Networked Control System Using RTT Measurement over USN

RTT 측정을 이용하는 USN 기반 Networked Control System

  • 이현철 (부산대학교 전자공학과) ;
  • 김유종 (부산대학교 전자기판회로학과) ;
  • 최준영 (부산대학교 전자공학과)
  • Received : 2012.08.27
  • Accepted : 2012.09.25
  • Published : 2012.11.01


We design a NCS (Networked Control System) where the communication between sensors and controllers takes place over a USN (Ubiquitous Sensor Network). In order to measure time delays between sensors and controllers in real time, we design an algorithm to measure RTT (Round Trip Time) between USN nodes, and implement it into TinyOS of USN. By using the measured time delays, we construct the Smith predictor to compensate the time delays between sensors and controllers in real-time. For the real time experiment, we simulate the dynamic plant model, controller, and USN interface using Real-Time Windows Target provided in MATLAB. The USN interface in the Simulink model consists of serial ports, which connect the plant output and controller with USN nodes. The experiment results show that the time delays between sensors and controllers are precisely measured in real time; the Smith predictor appropriately compensates the time delays; and the stability is achieved in the closed-loop of the NCS.


Supported by : 한국연구재단


  1. J. P. Hespanha, P. Naghshtabrizi, and Y. Xu, "A survey of recent results in networked control systems," Proc. of IEEE, vol. 95, no. 1, pp. 1-26, Jan. 2007.
  2. M. Drew, X. Liu, A. Goldsmith, and K. Hedrick, "Networked control system design over a wireless LAN," Proc. of 44th Conf. Decision and Control and European Control Conf., pp. 6704-6709, Dec. 2005.
  3. Y. A. Millan, F. Vargas, F. Molano, and E. Mojica, "A wireless networked control systems review," LARC Robotics Symposium, pp. 1-6, Oct. 2011.
  4. H. H. Choi, "Variable structure control design for time-delay systems," Journal of Institute of Control, Robotics and Systems (in Korean), vol. 16, no. 12, pp. 1208-1211, Dec. 2010.
  5. G. S. Bae and Y. H. Joo, "Intelligent control for networked control systems with time-delay," Journal of Institute of Control, Robotics and Systems (in Korean), vol. 17, no. 2, pp. 139-144, Feb. 2011.
  6. H. Li, X. Li, J. Wang, and H. Ma, "Design of networked control system based on wireless sensor networks," Proc. of 2009 IEEE International Conference on Information and Automation, pp. 1140-1143, Jun. 2009.
  7. Y. H. Joo, I. H. Ra, G. B. Koo, and J. B. Park, "Decentralized fuzzy output feedback control of nonlinear networked control systems for wireless sensor network," Journal of Korean Institute of Intelligent Systems (in Korean), vol. 19, no. 3, pp. 323-328, Jun. 2009.
  8. O. J. M. Smith, "Closer control of loops with dead time," Chemical Engineering Progress, vol. 53, pp. 217-219, May. 1957.
  9. "TinyOS source,"
  10. R. Gao, H. Zhou, and G. Su, "Structure of wireless sensors network based on TinyOS," International Conference on Control, Automation and Systems Engineering (CASE), pp. 1-4, Jul. 2011.
  11. H. C. Yi, H. J. Kim, Y. J. Kim, and J. Y. Choi, "RTT estimation method in WSN," 2012 International Conference on Information and Computer Networks (ICICN 2012), IACSIT Press, Singapore, vol. 27, pp. 17-21, Feb. 2012.

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