On The Flight Control Algorithm About Post-Stall Attack Maneuvering

In order to improve the aircraft flying qualities, enhance the aircraft's survival and fighting capacity, countries are studying new flight control technology. Although China started late in this regard, but since the beginning of the 20th century, with the control theory and the rapid development of computer technology, modern flight control technology has been widely applied to China's fleet is equipped with more and more flight control system.Generally speaking, the aircraft's flight performance and flying qualities are determined by the aerodynamic characteristics of aircraft and engine characteristics.The aircraft's performance will change with the flight conditions changing. It is difficult for the pilot to control the aircraft effectively, especially in the attack maneuver flight of high angle. The aircraft is basically in a state of static instability in flight, its flight performance and flying qualities deteriorate rapidly. In view of this situation, the paper studied an effective method to resolve nonlinear control problems - dynamic inversion control based on reading a lot of relevant information at home and abroad, so that the deterioration of flight performance and flying qualities in the attack maneuver flight of high angle has been eased.The paper studied the kinetics characteristics of a certain type of aircraft starting with dynamic modeling. Some different movement equations of the aircraft are established according to its different campaign laws. The simulation results show the reasonableness of the model, at the same time reveals that the aircraft has different flight performance and flying qualities in flight of conventional flight and post-stall flight. Dynamic inversion control strategy can achieve effective control of the aircraft in the post-stall maneuver flight. It is an effective method of nonlinear feedback linearization, has the advantage of clear physical concept, widespread application and simple application, it is suitable for the realization of the project.It also found that the dynamic inversion control has some problems in practical application. Its limitations are excessive reliance on the system model and demand of reversibility of the system in the application.According to the movement characteristic of aircraft, the state variables of aircraft will be divided into two groups based on the principle of time-scale separation. And then we designed flight control system by using dynamic inversion control theory. The simulation results show that the designed controller can achive effective control of aircraft both in the conventional flight and in the post-stall maneuver flight, so that the light performance and flying qualities have been improved.The paper analysed the inverse error due to outside interference and cancellation error of nonlinear and compensate it by using the PI controller.