【作者】 凌纯清；

【导师】 徐成；

【作者基本信息】 湖南大学 ， 计算机应用技术， 2004， 硕士

【摘要】 面对嵌入式系统领域日益激烈的市场竞争，设计周期长短成为产品能否占领市场的一个重要因素，因而提高系统的设计层次以缩短设计周期至关重要。目前嵌入式系统一般采用系统级设计方法，这样可以科学地划分系统的软件与硬件，避免设计的原理性错误，实现组件的可重用。系统级设计的关键是如何模拟系统的各个方面，以反应系统的真实行为。由于嵌入式系统的行为具有异构性，目前还没有一个平台能很好地实现对此类系统的建模与仿真，因此研究嵌入式异构系统的系统级设计方法学，对于嵌入式系统的系统级设计具有积极的理论指导意义。 本文主要研究嵌入式计算系统的系统级设计。首先研究了Ptolemy Ⅱ的系统级设计方法学；然后针对Ptolemy Ⅱ不能提供完备的角色库来满足所有系统需求的问题，研究了角色的软件结构，归纳出一套角色扩展的方法，并基于此方法，设计了一组MPEGAudio Layer Ⅲ的解码角色，实现对MP3文件的播放，从而验证此角色设计方法切实可行；随后针对Ptolemy Ⅱ对嵌入式异构系统具有较强的系统级设计能力，利用Ptolemy Ⅱ运用不同的PID算法对异构的电机调速控制器进行优化设计；最后在自主开发的DSP平台上采用增量PID算法和积分分离的PID算法分别实现电机调速控制器。测试结果表明积分分离的PID算法可明显地减少超调量，缩短电机的调速时间，此结果与Ptolemy Ⅱ的仿真结果基本一致，从而验证了Ptolemy Ⅱ对电机调速控制器建模仿真的正确性，表明Ptolemy Ⅱ能很好地指导嵌入式异构系统进行系统级设计。更多还原

【Abstract】 With the drastic market competition, it is a key factor in the embedded system’s design to shorten design cycle. At present, embedded systems usually adopt system-level design methodology, which can easily partition hardware and software of systems, avoid design principle’s error and realize components’ reuse. However, the key problem of system-level design is to simulate all aspects of the system for reflecting "real behavior" of the system. Unfortunately, for the heterogeneous characteristic of embedded systems, it is rare that a single platform can do well in designing these systems. Therefore, it is significant to study the system-level design methodology, which will lay solid basis of embedded system design.The paper mainly discusses the system-level design of embedded computing systems. The paper is organized as follows: Firstly, we study the actor-oriented design methodology in Ptolemy II. Secondly, pre-defined actor library in Ptolemy II can’t prove sufficient for all systems, so the paper introduces the software structure of the actor and summarizes an effective means to add the actor. A group of MP3 decoded actors are designed by using the above means, therefore MP3 file can be decoded and played in Ptolemy II, which verifies that the actor designing means is feasible. Thirdly, a motor speed-adjusting controller using different digital PID is modeled and simulated in Ptolemy II. Finally, the paper implements the motor speed-adjusting controller using integrator-disparted PID algorithm and increment PID algorithm on a DSP hardware platform. The test results show that the integrator-disparted PID algorithm can reduce the excessive turning-up and shorten motor speed-adjusting’s time significantly. The real performance results are approximately close to the simulation results in Ptolemy, which proves that Ptolemy can direct the design of the motor speed-adjusting controller correctly and feasibly.更多还原