BabelFuse data fusion unit with precision wireless clock synchronisation

A significant issue encountered when fusing data received from multiple sensors is the accuracy of the timestamp associated with each piece of data. This is particularly important in applications such as Simultaneous Localisation and Mapping (SLAM) where vehicle velocity forms an important part of the mapping algorithms; on fastmoving vehicles, even millisecond inconsistencies in data timestamping can produce errors which need to be compensated for. The timestamping problem is compounded in a robot swarm environment due to the use of non-deterministic readily-available hardware (such as 802.11-based wireless) and inaccurate clock synchronisation protocols (such as Network Time Protocol (NTP)). As a result, the synchronisation of the clocks between robots can be out by tens-to-hundreds of milliseconds making correlation of data difficult and preventing the possibility of the units performing synchronised actions such as triggering cameras or intricate swarm manoeuvres. In this thesis, a complete data fusion unit is designed, implemented and tested. The unit, named BabelFuse, is able to accept sensor data from a number of low-speed communication buses (such as RS232, RS485 and CAN Bus) and also timestamp events that occur on General Purpose Input/Output (GPIO) pins referencing a submillisecondaccurate wirelessly-distributed "global" clock signal. In addition to its timestamping capabilities, it can also be used to trigger an attached camera at a predefined start time and frame rate. This functionality enables the creation of a wirelessly-synchronised distributed image acquisition system over a large geographic area; a real world application for this functionality is the creation of a platform to facilitate wirelessly-distributed 3D stereoscopic vision. A ‘best-practice’ design methodology is adopted within the project to ensure the final system operates according to its requirements. Initially, requirements are generated from which a high-level architecture is distilled. This architecture is then converted into a hardware specification and low-level design, which is then manufactured. The manufactured hardware is then verified to ensure it operates as designed and firmware and Linux Operating System (OS) drivers are written to provide the features and connectivity required of the system. Finally, integration testing is performed to ensure the unit functions as per its requirements. The BabelFuse System comprises of a single Grand Master unit which is responsible for maintaining the absolute value of the "global" clock. Slave nodes then determine their local clock o.set from that of the Grand Master via synchronisation events which occur multiple times per-second. The mechanism used for synchronising the clocks between the boards wirelessly makes use of specific hardware and a firmware protocol based on elements of the IEEE-1588 Precision Time Protocol (PTP). With the key requirement of the system being submillisecond-accurate clock synchronisation (as a basis for timestamping and camera triggering), automated testing is carried out to monitor the o.sets between each Slave and the Grand Master over time. A common strobe pulse is also sent to each unit for timestamping; the correlation between the timestamps of the di.erent units is used to validate the clock o.set results. Analysis of the automated test results show that the BabelFuse units are almost threemagnitudes more accurate than their requirement; clocks of the Slave and Grand Master units do not di.er by more than three microseconds over a running time of six hours and the mean clock o.set of Slaves to the Grand Master is less-than one microsecond. The common strobe pulse used to verify the clock o.set data yields a positive result with a maximum variation between units of less-than two microseconds and a mean value of less-than one microsecond. The camera triggering functionality is verified by connecting the trigger pulse output of each board to a four-channel digital oscilloscope and setting each unit to output a 100Hz periodic pulse with a common start time. The resulting waveform shows a maximum variation between the rising-edges of the pulses of approximately 39¥ìs, well below its target of 1ms.

单片机在定时数据采集器上的应用

本文介绍了一种自制单片机多通道数据采集及处理小系统。将其用在波浪能转换装置上，定时测量装置的发电量、电压、电流等。被测数据存放在带电保护的RAM内，系统配置RS232接口，与IBM微机通讯，便于采集的数据作进一步处理。

基于TCP/ IP 协议的CSR离子泵电源远程监控软件系统设计

This paper discuss a Ion-pump Power Supply control system making use of RS232 series bus and Intranet.The system s hardware VAC800 is composed of MSP430F149 mixed-signal processors produced by TI and UA7000A network model.MSP430F149 has advantages of ultra-low-power and high-integration.The Ion-pump Power Supply control system has the characteristics of strong function,simple structure,high reliability,strong resistance of noise,no peripheral chip,etc.Visual studio 2005 is used to design the system s softwa...中文文摘：论述了通过RS-232总线和Intranet网络,来实现对远端的离子泵电源的监测与控制。系统硬件VAC800由TI公司的MSP430F149混合信号处理器和UA7000A网络模块构成。MSP430F149具有超低功耗和高集成度等优点,利用它构建的离子泵电源监控系统功能强大,结构简单,可靠性高,抗干扰能力强。系统软件采用visual studio 2005设计。本监控系统能够很好地完成对加速器离子泵电源监视与控制。

应用于HIRFL-CSR中的RS485通讯路由器

本文介绍了为适应HIRFL-CSR(兰州重离子加速器冷却储存环)工程自动化控制现场的通信要求而自主研发的一种通信设备,以及系统硬件电路设计、控制软件设计、工作方式和特点。此设备可快速组建RS485通信网络并且接入以太网,兼容Ethernet、RS232和RS485通信标准协议,特别是增加了光纤接口方便地接入工业光纤通信网络,进一步扩展了其使用范围。此设备在HIRFL-CSR加速器和储存环控制系统中被广泛使用,在使用中表明可满足系统自动控制通信要求。此设备具有实现简单、易于维护、可扩展性好及成本低廉等特点,在其它自动化工业控制领域也有一定的推广空间。

微控器在试验中实现的前端设备远程复位控制

介绍了用微控制器实现的兰州重离子加速器冷却储存环工程(HIRFL-CSR)束流注入线电源控制系统中前端网关的远程复位控制,其中包括用AT89C51单片机实现的前端智能电路模块、AT89C51单片机的运行程序、中心控制室通讯应用程序。该系统成功实现了科研中束流调节人员可以在不用到现场的情况下远程复位前端发生死机的网关。该系统工作稳定,抗干扰强,没有发生误操作,实现了科研当中对前端设备的远程控制,大大提高了科研工作人员的工作效率。

应用于HIRFL-CSR控制系统中的光纤通信路由器

介绍了专门针对国家重大科学工程HIRFL-CSR控制要求而设计开发的光纤通信路由器。包括设计原理、硬件组成及应用范围。该光纤路由器具备RS232、RS485、标准以太网接口和光纤接口,可建立上述接口设备与光纤接口设备的光纤通讯网络。在工程中应用这种交换机解决了通信干扰等问题,满足了工程控制要求。

电子加速器调压器自控系统

为满足我所电子加速器的控制要求而自主研发了调压器控制系统。该系统的设计包括系统硬件设计、电路设计、工控机和单片机控制软件设计。控制功能模块采用RS232和RS485通信接口,可以根据需要选装光纤接口建立工业光纤通讯网络,进一步扩展使用范围并提高通讯系统的可靠性。实际应用表明,系统在无人值守情况下可自行调整并稳定调压器输出电压,可满足电子加速器调压器的精确控制和自动控制要求。该系统依据通用设计原则,具备实现简单、易于维护、可扩展性好及成本低廉等特点,在其他工业控制自动化领域也有一定的应用价值。

两种在HIRFL-CSR中使用的光纤通信适配器

介绍了两种针对HIRFL-CSR控制特点,自主开发设计的光纤通信适配器。包括设计思路、工作原理、硬件组成及应用范围。如何利用这两种光纤适配器远程控制具备RS232或RS485接口的仪器设备。在工程中应用这两种适配器和光纤替代RS485总线解决了通信干扰问题,满足了工程控制要求。

总线控制器的设计及其在CSR控制系统中的应用

HIRFL-CSR(兰州重离子冷却储存环)是国家“九五”重大科学工程之一。CSR控制系统是保证CSR正常运行的重要环节。这是一个基于以太网的分布式控制系统，它由两部分组成：总体控制服务器系统和前端控制服务器系统。 本文介绍了应用于CSR前端控制系统中的嵌入式总线控制器。首先介绍了嵌入式总线控制器的硬件设计方案。系统以32位高速双以太网处理器JUPITER为核心。JUPITER是一款低成本、高性能、建立在以太网系统基础之上的处理器。该系统的外阴电路主要包括存储模块、接日模块、总线控制模块。接口模块有RS485、RS232和网络接口电路。其次论述了嵌入式操作系统uClinux的体系结构以及uClinux与标准Linux的不同之处。论文从uClinux的内核结构出发，讨论了源代码的组织结构，概括分析了uClinuxlj勺内存管理、进程管理。最后介绍了uClinujx统的移植方法和应用实现。uClinux移植主要包括引导装载程序、uClinux内核和文件系统三个部分。在引导装载程序的移植过程中，论文重点给出了一种固化引导装载程序的方法；在uClinux内核移植中，讨沦了交叉编译环境l为建立和uClinux内核配置方法，总结了uClinux内核移植的层次结构和具体的移植过程。沦文通过对嵌入式处理器的分析，以及对嵌入式操作系统移植的探讨，展示了嵌入式系统开发的核心技术，对眠入系统的开发应用具有一定的实际意义。

基于ARM Linux的门禁系统的设计与实现

门禁系统主要负责对出入通道进行管制，是社区楼宇安全监控系统的一部分。传统的门禁系统通常采用密码识别、卡片识别的方式进行验证，由于密码、卡片容易被盗用、丢失，系统安全性不高。在通信方式上传统门禁系统通常采用RS485或者RS232连接，传输距离、速度和连接终端数均受限制。本文提出的人像识别门禁系统解决方案采用ARM-Linux系统平台，依靠社区宽带综合业务网的传输和存储能力，结合密码、RFID和人像识别三种识别方式，利用网络技术和生物识别技术达到识别率高、响应速度快、扩展能力强的要求，并能够与驻地网的其它业务集成，提供业务级的联动服务。此外，该门禁系统还支持用户使用电话开门，由服务器完成对用户来电的识别和防伪验证。本文工作的主要贡献是：参与了ARM-Linux系统的裁剪、移植和声卡驱动的修改；建立了ARM-Linux交叉编译环境；完成了门禁前端软件系统的整体设计和实现；完成了服务器软件电话呼叫响应子系统的设计。

CAN总线及USB技术在路桥收费系统中的应用研究

本文以中国科学院沈阳自动化研究所自动化装备研究室的项目——路桥收费系统为背景。首先阐述了路桥收费系统的组成结构，重点讨论了传统的收费控制子系统的构成和功能。然后在深入分析原有系统不足的基础上，本文提出了采用CAN总线技术和USB接口技术来构建一种全新的收费控制子系统的方法。并对这种方法进行了深入的研究，设计并实现了组成系统所需的核心器件，构成了原型系统，对系统的可行性进行了验证。 CAN总线是目前在中小型测控系统中应用非常广泛的总线之一，它非常适用于收费控制子系统中。USB接口技术是近几年来兴起的新型接口技术，它为外围设备与计算机的连接提供了一种方便、快捷的方法。在我们的系统中以基于USB的新型CAN适配卡代替了以往普通的CAN适配卡，为控制计算机联入CAN网开拓了新思路。 本文详细地阐述了系统中核心器件RS232/CAN、CAN/USB协议转换卡的设计与实现及原型系统的构建和测试方法。主要内容分为系统硬件的设计与实现、系统软件的设计与实现和测试系统的设计与调试三部分。具体包括了核心器件的设计原理、电子元器件的选择、电路原理图的设计、PCB板的制作、硬件的焊接与调试及协议转换卡的固件设计、驱动程序设计、上位机测试程序设计。最后利用所设计的软硬件构建了原型系统并进行了测试。

变速箱智能涂胶机系统设计及实现

目前变速箱涂胶主要采用人工作业，本项目是为实现了该类设备的自动化而研制的智能控制系统。本文根据株州齿轮厂提出的设计要求，在查阅大量有关文献基础上，分析了涂胶的全部工艺，设计并开发了经济实用数控涂胶机，符合国情，推动了我国变速箱自动化装配线的发展。本文完成了以下研究工作和创新性成果： 系统采用一种基于PC机和运动控制卡的开放式、模块化的智能控制系统方案，用运动控制卡和交流伺服组成闭环控制系统，实现了在线编程和运动控制的并行处理。 采用模块化的结构对涂胶机实行分层控制，涂胶机采用手动和自动两种工作方式，应用先进的示教方法实现涂胶机的开放性，并且对整个涂胶机实现实时监控以及智能保护。 论文提出了一种智能保护系统方案。通过胶嘴定位系统进行位置检测，利用红外传感器进行生产区域安全防护，对伺服报警信号进行监控和设计三重限位保护等方法，切实增强了系统的安全性和稳定性。 开发了数控系统的仿真器，使用户在涂胶前就可以看到胶线的轨迹，防止发生浪费。同时开发了数控系统的执行控制器。实现了数控程序的编辑和管理，以及通过RS232串行接口接收用户离线编写的数控程序。在智能涂胶机上进行实际涂胶，涂胶效果良好。 课题开发的涂胶系统的速度为4.8米/分钟，涂胶精度为0.01毫米，已经远远超过了现场要求的涂胶精度，而且在制造和维护成本上占有很大优势，获得了用户好评。

Implementação de espalhamento espectral por seqüência direta

O presente trabalho tem como objetivo a descrição e apresentação dos resultados obtidos através de simulações e implementação da técnica de modulação por espalhamento de espectro (Spread Spectrum). Maior ênfase será dada à técnica de espalhamento por seqüência direta (DSSS), dada a larga utilização nos sistemas de comunicação correntemente em uso, assim como serão apresentados os resultados de simulações e implementação de um sistema de comunicação Spread Spectrum utilizando o microcontrolador PIC 16F876 para a interligação de computadores padrão PC via interface serial RS232.

Performance evaluation on electronic control systemsfor field sprayers using programmable logic controllers

The aim of this study was to develop a laboratory method for time response evaluation on electronically controlled spray equipment using Programmable Logic Controllers (PLCs). For that purpose, a PLC controlled digital drive inverter was set up to drive an asynchronous electric motor linked to a centrifugal pump on a experimental sprayer equipped with electronic flow control. The PLC was operated via RS232 serial communication from a PC computer. A user program was written to control de motor by adjusting the following system variables, all related to the motor speed: time stopped; ramp up and ramp down times, time running at a given constant speed and ramp down time to stop the motor. This set up was used in conjunction with a data acquisition system to perform laboratory tests with an electronically controlled sprayer. Time response for pressure stabilization was measured while changing the pump speed by +/-20%. The results showed that for a 0.2 s ramp time increasing the motor speed, as an example, an AgLogix Flow Control system (Midwest Technologies Inc.) took 22 s in average to readjust the pressure. When decreasing the motor speed, this time response was down to 8 s. General results also showed that this kind of methodology could make easier the definition of standards for tests on electronically controlled application equipment.

IEEE 1451-based multi-interface module (I2M) for industrial processes automation

This paper describes the implementation of a multi-interface module (I2M) for automation of industrial processes, based on the IEEE1451 standard. Process automation with I2M can communicate through either wires or using wireless communication, without any hardware or software changes. We used FPGA resources to implement the I2M functions FPGA, with a NIOS II processor and ZigBee communication system (IEEE802.15), as well as RS232 serial standard. Part of the project was done in the SOPC Builder environment, which gave the designer flexibility and speed to implement the NIOS II-based microprocessor system. To test the I2M implementation, a didactic Industrial Hydraulic Module (MHI-01) was used to simulate two industrial processes to be controlled by the system proposed.