This paper presents technical solutions for an autonomous robot running GNU/Linux. While the majority of article focused on the software implementation, we will slightly describe some of our mechanical and electrical solutions as well. The paper outlines several interesting software built for embedded real- time application. (more…)

With the maturing of the Realtime Preemption Patches (RT-Preempt) and their stepwise integration to the Mainline Linux kernel since version 2.6.18, we set out to answer the questions:

• How good is RT-Preempt with respect to the worst-case latency?
• How expensive is RT-Preempt with respect to a possible performance degradation of the system?

Taking that a lot of the preemption techniques… (more…)

Linux as a general-purpose operating system is designed to support the services required by most generic applications. Today, there is a new generation of real-time applications that are interactive, computation-intensive, and I/O-bound. In the past years, operating system research has addressed each of these challenges in turn. (more…)

A commonly used hardware in-the-loop environment is the dSPACE1 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…)

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…)

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…)

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 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…)

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…)

“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…)

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…)

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 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…)

RTLinux-GPL1 is an RTOS which uses a dual-kernel approach, that is, executing a real-time kernel (RTLinux-GPL itself) jointly with a general purpose OS (Linux). By using this approach, complex real-time application with both, hard and soft real-time requirements can be implemented easier. (more…)

The Dresden Real-Time Operating Systems Project (DROPS) is a research project aiming at the support of applications with Quality of Service requirements. In the DROPS project a key component is L4Linux, the Linux server on top of the L4 microkernel. Now DROPS could provide to concurrent execution of many instances of L4Linux like Xen but there is no feasible interface to implement communication between… (more…)