A robust temperature trajectory following control system for space vehicle testing

The paper presents a new control scheme for high temperature trajectory following problems. In particular, as a study case, the thermal stress conditions occurring on parts of space vehicle during the re-entry phase is considered. The model of the thermal process, in the lumped parameter domain, is described by a quasi-linear system depending on a number of parameters which are uncertain and varying with the operating conditions. An ad hoc nonlinear trajectory following control system is proposed together with a robust performance analysis, which makes use of the recent concept of quadratic stability with an H_∞ norm bound. The analysis technique allows one to evaluate the stability of the closed loop in the presence of time varying parameters and uncertainties, and the rejection of disturbances acting at the system input. An LMI based synthesis procedure is also proposed to increase the closed loop system performance. Numerical simulations are carried out to show the effectiveness of the control algorithm