Research On Autonomous Flight Control Key Technologies

This dissertation mainly investigates the problem of automatic control and path planning in the design of autonomous control of unmanned aerial vehicles (UAVs) based on the development of flight control theory and optimal theory. Faced with the inherently unstable characteristics of modern aircraft, we design an inner control loop of stability augmentation system (SAS) according to Military Specifications using linear control theory and neural network. Then we use intelligent control and dynamic inversion we design a robust tracking controller for UAVs. Finally, we design a path planner added to the autonomous control system to meet a certain extent of autonomous flight capability. Integrating intelligent control, robust control, optimal theory and the requirement of autonomous control we investigated UAVs autonomous control carefully.The main works of this dissertation are as follows:1. With the advent of fly-by-wire flight control technology, it is now possible to shape the handling qualities of an aircraft to desired specifications. The development, background and system structure of autonomous control are studied, and the mainly three kinds of them all over the world are analyzed and compared in order to generalize the characteristics of each one. Then we proposed an autonomous control system structure suitable for our research object including SAS, tracking control system and path planner. We also investigate the modeling of six-degree of freedoms nonlinear equations for UAVs.2. In multivariable control system design, eigenstructure assignment (EA) has been an active topic of research over the past decades. One of the drawbacks of EA techniques as compared with some other multivariable techniques is that the synthesis procedure does not guarantee stability robustness with respect to parameter variations in the system design. In this dissertation, a flight control system design using multi-objective EA based on LMI is investigated to enhance the performance of modern aircraft according to Military Specifications and flying quality requirements and to be used for mode decoupling. According to left-over freedom in eigenvector and the solution of the aircraft control system design is derived using the proposed method, meanwhile, we find that this kind of design method can be classified into an...