Real Time Operating System

This paper presents a method to mitigate high latency in the teleoperation of unmanned ground systems through display prediction and state estimation. Specifically, it presents a simulation environment which models both sides of the teleoperation system in the laboratory. The simulation includes a teleoperated vehicle model to represent the dynamics in high fidelity. The sensors and actuators are modeled as well as the communication channel. The latency mitigation approach is implemented in this simulation environment, which consists of a feed-forward vehicle model as a state estimator which drives a predictive display algorithm. These components work together to help the operator receive immediate feedback regarding his/her control actions. The paper contains a technical discussion of the design as well as specific implementation. It concludes with the presentation of some experimental data which demonstrate significant improvement over the unmitigated case.

We propose a static periodic task allocation scheme for a distributed real-time system. The periodic task consists of task threads which may communicate and share resources. A graph partitioning process and a thread sequencing algorithm are applied to these threads to yield local schedules. The exact analysis is then obtained and further re nements are performed if the worst case response time of a task is greater than its deadline

The last decade a trend can be observed towards multi-processor Systems-on-Chip (MPSoC) platforms for satisfying the high computational requirements of modern multimedia applications. The research community has mainly focused on communication issues (e.g. bus vs. networks-on-chip). Real-time operating systems for MPSoCs however, have gotten very little attention. Existing techniques like rate-monotonic scheduling from the real-time community are rarely applicable, because contemporary high-performance media processors (like Cell, graphics processors) do not support preemption. Furthermore, rate-monotonic scheduling cannot deal with multiple (heterogeneous) processors, data dependencies, and dynamically varying execution times that characterize modern media applications. This paper proposes new techniques to manage the computational resources of MPSoCs at run-time. We compare a centralized resource manager (RM) to two versions (Credit based and Rate based) of a novel, more distributed RM. The distributed RMs are developed to cope with a larger number of processors as well as concurrently executing applications. Experiments show that our distributed resource managers are more scalable, deal better with application and user dynamics, and require less buffering, while effectively enforcing throughput constraints.

this paper aims to contribute to the efforts of design community to demonstrate the effectiveness of the state of the art Field Programmable Gate Array (FPGA), in the embedded systems development, taking a case study in the biomedical field. With this design approach, we have developed a System on Chip (SoC) for cardiac monitoring based on the soft processor MicroBlaze and the Xilkernel Real Time Operating System (RTOS), both from Xilinx. The system permits the acquisition and the digitizing of the Electrocardiogram (ECG) analog signal, displaying heart rate on seven segments module and ECG on Video Graphics Adapter (VGA) screen, tracing the heart rate variability (HRV) tachogram, and communication with a Personal Computer (PC) via the serial port. We have used the MIT_BIH Database records to test and evaluate our implementation performance. In terms of the resources utilization, the implementation occupies around 70% of the used FPGA, namely the Xilinx Spartan 6 XC6SLX16. The accuracy of the QRS detection exceeds 96%.

Nowadays operating systems are inseparable part of computer systems. Real-time operating systems (RTOS) are a special kind of operating systems that their main goal is to operate correctly and provide correct and valid results in a bounded and predetermined time. RTOSs are widely used in safety-critical domains. In these domains all the system's requirements should be met and a catastrophe occurs if the system fails. Hence, fault tolerance is an essential requirement of RTOSs employed in safety-critical domains. In the past decades, several fault tolerance techniques have been proposed to protect different parts of an RTOS against faults and errors. In this paper, after presenting primary concepts of RTOSs, some features of these operating systems are reviewed and then a number of fault tolerance techniques that can be applied to each feature and their impact on system reliability is investigated. The main contribution of this work is to review and categorize several fault tolerance techniques applicable to RTOSs based on the operating system's features.

Today's consumer electronic devices feature multiple applications which have to share scarcely available resources. We consider a priority-processing-based video application, which comprises multiple scalable video algorithms (SVAs) that are executed on a shared, virtual platform. This application is given a guaranteed processor share by means of a constant-bandwidth server (CBS). A decision scheduler distributes the assigned processor share among the SVAs on a time-slot basis, with the aim to maximize their overall output quality. To correctly distribute this processor share based on fixed-sized time slots, we introduce the concept of a virtual timer. This timer only advances when its associated virtual platform is executing. Because priority processing can guarantee real-time performance even under fluctuating load, we apply a resource reclaiming mechanism to our CBS which makes it possible to efficiently exploit spare processor time 1 .

The problem of maximizing quality of service (QoS) of real-time systems subject to both schedulability and energy constraints is addressed. A discrete system consisting of tasks with multiple operating modes, and which can be executed by the processor at different frequency/voltage levels, is considered. Although the system reconfiguration scheme assumes the earliest deadline first (EDF) policy and soft realtime tasks, it can be extended to other scheduling policies and handle hard real-time tasks. The described solution is suitable for adaptive real-time embedded systems which require energy savings associated to QoS. Despite being NP-Hard, the reconfiguration problem can be solved with a mixed-integer linear-programing solver sufficiently fast.

Real-time scheduling theory is designed to provide a priori verification that all real-time tasks meet their timing requirements. However, this body of theory generally assumes that resources are instantaneously pre-emptable and ignores the costs of systems services. In previous work [1, 2] we provided a theoretical foundation for including the costs of the operating system scheduler in the real-time scheduling framework. In this paper, we apply that theory to the Real-Time (RT) Mach scheduler. We describe a methodology for measuring the components of the RT Mach scheduler in user space. We analyze the predicted performance of different real-time task sets on the target system using the scheduling model and the measured characteristics. We then verify the model experimentally by measuring the performance of the real-time task sets, consisting of RT Mach threads, on the target system, The experimental measurements verify the analytical model to within a small percentage of error. Thu...

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Water is an important resource in human life. About 80 to 90% of water is used in agriculture. Considering that due to the daily growth of globalization, the consumption of water is also increasing. Today, automation is one of the important roles in the field of agriculture. Agriculture is the main occupation in our country. India's main source of income is agriculture, so development of agriculture is important. Also, most irrigation systems are manually operated these days. The traditional techniques available are drip irrigation, sprinkler irrigation etc. Using drip irrigation we can save water and fertilizers given to the crops. Whenever there is a change in temperature, humidity and current rain status in the surroundings, these sensors will detect the change in temperature and humidity and give the raspberry pi an interrupt signal. This paper mainly focuses on reducing water wastage and minimizing manual labour in the field during irrigation to save the farmer's time, money and energy. In this paper, we have designed and tested an IoT-enabled smart drip irrigation system using ESP32 to automate the irrigation process. The ESP32 communicates with the Arduino IOT cloud app, which is used to collect irrigation data, manually water plants, turn off automatic watering, and draw graphs based on sensor data. We connected the ESP32 to a soil moisture sensor, a temperature sensor, an air humidity sensor. The ESP32 regularly checks whether the soil is dry. If the soil is dry and the soil temperature is suitable for watering, the ESP32 will open the solenoid valve and water the plants. The operating time of the drip irrigation system is determined based on the flow rate measured by the water flow sensor. The ESP32 reads the humidity sensor readings and alerts the user when the humidity is too high or too low. The user can turn off the automatic watering system according to the humidity value.

Gait analysis using wearable sensor is cheap, convenient, and efficient way of providing useful information for health related applications. It is used as a clinical tool in the rehabilitation, sport activities, and diagnosis of medical conditions. Gait analysis is used for non-automated and automated continuous monitoring improvement of patient recovery. Automated systems are important in assisting physicians for knowing the status of patient recovery. This study presents preliminary steps of designing a clinical decision support system for monitoring the improvement of patient by considering the parameters like steps taken, distance covered, and speed covered and observed angle of patient. This study compares the gait parameters of two patients by considering above parameters .The new system was built using three-axis accelerometers to automatically detect walking speed, angle of variation, steps taken per unit time, calories burnt. A progressive improvement in patient can be obse...

Although modern computer systems process increasing amounts of sensitive, private, and valuable information, most of today's operating systems (OSs) fail to protect confidential data against unauthorized disclosure over covert channels. Securing the large code bases of these OSs and checking the secured code for the absence of covert channels would come at enormous costs. Microkernels significantly reduce the necessarily trusted code. However, cost-efficient, provable confidential-data protection in microkernel-based systems is still challenging. This thesis makes two central contributions to the provable protection of confidential data against disclosure over covert channels: • A budget-enforcing, fixed-priority scheduler that provably eliminates covert timing channels in open microkernel-based systems; and First and foremost, I would like to thank my kids, my wife, and my parents for their continuing love and support. I would like to thank my advisor, Prof. Hermann Härtig, for his support and gainful criticism. Furthermore, I would like to thank the second reviewer of this thesis, Prof. Erik Poll, for his detailed and helpful comments and for the opportunity to learn many things during my visits of the Digital Security Group in Nijmegen. This thesis would not have become reality without the help of many people. Special thanks go to the members of the Operating Systems Group at TU Dresden. In particular, I would like to thank Dr. Claude-Joachim Hamann for the many insightful discussions about schedulers and scheduling theory and Benjamin Engel for his help in moving this work into the right direction. Thanks also for your helpful comments when we switched sides and you started commenting on my thesis. Last but not least, I want to thank Hendrik Tews and Tjark Weber for the joy and pleasure I had working with you in Robin. Thanks Hendrik for prove reading my work and especially for teaching an operating-systems guy like me this strange topic called formal methods. Finally, those of you who like me had the pleasure of being invited to one of Hermann's famous parties will surely agree with me and with the dolphins leaving earth [Ada79]: "So long, and thanks for all the fish". v Erkl ärung Hiermit versichere ich, dass die hier präsentierte Arbeit das Ergebnis meiner alleinigen und orginären Forschung ist. Diese Arbeit ist ohne die Zuhilfenahme unzulässiger Hilfe endstanden. Alle genutzen Hilfsmittel sind als solche gekennzeichnet. Die aus fremden Quellen direkt oder indirekt übernommenen Gedanken sind in meiner Arbeit als solche kenntlich gemacht. Ich versichere weiterhin, dass ich die vorliegende Arbeit nicht in gleicher oder in ähnlicher Form einer anderen Prüfungsbehörde zum Zwecke der Promotion vorgelegt habe. Diese Arbeit wurde noch nicht veröffentlicht. Sie ist Bestandteil meines ersten Promotionsversuchs. Marcus Völp vii CHAPTER 1. INTRODUCTION In this dissertation, I strive for the provably perfect protection of confidential data against software-centric covert channels in low-level operating-system code. Perfect means that even the leakage of a single bit of information is considered harmful. To provably protect confidential data in operating systems, I propose to combine the complementary strength of two technologies: microkernels and security type systems, a static language-based information-flow analysis. Hence, this thesis is about provable confidentialdata protection in microkernel-based systems. In this combined approach, the role of the microkernel is to avoid covert channels by isolating differently classified applications, legacy OS instances and operating-system servers 2 . The role of security type systems is to prove the absence of those security policy violating information flows that isolation cannot sensibly avoid. These are the illegal information flows that follow from invocations of the microkernel or from invocations of operating-system servers that simultaneously operate on behalf of differently classified clients and that cannot be reinstantiated for each such client. In the following, I shall call these servers the multilevel servers of the analyzed microkernel-based system. The microkernel and the multilevel servers I shall call collectively the multilevel components of such a system. The remainder of this introduction is organized as follows: next, I give a more detailed introduction on microkernels, on security type systems, and on the roles they play in the provable protection of confidential data in microkernel-based systems. Section 1.3 summarizes the contributions that this thesis makes and highlights the challenges that must be addressed. Section 1.4 discusses the scope of this thesis and the limitations of the results it presents, Section 1.5 concludes this introduction by giving an outline of the remainder of this thesis. The design philosophy of microkernel-based systems [WCC + 74] is to implement a universally applicable and absolutely reliable kernel -the microkernel. This kernel should implement only those mechanisms that allow for a convenient, flexible, and efficient implementation of OS facilities and policies outside the kernel. The determining criteria for tolerating a mechanism in the kernel is whether a required system functionality cannot be implemented if this mechanism would reside outside the kernel [Lie95]. Although first-generation microkernels [ABB + 86, ZPS99, BCE + 94, SESS96, ADH89] were rather large, inflexible, and slow, second-generation microkernels [Lie95, Hil92, HK93, Sha99, KV05, DdEE, SK08, PSLW09, Han99] have been able to demonstrate that these characteristics are not inherent. Second-generation microkernels achieve their goals with only three abstractions and two mechanisms:

The embedded system area today is faced with the challenge of implementing the applications that can execute efficiently on limited resources and that meet nonfunctional requirements such as timeliness, robustness, dependability and performance. At the core, these requirements need to be managed by the operating system. Thus, an embedded operating system has to address not only the aforementioned issues but also the issues arising out of the requirements of newer embedded applications. Such types of constraints are difficult to meet in an embedded operating system and this is the reason that the contemporary embedded operating systems are designed for specific application areas. This research work aims at identifying a common and adaptive framework for embedded operating systems so that a customized embedded operating system can be generated according to the requirements of an application.

The Stream Control Transmission Protocol (SCTP) is an IETF-standard transport layer protocol in the IP protocol suite. SCTP is very attractive for data communication over satellite networks due to its unique features such as multihoming and multistreaming that are not present in TCP. SIGMA, an SCTP-based mobility management scheme, has been developed for space networks. RTEMS, an open source Real Time Operating System (RTOS), is used by the computers onboard several spacecraft. The network stack of RTEMS does not include SCTP. The objective of this paper is to describe the issues and challenges in implementing SCTP on the RTEMS operating system. The lessons learned will be helpful to implement SCTP in other operating systems.

Assume that a real-time program P T consisting of a number of parallel processes is executed on a system having a set Pr of processors which are shared between the processes by a real-time scheduler S T . Assume that P T must meet some timing deadlines. We show that such an implementation of P T can be represented as a transformationL( P T ) and that the deadlines of P T will be met if they are satisfied by the timing properties of the transformed program. The condition for feasibility of a real-time program executed under a scheduler is formalized and rules are provided for verification. The scheduler S T can be specified generically and applied to different programs, making it unnecessary to introduce low-level operations such as scheduling primitives into the programming language. Thus real-time program specification and Schedulability can be considered in the same framework and the timing properties of a program can be determined at the specification level. By separating the spe...

FreeRTOS is a popular real-time operating system, which has been under a significant attention in the last years due to its main advantages: it is open source, portable, well documented and implemented on more than 30 architectures. FreeRTOS execution environment is dynamic, preemptive and priority based, but it is not suitable for hard real-time tasks, because it provides task execution determinism only to a certain degree and cannot guarantee the absence of task execution jitter. As a solution to this problem, we propose a hard real time execution extension to FreeRTOS in order to support a particular model of HRT tasks, called ModXs, which are executed with no jitter. This article presents a detailed analysis, in terms of scheduling, task execution and memory usage of this hard real time execution environment extension. The article is concluding with the advantages this extension brings to the system compared to the small memory and timing overhead introduced.

The paper describes real time extensions to the Open Object Oriented Database system using the RTSORAC data model. This model combines an object oriented data model, real time requirements, flexible transactions, semantic relationships among objects, and active database features. Several extensions to the Open Object Oriented Database system, including development of interfaces for real time objects and real time transactions, use of a real time operating system, incorporation of real time object management, and incorporation of real time transaction management, are also described

How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative Real-time process manager and its application in robotics, U.

How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative Real-time process manager and its application in robotics, U.

Preemptive real-time operating systems allow the kernel to stop a running task to execute other task with higher priority. The tasks compete for the resources producing anomalies such as starvation, deadlock and priority inversion that can reduce the perceived performance of the system. The scheduler is in charge of the synchronization when priorities are considered and of avoiding these anomalies to occur. Among the FOSS 1 community, the RTAI 2 real-time extension for the Linux kernel is one of the most applied and with major projection within the automatic control area. To synchronize priority tasks, RTAI has implemented the Priority Ceiling and the Priority Inheritance mechanisms. The main goal of this work is analyze the functioning of these mechanisms for different situations, in RTAI/Linux-GPL.

Kernel based system: Kernel based system uses a real time kernel, available from a vendor or developed in house, to manage such real time entities as task and interrupts. The logic for the real time application is coded separately from the kernel, and then linked with it to form the complete real time system. OS based system: OS based systems differ from Kernel-based systems only in the range of functions provided by an OS compared to a kernel. A real time OS provides normal OS functions (file system, User interface, etc.) in addition to the real time functions supplied by a kernel. Soft real-time system has average manages on its deadline. Deadlines are still important but any missing of a deadline doesn't cause catastrophic failures. For example, consider the playback of a motion video on your screen, during

Nowadays more and more resources are thrown for improving performance of existing software/hardware systems to produce new ones more powerful than ever. In the world of embedded systems and real-time systems anything is crucial – software applications, involving ...

Management, allocation and scheduling of heterogeneous resources for complex distributed real-time applications is a challenging problem. Timing constraints of applications may be fulfilled by a proper use of real-time scheduling policies, admission control and enforcement of timing constraints. However, it is not easy to design basic infrastructure services that allow for an easy access to the allocation of multiple heterogeneous resources in a distributed environment. In this paper, we present a middleware for providing distributed soft real-time applications with a uniform API for reserving heterogeneous resources with real-time scheduling capabilities in a distributed environment. The architecture relies on standard POSIX OS facilities, such as time management and standard TCP/IP networking services, and it is designed around CORBA, in order to facilitate modularity, flexibility and portability of the applications using it. However, real-time scheduling is supported by proper extensions at the kernel-level, plugged within the framework by means of dedicated resource managers. Our current implementation on Linux supports reservation of CPU, disk and network bandwidth. However, additional resource managers supporting alternative real-time schedulers for these resources, as well as additional types of resources, may be easily added. We present experimental results gathered on both synthetic applications and a real multimedia video streaming case study, showing advantages deriving from the use of the proposed middleware. Finally, overhead figures are reported, showing sustainability of the approach for a wide class of complex, distributed, soft real-time applications.

In a Real Time System, when a high priority task is scheduled, it preempts ongoing lower priority tasks and sometimes it preempts even the kernel too. In normal cases, the time needed for the preemption is too small and hence is not considered in task scheduling. But, in some mission critical hard real time systems, even a small fraction of a second should be taken into account as it could affect the deadline. This research work proposes two models -embedded model and software model, among which the latter has been used for the experiment that calculates the kernel preemption time. The hardware model consists of a triangular wave generator called TRIANG that takes timer values from real time tasks and sends outputs to a comparator module. Finally, the comparator compares the time differences, and hence, calculates the kernel preemption time. Whereas the software model uses the RT-Linux architecture in which device drivers are used instead of hardware components. A high precision timer clock is also used to measure the task release times. The results from the experiments show that the release time jitter due to the kernel preemption is found to be fluctuating in the range of -94 and +93 microseconds in 3% of the cases. So, the kernel preemption time for the hard and mission critical real time systems is taken to be less than 99 microseconds. Whereas 85% of the cases have release time jitters of single digit only. So, the kernel preemption time in average case is considered to be less than 9 microseconds.

This paper describes a tool set for on-line and off-line runtime formal verification of system of systems (SoS) using rapid source-code instrumentation of complex C, C++, and Java applications. The tool set consists of two Eclipse plugins: an automatic source code instrumentation tool and an XML-to-JUnit log-file converter. The automatic instrumentation tool inserts code snippets in the source code of the system under test. During the SUT's execution the code snippets create a log stream (file or socket stream) in XML format. The XML-to-JUnit log-file converter transforms this stream into equivalent JUnit tests within the Eclipse environment. These test scenarios are then executed against statechart-assertion formal specifications, thereby performing runtime verification. The tool set enables runtime verification of formal specifications that contain real-time constraints and is capable of performing such verification for applications running on most popular real-time operating systems.

Critical industrial applications or fault tolerant applications need for operating systems (OS) which guarantee a correct and safe behaviour despite the appearance of errors. In order to validate the behaviour of an operating system in front of errors, software fault injection techniques can be used. These techniques can be used to corrupt the information of some of the operating system calls to see how the system react in front of invalid or corrupted values at the kernel calls. The research work presented in this paper is about the development and results obtained from the experimentation on software fault injection in an embedded system composed by a Real-Time Operating System (RTOS) like MicroC/OS-II and a microcontroller as the Infineon C167. A software fault injection tool has been developed. The methodology proposed treated the operating system as a black-box where the source code was not available. With this objective a layer between the operating system and the application to be executed has been developed. OS error detection coverage has been measured and observations about OS critical data structures to be improved have been commented, in order to improve the final robustness of the operating system.

This work is to observe the performance of PC based robot manipulator under general purpose (Windows), Soft (Linux) and Hard (RT Linux) Real Time Operating Systems (OS). The same open loop control system is observed in different operating systems with and without multitasking environment. The Data Acquisition (DAQ, PLC-812PG) card is used as a hardware interface. From the experiment, it could be seen that in the non real time operating system (Windows), the delay of the control system is larger than the Soft Real Time OS (Linux). Further, the authors observed the same control system under Hard Real Time OS (RT-Linux). At this point, the experiment showed that the real time error (jitter) is minimum in RT-Linux OS than the both of the previous OS. It is because the RT-Linux OS kernel can set the priority level and the control system was given the highest priority. The same experiment was observed under multitasking environment and the comparison of delay was similar to the preceding evaluation.

Performance engineering aims to meet a system's resource constraints which implies to make the code as lean as possible. Robustness engineering has to support fault identification and fault recovery. To make a system sufficiently robust, code needs to be added. Hence, robustness engineering is in conflict with a system's performance. This paper will discuss this potential conflict in the context of operating systems. Operating systems are significantly impacting performance and robustness properties according to what they are providing or do not support. Current practices and related impacts are identified and recommendations are given how this conflict can be minimised.

It is seen that the number of Electronic Control Units (ECUs) in the automotive has grown significantly in recent years. In today's luxury cars, up to 2500 signals are exchanged by up to 70-80 ECUs. The number communication channels implement required realize such systems is about n2, here n is the number of ECUs in the automobile. This complexity requires the use of communication networks between them and to manage the functionality of these ECUs the Real-Time Operating Systems (RTOS) is used. This real world scenario has motivated us to give the hands on experience to students by introducing integrated course projects, which includes the use of Real-Time Operating Systems (RTOS) in automotive embedded systems. This activity also involves creating an industry like environment for execution of the project. Deployment of more advanced control strategies and integration of sub modules were the major technical outcomes of the activity.

The needs for run-time data storage in modern wired and wireless network applications are increasing. Additionally, the nature of these applications is very dynamic, resulting in heavy reliance to dynamic memory allocation. The most significant problem in dynamic memory allocation is fragmentation, which can cause the system to run out of memory and crash, if it is left unchecked. The available dynamic memory allocation solutions are provided by the real time Operating Systems used in embedded or general-purpose systems. These state-of-the-art dynamic memory allocators are designed to satisfy the run-time memory requests of a wide range of applications. Contrary to most applications, network applications need to allocate too many different memory sizes (e.g. hundreds different sizes for packets) and have an extremely dynamic allocation and de-allocation behavior (e.g. unpredictable web-browsing activity). Therefore, the performance and the de-fragmentation efficiency of these allocators is limited. In this paper, we analyze all the important issues of fragmentation and the ways to reduce it in network applications, while keeping the performance of the dynamic memory allocator unaffected or even improving it. We propose highly customized dynamic memory allocators, which can be configured for specific network needs. We assess the effectiveness of the proposed approach in two representative real-life case studies of wired and wireless network applications. Finally, we show very significant reduction in memory fragmentation and increase in performance compared to state-of-the-art dynamic memory allocators utilized by real-time Operating Systems.

PORT is a real-time operating system designed to operate over a large set of computer systems. It can run on computers with different architectures. It makes use of a common high-level language for both the system and application programs. As the system is implemented by the identical software on different hardware, it will have the similar interface to user programs. Hence, application programs which use PORT are highly portable. PORT enables viewing programs as networks of communicating processes by providing efficient interprocess communication primitives.

This paper deals with the experimental design and implementation of a rapid prototype system dictated for electric drive applications using RTOS. The developed system with small size, low cost, and high efficiency, depends basically on the personal computer (PC) processor without the need to any external processor (e.g. digital signal processor (DSP)) to get the fast execution of control algorithms, and to support floating point operations. The PC-based rapid-prototyping system consists of an extension kit with all required interface boards to do the simulation and implementation of electrical drive algorithms. Almost all designed boards are based on programmable-logic devices (PLD) to reduce cost and size. To operate the hardware of the proposed system, a free available open source real-time operating system (RTOS) kernel under Linux is used. As case study from electric drive applications a Direct Model-based Predictive Current Control MBPC is selected as one of most complicated closed-loop control algorithm in this field, and some of experimental results are given in order to demonstrate the good functionality of the conceived system.

The Operating System (OS) is a major part of embedded software systems and its robustness has considerable influence on the robustness of the entire system. Thus, its robustness testing is critical for assessing the dependability of the system. In this paper, a state-aware approach is proposed to evaluate the robustness of components of embedded real-time OSs in the presence of different types of faulty inputs. This approach leads to identifying critical OS states, their criticality level, and the maximum and minimum level of the OS robustness. It also facilitates comparing the robustness level of OS's components and helps the system developers to select the most appropriate fault tolerance techniques by considering the robustness level and timing limitations. The experimental results demonstrate the ability of the proposed approach in providing more information about the robustness vulnerabilities in the states of the system.

Massively Distributed Control Nets (MDCN) is a CAN (Controller Area Network) based high-level protocol that has the following features: (1) Three types of communication: individual, group and broadcast, with eight priority levels. (2) Addressing of up to 254 nodes and groups in standard CAN format, and up to 100,000's in extended CAN format. (3) I/O (node-to-node) and port (point/process-to-point/process) communications, where I/O is mostly reserved for system processes with high priorities and short message sizes, and port is for user applications, with lower priorities and possibly large message sizes. Compared to the existing widely used high-level CAN protocols, MDCN can address more communication nodes, has simpler APIs, is easier and more efficient to implement. Also the bridge protocol is transparent to users as whether it is a single CAN bus or a networked CAN buses. MDCN is currently implemented in C for MPC555 TouCAN controller on the Real-Time Operating Systems vxWorks, and in Java on host PC. The API is designed and implemented for multi-threaded environments. MDCN is a general protocol that not only can be applied to modular robots, but also can be applied to any industry control or automation using CAN bus network with hundreds of communication nodes.

The neural networks find today many applications in different kinds of real-time working systems. To obtain short execution times in machine vision systems or in real-time decision-making systems, becomes a question of first importance. Therefore, the requirements to the recognition stage in such systems in reference to reduce the reaction time grow up. In this research, a neural network MLP structure is proposed for recognition of 2D objects intended for implementation in a real-time working system, based on PLC modules. A new method for choosing the appropriate input set and optimizing the MLP structure with the aim to reduce the execution time is developed. The method is tested with different kinds of captured 2D objects for real-time work of a PLC S7-314. The achieved good results give approve that the proposed method could be applied in other real-time systems.

The Open Group Future Airborne Capability Environment (FACE ™ ) Consortium has developed a reference architecture and standard for real-time embedded avionics systems. The FACE Technical Standard defines required capabilities for real-time operating systems (RTOS), portable components, and a shared data model to facilitate information exchange between components. FACE RTOS requirements are based on ARINC 653 and POSIX 1003.1b with tailoring to address the safety and security needs of avionics systems. Deos is a safety-certified RTOS that supports ARINC 653 but not POSIX. In contrast, RTEMS is an open source RTOS that supports POSIX but not ARINC 653. Integrating a paravirtualized RTEMS with Deos combines the strengths of both and provides a path to conformance with the FACE Safety Base operating system profile. This paper presents the FACE operating system profiles and discusses the technical challenges of the paravirtualization and integration effort.

Abstract. The exploration of space is a driving force for mankind for understanding the universe. However, due to limitations in exploration and due to requirements for prolonged life support, it has become only possible to explore deep reaches of space through the use of robotic space probes. Through the efforts of NASA and ESA many robotic space probes have been launched to explore nearby asteroids' and comets. However, for these types of deep space missions, the robotic space probe is often far from Earth and requires ...

A compound service comprising one or more tasks, occurring unpredictably and constrained by a single deadline m a y not be successfully scheduled. A goal for managing such services is to maximize the success ratio SR, i.e. the percentage of successfully scheduled services. This paper describes an adaptive run-time scheduling method for improving the SR of a real-time distrrbuted system. Simulation i s used to obtain performance results.

A compound service comprising one or more tasks, occurring unpredictably and constrained by a single deadline m a y not be successfully scheduled. A goal for managing such services is to maximize the success ratio SR, i.e. the percentage of successfully scheduled services. This paper describes an adaptive run-time scheduling method for improving the SR of a real-time distrrbuted system. Simulation i s used to obtain performance results.

As artificial intelligence technology becomes less intensive and more accessible, it
creates more opportunities for artificial intelligence applications within new hardware and
software devices. This project explores the process of integrating a large language model, GPT-2,
onto a real-time operating system known as QNX within the hardware constraints of a Raspberry
Pi. There were two attempts at implementing this model, the first was installing python on to the
QNX operating system, while the second attempt was to utilize a cross-compiling feature in
order to run the GPT-2 model. The results were unfortunate as the QNX Momentics IDE had a
bug within its software that did not allow us to cross-compile in the way we had planned before,
as a final result we had to shift the GPT-2 model onto Linux. These results showcase that the
QNX operating system and IDE are not fully capable of integrating a GPT-2 model with python
due to issues with the IDE.

Real-time operating system services are required to support multimedia systems that rely heavily of the workstation processor for control of the audio and video processors and movement of audio and video data. Such services are typically not available in existing workstation operating systems. This note comments on the requirements for such services and briefly describes the YARTOS kernel; an operating system kernel that provides real-time communication and computation services.

In this contribution the existing relations between the imprecise computation and the fault tolerant control (FTC) are analyzed. From those relations one settles down like constructing FTC systems according to the model of imprecise computation. The found relations establish that the ...