Design of microsatellite attitude control with multiplicative perturbation of controller

Due to the space missions´ limited budget, microsatellite would be an economical choice, so there has been a great decrease in size and weight. Micro satellite is vulnerable to space environmental disturbances and perturbation of controller. As to the multiplicative perturbation in attitude controller, this paper investigates a robust H_∞ controller design with model uncertainties and subject to external disturbances and controller´s multiplicative perturbations. By using linear matrix inequality (LMI) method, the numerical solution of state feedback controller in terms of multiplicative perturbation can be efficiently solved. The performance differences between the non-fragile control and the mixed H₂/H_∞ control without considering controller´s multiplicative perturbation are discussed in detail. The attitude control design taking controller perturbation into account shows excellent effectiveness with respect to simulation results.