Analytical aeropropulsive-aeroelastic hypersonic-vehicle model with dynamic analysis

Chavez, Frank R.; Schmidt, David K.

doi:10.2514/3.21349

Cited by 307 publications

(161 citation statements)

References 1 publication

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“…Because of the rapid identification of the change in the inner-loop bandwidth, these gains also rapidly change to their new values corresponding to adaptation laws given in Eq. (6). Note that the time histories seen in both Figure 8 and Figure 9 are more irregular before the elevon failure and smoother afterwards.…”

Section: Failed Elevon With Guidance Reconfigurationmentioning

confidence: 77%

A reconfigurable guidance approach for reusable launch vehicles

Schierman

Ward

Monaco

et al. 2001

AIAA Guidance, Navigation, and Control Conference and Exhibit

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A guidance system with reconfiguration capabilities has been developed for reusable launch vehicles (RLVs). The focus of the development is on reconfiguration after a catastrophic effector failure during final approach -a failure that would otherwise cause loss of the vehicle. We assume here that the vehicle employs a reconfigurable inner-loop control system that recovers some maneuvering capabilities and maintains attitude stability. However, for RLVs, it is often the case that nominal performance cannot be fully recovered, and the outer-loop guidance system must account for the degraded response characteristics. Two approaches are presented. The first approach augments the existing production guidance system with adaptation capabilities. A case study shows that stability is maintained following a primary pitch effector failure. However, it is shown that the trajectory commands to the guidance loops must also be re-targeted in order to achieve a safe landing. The second approach employs an on-line optimal trajectory re-targeting algorithm. A database of neighboring optimal trajectories is encoded in an efficient manner and interrogated on line at regular intervals. Given the current states and certain vehicle parameters, this procedure generates optimal guidance commands and integrates the optimal trajectory to the next update point. A proof-of-concept study of this approach was performed. Following a primary speed control failure, the study shows that this approach achieves acceptable landing conditions.

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Section: Failed Elevon With Guidance Reconfigurationmentioning

confidence: 77%

A reconfigurable guidance approach for reusable launch vehicles

Schierman

Ward

Monaco

et al. 2001

AIAA Guidance, Navigation, and Control Conference and Exhibit

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“…Schmidt's conclusions were based on the linearized dynamics of a simplified model of the longitudinal dynamics of an air-breathing hypersonic vehicle. 2 More recently, Bolender and Doman 3 developed a non-linear model of an air-breathing hypersonic aircraft similar to that of Chavez and Schmidt 2 that exhibits the same qualitative characteristics as above.…”

Section: Previous Work By Schmidtmentioning

confidence: 99%

Flight Path Angle Dynamics of Air-Breathing Hypersonic Vehicles

Bolender¹,

Doman²

2005

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The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTESConference paper preprint to be presented at the 2006 AIAA Guidance, Navigation, and Control Conference, 24 Aug 06, Keystone, CO. This report contains color. This work has been submitted to 2006 AIAA Guidance, Navigation, and Control Conference proceedings. If this work is published, it is considered a work of the U.S. Government and is not subject to copyright in the United States. ABSTRACTThe flight path dynamics of aircraft are often characterized by the presence of a right-half plane zero in the elevator-to-flight path angle transfer function. For most aircraft, the frequency of this zero is high enough that it does not limit the bandwidth of the flight control system. This is not the case, however, with air-breathing hypersonic aircraft. This class of aircraft is characterized by unstable longitudinal dynamics, strong loop interactions, and the presence of non-minimum phase transmission zeros. In the case of flight-path angle and velocity control, the presence of a low frequency transmission zero severely limits the achievable bandwidth. We show that the frequency of the zero is related to the instantaneous center-of-rotation of the aircraft, which is dependent upon the amount of lift produced by the longitudinal control effectors. In order to improve flight-path control, we investigate the feasibility of an aircraft configured with redundant pitch control effectors. The additional effector moves the instantaneous center-of-rotation, and as a result, the location of the zero. The trade-off is that the path-attitude decoupling inherent in hypersonic aircraft becomes more pronounced. Results are given for both a rigid hypersonic aircraft model and a model that includes the effects of the first fuselage bending mode. SUBJECT TERMS AbstractThe flight path dynamics of aircraft are often characterized by the presence of a right-half plane zero in the elevator-to-flight path angle transfer function. For most aircraft, the frequency of this zero is high enough that it does not limit the bandwidth of the flight control system. This is not the case, however, with air-breathing hypersonic aircraft. This class of aircraft is characterized by unstable longitudinal dynamics, strong loop interactions, and the presence of non-minimum phase transmission zeros. In the case of flight-path angle and velocity control, the presence of a low frequency transmission zero ...

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“…The scramjet engine model is that used in 28,60 . It consists of an inlet, an isentropic diffuser, a 1D Rayleigh flow combustor (frictionless duct with heat addition 47 ), and an isentropic internal nozzle.…”

Section: Symbolmentioning

confidence: 99%

Control-Relevant Modeling, Analysis, and Design for Scramjet-Powered Hypersonic Vehicles

Rodriguez

Dickeson

Sridharan

et al. 2009

16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference

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Within this paper, control-relevant vehicle design concepts are examined using a widely used 3 DOF (plus flexibility) nonlinear model for the longitudinal dynamics of a generic carrot-shaped scramjet powered hypersonic vehicle. Trade studies associated with vehicle/engine parameters are examined. The impact of parameters on control-relevant static properties (e.g. level-flight trimmable region, trim controls, AOA, thrust margin) and dynamic properties (e.g. instability and right half plane zero associated with flight path angle) are examined. Specific parameters considered include: inlet height, diffuser area ratio, lower forebody compression ramp inclination angle, engine location, center of gravity, and mass. Vehicle optimizations is also examined. Both static and dynamic considerations are addressed. The gap-metric optimized vehicle is obtained to illustrate how this controlcentric concept can be used to "reduce" scheduling requirements for the final control system. A classic inner-outer loop control architecture and methodology is used to shed light on how specific vehicle/engine design parameter selections impact control system design. In short, the work represents an important first step toward revealing fundamental tradeoffs and systematically treating control-relevant vehicle design.

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Analytical aeropropulsive-aeroelastic hypersonic-vehicle model with dynamic analysis

Cited by 307 publications

References 1 publication

A reconfigurable guidance approach for reusable launch vehicles

A reconfigurable guidance approach for reusable launch vehicles

Flight Path Angle Dynamics of Air-Breathing Hypersonic Vehicles

Control-Relevant Modeling, Analysis, and Design for Scramjet-Powered Hypersonic Vehicles

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