Accession Number : ADP007940

Title :   Navigation Guidance and Trajectory Optimization for Hypersonic Vehicles,

Corporate Author : HONEYWELL SYSTEMS AND RESEARCH CENTER MINNEAPOLIS MN

Personal Author(s) : Schultz, R. L. ; Hoffman, M. J. ; Case, A. M. ; Sheikh, S. I.

Report Date : DEC 1990

Pagination or Media Count : 22

Abstract : A computationally efficient, real-time trajectory optimization and guidance approach for hypersonic aircraft is described. The optimization algorithms compute, in flight, minimum fuel trajectories within constraints from the current aircraft position to its final destination. In flight trajectory computation can provide a high degree of vehicle autonomy which could greatly reduce aircraft ground support costs. The optimization approach is based on Euler-Lagrange theory and energy-state approximations. A three-dimensional, spherical earth, aircraft motion model, with constraints on temperature, dynamic pressure and stall, is employed. An exact optimal iterative solution method and an approximate closed-form feedback solution method are developed. In the exact approach, solutions are computed By iteration on adjoint constants. Each iteration requires a complete forward trajectory integration. In the approximate closed-form feedback approach, the adjoint constants are expressed in terms of the states. No forward trajectory calculations are required, thus, the computations are minimal. Minimum-fuel climb to orbit, powered abort, and unpowered abort trajectories are computed with both methods. The approximate closed-form feedback solution closely matches the optimal iterative solution.

Descriptors :   *GUIDANCE, *HYPERSONIC AIRCRAFT, *TRAJECTORIES, *AIR NAVIGATION, ABORT, AIRCRAFT, ALGORITHMS, APPROACH, COMPUTATIONS, CONSTANTS, COSTS, DYNAMIC PRESSURE, DYNAMICS, ENERGY, FEEDBACK, FLIGHT, FUELS, GROUND SUPPORT, INTEGRATION, ITERATIONS, MODELS, MOTION, OPTIMIZATION, ORBITS, PRESSURE, REAL TIME, TEMPERATURE, THEORY, THREE DIMENSIONAL, TIME, VEHICLES.

Subject Categories : Research and Experimental Aircraft
      Flight Control and Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE