| Folding wing is the key technology to match carrier-based aircraft with aircraft carrier.With the folding wing technology,the span siza of carrier-based aircraft can be reduced,so that the aircraft carrier can accommodate as many carrier-based aircrafts as possible in the limited deck space,and enhance the combat effectiveness.The J-20,F-22 and F-35 fighters all adopt a multi-wing coordinated control scheme.The wings are folded to increase the maneuverability of the aircraft if necessary.The future development trend of aircraft is more electric and all-electric aircraft,and the folding wing with electric actuation technology can not only avoid some problems caused by hydraulic transmission,but also has many advantages such as reducing aircraft weight and improving maintainability.Based on the above background,this article takes the electrically-actuated folding wing as the research object,and conducts in-depth research on key issues such as its folding mechanism,aerodynamic analysis,dynamic simulation,control strategy and reliability evaluation.The specific research contents are as follows:(1)According to the requirements of folding wing,the aerodynamic characteristics of the airfoil were analyzed,and the appropriate airfoil was selected by the comprehensive index evaluation method.In order to meet the related requirements of compact structure and light weight,the relevant parameters of the folding mechanism were determined based on the planar mechanism analysis method.(2)In order to ensure the flight safety and the accuracy of dynamics simulation,the numerical calculations were analyzed by using the computational fluid dynamics method.The aerodynamic characteristics of the outer wing and folding wing were analyzed in detail,and the change trend of the lift and drag of folding wing with the angle of attack was analyzed.The results showed that folding wing can solve the contradiction between the high and low speed performance requirements of the aircraft,and at the same time,the remedial measures for the abnormal folding of the wings during the flight were given according to the simulation results.(3)Three-dimensional models of the inner wing,outer wing and folding mechanism were established and assembled in CATIA.At the same time,the wing folding process before and after aerodynamic loading was simulated in LMS Virtual.Lab Motion.The simulation results were analyzed from the perspectives of kinematics and dynamics,and the results showed that the aerodynamic load effect increased the maximum driving load of the actuator by 34.63% and reduced the maximum load by 25.47%.(4)Aiming at the electric control of the folding wing,the three-loop position servo control strategies of current loop,speed loop and position loop were designed.At the same time,combined with the mathematical model of the brushless DC motor and the transmission mechanism,the simulation model of the brushless DC motor and the position servo of the folding wing system were established in MATLAB/Simulink.The control system was simulated and analyzed,and the results showed that the system had good dynamic stability and tracking performance.(5)In order to improve the reliability of the folding wing control system,the reliability of the folding wing control system was quantitatively analyzed based on GO method.The GO model of the system was established.The probability of the successful operation of the system was 0.9999649 by using the GO method probability formula,and the probability of success calculated by fault tree analysis method was 0.9999556.It was verified that the reliability of the folding wing control system can meet the requirements.The research results of the thesis can provide a certain theoretical reference for the design and control of the electrically actuated folding wing system. |
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