive, parallel architectures in the modeling of human motor-control performance. In this paper, some of the models that have been used in the study of motor control are reviewed, and some open questions are formalized and discussed. The main topics are adaptive and artificial neural-network control, parameter estimation, nonlinear properties of the muscles, and parallelism and redundancy     

基于PCI的某发动机试车数采系统的实现

介绍了一种基于PCI总线的某发动机试车数据采集系统的硬件设计与实现。系统以3种高速数据采集卡为硬件平台,以模拟传感器信号通过该采集系统进行系统测试,实现发动机试车数据高速采集、传输和存储。经试验,系统具有高速、可靠和经济实用等特点。     

基于紫外探测的发动机点火均衡测试系统设计

针对航空活塞发动机点火均衡性目视检查时肉眼判别存在缺陷漏检等差错隐患,结合紫外探测技术和虚拟仪器技术设计了四缸航空活塞发动机点火强度均衡性测试系统。系统通过四通道紫外探测器探测发动机点火辐射的紫外光子并将其转换为脉冲电信号,通过多通道数据采集卡采样后传送到计算机完成紫外辐射强度计算。对某待修磁电机点火系统进行测试,准确的检测出点火系统各电嘴点火强度的不均衡性,能够为点火系统故障排除提供可靠的技术依据。     

一种优化的微测热辐射计热学参数性能测试分析方法

优化的微测热辐射计热学参数的测试方法,与传统测试方法相比,能够实现热导和响应时间的精确测量,克服热学参数评估依赖仿真的缺陷,且该方法易于实现,工程应用性强.通过对研制的微测热辐射计性能进行相应的测试,确定了该测试方法准确、可靠.     

火电机组一次调频逻辑优化与试验分析

对火电机组一次调频系统的构成、特点等进行了分析,对机组一次调频逻辑优化与试验方法及数据进行了阐述和分析,对于规范机组一次调频试验,改善提高机组一次调频性能,满足电网一次调频运行技术指标要求具有重要意义。     

基于非线性控制方法的AQM算法

首先利用非线性控制方法中的积分反步法设计了一种AQM算法,接着使用非线性控制方法中的模糊滑模变结构控制方法进行AQM算法的设计.仿真结果表明,与积分反步法相比,基于模糊滑模变结构控制的AQM算法性能上优于基于积分反步法的AQM算法.与基于线性控制方法的PID控制方法相比,基于积分反步法的AQM算法性能上优于基于PID控制的AQM算法.     

基于FPGA的电压控制测试系统实现

介绍一种基于FPGA的电压控制测试系统。系统通过FPGA完成和上一级系统的通信,接收命令和数据、转化命令和数据以控制DA和AD的工作,实现对电路的输出电压控制和测试。通过Verilog语言编写逻辑程序,在FPGA中转化数据为串行,输出至DA以对电路施加激励,控制电路输出电压;然后控制AD采样硬件电路输出,并把采样数据转...     

左心室转子多路测试与控制系统

在工业生产和科学技术研究的各行业中,常常利用PC或工控机对各种数据进行采集.数据采集技术是信息科学的重要分支,是传感器、信号获取、存储与处理等信息技术结合.左心室转子位移多路测试系统是一种由4个部分构成的系统,包括电涡流传感器多路数据采集,A/D转换,高速的处理芯片DSP,12864液晶显示,多路DA功率驱动.主要是通过电涡流传感器采集信号,利用A/D转换器采集人工心脏转子位移信号,再通过PID实现对系统的控制,并且将多路采集的数据在12864液晶显示屏上直观的显示出来.     

视讯系统中高性能存储管理的实现

视讯系统中,收发双方利用网络队列来缓存媒体数据包,每个队列占据一定大小的存储空间,如何高效率的管理这段存储空间对于视讯系统的性能来说至关重要。文章首先介绍了高性能存储管理策略的关键技术及利用存储管理应用解决若干实现问题;然后描述策略的具体实现,包括存储空间的组织结构,分配、释放媒体数据包的操作流程;最后通过实验分析其相对于FIFO策略的优化效果。     

An analytical circuit based nonlinear thermal model for capacitor banks

The thermal couplings among capacitors in a bank could significantly alter the reliability performance compared to a single capacitor. The impact of thermal coupling is becoming stronger for high power density systems due to more stringent constraint in volume. Prior-art studies take into account the thermal coupling effects of a capacitor bank by either Finite Element Method (FEM) or experimental characterization, which are case dependent and time-consuming. This paper proposes a nonlinear mathematical model for capacitor banks based on physics of thermal conduction, convection, and radiation. A simplified version of the model is also obtained and represented by an RC circuit network, which enables computational-efficient thermal stress modeling. The proposed models are convenient to use to support model based sizing of capacitor banks and is scalable for multi-cell rectangle layout. A case study with experimental testing is discussed to verify the accuracy of the models.