The Research And Application Of Modeling & Simulation Of Embedded Systems

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.