• Title/Summary/Keyword: Fixed Priority Scheduling

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A Study on Probabilistic Response-time Analysis for Real-time Control Systems (실시간 제어시스템의 확률적 응답시간 해석에 관한 연구)

  • Han, Jae-Hyun;Shin, Min-Suk;Hwang, In-Yong;SunWoo, Myoung-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.3
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    • pp.186-195
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    • 2006
  • In real-time control systems, the traditional timing analysis based on worst-case response-time(WCRT) is too conservative for the firm and soft real-time control systems, which permit the maximum utilization factor greater than one. We suggested a probabilistic analysis method possible to apply the firm and soft real-time control systems under considering dependency relationship between tasks. The proposed technique determines the deadline miss probability(DMP) of each task from computing the average response-time distribution under a fixed-priority scheduling policy. The method improves the predictable ability forthe average performance and the temporal behavior of real-time control systems.

Implementation of Operating Software for Small Multi-Jointed Robots (소형 다관절로봇을 위한 운용 소프트웨어 구현)

  • Son, Hyun-Seung;Kim, Woo-Yeol;Kim, Young-Chul
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.9
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    • pp.946-951
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    • 2009
  • The small multi-jointed robots for most education are developed with the way of firmware. But the firmware may be very difficult to develop as gradually increasing throughputs and control routines. Due to limit of firmware we try to use on RTOS, but hard to adapt on the small multi-jointed robots. It would be hard to install RTOS into the small multi-jointed robots because of the size capacity of RTOS, and lack of libraries for control of the particular hardware. Moreover, even its RTOS with many functions causes its to make overheads scheduling, TCB (Task Control Block), and task states. Also to keep maintenance of RTOS, it is composed of components for the whole structure of my proposed RTOS. Additionally, We provided with libraries of servo motor and sensor control and developed RMS (Rate Montonic scheduler) to handle tasks on real time and reduce overheads. Therefore, It is possible to work the fixed priority and task preemptive way. We show one example of the multi-jointed robot installed with my proposed RTOS, which shows to obstacle avoidance and climbing up the slope.