高空台飞行环境模拟系统温度延时不确定性μ综合设计

Aiming at the control problem of large temperature delay of flight environment simulation system (FESS) of altitude ground test facilities (AGTF), a two degree-of-freedom μ synthesis control design method considering temperature delay uncertainty is proposed. A complete and accurate nonlinear model of FESS is established. The FESS modeling uncertainties caused by variable specific heat volume differential equation, pipe heat transfer, control valve flow characteristics, hydraulic servo system dynamics, sensor gain, and temperature delay are considered in this model. By considering the actuator parameter and temperature delay uncertainty of FESS, a two degree-of-freedom μ synthesis control design method is presented. To ensure the designed μ synthesis controller has good robust servo tracking performance, the performance and control output weighting functions are designed according to the frequency division weighting principle. The μ synthesis controller is designed by using the D-K iteration method. A typical engine test condition with Zoom-Climb and Mach Dash is supposed to verify the servo tracking performance of the designed μ synthesis controller. The simulation results show that the relative steady-state and transient errors of temperature and pressure of FESS are both less than 1.5% and 3%, respectively.