旋转体转动特性测试系统的研制

通过一种测试系统的研制,介绍了一种新型微控制器的应用,提出了利用片内高精度ADC简化传感器接口电路,并利用片内DAC做信号调理电路的电压基准,实现测量基准的自适应的方法。经实验验证,这种接口设计达到了预期的目的。     

Optimal NT policies for M/G/1 system with a startup and unreliable server

This paper studies the control policies of an M/G/1 queueing system with a startup and unreliable server, in which the length of the vacation period is controlled either by the number of arrivals during the idle period, or by a timer. After all the customers are served in the queue exhaustively, the server immediately takes a vacation and operates two different policies: (i) the server reactivates as soon as the number of arrivals in the queue reaches to a predetermined threshold N or the waiting time of the leading customer reaches T units; and (ii) the server reactivates as soon as the number of arrivals in the queue reaches to a predetermined threshold N or T time units have elapsed since the end of the completion period. If the timer expires or the number of arrivals exceeds the threshold N, then the server reactivates and requires a startup time before providing the service until the system is empty. Furthermore, it is assumed that the server breaks down according to a Poisson process and his repair time has a general distribution. We analyze the system characteristics for each scheme. The total expected cost function per unit time is developed to determine the optimal thresholds of N and T at a minimum cost.     

基于虚拟平台的温度监测系统

通过基于Proteus和MPLABIDE软件虚拟平台进行温度监测系统的前期开发,采用LM35电压型温度传感器采集温度数据,并经信号调理后传送至PICl8F4520单片机A／D模块,单片机处理A／D模块转换结果,在LCD上显示温度信息,在温度超限时驱动报警电路工作。仿真结果表明,所设计的系统能有效地实现0～100℃范围内温度的准确监测,节约开发成本。     

基于PIC单片机PWM模式的音乐播放系统设计

针对51单片机I/O定时翻转电平驱动蜂鸣器方法存在的缺点,以PIC单片机为核心控制元件,利用内部PWM硬件资源,实现了简易音乐播放系统设计。通过改变PWM端口输出脉冲信号频率及脉宽,驱动蜂呜器发出不同音调,并结合单片机内部定时器中断控制音调高低及节拍长度,此外可通过4×4矩阵键盘实现简单音乐弹奏。实验结果表明,该系统硬件电路简单,软件占用CPU时间少,易控制音乐音调及节拍,音色纯正,具有一定的实用与参考价值。     

基于飞思卡尔微处理器的数字传感器设计

介绍了基于飞思卡尔MC9S08QE8微处理器的数字传感器的组成,详细分析了其工作原理,给出了信号调理模块、AD转换模块和RS-485通信模块的设计与实现方式。该数字传感器体积小、抗干扰能力强、精度高,满足了设计要求。     

基于单片机的全数字化送丝机电源

研究了基于平均PID控制的气体保护焊机用全数字化送丝机电源.送丝机电源主电路采用可控硅单相全波整流电路,结构简单,成本低,运行可靠.设计了基于STC12C5616AD单片机的送丝机电源全数字化控制系统,其中硬件电路包括同步信号产生电路,单片机最小系统,光电隔离驱动电路等;软件程序包括同步信号判断程序,平均PID程序,定...     

基于PS/2协议的16×8矩阵键盘设计

本文采用STC89C58RD+单片机设计了16×8矩阵键盘,实现了PS/2协议,键值修改方便,可应用于各种基于计算机的控制系统。单片机通过定时器中断进入键盘扫描程序,翻转扫描查询法查询矩阵键盘中是否有键值变化。如果有键被按下,则通过查询键值表将该键对应的通码发出;如果有按键抬起,则将该键对应的断码发出。该矩阵键盘可扫描128个按键,满足绝大多数系统需求。所有键值存储在一张表中,对于不同的系统,只需要制作外形不同的矩阵键盘电路,并通过修改键值表即可轻松移植。     

高速行驶车辆位置信息快速检测系统设计

设计了基于地感线圈的高速公路车辆位置信息检测器,采用具有输入捕捉和定时器功能的单片机,捕捉振荡信号频率的变化判断车辆位置。系统通过单片机定时模块获取多个脉冲的持续时间,通过增加脉冲数的方式增加计时时间,提高位置信息检测的精度。为了提高检测方法的鲁棒性,系统在计数持续脉冲总时间的过程中,也在实时测试每个脉冲的时间,去除脉冲时间过短的高频干扰信号。设计了自动复位功能,如若在设定时间内检测不到车辆到来,则通过外部电路使单片机复位,防止系统工作异常。系统经模拟试验测试表明,设计的振荡电路能够产生稳定的振荡信号,当模拟车辆通过时,系统能较快响应车辆位置变化。     

基于Zig Bee技术的智能调光开关设计

根据智能家居的发展方向和用户需求,设计了一种基于Zig Bee技术的智能调光开关系统。设计方案采用新一代SOC芯片CC2530作为系统的无线收发模块,使得模块具备成本低、功耗小、高可靠、自组网、超视距通信等能力。采用ARM7嵌入式处理器LPC2132作为系统的微控制器模块,简化设计提高可靠性,使得系统具备分布处理能力。通过检测市电的过零点,开启延时定时器,定时器超时后触发双向可控硅导通的时间点来达到调光的目的。结果表明:本设计能够使家居照明系统更具可控性,更节能,使得家居环境更加舒适。     

Optimizing smart manufacturing systems by extending the smart products paradigm to the beginning of life

The research objective of this work is to enhance the perception of, sensing in, and control of smart manufacturing systems (SMS) by leveraging active sensor systems within smart products during the manufacturing phase. Smart manufacturing utilizes rich process data, usually collected by the SMS (e.g., machine tools), to enable accurate tracking and monitoring of individual products throughout the process chain. However, until now, the to-be-manufactured product itself has not contributed to the sensing and compilation of product and process data. More specifically, data measured from the product’s structure during its own fabrication. In this paper, we discuss and evaluate the opportunity to actively use the capabilities of smart products within a SMS in terms of technical and economic feasibility. This opportunity emerged only recently with the advancements in smart products engineering. In this research, we developed a smart product prototype and evaluated it on a SMS testbed (CPlab) with eight distinct, fully-connected manufacturing processes. The results of the conducted experiments show the possibility to uniquely identify two distinct ‘fingerprints’ of manufacturing processes solely based on data provided by sensors within the smart product itself. The sensor data was collected directly from the smart product before manufacture was completed, yet after the intended sensor functionality during the product’s use phase was activated. The capability to automatically, accurately, and reliably identify process signatures and even inform the optimization of manufacturing parameters creates new opportunities for improvements in quality, scheduling, and seamless transparency across the whole value chain.     

Hysteresis correction of tactile sensor response with a generalized Prandtl–Ishlinskii model

Tactile sensors are basically arrays of force sensors. Most of these force sensors are made of polymers or conductive rubber at lower cost, especially in the case of large area low-medium resolution tactile sensors. The consequence of such a decrease in cost and complexity is a worsening in performance. Hysteresis and drift are two main sources of error. Other tactile sensors do not present such limitations per se, however they are covered by a protective elastic layer in their final location and this covering can also lead to limitations. This paper presents a method to reduce the error caused by hysteresis in tactile sensors. This method is based on the generalized Prandtl–Ishlinskii model that has been applied to characterize hysteresis and saturation nonlinearities in smart actuators. The approximation error depends on several parameters as well as on the envelope functions that are chosen. Different alternatives are explored in the paper. Moreover, the model can also be inverted. This inverse model allows the force values to be obtained from the tactile sensor output while reducing the errors caused by hysteresis. In this paper the results of such an inversion are compared with other alternatives to register the data that do not compensate hysteresis. The average value of the hysteresis error measured in the experimental curve is 7.20% for an input range of 206?kPa, while this error is 1.51% following the compensation procedure. Since the implementation of tactile sensors usually results in the electronics being close to the raw sensor, and this hardware is also commonly based on a microcontroller or even on a FPGA, it is possible to add the algorithms presented in this paper to the set of compensation and calibration procedures to run in the smart sensor.     

A self‐reset ambient‐light sensor system for low‐temperature polycrystalline‐silicon active‐matrix displays

Abstract— A new digital ambient‐light sensor system has been designed and fabricated on a glass substrate using a conventional low‐temperature polycrystalline‐silicon (LTPS) technology. In the proposed system, analog‐to‐digital conversion (ADC) is performed in the time domain instead of the voltage domain and is combined with a light‐detection process. The proposed system employs self‐reset architecture and requires only one comparator for n‐bit digital output. Because the complex analog circuitry is eliminated from the system, it can be readily integrated on the glass substrate.     

线阵CCD信号采集与处理系统研究

介绍了一种线阵CCD信号采集和处理系统。利用仪表放大器对CCD输出信号进行滤波和放大,然后进行A/D变换。使用了双端口存储器,一组端口用于存储A/D转换结果,另一组实现单片机的访问。采用高速单片机提高数据处理速度,并完成较为复杂的算法以提高计算精度。CPLD用于驱动CCD和协调电路各部分的工作。实验表明该系统能从精度和速度两方面满足应用要求。     

基于PIC单片机的智能漏电火灾报警系统的设计

介绍了基于PIC16F877A单片机的漏电火灾报警控制系统的硬件组成和软件设计方法,采用了SPI总线方式实现单片机与各个功能模块之间的信号传递,通过VFD显示系统状态及故障信息.重点介绍了用单片机定时中断实时采样多组数据的设计方法,并给出了部分硬件原理图和定时中断采样程序流程图.实验表明,该系统稳定可靠,能提供实时准确的保护.     

A pseudoconservation law for a time-limited service polling system with structured batch poisson arrivals

We consider a cyclic-service queueing system (polling system) with time-limited service, in which the length of a service period for each queue is controlled by a timer, i.e., the server serves customers until the timer expires or the queue becomes empty, whichever occurs first, and then proceeds to the next queue. The customer whose service is interrupted due to the timer expiration is attended according to the nonpreemptive service discipline. For the cyclic-service system with structured batch Poisson arrivals (M^x/G/1) and an exponential timer, we derive a pseudoconservation law and an exact mean waiting time formula for the symmetric system.     

基于HT46R64的数字定时器设计

HT46R64型单片机内部集成了实时时钟,LCD驱动以及A/D转换外设等,是专为需要LCD和A/D转换的产品而设计的芯片。设计了基于HT46R64的定时器系统,定时为WEEKDAY方式,实验结果验证了设计的有效性和可行性,是一款性价比很高的产品。     

Exploring conflicts in rule-based sensor networks

This paper addresses rule conflicts within wireless sensor networks. The work is situated within psychiatric ambulatory assessment settings where patients are monitored in and around their homes. Detecting behaviours within these settings favours sensor networks, while scalability and resource concerns favour processing data on smart nodes incorporating rule engines. Such monitoring involves personalisation, thereby becoming important to program node rules on the fly. Since rules may originate from distinct sources and change over time, methods are required to maintain rule consistency. Drawing on lessons from Feature Interaction, the paper contributes novel approaches for detecting and resolving rule-conflict across sensor networks.     

一种基于薄膜铂电阻的风速测试仪的设计

本文介绍了一种基于热线热膜技术的风速测试仪.系统以单片机P89C51为核心,以薄膜铂电阻温度传感器Ptl00作为测量器件采集数据,ADC0809接收数据并进行模数转换,单片机处理数据,4位LED数码管显示测量风速值.文中对系统的软、硬件设计作J详细的介绍.通过利用此系统测量实际风速,测量下限低,成本低,显示分辨率达到0...     

A novel prebuffering scheme for IPTV service

The Internet Protocol TeleVision (IPTV) network utilizes the broadband IP network to provide users the TV service. Due to the limited bandwidth of the IP network, IPTV does not broadcast the content of all channels to its users. The channel zapping time (i.e., the delay between the time when the user switches to a new TV channel and the time when the content of the new TV channel is received by the user) and content miss (i.e., the content of the new TV channel arrives after the user switches to another TV channel so that the user did not watch the content of the new TV channel) significantly affect the QoS of IPTV service. This paper proposes Dynamic Prebuffering Scheme (DPS) that dynamically prebuffers the content of TV channels in the Home Gateways (HGs) based on the user’s behavior to reduce the channel zapping time and the content miss probability. A prebuffer timer is implemented in DPS to reduce the bandwidth consumption. Both the analytic model and simulation experiments are developed to investigate the performance of DPS. The simulation results show that the performance enhancements are bounded by the setup of the number of prebuffering channels and the prebuffer timer. Based on the performance study, the IPTV operators can properly set the number of prebuffered channels and the prebuffer timer to obtain good performance. Our study indicates that DPS can significantly reduce the channel zapping time and the content miss probability by slightly increasing bandwidth consumption.     

Needle-type in situ water content sensor with polyethersulfone polymer membrane

A needle-type water content sensor with a polyethersulfone (PES, poly(4-phenoxy-co-4-benzensulfone)) polymer membrane is proposed for the low-invasive, direct in situ measurement of plant water content (PWC). When the PWC sensor is inserted into a plant, the electrical impedance of PES is determined by the amount of absorbed water, which indicates the PWC. In situ measurement of PWC was successfully demonstrated for a strawberry plant (Fragaria × ananassa) and the application feasibility of the sensor to in situ PWC measurement for irrigation agriculture was verified.