Driver Modeling And Handling Stability Analysis Of Multi-axis Vehicle

with the features of heavy loading capacity,large Overall dimensions,complicated structure and poor、changeful working conditions,Multi-axle vehicle is very prone to causing veer distortion when driving at high speed,it also has the possibillity to drift even under the condition of low speed,which can lead to security accident.Therefore it is necessary to further study the handling stability of the multi-axle vehicle.An effective driver model is the essential factor in the closed-loop evaluation of handling stability.For this reason,a driver-vehicle-road closed-loop aimed at Multi-axle vehicle which can do some intensive study on handling stability should be established.On the basis of the research,it has great direction sense and valuable theory reference to the Multi-axle vehicle’s design,manufacture and capability improvement.Firstly,this paper respectively introduces the development of studies on driver model and handling stability both at home and abroad,as well as the evaluation index and test methods of handling stability.Secondly,analysing the structural characteristics of Multi-axle vehicle,a simplified dynamics simulation model which include suspension system,power system,the body,tires and the road and so on is established,based on full understanding of the relationships among actual structure of Multi-axle vehicle.In order to reduce the tedious modeling process and Make the objective clearly,the dynamics model is moderately simplified and established by regarding a majority of parts as rigid bodies except the tires.Thus we can establish a highly reliability dynamics model,which gives adequate preparation to the handling stability of Multi-axle vehicle.Then,based on preview follower theory,the driver model aimed at direction control on the basis of lateral acceleration feedback is established;based on PID control theory,the driver model aimed at speed control is established.On account of research contents above,a brand new comprehensive direction and speed driver model for multi-axle vehicle is established by integrating direction and speed driver model.Solve the coupled problem between direction control and speed control,and then amend characteristic parameters of driver model to meet the requirements of following any speed under arbitrary path.After that,connect the drive model to the Multi-axle vehicle model which is established in Adams/view through Subroutine in Adams/solver,in order to make the drive model applied to complex vehicle model,which lays a foundation for deeper analysis human-vehicle-road closed-loop system.In the end,on the bases of analyzing the domestic and foreign existing evaluation criterion and testing technique in handling stability,combined with the characteristics of multi-axis vehicle,take exploration research on handling stability evaluation of multi-axle vehicle.Separately conduct steady static circular,step angle input of steering wheel,pylon course slalom,double lane and lemniscate test under different speed and different angle,and give the processing method of test data.The parameters obtained from the simulation are fitted for the corresponding curve which states change law of the state parameters.From this we can analyze and assess the stable steering characteristic,transient response characteristic,Steering portability and so on both from objective aspect and subjective aspect.The simulation result verify the effectiveness and correctness of both multi-axis vehicle model and driver model.Discusse some basic factors such as driver,vehicle driving system,steering system and overall structure and so on which greatly influence the vehicle handling and stability.