• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1117-1123
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• 2008

This paper implements dual-kernel system using standard Linux and real-time embedded Linux for the real-time control of intelligent robot systems. Such system provides more useful services including standard Linux thread that is easy to implement complicated tasks and real-time tasks for the deterministic response to velocity control. Here, an open source real-time embedded Linux, XENOMAI, is ported on embedded target board. And for interfacing with motor controller we adopted a real-time serial device driver. The real-time task was implemented with a priority to keep the cyclic control command for trajectory control. In order to validate deterministic response of the proposed system, the performance measurement of the delay in performing trajectory control with feedback loop is evaluated with non real-time standard Linux. The proposed software architecture is anticipated to take advantage of features in both standard Linux and real-time operating systems for the intelligent robot systems.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.173-179
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• 2013

This paper describes a testbed that was designed and implemented for the development of KSLV-II onboard equipment simulator. It used the CPCI-based industrial hardware system for scalability and the QNX real-time operating system for reliability and real-time simulation. In addition, a real-time application under QNX for function simulations of the KSLV-I PDU was developed and it was verified through interface experiments with KSLV-I upper-stage test equipment. The implemented simulator testbed will be used to verify the development feasibility in the design and development phase of a real KSLV-II onboard equipment simulator.

• The Journal of Korea Robotics Society
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• v.7 no.4
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• pp.292-298
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• 2012

It is a real-time system that the system correctness depends not only on the correctness of the logical result of the computation but also on the result delivery time. Real-time Operating System (RTOS) is a software that manages the time of a microprocessor to ensure that the most important code runs first so that it is a good building block to design the real-time system. The real-time performance is achieved by using real-time mechanisms through data communication and synchronization of inter-task communication (ITC) between tasks. Therefore, test on the response time of real-time mechanisms is a good measure to predict the performance of real-time systems. This paper aims to analysis the response characteristics of real-time mechanisms in kernel space for real-time embedded Linux: RTAI and Xenomai. The performance evaluations of real-time mechanism depending on the changes of task periods are conducted. Test metrics are jitter of periodic tasks and response time of real-time mechanisms including semaphore, real-time FIFO, Mailbox and Message queue. The periodicity of tasks is relatively consistent for Xenomai but RTAI reveals smaller jitter as an average result. As for real-time mechanisms, semaphore and message transfer mechanism of Xenomai has a superior response to estimate deterministic real-time task execution. But real-time FIFO in RTAI shows faster response. The results are promising to estimate deterministic real-time task execution in implementing real-time systems using real-time embedded Linux.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.198-203
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• 2004

This paper describes a real-time control architecture for DUSAUV (Dual Use Semi-Autonomous Underwater Vehicle), which has been developed at Korea Research Institute of Ships & Ocean Engineering (KRISO), KORDI, for being a test-bed oj development of technologies for underwater navigation and manipulator operation. DUSAUV has three built-in computers, seven thrusters for 6 degree of freedom motion control, one 4-function electric manipulator, one pan/tilt unit for camera, one ballasting motor, built-in power source, and various sensors such as IMU, DVL, sonar, and so on. A supervisor control system for GUI and manipulator operation is mounted on the surface vessel and communicates with vehicle through a fiber optic link. Furthermore, QNX, one of real-time operating system, is ported on the built-in control and navigation computers of vehicle for real-time control purpose, while MicroSoft OS product is ported on the supervisor system for GUI programming convenience. A hierarchical control architecture which consist of three layers (application layer, real-time layer, and physical layer) has been developed for efficient control system of above complex underwater robotic system. The experimental results with implementation of the layered control architecture for various motion control of DUSAUV in a basin of KRISO is also provided.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.159-168
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• 2002

Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the Real Time Simulation Programing(RTSP) structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The RTSP scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The RTSP structuring scheme is a syntactically simple but semantically Powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C+ + and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.71-74
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• 1996

The concept of uniformity in control implementation is exploded for improving efficiency of design procedure. A controller area operating system which includes real time kernel and control specific shell are developed. Three examples are discussed for the validation of tile system.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1997.11a
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• pp.417-433
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• 1997

A real-time operating system has focused primary on techniques to minimize processing time, with a secondary emphasis on system reliability issues. Conversely, fault-tolerant system has concentrated on using recourse and information redundancy to maximize the availability and reliability of the system, with a lesser emphasis on performance. We have developed a fault-tolerant and real-time operations system which support a powerful concurrent runtime environment under the above requirements. In this paper, we present an overview of real-time systems, design and implementation of a duplex architecture using advanced concepts and technologies such as fast " fault detection", "fault isolation" and "fault recovery" Because the duplex architecture has two dentical hardware elements and has several recovery steps and hierarchy to facilitate a fast recovery which must be proceeded by a prompt fault detection and isolation. Thus it makes possible to minimize the overhead of the systems including hardware and software and guarantee the service continuity of he systems.

• Journal of the military operations research society of Korea
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• v.25 no.1
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• pp.199-214
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• 1999

The Constructive Battle Simulation Model is very important to the recent military training for the substitution of the field training. However, real battlefield systems operate under real-time conditions, they are inherently distributed, concurrent and dynamic. In order to reflect these properties by the computer-based simulation systems which represent real world processes, we have been developing constructive simulation model for several years. Conventionally, scheduling and resource allocation activities which have timing constraints, we elaborated on these issues and developed the simulation system on commercially available hardware and operating system with lock-free resource allocation scheme and rate monotonic scheduling.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1348-1357
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• 2006

In a hybrid three-layer control architecture(deliberative, sequencing, and reflexive), the lowest reflexive layer consists of resources, actions, an action coordinator, and motion controllers. Because the execution of individual components in the reflexive layer should be done in real-time, each component has to be simple and, due to this reason, the Linux-RTAI(Real-Time Application Interface for Linux) has been used as an operating system. In this paper, a navigation control architecture, which combines the components in the reflexive layer and the navigation-related modules in the sequencing layer, is proposed. And then, as basic components, four actions(Goto, Avoid, Move, and EmergencyStop) are designed. Experimental results confirm the effectiveness of the proposed architecture and the performance of individual associated actions.

• Journal of Aerospace System Engineering
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• v.1 no.1
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• pp.60-66
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• 2007

The importance of software development in the integration of an avionics system is continuously increasing. And we can expect enlarged soft ware portion in the system integration for the more intelligent, reliable, and automated avionics system. For an avionics system software development the selection of a real-time operating system and internal avionics data bus protocol is very important from the viewpoint of the integration with the system hardware. In this paper, we present current trend of an avionics system software development including software development methodology, software development process, and international software process assessment improvement model.