As embedded systems evolve, there is greater dependency on the real-time operating system (RTOS) to abstract the complex hardware. In return for the services provided, the RTOS consumes CPU cycles, thereby imposing a processing overhead on the CPU. In this paper, we review some of the techniques that have been proposed in literature for reducing the CPU utilisation by the RTOS primitives, including our… (more…)

In focusing the efficacy of reconfigurable computing, one of the important dimensions is the partitioning of the Field Programmable Gate Arrays [FPGAs]. As the amount of reconfigurable resources in a single-chip FPGA is increased tremendously, it allows the change of hardware tasks at run-time. (more…)

Runtime reconfigurable embedded systems target an architecture consisting of a reconfigurable system-on-chip (RCSoC), which has hardcore or softcore general-purpose processor (GPP) and field programmable gate arrays (FPGAs). The architecture provides common execution semantics for software and hardware tasks. (more…)

Applications that require a combination of high-performance computing capabilities and real-time behavior, although pervasive (simulation, medicine, training, multimedia communications), often rely on specific hardware and software components that make them high performance but expensive, and quite difficult to develop, validate and moreover upgrade. (more…)

Real Time applications involve time-critical tasks, which are to be run in a high precision scheduling environment always meeting the timing constraints. Applications which run on RT Linux uses a hard real-time kernel for tasks which needs real-time processing and the Linux OS for other non real-time tasks. (more…)

Scilab/Scicos is an open source project developed at the INRIA (Insitut National de Recherce on Informatique et on Automatique) in France which can be used to successfully replace other commercial and expensive software in solving mathematical and control problems. This software integrates a code generator for Scicos which has been modified and completed to automatically generate a code for the RTAI-Lab… (more…)

This paper describes a fixed-point arithmetic implementation of linear time-invariant digital filters in the C programming language, targeted for the use in real-time applications. FIR and IIR filters are presented in different configurations and representations, such as direct and transposed forms, as well as wave, state-space and normal forms. (more…)

RTLinux does not support direct access to any kind of permanent massive storage system, and in particular IDE hard disks. When a RTLinux thread has to store data on the hard disk, it has to use the Linux services. The usual way of doing the transfer is by means of RTFifos: a rtl-task sends the data to Linux through an RTfifo, and then, a Linux process writes this data on the hard disk. (more…)

There is a strong tendency towards using modern Personal Computers for various tasks they are not designed for. This also includes audio and video processing. Audio and Video data is real-time data. It needs to be dispatched within predefined and fixed time windows to avoid perceivable lags and dropouts. (more…)

This work-in-progress report describes a distributed hybrid architecture that imparts autonomous intelligence capabilities of “perception-decision-action” to an ALV (Autonomous Landing Vehicle) control unit. The system is shown to degenerate to a remote thread execution mechanism of a real-time operating Linux system where the kernel instantiation is control strategy dependent. (more…)

This paper describes an implementation of the Linux kernel and applications on a unique commercial-off-the-shelf component based space borne computer system. This system, called the parallel processing unit has been developed for the X-Sat micro-satellite mission. Interfaces using the kernel device driver model are utilised to allow seamless application interaction with the system hub. (more…)

Embedding Linux in a carrier-grade application, like a Microwave Point-to-Point Radio Link, has many interesting concerns. These concerns range from technical issues, cost calculation issues to even political or licensing issues. However, when compared to an existing proprietry-only product which binds a company to long development cycles, it has many relatively obvious advantages. (more…)

Hard Real-Time Control (HRTC) is to be intended in terms of the relative time scales of the electromechanical components of the mechatronic system to be controlled. MicroElectroMechanical Structures (MEMS) or Drive-by-Wire (DbW) applications are good examples of hard real-time controls. (more…)

Real Time Linux is rapidly finding application in several embedded systems because it is scalable, customizable and has a good development environment. However, problems arise on systems with low memory, and on systems that require to be booted fast. Linux is not optimized to boot fast, and requires at least 4MBytes of RAM. (more…)

Hardware-In-Loop-Simulator (HILS) is an important step in system design & development. In the present work a systematic approach has been adopted in creating the HILS for autonomous navigation of a Mini Aerial Vehicle (MAV). The issues addressed in this paper are 1. real time simulation of flight dynamics, 2. (more…)