Abstract A reconfigurable control law for the full X-33 flightenvelope has been designed to accommodate a failedcontrol surface and redistribute the control effort amongthe remaining working surfaces to retain satisfactorystability and performance. An offline nonlinearconstrained optimization approach has been used for theX-33 reconfigurable control design method. Using anonlinear, six-degree-of-freedom simulation, three Qbetaexample failures are evaluated: ascent with a left bodyflap jammed at maximum deflection; entry with a right RCSinboard elevon jammed at maximum deflection; andlanding with a left rudder jammed at maximum TAEMdeflection. Failure detection and identification arexaccomplished in the actuator controller. Failure responsecomparisons between the nominal control mixer and the xreconfigurable control subsystem (mixer) show thectbenefits of reconfiguration. Single aerosurface jammingfailures are considered. The cases evaluated are 13representative of the study conducted to prove theadequate and safe performance of the reconfigurable Ycontrol mixer throughout the full flight envelope. The 8X-33 flight control system incorporates reconfigurableflight control in the existing baseline system.
[1]
David Bodden,et al.
Multivariable control allocation and control law conditioning when control effectors limit
,
1994
.
[2]
John J. Burken,et al.
Updated Results of Deterministic Reconfigurable Control Design for the X-33 Vehicle
,
1998
.
[3]
Charles Hall,et al.
X-33 Attitude Control System Design for Ascent, Transition, and Entry Flight Regimes
,
1998
.
[4]
R. Fletcher.
Practical Methods of Optimization
,
1988
.
[5]
T. M. Williams,et al.
Practical Methods of Optimization. Vol. 1: Unconstrained Optimization
,
1980
.
[6]
Roger Fletcher,et al.
A Rapidly Convergent Descent Method for Minimization
,
1963,
Comput. J..