A Search for the Minimum-Fuel Landing Trajectory of a Tilt-Wing VTOL Aircraft.

Abstract

Optimal control techniques are used to find the minimum-fuel landing trajectory of a tilt-wing VTOL aircraft. A fourth-order, nonlinear, mathematical model of the XC-142A was used, employing three controls: wing incidence, thrust and a limited authority pitch control. Optimization was accomplished by the conjugate gradient method using penalty functions to control terminal error and constrained variables. A control variable transformation was used to constrain the controls. To start the optimization algorithm, initial controls were computed to perform a landing trajectory with the model without exceeding the constraints. The increase in computing time due to the transformation was negligible. Convergence to terminal conditions was hindered by a wing lift anomaly. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1969
Accession Number
AD0860596

Entities

People

  • Harold A. Brattland

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Airframes
  • Algorithms
  • Convergence
  • Heuristic Methods
  • Mathematical Models
  • Mathematics
  • Models
  • Optimization
  • Terminals
  • Tilt Wing Aircraft
  • Tilt Wings
  • Trajectories
  • Vehicles

Readers

  • Aviation Science / Aeronautics.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Systems Analysis and Design