Research On Key Technologies Of Semi-active Mounting In Cab Of Truck

In recent years,with the rapid development of logistics transportation industry,the technical requirements of freight transportation are constantly improved.Trucks play an important role in the transportation industry.During long-distance transportation,the vibration of the cab directly affects the physical and mental health of the passengers and transportation safety.The semi-active suspension has advantages of merging active suspension,as the better vibration control effect,and passive suspension including low price.It is getting more and more attention by automobile industry.The research team cooperates with a vehicle enterprise to carry out the cab semi-active suspension researches.The main purpose of the first stage is to realize the closed-loop process of semi-active mount.Building a model,model-algorithm simulation,software and hardware integration-sample,truck test,and to establish the whole system.The specific research contents are as follows:(1)The model of air spring and the mathematical model of damping force characteristic curve were established.Establish air spring model with height valve and additional cylinder.For the analysis of continuous damping control(CDC)shock absorber,under the condition that the current affects the damping force of the shock absorber fully,according to the test data of the CDC shock absorber provided by the enterprise,the characteristic curve of the exciting speed and the recovery and compression damping force of the CDC shock absorber was defined under the condition that the shock absorber enters different current.The established shock absorber model provided a necessary basis for the subsequent study of the vibration characteristics of the semi-active suspension of the truck cab.(2)Vehicle dynamics modeling and semi-active mount numerical simulation.Based on a certain type of truck,the mathematical model of 12-degree-of-freedom truck was set up.Basing on the idea of whole vehicle sky-hook damping control algorithm,The results from Matlab /Simulink showed that compared with passive damping suspension system,semiactive control significantly improves cab comfort.(3)Design and integrate hardware and software of semi-active suspension control system.The STM32F407ZGT6 microcontroller developed by ST company was selected,as the control chip of the semi-active mount system,the semi-active mount control hardware was designed and made,the semi-active mount control program was developed and the hardware and software integration of the semi-active mount control system was realized.Taking a company’s truck products as an example,the semi-active suspension was truck tested.The results showed that compared with passive mount,semi-active mount on the secondary cement pavement,the vertical acceleration RMS value of cab seat is reduced by13.9% and the lateral decrease is 19.5%.