Dynamic Simulation For Electromechanical Actuator Servo System Of High-speed Vehicle

In accordance with the energy used, Steering servo system can usually bedivided into pneumatic steering, hydraulic steering, electeromechanical steering.Traditional rockets and missiles adotp the pneumatic steering servo system or thehydraulic steering servo system, with the greet development of aerospacetechnology and a variety of study on the advanced precision-guided weapons, we arestrict on the overall performance of steering gear. Electeromechanical steering issimple and reliable, easy to control, and cost less, those advantages attractedwidespread attention and deeper research. At prfesent, domestic and foreign researchon electeromechanical steering system focused on control method, and there is fewstudy of dynamic characteristics of electeromechanical steering system, the system’sstructural dynamics characteristics have a great influence on the stabilityelectromechanical steering and overall accuracy, so based on the model ofelecteromechanical steering system, the article gived a study of various aspects ofthe system and the overall dynamics, built up a method of studying the dynamics ofthe electromechanical steering servo system, lay a foundation to studying of steeringaeroelasticity and contral system.Firstly, it set up a kinematic model of electromechanical steering servo system.Based on the Herz contact theory, this article studied the elastic deformation of theplanetary roller screw, also deduced the transmission ratio of the planetary rollerscrew. At the same time, it gave the theoretical analysis of the electromechanicalsteering servo system’s kinematic relationship; Based on those, it conducted akinematic simulation by Adams, had got the law of the actual load transmission,laying a foundation to studying on dynamics research of the electromechanicalsteering servo system.It established the finite element model of Electromechanical steering servosystem, combined with kinematic analysis, can get the load boundary conditions.Respectively, it simulated for the dynamics characteristics of key connection,planetary roller screw, the guide mechanism and lug connection, with emphasis onthe contact gap, collision and friction’s response to dynamic characteristics. Theresults showed that: after the key connection is inverted, the double key structure ismore quickly than the single one, the angular displacement of no clearance gap islarger than the other one; for the planetary roller screw, the elastic deformation ofthe roller increases by preload’s grew; guiding mechanism’s angular displacement iscorrespond with the amount of the nut’s backlash, but the maximum axial displacement of the nut has nothing to do with the amount of backlash; the larger thefriction of pin is, the more delay for the dynamic response.Based on the previous kinematics and dynamics study, established themathematical model of electromechanical steering servo system, dealing withhigh-order dynamics systems, used Matlab/Simulink to study the dynamics ofelectromechanical steering servo system, and thus validated the finite elementanalysis and dynamic mathematical model.