Singular perturbation methods for discrete time systems

Some problems associated with applications of the singular perturbation method to the two-time scale discretized time systems are addressed. In practice, the small parameter of the fast time system is often implicit or unknown. A redefinition of the two-time scale property is proposed to resolve this and other related problems. Application to optimal regulators, design tradeoffs, and performance evaluation are also discussed. A practical example of a large space structure system is used to demonstrate the design procedure for implementing the singular perturbation techniques.