Development of a hybrid direct-indirect adaptive control system for the X-33

Doman, David B.; Ngo, Anhtuan D.; Leggett, David; Saliers, Meredith; Pachter, Meir

doi:10.2514/6.2000-4156

Cited by 17 publications

(6 citation statements)

References 10 publications

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“…Direct adaptive schemes rely less on this feature because they generally adapt based only on tracking error behavior; however, the combination of direct and indirect adaptive techniques may lead to better performance than could be achieved by using either technique alone. Research combining the two approaches with application to space access has been sparse; however, one effort is documented [31].…”

Section: The Role Of Integrated Vehicle Health Management Systemsmentioning

confidence: 99%

Progress in Guidance and Control Research for Space Access and Hypersonic Vehicles

Doman

Oppenheimer

Bolender

2006

Proceedings of the 45th IEEE Conference on Decision and Control

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Over the past decade, both NASA and the U.S. Air Force have directed significant efforts aimed at reducing the cost of access to space as well as improving the reliability and safety of launch vehicles. From a guidance and control perspective, efforts have focused on the development of fault tolerant autonomous systems that can recover vehicles from failures or damage when physically possible. The state of the art is summarized in this manuscript and some of the challenges preventing widespread use of some of the techniques are discussed. The integration of vehicle health management systems with adaptive guidance and control is also discussed.

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Section: The Role Of Integrated Vehicle Health Management Systemsmentioning

confidence: 99%

Progress in Guidance and Control Research for Space Access and Hypersonic Vehicles

Doman

Oppenheimer

Bolender

2006

Proceedings of the 45th IEEE Conference on Decision and Control

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“…An alternative to the mixed optimization algorithm is the two-stage algorithm of [3], [24], where the first stage minimizes the error and the second stage minimizes the control deflection. Both problems may be solved as linear programs.…”

Section: C-17 Modelmentioning

confidence: 99%

“…The control derivatives of any unused surface cannot be determined. Recent reconfigurable control experiments using these methods [23], [24], [25] have indeed showed the need for separate excitation mechanisms, which typically used random noise injection. Interestingly, direct allocation gives good and consistent results in all three cases.…”

Section: Identifiability Considerationsmentioning

confidence: 99%

Evaluation of Optimization Methods for Control Allocation

Bodson

2002

Journal of Guidance, Control, and Dynamics

529

217

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The paper evaluates the performance and computational requirements of optimization methods for control allocation. Two control allocation problems are formulated: a direct allocation method that preserves the directionality of the moment, and a mixed optimization method that minimizes the error between the desired and the achieved moments as well as the control effort. The constrained optimization problems are transformed into linear programs, so that they may be solved using well-tried linear programming techniques such as the simplex algorithm. The paper discusses a variety of techniques that may be applied for the solution of the control allocation problem in order to accelerate computations. Performance and computational requirements are evaluated using aircraft models with different numbers of actuators and with different properties. In addition to the two optimization methods, three algorithms with low computational requirements are also implemented for comparison: a redistributed pseudoinverse technique, a quadratic programming algorithm, and a fixed-point method. The major conclusion of the paper is that constrained optimization may be performed with computational requirements that fall within an order of magnitude of those of simpler methods. The performance gains of optimization methods, measured in terms of the error between the desired and achieved moments, are found to be small on the average, but sometimes significant. A variety of issues are discussed in the paper that affect the implementation of the various algorithms in a flight control system.

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“…Lower development costs might also result from their self-designing capabilities. Recent articles include those reporting on ight tests of the VISTA F-16, 1 on the results of the RESTORE program, 2;3 on simulations of the X-33 hypersonic vehicle, 4 and on other studies of a variety of recon gurable control algorithms. 5¡11 Most of the available algorithms have been designed to replace conventional ight-control systems for piloted aircraft.…”

Section: Introductionmentioning

confidence: 99%

Reconfigurable Nonlinear Autopilot

Bodson

2003

Journal of Guidance, Control, and Dynamics

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The paper proposes a recon gurable ight-control system for the tracking of altitude, heading, sideslip, and velocity commands. The control law can serve for the command of unmanned air vehicles or as an autopilot for piloted aircraft. The inner core of the algorithm consists of a recon gurable control system providing tracking of pitch-, roll-, and yaw-rate commands. It is based on a model reference control law and a stabilized recursive leastsquares algorithm. The outer loop is based on a linear design, with compensation for the nonlinear couplings arising from ight dynamics. Some parameters of the outer loop are identi ed in real time in order to adapt to varying ight conditions. The algorithm is evaluated using a nonlinear F-16 simulation model. The results demonstrate the consistent performance of the algorithm through various ight conditions, as well as its turn coordination capabilities, its recon guration after a oating left elevator failure, its ability to move across the power curve, and its tolerance to measurement noise and turbulence.

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Development of a hybrid direct-indirect adaptive control system for the X-33

Cited by 17 publications

References 10 publications

Progress in Guidance and Control Research for Space Access and Hypersonic Vehicles

Progress in Guidance and Control Research for Space Access and Hypersonic Vehicles

Evaluation of Optimization Methods for Control Allocation

Reconfigurable Nonlinear Autopilot

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