外文翻译TrueTime计算机资源共享下闭环控制模拟.docx

外文原文和译文15th IFAC World Congress on Automatic Control, Barcelona, Spain, July 2002.TrueTime: Simulation of Control Loops Unde Shared Computer ResourcesDan Henriksson, Anton Cervin, KarlErik ?rzénDepartment of Automatic ControlLund Institute of TechnologyBox 118, SE22100 Lund, Sweden{dan,anton,karlerik}@control.lth.seAbstractThe paper presents TRUETIME, a MATLAB/Simulink-based simulator for real-time control systems. TRUETIME makes it possible to simulate the temporal behavior of multitasking real-time kernels containing controller tasks and to study the effects of CPU and network scheduling on control performance. The simulated Real-time kernel is event-driven and can handle external interrupts as well as fine-grainedDetails such as context switches. Arbitrary scheduling policies may be defined, and the control tasks may be implemented using C functions, M functions, or Simulink block diagrams. A number of examples that illustrate the use of TRUETIME are presented.1. IntroductionMost computer control systems are embedded systems where the computer is a component within a larger engineering system. The controllers are often implemented as one or several tasks on a microprocessor using a real-time kernel or a real-time operating system DRTOSE. In most cases the microprocessor also contains other tasks for other functions, e.g., communication and user interfaces. The kernel or OS typically uses multiprogramming to multiplex the execution of the different tasks on a single CPU. The CPU time and the communication bandwidth, hence, can be viewed as shared resources which the tasks compete for.Computer-based control theory normally assumes equidistant sampling intervals and negligible or constant control delays, i.e., the latency between the sampling of the inputs to the controller and the generation of the outputs. However, this can seldom be achieved in practice. Tasks interfere with each other through preemption and blocking due to communication. Execution times may be d