Real-time I/O scheduling, specifically disk scheduling, has frequently received far less attention than other aspects of real-time theory. Nevertheless, several proposals have addressed this area meaning to merge the real-time CPU scheduling along with traditional I/O scheduling to provide real-time disk response. (more…)

The processor Cell Broadband Engine (Cell/B.E.) is used inside the Playstation 3. The Cell/B.E. is a multi-core processor with heterogenous cores. Each core has its own memory. But all cores can communicate with each other using a high speed bus. (more…)

Xtratum is a nanokernel designed for providing domain support to execute concurrently several operating systems on a single computer. These domains are in the same hardware but running temporally and spatially isolated. As a very thin virtualization layer virtualizing the essential resources (interrupt, timer, memory, and CPU), XtratuM is suitable for embedded real-time systems, and at least one of those… (more…)

A PROFINET system built out of ERTEC Switch ASICs allows to keep the nodes of a network synchronized with an accuracy below 1sec. While still allowing regular IP communication, it also guarantees the timely arrival of cyclic messages below that mark. These features are particularly required for the motion control part of automation systems. (more…)

The emergence of slice-based computing model has raised high demand on replacing the interface- based addressing model with user-oriented addressing (UOA) paradigm. Assigning IP addresses to users instead of interfaces or hosts help us to realize high-granularity controls on port resource utilization, identity authentication, and quality of service. (more…)

“If computers systems technology is to be effectively and safely exploited, it is essential that those responsible for making decisions have sufficient guidance on the safety aspects on which to make these decisions” [IEC 61508-1 Introduction] (more…)

Networked control systems are made up of several computer nodes communicating over a communication channel, cooperating to control a plant. The stability of the plant depends on the end to end delay from sensor to the actuator. Although computational delays within the computer nodes can be made bounded, delays through the communication network are generally unpredictable. (more…)

Resource reservations have been proven to be an effective technique to support hard and soft real-time applications in open systems, and some implementations for Linux have already been proposed in the past. However, such implementations generally focus on providing guarantees to real-time applications, disregarding the performance of non real-time activities. (more…)

A commonly used hardware in-the-loop environment is the dSPACE system, whose strength is aimed at high flexibility and processing speed, but involves rather costly hardware and software license fees. In our proposed paper we elaborate a scalable hardware platform running a low-cost RTLinux open source system of comparable processing speed. (more…)

Today's trends in Control Engineering and Computer Engineering are blending gradually into a slightly challenging area, the improvement of Real-Time implementations. Applications should timely deliver synchronized data-sets, minimize latency and jitter in their response and by using an efficient scheduling algorithm to be able to determine various system resources to meet optimal allocation and their… (more…)

In this paper, an RTAI-Linux based distributed platform for the control of the PUMA 560 robotic manipulator is presented. From the mechanical point of view, the PUMA 560, besides being one of the first and most popular 6-DOF anthropomorphic manipulator, is still a very good example of implementation of small size robotic arms. (more…)

A FIFO is a First In First Out data queue for sharing data between multiple tasks or threads. Fifos are one of the most basic communication mechanisms used in real-time operating systems. Especially for two real-time tasks or between a real-time task and non-real-time process, it is effective because it allows non-blocking as well as blocking semantics, which is mandatory to avert priority inversion… (more…)

This work describes the integration of the hard real-time UDP/IP stack rtludp-0.1.1 into the Realtime Ethernet Device Driver (REDD) of the free real-time Linux distribution RTLinux/GPL. The current implementation of REDD misses a high-level communication protocol as it is present for non-real-time TCP/IP. (more…)

With the stepwise integration of the Real-time Preemption Patches (RT-Preempt) into the Mainline Linux kernel and their support for architectures other than Intel and AMD, there are now a number of choices which board to use for a particular embedded real-time project running Mainline Linux. (more…)

ABB is one of the leading solution providers for Industrial automation, Power technologies and Robotics. This makes ABB a vendor of several mission critical embedded devices. Most of these devices are characterized by stringent real time requirements. Real-time patches/extensions to Linux open up new possibilities to applying open source software in industrial real-time embedded applications. (more…)