Print Email Facebook Twitter Investigation on a passenger ride-comfort improvement system with limited control surface actuator performance for a flexible aircraft Title Investigation on a passenger ride-comfort improvement system with limited control surface actuator performance for a flexible aircraft Author Erkelens, L.J.J. Schuring, J. Institution National Aerospace Laboratory NLR Date 1975-11-28 Abstract For the low wing-loading aircraft, considered in this investigation, vertical acceleration appeared to be an important factor concerning passenger comfort. To reduce vertical motions, a ride-comfort improvement system was introduced. Determination of parameters of the system, like gains and allowable performance limitations, required analog simulation because of strong non-linearities. Symmetric aircraft dynamics, ride-comfort improvement system and atmospheric turbiolence were presented by mathematical models. The aircraft's model consisted of two rigid body and three structural modes. The ridecomfort improvement system comprised fast-moving auxiliary flaps, over the entire flap span, being commanded by a vertical acceleration sensor. The driving actuators were subject to acceleration, rate and displacement limits. Vertical atmospheric turbulence was modelled according to the Dryden spectrnun. A phugoid instability attitude-hold system. A more serious problem was posed by a limit cycle instability, due to interference of the wing bending mode with the actuator rate limitation. Decoupling of wing bending motion and flap action was provided by relocation of the acceleration sensor. An optimization of the ride-comfort improvement system was carried out, by means of parameter variation, and resulted in a satisfactory performance. Reductions in vertical acceleration up to about 50 % were obtained, in heavy turbulence, realistic actuator characteristics being included. Subject acceleration controlanalog simulationactuatorsflexible aircraftgust alleviatorsatmospheric turbulencemathematical modelscomfort To reference this document use: http://resolver.tudelft.nl/uuid:32d48874-f7ce-4559-9f10-8faa3a490fe9 Publisher Nationaal Lucht- en Ruimtevaartlaboratorium Access restriction Campus only Source NLR-TR 75140 U Part of collection Aerospace Engineering Reports Document type report Rights (c)1975 National Aerospace Laboratory NLR Files PDF NLR_TR_75140_U.pdf 28.21 MB Close viewer /islandora/object/uuid:32d48874-f7ce-4559-9f10-8faa3a490fe9/datastream/OBJ/view