1,720,970 research outputs found
Trajectory Optimization Procedures for Rotorcraft Vehicles Including Pilot Models, with Applications to ADS-33 MTEs, Cat-A and Engine Off Landings
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Trajectory Optimization Procedures for Rotorcraft Vehicles, Their Software Implementation and Applicability to Models of Varying Complexity
No full textThis paper describes numerical procedures for the solution of trajectory optimization problems in rotorcraft flight mechanics. We specifically consider procedures which can be easily interfaced with black-box flight simulators, with minimal assumptions on the functionalities of such third-party software components, and which can cater to a wide range of vehicle models of varying complexity. At first we identify in the direct approach to the solution of maneuver optimal control problems the method of choice for this class of problems. Next, we formulate the direct transcription and the direct multiple shooting approaches, we discuss their characteristics and identify their respective optimal application areas. Finally, we describe the functionality and architecture of a general purpose code implementing both methods. The capabilities of the proposed procedures are demonstrated with the help of practical examples of industrial relevance, regarding both helicopters and tilt-rotors
Maneuvering Multibody Dynamics - New Developments for Models with Fast Solution Scales and Pilot-in-the-Loop Effects
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Trajectory Optimization Strategies for the Simulation of the ADS-33 Mission Task Elements
No full textThis paper is concerned with the formulation of ADS-33 Mission Task Elements (MTEs) as trajectory optimization problems, and describes efficient numerical solution procedures for this class of problems. MTEs are maneuvers specifically designed to quantify the Handling Qualities of rotorcraft vehicles. Here we show that MTEs, being characterized by a mission target which must be accomplished while satisfying a set of constraints, can be readily described in a precise mathematical sense by defining equivalent constrained optimal control problems, whose solution yields the best possible performance of a given helicopter in performing a given MTE. The capabilities of the proposed methodology are demonstrated with the help of representative numerical simulations
Fast Free Wake: a Possible Approach to Real-Time Rotor Wake Simulation
No full textAccounting for wake-body interference effects in real-time simulations is still a challenge. To this aim the Fast Free Wake (FFW) model has been developed. It consists in a simple elaboration of the free-wake concept: vortex rings are released every certain time step from the rotor disk, and then they are free to move, interacting with all the other vorticity sources in the flow field without constraints. Wake deformation is accounted for by rings movement and diameter variation, while vorticity strength is directly related to the instantaneous rotor thrust value. The model has been developed, implemented, and then validated in hover, forward flight, vertical flight both In Ground Effect (IGE) and Out of Ground Effect (OGE). The computational efficiency of the model has been deeply investigated and the real-time running capability has been confirmed. The low computational cost required by FFW, together with its fair accuracy, makes the proposed model a valid tool for real-time flight mechanics simulations
Trajectory Optimization Procedures for Rotorcraft Vehicles, Their Software Implementation, and Applicability to Models of Increasing Complexity
No full textThis paper describes numerical procedures for the solution of trajectory optimization problems in rotorcraft flight mechanics. Specifically, procedures are considered that can be easily interfaced with black box flight simulators, with minimal assumptions on such third-party software components, and that can cater to a wide range of vehicle models of increasing complexity. First, the direct approach to the solution of maneuver optimal control problems is identified as the method of choice for this class of problems. Next, the direct transcription and the direct multiple shooting approaches are formulated, their characteristics are discussed, and their respective optimal application areas are identified. Finally, the functionality and architecture of a general-purpose code implementing both methods is described. The capabilities of the proposed procedures are demonstrated with the help of practical examples of industrial relevance, regarding both helicopters and tiltrotors
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