Guidance strategies for near-optimum take-off performance in a windshear
This paper is concerned with guidance strategies for near-optimum performance in a windshear. This is a wind characterized by sharp change in intensity and direction over a relatively small region of space. The take-off problem is considered with reference to flight in a vertical plane. First, trajectories for optimum performance in a windshear are determined for different windshear models and different windshear intensities. Use is made of the methods of optimal control theory in conjunction with the dual sequential gradient-restoration algorithm (DSGRA) for optimal control problems. In this approach, global information on the wind flow field is needed. Then, guidance strategies for near-optimum performance in a windshear are developed, starting from the optimal trajectories. Specifically, three guidance schemes are presented: (A) gamma guidance, based on the relative path inclination; (B) theta guidance, based on the pitsch attitude angle; and (C) acceleration guidance, based on the relative acceleration. In this approach, local information on the wind flow field is needed. Numerical experiments show that the guidance schemes (A), (B), (C) produce trajectories which are quite close to the optimum trajectories. In addition, the near-optimum trajectories are considerably superior to the trajectories arising from alternative guidance schemes. An important characteristic of the guidance schemes (A), (B), (C) is their simplicity. Indeed, these guidance schemes are implementable using available instrumentation and/or modification of available instrumentation.
dual sequential gradient-restoration algorithm
scientific article; zbMATH DE number 3924626
scientific article