Modeling and control for simulated wind in immersive virtual environment

This study is a contribution towards ongoing research to enhance immersion in the University of Utah Treadport Virtual Environment (UUTVE) by adding wind display. A wind tunnel built around this virtual environment called the Treadport Active Wind Tunnel (TPAWT) includes an intricate flow network that provides controllable air flow into the UUTVE. This study investigates the system modeling, characterization and control strategies for the ducts, valves, and vents comprising the TP AWT. A unique valve design and assembly into the duct overcomes design challenges and allows control of wind entering the virtual environment. A lumped parameter model of the flow network unified with empirical mappings and flow characterization based on experiments form the basis for controller design. Robust nonlinear control strategies based on a sliding surface are developed and implemented to regulate flow velocity exiting the vents. Controller performance is evaluated by combined experimental and simulation techniques. The addition of a feedforward loop and integrator reset show -85% improvement in performance and the velocity control of wind exiting the vents is achieved in less than Is.