Implementation of Real-Time Thermal Environment for Virtual Reality Using Gain Scheduling and Cascade Control

게인 스케쥴링과 캐스케이드 제어에 의한 가상현실용 열환경의 실시간 구현

  • Sin, Yeong-Gi ;
  • Jang, Yeong-Su (Heat Flowing Control Research Center, Korea Institute of Science and Technology) ;
  • Kim, Yeong-Il (Heat Flowing Control Research Center, Korea Institute of Science and Technology)
  • 신영기 (세종대학교 기계항공공학부) ;
  • 장영수 (한국과학기술연구원 열유동 제어연구센터) ;
  • 김영일 (한국과학기술연구원 열유동 제어연구센터)
  • Published : 2001.07.01


A real-time HVAC system is proposed which implements real-time control of thermal environment for virtual reality. It consists of a pair of hot and cold loops that serve as thermal reservoirs, and a mixing box to mix hot and cold air streams flowing if from loops. Their flow rates are controlled in real-time to meet a set temperature and flow rate. A cascade control algorithm along with gain scheduling is applied to the system and test results shows that the closed-loop response approached set values within 3 to 4 seconds.


  1. W. F. Stoecker and P. A. Stoecker, 'Microcomputer control of thermal and mechanical systems,' Van Nostrand Reinhold book, ISBN 0-442-20648-8, 1989
  2. A. F. Mills, 'Heat transfer,' Irwin, pp. 32-33, 1992
  3. F. McQuiston and J. Parker, 'Heating, ventilating, and air conditioning analysis and design,' Wiley & Sons Inc., 1997
  4. C. Brosilow and K. Stryczek, 'Incorporating process uncertainty and analytic design of PID controllers into undergraduate process control,' Computers in Engineering Education, vol 4, no. 3, Aug., 1996<217::AID-CAE4>3.0.CO;2-G
  5. A. Corripio, 'Tuning of industrial control systems,' An Independent Learning Module, Instrument Society of America, pp 137-151, 1990
  6. E. Darlin, 'Designing and tuning digital controllers,' Instruments and Control Systems, vol. 41, 1968
  7. B. Anderson and J. Moore, 'Optimal filtering,' Prentice-Hall, Englewood Cliffs, 1979
  8. G. Scorletti and L. Ghaoui, 'Improved LMI conditions for gain scheduling and related control problems,' Int. J. of Robust and Nonlinear Control, vol. 8, pp 845-877, 1998<845::AID-RNC350>3.0.CO;2-I