Performance Analysis And Parameter Optimization Of Displacement-sensitive Shock Absorber

The automotive shock absorber is a key component of the suspension system,which plays an important role in the riding comfort,driving safety and handling stability of the car.The damping of adjustable shock absorber is more changeable than traditional hydraulic shock absorber,which can meet the vehicle various performance requirements very well.The displacement-sensitive shock absorber is a new type of variable damper that is improved by opening displacement-sensitive groove on the basis of a traditional hydraulic damper.The shock absorber utilizes piston displacement changes to automatically change the damping to meet various driving performance of the vehicle.It has a wide application prospect in the automotive field.Therefore,it is of great practical significance to carry out theoretical research on displacement-sensitive shock absorber.Main contents are as follows:(1)A displacement-sensitive shock absorber is designed based on the structure of single-tube shock absorber.The damping force calculation formula for the displacement-sensitive shock absorber is deduced in detail within the combination of relevant knowledge about fluid mechanics and the analysis of relationship between the oil flow in recovery stroke and compression stroke.(2)Matlab/Simulink software is used to establish a displacement-sensitive damper simulation model and analysis on the damping characteristics at different positions of displacement-sensitive groove.The correctness of simulation model is verified under the comparison of experimental damping characteristics data.The model is used to analyze the influence of piston valve parameters change and sensitive groove parameters change on its damping characteristics.(3)The 1/2 vehicle vibration model with a displacement-sensitive damper is built.The conditions for the comfortable vehicle ride are researched on different conditions such as road surfaces,vehicle loads and vehicle speeds.The comparisons are analyzed under the effects between displacement-sensitive shock absorber and traditional shock absorber onthe comfort ride of vehicle.The results show that the displacement-sensitive shock absorber has a certain advantage in damping vehicle vibration.(4)Based on the evaluation index of vehicle ride comfort,the 1/2 vehicle vibration system of the coupling displacement-sensitive shock absorber is taken as the object of study,and the ride comfort under different vehicle loads are taken as research objectives.The data integration platform is established for Isight and Matlab/Simulink.NSGA-II Genetic Algorithm is used to optimize sensitive slot parameters of displacement-sensitive vibration absober.The results show that the damping performance of the optimized displacement-sensitive damper is further improved,which satisfies the requirements for matching vehicle damping.