| Guided rocket is a low cost intelligent ammunition equipped with guidance and control device in front of rocket warhead,which has been widely used in national defense equipment.As the main executive component of guided rocket flight control system,the steering gear system has complex structure,long development period and high cost,and prominent reliability problems.The traditional reliability test and evaluation method requires a large number of newly developed products to carry out the test,which is usually carried out in the late development period,and the test period is long and the cost is high.The engineering practice shows that the traditional reliability design analysis and test evaluation method is more and more difficult to meet the development requirements of guided rocket steering gear system.In practical work,the performance parameters of the steering gear system inevitably have random uncertainties,which will directly affect the performance of the steering gear system at work,directly affect the operational effectiveness of guided rocket,and in serious cases will cause serious accidents that delay the aircraft.Therefore,it is necessary to study the performance and reliability of steering gear system of guided rocket in service.This paper took the steering gear system of a certain type of guided rocket as the research object,determined the random performance parameters affecting the steering gear system,and established the mathematical model,simulation model and reliability model of the rudder wing opening mechanism and steering gear control system of the steering gear system according to the composition and working principle of the steering gear system.Considering the random uncertainty of performance parameters,the surrogate model method was used to simulate the performance reliability of the steering gear system.The main work contents are as follows:(1)The potential failure modes and influencing factors of the steering gear system were analyzed,and the main intermechanism friction,rudder wing and rotor shaft clearance,spring stiffness were determined as the random parameters affecting the operating performance of the rudder wing opening mechanism;The friction between push rod and fork,clearance of ball screw,control parameters,sensor parameters and clearance of steering gear were determined as the random uncertain parameters that affect the performance of steering gear control system,and the solution method of stochastic reliability model was analyzed.(2)The dynamic model of the rudder wing opening mechanism was established,and the aerodynamic load of the rudder wing opening was determined by CFD simulation.The rigidflexible coupling dynamic parametric simulation model of the rudder wing opening mechanism under the service state of guided rocket was established in ADAMS platform,and the model was verified.The influence of random parameters on the performance of the rudder wing opening mechanism was studied by simulation,and the main random parameters of the rudder wing opening mechanism were screened.(3)The mathematical modeling of the steering gear control system was carried out.The simulation model of the steering gear control system and the dynamics model of the mechanical transmission system were established respectively in Matlab/Simulink and ADAMS.On this basis,the electromechanical co-simulation model of the electric steering gear control system was established by using Matlab/Simulink.And the model was verified.The influence law of random parameters on the performance of steering gear control system was studied by simulation,and the main random parameters affecting the performance of steering gear control system were screened.(4)Considering the random uncertainty of performance parameters,the performance reliability of the servo system in service state was studied.By using Isight software,the neural network(RBF),Kriging and response surface(RSM)surrogate models corresponding to the performance indexes of the steering gear system with random uncertain parameters were established respectively.The surrogate models with the highest accuracy were selected by analyzing and comparing,and the performance reliability of the steering gear system was calculated by combining the six sigma principle and Monte Carlo method.The performance reliability of rudder wing opening mechanism is 0.9973,and the performance reliability of steering gear control system is 0.999.According to the reliability model of steering gear system,the performance reliability of steering gear system is 0.9963,which effectively evaluates the reliability of steering gear system.In addition,the reliability calculation results show that the reliability of rudder wing opening synchronization time was relatively low.The analysis reason is that the guided rocket adopts compression spring drive mode.During the working process,the spring stiffness is susceptible to external environment interference,which produces large random uncertainty on the driving torque of the four rudder wings,resulting in the relatively dispersed rudder wing opening synchronization time. |
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