Academic
Publications
TRUETIME: Real-time Control System Simulation with MATLAB/Simulink

TRUETIME: Real-time Control System Simulation with MATLAB/Simulink,Dan Henriksson,Anton Cervin,Karl-Erik Årzén

TRUETIME: Real-time Control System Simulation with MATLAB/Simulink   (Citations: 17)
BibTex | RIS | RefWorks Download
Traditional control design using MATLAB/Simulink, often disregards the temporal effects arising from the actual implementation of the controllers. Nowadays, controllers are often implemented as tasks in a real-time kernel and communicate with other nodes over a network. Consequently, the constraints of the target system, e.g., limited CPU speed and network bandwidth, must be taken into account at design time. For this purpose we have developed TRUETIME, a toolbox for simulation of distributed real-time control systems. TRUETIME makes it possible to simulate the timely behavior of real-time kernels executing controller tasks. T RUETIME also makes it possible to simulate simple models of network protocols and their influence on networked control loops. TRUETIME consists of a kernel block and a network block, both variable-step S-functions written in C++. T RUETIME also provides a collection of MATLAB functions used to, e.g., do A/D and D/A conversion, send and receive network messages, set up timers, and change task attributes. The T RUETIME blocks are connected with ordinary continuous Simulink blocks to form a real-time control system. The TRUETIME kernel block simulates a computer with an event-driven real-time kernel, A/D and D/A converters, a network interface, and external interrupt channels. The kernel executes user-defi ned tasks and interrupt handlers, representing, e.g., I/O t asks, control algorithms, and communication tasks. Execution is defined by user-written c ode functions (C++ functions or m-files) or graphically usin g ordinary discrete Simulink blocks. The simulated execution time of the code may be modeled as constant, random or even data-dependent. Furthermore, the real-time scheduling policy of the kernel is arbitrary and d ecided by the user. The TRUETIME network block is event driven and distributes messages between computer nodes according to a chosen network model. Currently five of the most common medium access control proto cols are supported (CSMA/CD (Ethernet), CSMA/CA (CAN), token-ring, FDMA, and TDMA). It is also possible to specify network parameters such as transmission rate, pre- and post-processing d elays, frame overhead, and loss probability. TRUETIME is currently used as an experimental platform for research on flexible approaches to real-time implementation and sched uling of controller tasks. One example is feedback scheduling where feedback is used in the real-time system to dynamically distribute resources according to the current situation in the system.
Published in 2007.
Cumulative Annual
View Publication
The following links allow you to view full publications. These links are maintained by other sources not affiliated with Microsoft Academic Search.
Sort by: