Jorge E. Tierno

A convex approach to robust H2 performance analysis

In this paper, we consider the problem of assessing worst-case H2 performance for MIMO systems and we give an LMI based sufficient condition for robust performance under LTI (not necessarily causal) model uncertainty, having the same complexity as H~ conditions for the same problem. In addition, we show that this condition is indeed necessary and sufficient for MISO and SIMO systems under a class of LTI uncertainty, and for MIMO plants under (arbitrarily slow) LTV uncertainty.

Influence of prognostic health management on logistic supply chain

In this paper, we discuss the problem of determining performance metrics for preemptive condition-based maintenance, also referred to as prognostic health maintenance (PHM). This performance is tightly coupled to the properties of the logistics supply chain. Further, the optimal supply chain design is, in fact, sensitive to the capabilities of the PHM system. We formulate this joint optimization problem, which can be shown to be equivalent to a shortest path problem (SPP). The properties of the solution elucidate the design tradeoffs in using damage prediction technologies in the overall health management solution

Modifying HYTECH to automatically synthesize hybrid controllers

We present HONEYTECH, a tool for automatic synthesis of hybrid controllers. HONEYTECH is an extension of the HYTECH tool, with added features for linear hybrid automata region analysis. The tool has been used to implement the Wong-Toi hybrid controller synthesis algorithm and has been tested on several examples. We present an extension of the algorithm to include parametrized controllable transitions. We discuss the HONEYTECH implementation of the algorithm and its application to a very simple navigation control system. We also present a brief performance evaluation of the algorithm for increasing scales of magnitude of the control problem.

Phase-lead compensation of pitch axis control laws via McFarlane-Glover H/sub /spl infin// loop shaping

The McFarlane-Glover (1992) loop shaping approach is used to systematically generate compensators for fixed architecture control law. We present results obtained with the technique on realistic fixed wing aircraft models.

Control of LEO satellite clusters

We discuss the application of the perceptive control theory to the control of satellites flying in formation. We present the algorithms used and discuss some of their properties.

A convex approach to robust H/sub 2/ performance analysis

The problem of assessing robust H/sub 2/ performance (as a first step towards robust H/sub 2/ synthesis) has been open for the last two decades. Moreover, while convex characterizations of the worst H/sub 2/ performance are available for SISO plants, a counterexample has pointed out that these characterizations are potentially conservative for MIMO plants, with a gap size that increases with the number of inputs. We consider the problem of assessing worst-case H/sub 2/ performance for MIMO systems and we give an LMI based sufficient condition for robust performance under LTI (not necessarily causal) model uncertainty, having game complexity as H/sub /spl infin// conditions for the same problem. Moreover, we show that this condition is indeed necessary and sufficient for MIMO plants under (arbitrarily slow) linear time varying uncertainty and for MISO and SIMO systems under a class of LTI uncertainty.

Robust H2 and generalized H2 performance analysis

Abstract The problem of assessing robust H 2 performance (as a first step towards robust H 2 synthesis) has been open for the last two decades. In this paper we give sufficient conditions for robust H 2 and generalized H 2 performance under LTI, not necessarily causal, model uncertainty. These conditions have complexity roughly comparable to that of H∞ conditions for the same problem. Moreover, we show that in the case of MISO and SIMO systems these conditions are indeed necessary and sufficient, when the uncertainty structure has one scalar or two full blocks.

PRACTICAL UPPER AND LOWER BOUNDS FOR ROBUST Ui PERFORMANCE UNDER LTI PERTURBATIONS

Upper and lower bounds for the worst case %2 norm of an uncertain system are developed. Structured linear time invariant uncertainty with bounded Hoo norm is considered. The method is based on an extension of the structured singular value /x. Computation methods are discussed.