Analysis and Simulation of Controller Timing

The article presents two MATLAB-based tools for analysis and simulation of real-time control systems: JITTERBUG and TRUETIME. JITTERBUG allows the user to compute a quadratic performance criterion for a linear control system under various timing conditions. The control system is described using a number of continuousand discrete-time linear systems. A stochastic timing model with random delays is used to describe the execution of the system. The tool can also be used to investigate aperiodic controllers, multirate controllers, and jitter-compensating controllers. TRUETIME facilitates event-based co-simulation of a multitasking real-time kernel containing controller tasks and the continuous dynamics of controlled plants. The simulations capture the true, timely behavior of real-time controller tasks and communication networks, and dynamic control and scheduling strategies can be evaluated from a control performance perspective. The controllers can be implemented as Matlab functions, C functions, or ordinary discrete-time Simulink blocks. A number of examples that illustrate the use of the tools are given.