Mu-synthesis in state space; applied to a typical Satellite Launch Vehicle

Different design techniques are available for the control of Satellite Launch Vehicles. Each does have its own advantages. Problems with uncertainties and external disturbances are of a major concern in any design. Robust control is known to be of good use in this context. μ synthesis comes under the robust control category, which has attained considerable attention. μ synthesis based controller stablises the system for parameter uncertainities within a given range, for which the controller is designed. The μ value or the structured singular value is the parameter to be optimised so as to obtain robust performance. It is a framework capable of dealing with dynamic structured uncertainties in an efficient way. An attempt is made to design a controller for a satellite launch vehicle, implementing μ-synthesis in the state-space domain. It is expected to have less sensitivity to parameter uncertainties and have a good control over the system. Conventional designs make use of equations while most of the constraints layed down on physical systems are in the form of inequalities. Thus the problem is formulated using Linear Matrix Inequalities, so that a superior controller is possible.