M. Krstic Dept. Mechanical Engr. University of Maryland College Park, MD 20742 J. M. Protz and J. D. Paduano Massachusetts Institute of Technology Cambridge, MA 02139 P. V. Kokotovic Dept. Electr. & Comp. Engr. University of California Santa Barbara, CA 93106 Abstract. A new systematic method for nonlinear control design|backstepping|is applied to low-order compression system models. Backsteppi...

In this study of the nonlinear H∞-optimal control design for strict-feedback nonlinear systems our objective is to construct globally stabilizing control laws to match the optimal control law up to any desired order, and to be inverse optimal with respect to some computable cost functional. Our recursive construction of a cost functional and the corresponding solution to the Hamilton-Jacobi-Isa...

A new suboptimal control design technique is proposed for a class of cascaded non-linear systems. The design is based on a forward recursive design rather than a backstepping design, and it utilizes a non-linear tracker derived using the state-dependent algebraic Riccati equation approach. The proposed design has two distinct features. First, it provides suboptimal performance with respect to a...

Equipping a fixed wing unmanned air vehicle (UAV) with low-level autopilots, we derive high-level velocity and roll angle control laws for the UAV. Backstepping techniques are applied to design the velocity and roll angle control laws from known velocity and heading angle control laws that explicitly account for velocity and heading rate constraints of the UAV. Regarding unknown autopilot const...

In this paper, we consider a class of second-order uncertain nonlinear systems. Besides parametric uncertainties, a non-parametric uncertainty may exist in every state equation or channel with its effects bounded by a known function. Such a bounding function is allowed to depend on all system states which means that the actual system does not need to meet the triangular structure. Therefore the...

This paper addresses the design of a robust prediction-based controller for linear systems with both input and state delays. We extend the usual prediction-based scheme to state delay and prove its robustness to sufficiently small delay mismatches. Our approach is grounded on the linking of two recently proposed infinite-dimensional techniques: a Complete-Type Lyapunov functional, which enables...

This paper considers the problem of attitude synchronization control of a group of flexible spacecraft under an undirected communication graph and in the absence of measurements of both modal variables and spacecraft angular velocities. To solve this problem, a nonlinear observer is introduced to estimate the unmeasurable modal variables and spacecraft angular velocities. Then, the backstepping...

A novel robust adaptive controller is presented for a wide class of strict feedback uncertain nonlinear system with unknown virtual control coefficients under bounded exogenous disturbances. Combined Nussbaum gain with the backstepping technique, the proposed design algorithm, which does not require a priori knowledge of the signs of the unknown virtual control coefficients, is proved to be abl...