Regulation of Settling Chamber Pressure in a Hypersonic Wind Tunnel using LQR Controller

Wind tunnels are used to study the aerodynamic properties of space specimen under test. Hypersonic wind tunnel is used to simulate flight conditions of space vehicles in hypersonic flow regime. This paper aims to design and analyze the performance of a Linear Quadratic Regulator (LQR) based controller for the regulation of pressure inside the settling chamber of a hypersonic wind tunnel. The design is carried out using optimal state feedback controller gain matrix of the linear model of the tunnel system which is completely state controllable and observable. Simulation results show that the change in set point does not affect the settling time whereas the peak overshoot increases with increase in set point. The settling time as well as the peak overshoot are improved when the value of weighing matrix is increased