No abstract

This paper presents a comparative study of three linear-parameter-varying (LPV) modeling approaches and their application to the longitudinal motion of a Boeing 747 series 100/200. The three approaches used to obtain the quasi-LPV models are Jacobian linearization, state transformation, and function substitution. Development of linear parameter varying models are a key step in applying LPV control synthesis. The models are obtained for the up-and-away flight envelope of the Boeing 747-100/200. Comparisons of the three models in terms of their advantages, drawbacks, and modeling difficulty are presented. Open-loop time responses show the three quasi-LPV models matching the behavior of the nonlinear model when in the trim region. Differences between the models are more apparent as the response of the aircraft deviates from the nominal trim conditions. Nomenclature c 1 , . . . , c 9 = inertia coefficients c = wing chord, m F dec = decomposition function m = aircraft mass, kḡ q = dynamic pressure, N/m 2 S = reference surface area, m 2 s α , c α = sine, cosine AoA w(t) = nonscheduling states x, z cg = aircraft center of gravity position x, z axis, m z(t) = scheduling states z eng = engine position z axis, m α = angle of attack (AoA), deg α w = wing design plane α w = α + 2 deg ρ(t) = scheduling vector

No abstract

This paper presents a novel approach to the design of road adaptive active suspensions via a combination of linear parameter-varying control and nonlinear backstepping techniques. Two levels of adaptation are considered: the lower level control design shapes the nonlinear characteristics of the vehicle suspension as a function road conditions, while the higher level design involves adaptive switching between these different nonlinear characteristics, based on the road conditions. A quarter car suspension model with a nonlinear dynamic model of the hydraulic actuator is employed. Suspension deflection, car body acceleration, hydraulic pressure drop, and spool valve displacement are used as feedback signals. Nonlinear simulations show that these adaptive suspension controllers provide superior passenger comfort over the whole range of road conditions.

Abstract-This paper describes the application of a novel methodology for high-level control and coordination of autonomous vehicle teams and its demonstration on high-fidelity models of the organic air vehicle developed at Honeywell Laboratories. The scheme employs decentralized receding horizon controllers that reside on each vehicle to achieve coordination among team members. An appropriate graph structure describes the underlying communication topology between the vehicles. On each vehicle, information about neighbors is used to predict their behavior and plan conflict-free trajectories that maintain coordination and achieve team objectives. When feasibility of the decentralized control is lost, collision avoidance is ensured by invoking emergency maneuvers that are computed via invariant set theory.

No abstract

Abstract-We propose a method to compute invariant subsets of the region-of-attraction for asymptotically stable equilibrium points of polynomial dynamical systems with bounded parametric uncertainty. Parameterindependent Lyapunov functions are used to characterize invariant subsets of the robust region-of-attraction. A branch-and-bound type refinement procedure reduces the conservatism. We demonstrate the method on an example from the literature and uncertain controlled short-period aircraft dynamics.Index Terms-Branch-and-bound, parameter uncertainty, region-of-attraction (ROA).

Current practice for flight control validation relies heavily on linear analyses and nonlinear, high-fidelity simulations. This process would be enhanced by the addition of nonlinear analyses of the flight control system. This paper demonstrates the use of region of attraction estimation for studying nonlinear effects. A nonlinear polynomial model is constructed for the longitudinal dynamics of NASA's Generic Transport Model aircraft. A polynomial model for the short period dynamics is obtained by decoupling this mode from the nonlinear longitudinal model. Polynomial optimization techniques are applied to estimate region of attractions around trim conditions. CONTROL ENGINEERING PRACTICEPAPER CHECKLIST for the preparation of papers.Please ensure that your paper conforms to the following guidelines. PREFERRED FORMAT AND LAYOUT: