A novel approach to H2/H∞ robotic control with state estimation feedback

We consider the problem of designing H_∞ controllers for linear continuous- and discrete-time systems with upper bound constraints on the steady-state variances. The feedback is based on the state estimation. The goal of this problem is to design the state estimation feedback controller such that: 1) the steady-state variance of each state is not more than the individual prespecified upper bound; and 2) the H_∞ norm of the transfer function from disturbance inputs to state estimate output meets the prespecified upper bound constraint, simultaneously. An algebraic matrix equation approach is developed to solve the problem addressed. Both the existence conditions and the explicit expression of desired controllers are derived, and an illustrative simulation example is used to demonstrate the applicability of the proposed design procedure in a manipulator control problem