Research On The Autonomous Flight Control System Of Muti-rotor Aircraft

In the past few decades, with the rapid development of transducers microminiaturization and various control techn iques, Unmannded Aerial Vehicle(UAV) appears more and more in the public, while multi-rotor aircraft has become a hot research field for its simple structure and flexible control strategy. In this thesis, a multi-rotor aircraft is studied, including its autonomous flight control system and practical applications. The main work of this thesis can be summarized as follows:1. A mathematical model of the flight system in vertical direction is analyzed on the basis of multi-rotor aircraft operating principles, combining the single propeller aerodynamic performance, then the structural composition of the hardware system is designed and studied from the perspective of modularization. Creteria for selection is provided acc ording to the particular application.2. A general autonomous flight control system is developed. This control system is based on the commercially available flight control product, and use the flight control signal access technology to control the flight s ystem autonomously. This procedure is able to enhance stability and flexibility of the programmable autonomous flight control system, while the secondary development capability is also enhanced. Moreover, by capturing and generating control signals from DS P, the flight control signal can be identified and calibrated automatically, which siplifies the advance matching procedure of the control systems.3. A altitude control system based on the Active Disturbance Rejection Control technique is designed to eliminate the unmeasured disturbance of the stable control system in low altitude flight. The stable and reliable height information is obtained by collecting, compensating, outliers eliminating and filtering the height data, then the order of the controlled s ystem model is identified by experiments, which provides the necessary priori knowledge for the feed-forward disturbance compensation with linear Extended State Observer(ESO). Active Disturbance Rejection Controller(ADRC) is employed to control the height of the nominal model, and simulation results verify the efficiency of the proposed algorithm.4. Several typical applications that combine the vision-based navigation system are further stusied on the basis of the autonomous flight control system. With the eight-rotor aircraft platform, lacalization and tracking of the moving and static targets are fulfilled, and spatial lacalization of the ground targets is accomplished with the altitude control system. Moerover, autonomously recognition, grab and stack up of the specific objectives on ground are also fulfilled with the airborne mechanical grab structure.