Structured Robust Control for a Hang Glider

Abstract

No one can deny the significant role of gliders in founding the aviation industry, so far in its evolutionary progress. Gliders are eco-friendly as they exploit the energy from the atmosphere from mother nature without a necessity for a power plant and they remain a loft in air by soaring utilizing the updrafts and air currents. Nevertheless, they are still limited in aspects of range, endurance, speed, control and stability. However, nowadays, the aviation industry seeks to go green as a result of the great air pollution caused by the large amounts of smokes and gases generated from the massive amount of fuel combustion. Maybe using modern automation technologies and making use of some glider’s features, but at the same time maintain the performance and the efficiency of the modern aircrafts can lead to new green innovations in the field of aviation. This thesis is proposing a design of a controller for the Hiway Demon hang glider to guarantee the stability of the system with certain level of performance and to enhance the system’s rejection to the disturbances affecting it drastically during soaring. The controllers are designed using classical (Inversion Formula) control technique and advanced (robust) control technique. The nonlinear state-space model of the aircraft is linearized. After that, it is decoupled into lateral and longitudinal models. The longitudinal model is reduced to short period model in order to facilitate the analysis and the design of the controllers. The pitch rate channel is stabilized, while the lateral model suffered of instability problems, but a suggestion proposing to apply a Multi-DOF controller on the model in the near future. The controllers are evaluated in terms of disturbance rejection, noise attenuation and control efforts. The robust control approach has exhibited better convenience for such application than the classical control approach especially in term of disturbance rejection.