Nonlinear Optimal Control Of Aircraft Arresting Process

In the landing process of carrier-borne aircraft, the aircraft is expected to be still in a shorter run way compared with normal aircraft. In order to achieve this goal, engineers have designed aircraft arresting system, which is a very important carrier-borne equipment. The design and realization of the control law for the arresting system directly influence the overloading that an aircraft can bear, the distance for arresting, the tension in the arresting cable and ultimately determine the effectiveness of arresting. Therefore, in the developing process of the arresting system, we are motivated to find the optimal deceleration rate and an effective control method.Oversea research on this topic started earlier in the 1920s and their technology is well developed compared with domestic results. However, the search for related documents and articles results in only a few full-text research reports with large numbers of abstract. In China, engineers and scholars have endeavored to develop their arresting system, but the corresponding research is at a premature stage. In order to promote their incomplete research, this thesis takes the elasticity of the arresting cable into the nonlinear dynamics model generated by the motion of the arresting cable in a large area. Based on this nonlinear model, optimization method is employed to find the optimal deceleration trajectory after the contact of aircraft and the arresting cable. Then, feedback linearization is used to tracking the optimal deceleration trajectory in a closed loop. Compared with control method based on the analysis of energy in the past, this method is more powerful in keeping deceleration at a constant level. Therefore, this model-based optimization and control law is more effective. The results of the simulation also indicate that, near the end of the arresting process, the results obtained with and without the elasticity of the arresting cable differ with each other in a dramatic way. Moreover, the numerical experiment proves that feedback linearization can compensate the time-consuming nonlinear optimization method, so that make the control system more applicable. Because specification of control objectives and the operation of the control method are separate steps, the arresting system, which employs the proposed control method, can accommodate a large variety of aircraft in the arrestment.For the above results outlined, this thesis provides valid reason and practical plan for the improving of current aircraft arresting system. Therefore, it has important value in the practical application.