Anti-Windup Control for an Air-Breathing Hypersonic Vehicle Model

Wang

Advances in Mechanical Engineering

et al. 2015

A nonlinear constrained controller is designed for a reusable launch vehicle during re-entry phase in the presence of model uncertainty, external disturbance, and input constraint, via combining sliding mode control and adaptive backstepping control. Since the complex coupling between the translational and rotational dynamics of reusable launch vehicle, a control-oriented model derived from rotational dynamic is used for controller design. During the virtual control input design procedure, a dynamic robust term is utilized to compensate for the uncertainty. In addition, a filter is applied to handle ''explosion of terms'' problem during the actual control input design. To reduce the computational burden, adaptive law is used to evaluate the unknown norm bound of the lumped uncertainty. An auxiliary system is constructed to compensate for the input constraint effect. The stability of the closed-loop system is analyzed based on Lyapunov theory. Simulation results demonstrate the validity of the developed controller in providing stable tracking of the guidance command by numerical simulation on the 6-degree-of-freedom model of reusable launch vehicle.

Section: Attitude Modelmentioning

confidence: 99%

Robust adaptive constrained backstepping flight controller design for re-entry reusable launch vehicle under input constraint

Wang

Advances in Mechanical Engineering

et al. 2015

2009 American Control Conference

“…Future work will examine how the FER margin map and Figure 2) changes when a higher fidelity model [19,22] is used. We will also examine other constraint enforcement methods [12], [23]. …”

Section: Nonlinear Responses To Velocity Commands (Unconstrained)mentioning

confidence: 99%

“…This paper examines the importance of these margins and a method for enforcing the associated constraints. To do so, the paper exploits the modeling work discussed within [2,3,5,11,12]. Goals and Contributions of Paper.…”

Section: Introduction and Overviewmentioning

confidence: 99%

“…Items (1)-(4) have received little attention in the controls literature. Within [12], the authors address anti-windup issues for a hypersonic vehicle -specifically addressing constant (static) constraints associated with control surface deflection, total temperature across the combustor, and diffuser area ratio. To our knowledge, control systems that account for the nonlinear FER statedependent "saturation" considered in this paper have not been addressed elsewhere.…”

Section: Introduction and Overviewmentioning

confidence: 99%

See 1 more Smart Citation

Constraint enforcement for scramjet-powered hypersonic vehicles with significant aero-elastic-propulsion interactions

Soloway

Rodriguez

Dickeson

et al. 2009

In this paper, we examine the control of a scramjet-powered hypersonic vehicle with significant aeroelastic-propulsion interactions. Such vehicles are characterized by open loop unstable non-minimum phase dynamics, low frequency aero-elastic modes, significant coupling, and hard constraints (e.g. control surface deflection limits, thrust margin). Within this paper, attention is placed on maintaining acceptable closed loop performance (i.e. tracking of speed and flight path angle commands) while satisfying hard control surface deflection constraints as well as stoichiometrically normalized fuel-equivalency-ratio (FER) margin constraints. Control surface constraints are a consequence of maximum permissible aerodynamic loading. FER margin constraints are a consequence of thermal choking (i.e. unity combustor exit Mach number) and the fact that thrust loss may not be captured for FER greater than unity. Such limits are particularly important since the vehicle is open loop unstable and "saturation" can result in instability. To address these issues, one can design conservative (i.e. less aggressive or lower bandwidth) controllers that maintain operation below saturation levels for anticipated reference commands (and disturbances). Doing so, however, unnecessarily sacrifices performance -particularly when small reference commands are issued. Within this paper, the above issues are addressed using generalized predictive control (GPC). A 3DOF longitudinal model for a generic hypersonic vehicle, which includes aero-elastic-propulsion interactions, is used to illustrate the ideas.

2012 American Control Conference (ACC)

“…A chronological bibliography on saturating actuators (1957 -1995) can be found in [16]. Due to the unstable nature of hypersonic vehicles, saturation in the elevator channel can lead to instability [8,9,17]. Control of unstable systems with saturation constraints has been examined in [18][19][20].…”

Section: Introduction and Overviewmentioning

confidence: 99%

Constraint enforcement and robust tube-based control for scramjet-powered hypersonic vehicles with significant uncertainties

Sridharan

Rodriguez

Dickeson

et al. 2012

This paper examines the issues involved in controlling an air-breathing hypersonic vehicle (characterized by their unstable, non-minimum phase dynamics) in the presence of significant modeling uncertainty and nonlinearities (control saturations). Modeling of the vehicle exhaust (plume) is complicated, often requiring computational fluid dynamic (CFD) simulations to capture all relevant effects. The focus of this paper is on obtaining a control law that maintains the vehicle trajectory within an acceptable tube while enforcing control constraints in the presence of modeling uncertainty. A robust domain of attraction based approach is used to generate/validate a feasible tube. The computational aspects of such an approach is examined, and the benefits of a decentralized control technique is considered. This approach is compared with other techniques such as linear matrix inequalities based controller design. These approaches are applied to a command following scenario in order to illustrate the performance of the proposed approach.