基于PICl6F873的红外数字转速表的设计

针对普通转速表存在体积大、精度低等问题。给出以单片机为核心的红外转速表的组成系统结构及设计方法。论述信号检测、数据保护、时间读取、参数选择和以PICI6F873单片机为核心实现转速、日历时钟等电路的组成原理及程序设计分析。该系统可通过功能扩展广泛应用到其他领域。     

基于AT89C51的数字集成电路测试仪的设计

以单片机AT89C51为核心,通过串口与下位机通信,设计了一种通过电脑操作,单片机控制的数字集成芯片测试仪,该系统能对常用的20种74系列数字集成电路作出准确快速的功能检查。系统主要由控制及测试、上位机通信两部分组成。控制及测试部分以单片机AT89C51为核心组成,上位机通信部分由Vb编写的可视化用户界面和电平转换电路MAX232组成。     

基于FPGA的汽车转速表校验仪的设计

本设计根据直接频率合成器DDS的工作原理,在FPGA内部实现模拟汽车转速传感器输出信号,然后利用该信号驱动汽车转速表实际值的显示,最后再通过与转速理论计算值比较来完成对汽车转速表校验。该设计核心模块是脉冲产生模块,利用FPGA自身的技术优势,运用科学先进算法来完成此模块。以此来达到比基于单片机的传统转速校验仪更优的性能。     

自制通用转速表

本文介绍一个项目开发实例．为广大单片机爱好者．特别是51单片机爱好者提供一种设计思路。本文通过介绍基于单片机AT89S52的转速表设计,使读者熟悉单片机测量频率的方法。主要内容包括：光电转速传感器工作原理,显示控制芯片CH451L的工作原理,单片机硬件电路设计、软件程序及流程图、硬件制作与调试。     

新型高压断路器性能检测仪的研制

文章阐述了一种以８０９８单片机为核心的在新型高压断路器性能检测仪的设计，说明了其硬件组成及软件的内容。     

单片机无线通信系统的设计与实现

介绍了以STC89C52单片机为控制核心,以SPI总线接口为主从连接方式,选取nRF24L01为无线模块的的单片机无线数据通信系统。主要介绍了系统组成、硬件电路及软件设计。该系统能可靠稳定的实现无线数据传输,也便于扩展,应用于各个无线通信领域中。     

8098单片机在温度巡测仪中的应用

本文介绍了一种以８０９８单片机为核心的６４路温度巡回／定点检测仪的硬件系统组成及软件程序设计。     

GPS车辆监控系统车载单元的设计

介绍了基于GPS技术的车辆监控系统的组成原理及结构，给出了以主控单片机为核心的车载单元组成及具体软硬件实现方法，并讨论了在不同硬件条件对不同车辆的设计思想。     

MB90F549单片机在井下管柱状态检测系统中的应用

本文介绍了富士通公司MB90F540／545系列单片机的性能特点,阐述了以MB90F549为核心的井下管柱状态检测系统组成及基本功能,介绍了MB90F549单片机存储区结构及数据压缩存储技术,提出了低功耗的实现方法,描述了软件功能模块组成及流程图。基于MB90F549单片机的井下管柱状态检测系统性能可靠,有较大的实用价值。     

基于单片机的电缆测试仪的设计

介绍了以电缆固有的电参数为检测对象，以单片机为处理核心的电缆测试仪的设计原理及其基本组成。应用该仪表可快速检测电缆线路的频率特性，判断并定位电缆的断、短、混线故障的性质及故障点。     

Use of a Torque Motor as a Tachometer

Circuitry is described whereby an Aeroflex linear torque motor, used to deliver precise torque waveforms in the study of primate motor control, can be used as its own tachometer. This circuitry allows manipulanda using this type of motor to be made smaller, and with less moment of inertia, than would be possible with the installation of a separate tachometer unit.     

Improved digital tachometer with reduced sensitivity to sensornonideality

A constant sample-time digital tachometer, similar to Ohmae's “M/T” method, is described. This system is capable of accurate determination of shaft velocity, based on the outputs of an incremental encoder. Previous error analyses of such devices which consider only the asynchronous nature of counter operation are shown to be specious. It is highlighted that sensor nonidealities, including variations in the transition locations from their nominal values and phasing errors between encoder channels, can produce much larger tachometer errors. An estimate is made of the actual RMS output error, based on a simple encoder model and simplified analysis. It is shown that the error can be significantly reduced by operating four sub-circuits in parallel, each dealing with either a low-to-high or high-to-low transition of a single incremental encoder signal. A field-programmable-gate-array/digital-signal processor-based practical implementation is described. Both simulation and experimental results are presented which confirm the utility of the enhanced digital tachometer     

基于霍尔传感器的直流电机转速测量系统设计

本文介绍了基于霍尔传感器,采用单片机C8051F060控制的直流电机转速测量控制系统的工作原理及软硬件设计方法.通过7279实现在LED上直观地显示电机的转速值.此外,还可以根据需要调整控制电机的转速.测试结果表明,该转速测量系统满足设计要求,并且具有硬件结构简单,性价比较高,易于调节电机转速及系统性能稳定等优点.     

基于霍尔传感器的直流电机转速测量系统设计

本文介绍了基于霍尔传感器,采用单片机C8051F060控制的直流电机转速测量控制系统的工作原理及软硬件设计方法.通过7279实现在LED上直观地显示电机的转速值.此外,还可以根据需要调整控制电机的转速.测试结果表明,该转速测量系统满足设计要求,并且具有硬件结构简单,性价比较高,易于调节电机转速及系统性能稳定等优点.     

二阶系统性能改善的Matlab仿真分析

掌握系统性能随参数变化的规律性,对于分析和设计系统是十分重要的。在二阶系统中,一般采用比例一微分控制和测速反馈控制改善其性能。这里利用Matlab对校正前后的系统进行仿真,分析两种方法对二阶系统性能改善的效果。同时通过实例计算,得出比例一微分控制和测速反馈控制均可使系统快速性和稳定性提高。仿真结果表明,两种方法均可显著改善二阶系统的性能。     

Elimination of time delay from shaft-position or speed transducer outputs

The output of angle transducers, including those used for synchronous-generator rotor angles, need to be filtered to give a d.c. signal, and a filter limits the transient response. The letter shows that, if the speed is also available as a d.c. signal, for example from the filtered output of some form of tachometer, the filter delay can be eliminated by mixing the angle and speed signals in proper transient and steady-state proportions. This mixing requires an operational amplifier. A delay-free speed signal can also be achieved, provided that a separate accelerometer signal is available.     

Normal and emergency control of a string of vehicles by fixed reference sampled-data control

A fixed reference control scheme for automated highways is proposed. Each vehicle controls itself; thus multiloop feedback is avoided. A simple proportional-integral-derivative (PID) controller is selected from many alternatives. For emergency stopping, a PI controller using a tachometer on a braked wheel can bring a vehicle with rubber tires to a controlled skid-free stop.     

Step-Rate Modulation and Piecewise Linear Control to Adapt Stepping Motors to Low-Bandwidth Servos

Stepping motors provide precise digital control of speed, without tachometer feedback, and have no brushes to wear. This makes them useful in feedback control systems. However, the stepping motor's natural resonance and its requirement for limited acceleration can cause sustained vibrations and overshoots. Modulating a stream of stepping pulses at twice the resonance frequency with special sequences of ones and zeros overcomes resonance problems. Using a piecewise linear function relating the target stepping rate to the position error prevents saturated overshoots. This function can be generated automatically from more basic parameters of the control system.     

CS289指针式转速表驱动电路研究

CS289是指针式转速表专用驱动集成电路 ,本文通过对该电路的特性分析 ,就其使用中的技术问题展开了讨论     

基于FPGA和PCI的高精度测速板卡的设计与实现

经典的码盘数字测速方法有M法、T法、M/T法,但都有一定的不足。为了克服原有方法的不足,设计并实现了一种在较大速度范围都有良好精度和良好快速性的测速方法。电路采用FPGA实现,测速得到的数据通过PCI总线从设备控制器实现与控制计算机通信。从而根据实际传输的需要,简化了PCI从设备控制器,实现了PCI总线I/O普通读与猝发读数据的功能。