Research On Wave-off Decision And Manipulation Strategy Of Carrier-based Aircraft

To conduct the landing task and ensure the landing safety, the carrier-based aircraft must overcome the tough landing condition. This is the key point of carrier-based aircraft auto landing. This paper studies this key point bases on the longitudinal intelligent wave-off decision and wave-off manipulate strategy.Firstly, according to the knowledge of flight dynamics and aerodynamics, the carrier-based aircraft nonlinear model is built, the stability and manoeuvrability are analysed. Based on the analysis of nature aircraft, this paper designs Automatic Power Compensation System to improve the path control capability of aircraft and Automatic Carrier Landing System to guide the aircraft along the ideal glide path.Secondly, according to the distribution of touchdown points and hook-to-ramp clearance, the safe flight area is determined by simulation. With the the wave-off criteria, the wave-off area is defined. According to the relative position relations between the safe flight area and wave-off area, the wave-off decision system is established by defining wave-off zone and wave-off process. The simulation results of this system for different landing case indicate that this wave-off decision system can judge whether aircraft is in the wave-off zone and whether it is safe, so it can increase the efficiency and safety for carrier-based aircraft landing.Thirdly, compared with the traditional wave-off manipulate strategy,this paper proposes a combined manipulate strategy, which combines the angle of attack keeping control added with military power control. The control law is defined by PID and fuzzy respectively.The simulation results indicate that this combined manipulate strategy can decrease the wave-zone and increase the efficiency and safety for carrier-based aircraft landing.Finally, this paper proposes a new manipulate strategy to optimize the wave-off area. Added with military power, the elevator control is parameterized to satisfy the distance of wave-off is shortest and the hook-to-ramp clearance is highest as well as the angle of attack is less than stalling angle. The simulation results indicates that the new manipulate strategy can improve the wave-off performance and increase the landing safety.