Research On Shift Strategy Of Battlefield Road Survey Vehicle Based On Road Condition

With the changes in traditional combat methods and tactics,battlefield road survey vehicles that are responsible for surveying frontal terrain information and reconnaissance of enemy information before the main force have become more and more important.Due to the special use environment of battlefield road survey vehicles and other military vehicles,it is necessary to conduct targeted optimization research on the key technology of gear decision: In order to improve vehicle dynamics and safety,this thesis determined typical road surface characterization parameters,compared and analyzed different gear shift strategies,and finally formulated gear shift strategies that meets the dynamic requirements of battlefield road survey vehicles under special road conditions.The research conclusions can provide certain theoretical guidance for the actual vehicle development of battlefield road survey vehicles.This thesis focuses on the research on the shift strategy of a certain type of battlefield road survey vehicle.The survey vehicle can recognize different road types before switching to the corresponding shift strategy.In view of the lack of a unified standard for road surface classification,starting from the two aspects of pavement geometric characteristics and pavement mechanics characteristics,this thesis deeply analyzed the road surface roughness,slope,adhesion coefficient and rolling resistance coefficient,discussed its influence on the dynamic performance of the vehicle,and finally classified the road based on the above parameters.On the basis of determining the basic parameters of the vehicle and the structure of the transmission system,in order to simplify the development process of the shift strategy,this thesis established the vehicle power transmission system,road and shift strategy models based on the Car Sim/Simulink co-simulation platform.The power transmission system model mainly includes Engine model,clutch model,transmission model,transfer case model,differential,final drive model and tire model.This thesis used design performance indicators to verify the correctness of the simulation model.Based on the simulation model,using the optimal power shift strategy and the optimal economical shift strategy,this thesis simulated and analyzed the results of gears,vehicle speed,clutch status,displacement and fuel consumption.The simulation results showed that the two shift strategies can meet the practical application requirements of power and economy respectively.Aiming at ramp and low-attachment road,this thesis launched the research work on the shift strategy of survey vehicles under special road conditions: based on the two characterization parameters of slope and road adhesion coefficient,this thesis formulated the identification criteria for ramp and low-attachment road;This thesis adopted the scheme of optimizing the optimal power shift strategy to formulate the uphill shifting strategy,which solves the problem of shift cycle when the survey vehicle is climbing;based on fuzzy logic reasoning,this thesis formulated the downhill shift strategy,using Engine anti-drag torque assists braking to reduce the time of brake pedal manipulation,which can effectively avoid the problem of brake disc overheating;based on the principle of tracking the optimal slip rate and estimating the optimal road adhesion coefficient,this thesis formulated the low-attachment road shift control strategy,which integrates engine output torque control,modified shift strategy and gear intervention control.The low-attachment road shift control strategy can solve the problem of excessive tire slip when the survey vehicle is driving on low-attachment roads,and improve the vehicle’s power performance.There are 60 pictures,16 tables and 77 references in this thesis.