Research On Optimization Design Technology Of Ejection Mechanism Of A Carrier-based Aircraft Nose Landing Gear

The ejection take-off technique is the future direction of a carrier-based aircraft.The normal operation of the ejection rod driving mechanism is the key to ensure the safety of a carrier-based aircraft.Based on the research of the ejection rod driving mechanism of some foreign carrier-based aircraft,the boundary conditions of the driving device design were summarized,then two kinds of ejection rod driving mechanisms were put forward in this thesis.Theoretical calculation models were established based on Matlab/Simulink,and correctness of theoretical calculations were verified by comparison with simulation models.On the basis of theoretical models,ejection rod driving mechanisms' parametric models and optimization analyses were carried out.It provides a reference for the design of an ejection rod driving mechanism.Regarding the carrier-based aircraft's ejection rod driving mechanism as a research object,two kinds of motion constraint equations and dynamic equations were derived,considering the influence of the aerodynamic force,fast-extension over-load and output torque of the rotary actuator on the movement of the mechanism.Two kinds of driving mechanisms' theoretical calculation models and simulation models were built through Matlab/Simulink and LMS Virtual.Lab Motion.Results show that theoretical calculation results are consistent with simulation results.The B-type ejection rod driving mechanism has a larger rebound angular acceleration.Considering different rods' lengths combination,mechanism's performances are quite different.Therefore,based on theoretical analysis models,two ejection rod driving mechanisms' parameter models were established.Taking rods' lengths as design variables and the initial rebound angular acceleration of ejection rod as optimization target,the optimization was carried out with the combination optimization method under the condition of satisfying motion requirements of the ejection rod driving mechanism.The optimization result effectively improved the initial bounce angle acceleration of the ejection rod.Compared with two optimization results,it's further validated that the B-type ejection rod driving mechanism has a larger initial rebound angular acceleration.The reason why the B-type ejection rod driving mechanism has a larger initial rebound angle acceleration was explained by a statistical analysis of feasible solutions in the optimization process.