嵌入式实时系统在移动机器人中的应用研究

介绍了基于uC/OS-II的嵌入式实时系统的设计方法和步骤,并就其在移动机器人控制系统中的实现进行了研究与讨论。嵌入式实时系统可以在满足系统实时性的同时简化控制软件的开发,并使功能复杂的智能控制软件设计成为可能。为移动机器人的进一步的智能化发展作了基础性研究。     

嵌入式实时操作系统分析

实时多任务操作系统（RTOS）是嵌入式应用软件的基础和开发平台。在从功能、性能模型等角度对实时操作系统进行分析的基础上,描述了抢占式任务调度和中断禁止时间与中断延迟事件的实现。对Linux的系统调用功能的分析,是研究Linux内核源码几个很好的入口点之一。     

基于DSP的实时多任务嵌入式系统

介绍TMS320C2812的BIOS内核,实现实时多任务操作,扩展外部时钟的接口电路和AT49BV162内部结构。结合TMS320C2812的功能,介绍DSP在嵌入式系统中如何对Flash进行数据的读写操作。     

基于DSP的实时多任务嵌入式系统

介绍TMS320C2812的BIOS内核,实现实时多任务操作,扩展外部时钟的接口电路和AT49BV162内部结构.结合TMS320C2812的功能,介绍DSP在嵌入式系统中如何对Flash进行数据的读写操作.     

新型嵌入式多媒体系统架构

为了解决传统嵌入式多媒体系统架构设计中耦合度高的问题,提出了前台-中间件-后台的新型设计架构,将Qt/Embedded作为前后台的中间桥梁,使系统具有低耦合高内聚的特性。同时,采用HTML作为前台设计语言,提高了开发效率。     

嵌入式实时音乐语音识别系统的实现

设计并实现了一种嵌入式实时音乐语音识别系统.叙述了音乐语音识别系统硬件结构、软件流程,建立了一种基于多频段能量曲线分割结合过零率来检测端点的新方法,实验结果表明,该系统对特定人的平均识别率在96%以上.     

Optimizing download time of embedded multimedia objects for Web browsing

Notoriously high delays in accessing Web pages loaded with massive multimedia objects are highly undesirable. Inspired by the requirements of news agencies and other information providers to include multimedia content in their pages, this paper proposes a new solution to the problem of minimizing the Web response time. We consider an environment that consists of a central multimedia repository and various sites physically dispersed. Our approach is based on simultaneous downloading of some of the embedded multimedia objects from the repository, and the rest from the regional servers. We propose a cost model to formalize the relative benefits of the proposed scheme, and design an algorithm that replicates multimedia objects so as to take advantage of concurrency in data transferring. An extensive simulation study evaluates the performance of the proposed replication policy under storage and processing capacity constraints, as well as with various network transfer rates. Comparisons are carried out with alternative schemes.     

Optimizing mobile multimedia using SIMD techniques

Demand for mobile video applications is growing today in wireless handheld platforms. Optimizing instruction set architectures and employing SIMD techniques is a logical approach towards attaining higher performance in mobile multimedia applications. Intel? Wireless MMX™ technology has been designed to accelerate mobile multimedia and applications processing in a power efficient manner. This paper provides an overview of Intel? Wireless MMX™ technology, a 64-bit Single Instruction Multiple Data (SIMD) coprocessor for the Intel? XScale? microarchitecture, and the key features of the architecture that specifically enhance the multi-media performance. Tools and techniques for optimization are also described. Nigel C. Paver has 13 years experience with the ARM architecture, and in the Intel PCA Components group in Austin, Texas, he is responsible for the architecture and implementation of multimedia coprocessors for the Intel XScale micro-architecture. He is also involved in product architecture and definition of Intel PCA processors. Before Intel, Nigel was one of the lead designers of the early AMULET asynchronous ARM microprocessors at the University of Manchester. He was also vice president in a startup company which used asynchronous design techniques to produce a low-power asynchronous DSP core. Nigel holds a Master of Science degree and Ph.D. in computer science from the University of Manchester and a Bachelor of Science degree in electronics from UMIST. Moinul Khan is a multimedia product architect at Intel Corporation PCA Components group. He is responsible PCA graphics and security architecture. His research interests are virtual prototyping, signal processing algorithms and architecture and communications networking. Before joining Intel he was a technology specialist and founding member of a startup at ATDC, Georgia. He worked on his doctoral research at Georgia Center for Advanced Telecommunications Technology at Georgia Institute of Technology. He received his B.Tech form Indian Institute of Technology and MSEE from Georgia Tech. He also worked as a research member for Canadian Institute for Telecommunications Research and Bell Communications Laboratories. Bradley C. Aldrich joined Intel in 1997 where he is currently an architect within the PCA Components Group. His current work includes the development of coprocessor instruction support in addition to image capture and display technologies for XScale based application processors. He was previously a member of the Intel/Analog Devices joint development architecture team responsible for video enhancements for the Micro Signal Architecture. Prior to that he was a video system architect in Intel's Digital Imaging and Video Division working on CMOS sensors, still cameras, and tethered PC based video peripherals. He has also worked as a device engineer for Motorola and as a test engineer for Tektronix. He received a BSEE in 1988 and MSEE in 1994 from the University of Texas at San Antonio.     

Optimizing mobile multimedia using SIMD techniques

Demand for mobile video applications is growing today in wireless handheld platforms. Optimizing instruction set architectures and employing SIMD techniques is a logical approach towards attaining higher performance in mobile multimedia applications. Intel® Wireless MMX? technology has been designed to accelerate mobile multimedia and applications processing in a power efficient manner. This paper provides an overview of Intel® Wireless MMX? technology, a 64-bit Single Instruction Multiple Data (SIMD) coprocessor for the Intel® XScale® microarchitecture, and the key features of the architecture that specifically enhance the multi-media performance. Tools and techniques for optimization are also described.     

嵌入式运动目标提取实时图像处理系统

针对大数据量、高速传输复杂的图像处理算法,以Matrox Oddysey图像处理卡为基础,设计了多目标实时图像处理系统.提出了一种结合帧间减法与背景自适应更新的算法,完成实时交会处理任务,满足靶场弹道试验任务的实时性要求.自适应背景更新是一种有效的用于视频序列图像运动目标检测的算法.该领域中很多方法被提出来,但是很少提及用于实时处理系统.我们着眼于算法的高速性并提出一种足够快的方法用于弹道测量系统.用高斯分布建立每个像素的灰度模型,这个分布用来区分前景和背景像素以便用来更新背景模型.     

Tracking-error model-based predictive control for mobile robots in real time

In this paper, a model-predictive trajectory-tracking control applied to a mobile robot is presented. Linearized tracking-error dynamics is used to predict future system behavior and a control law is derived from a quadratic cost function penalizing the system tracking error and the control effort. Experimental results on a real mobile robot are presented and a comparison of the control obtained with that of a time-varying state-feedback controller is given. The proposed controller includes velocity and acceleration constraints to prevent the mobile robot from slipping and a Smith predictor is used to compensate for the vision-system dead-time. Some ideas for future work are also discussed.     

On-line system identification in real time using a minicomputer

The parameters of the dynamic model of a linear system are estimated from the measurements of the input and output data by using the recursive algorithm for matrix pseudoinverse. For measurements contaminated with noise, the stochastic approximation algorithm is employed in conjunction with the matrix pseudoinverse algorithm for obtaining unbiased least-squares estimates. Both the methods are tested on-line in real time using the PDP 11/45 minicomputer while the system is simulated on a TR-20 analogue computer. The results confirm the feasibility of using the algorithms to identify the parameters of a class of industrial processes on-line using a minicomputer. This has special application to the adaptive control of such processes, based on rapid identification of slowly-varying parameters.     

Accelerating embedded image processing for real time: a case study

Many image processing applications need real-time performance, while having restrictions of size, weight and power consumption. Common solutions, including hardware/software co-designs, are based on Field Programmable Gate Arrays (FPGAs). Their main drawback is long development time. In this work, a co-design methodology for processor-centric embedded systems with hardware acceleration using FPGAs is proposed. The goal of this methodology is to achieve real-time embedded solutions, using hardware acceleration, but achieving development time similar to that of software projects. Well established methodologies, techniques and languages from the software domain—such as Object-Oriented Paradigm design, Unified Modelling Language, and multithreading programming—are applied; and semiautomatic C-to-HDL translation tools and methods are used and compared. The methodology is applied to achieve an embedded implementation of a global vision algorithm for the localization of multiple robots in an e-learning robotic laboratory. The algorithm is specifically developed to work reliably 24/7 and to detect the robot’s positions and headings even in the presence of partial occlusions and varying lighting conditions expectable in a normal classroom. The co-designed implementation of this algorithm processes 1,600 × 1,200 pixel images at a rate of 32 fps with an estimated energy consumption of 17 mJ per frame. It achieves a 16× acceleration and 92 % energy saving, which compares favorably with the most optimized embedded software solutions. This case study shows the usefulness of the proposed methodology for embedded real-time image processing applications.     

Towards a low bandwidth talking face using appearance models

This paper is motivated by the need to develop low bandwidth virtual humans capable of delivering audio-visual speech and sign language at a quality comparable to high bandwidth video. Using an appearance model combined with parameter compression significantly reduces the number of bits required for animating the face of a virtual human. A perceptual method is used to evaluate the quality of the synthesised sequences and it appears that 3.6 kb s⁻¹ can yield acceptable quality.     

基于移动Agent嵌入式移动数据库系统的研究

介绍嵌入式移动数据库的概念及特点,针对嵌入式移动数据库在用户规模巨大时出现的不足,提出将移动代理应用于嵌入式移动数据库.接着分析了移动代理的特点和移动代理应用于嵌入式移动数据库的好处,最后详细讨论了基于移动代理的嵌入式移动数据库系统模型、系统结构和系统实现.     

A real time process management system using RFID data mining

Recently, there have been numerous efforts to fuse the latest Radio Frequency Identification (RFID) technology with the Enterprise Information System (EIS). However, in most cases these attempts are centered mainly on the simultaneous multiple reading capability of RFID technology, and thus neglect the management of massive data generated from the RFID reader. As a result, it is difficult to obtain flow information for RFID data mining related to real time process control. In this paper, we propose an advanced process management method, called ‘Procedure Tree’ (PT), for RFID data mining. Using the suggested PT, we are able to manage massive RFID data effectively, and perform real time process management efficiently. Then we evaluate the efficiency of the proposed method, after applying it to a real time process control system connected to the RFID-based EIS. For the verification of the suggested system, we collect an enormous amount of data in the Enterprise Resource Planning (ERP) database, analyze characteristics of the collected data, and then compute the elapsed time on each stage in process control. The suggested system was able to perform what the traditional RFID-based process control systems failed to do, such as predicting and tracking of real time process and inventory control.     

Compositional specification of real time embedded systems by priority time Petri Nets

An important key challenge in Embedded Real Time Systems (ERTS) analysis is to provide a seamless scheduling strategy. Formal methods for checking the temporal characteristics and timing constraints at a high abstraction level have proven to be useful for making the development process reliable. In this paper, we present a Petri Net modeling formalism and an analysis technique which supports not only systems scheduling analysis but also the compositional specification of real time systems. The proposed Priority Time Petri Net gives determinism aspect to the model and accelerates its execution. Indeed, a compositional specification of a PTPN for complex application and multiprocessor architecture that solves the problem of hierarchy is presented.     

System level fixed priority energy management algorithm for embedded real time application

Dynamic power management (DPM) and dynamic voltage scaling (DVS) are crucial techniques to reduce the energy consumption in embedded real-time systems. Many previous studies have focused on the energy consumption of the processor or I/O devices. In this paper, we focus on the problem of energy management integrating DVS and DPM techniques for periodic embedded real-time applications with rate monotonic (RM) policy and present a system level fixed priority energy-efficient scheduling (SLFPEES) algorithm. The SLFPEES algorithm consists of I/O device scheduling and job scheduling. I/O device scheduling is based on the dynamic power management with rate monotonic (DPM-RM) policy which puts devices into the sleep state when the idle interval is larger than devices break even time. Job scheduling is based on the RM policy and uses stack resource protocol (SRP) to guarantee exclusive access to the shared resources. For energy efficiency, the SLFPEES algorithm schedules the task with a lower speed and a higher speed. The experimental result shows that the SLFPEES algorithm can yield significantly energy savings with respect to the existing techniques.