Analytical Method for Computing Controller Gains of a Satellite Launcher

Abstract Satellite launchers are time-variant systems and, consequently, the frozen poles technique is applied, analyzing the plant inside some time interval where it can be considered invariant. The pole placement using the LQR method demonstrates nonsatisfactory time response and has a poor link between the weighting matrixes and the transitory response. An analytical method is proposed, so that the controUer gains are computed focusing time requirements as rise and settling time and ramp input error. This method allows the designer to be able to specify directly these characteristics; as a result, the poles/zeros are free to move regarding the transitory response.