ontrol systems are becoming increasingly complex from both the control and computer science perspectives. Today, even seemingly simple embedded control systems often contain a multitasking real-time kernel and support networking. At the same time, the market demands that the cost of the system be kept at a minimum. For optimal use of computing resources, the control algorithm and the control software designs need to be considered at the same time. For this reason, new computer-based tools for real-time and control codesign are needed. Many computer-controlled systems are distributed systems consisting of computer nodes and a communication network connecting the various systems. It is not uncommon for the sensor, actuator, and control calculations to reside on different nodes, as in vehicle systems, for example. This gives rise to networked control loops (see [1] ). Within the individual nodes, the controllers are often implemented as one or several tasks on a microprocessor with a real-time operating system. Often the microprocessor also contains tasks for other functions (e.g., communication and user interfaces). The operating system typically uses multiprogramming to multiplex the execution of the various tasks. The CPU time and the communication bandwidth can hence be viewed as shared resources for which the tasks compete. Digital control theory normally assumes equidistant sampling intervals and a negligible or constant control delay from sampling to actuation. However,
• TrueTime: this MATLAB/Simulink-based tool REF enables the simulation of the temporal behavior of controller tasks executed on a multitasking real-time kernel.
How does control timing affect performance? Analysis and simulation of timing using Jitterbug and TrueTime
IEEE Control Systems
IEEE Control Systems
Computer Science