| First of all, in this papers both turning theories and turning characteristics of 4WS automobile were illuminated; The two degrees of freedom and three degrees of freedom mathematical model of 4WS automobile were established, and the response character of yaw velocity and slip side angle of two degrees of freedom 4WS automobile were deduced. At this base, the steer characteristic of front and rear wheel proportional control 4WS and 2WS automobile on time domain together with frequency domain were comparative analyzed, and then the characteristic of high speed stabilize and low speed flexible of 4WS automobile were demonstrated.In the next place, rear wheel steering system as well as front and rear wheel turning control relation were established through internal module as well as relevant parameter modified base on ADAMS/car model block, thus 4WS automobile whole virtual prototype mode was created;The transient response characteristics and the steady state characteristics and the influence of wheel tire lateral deviation stiffness to turn ability.Once more, front and rear wheel turning fuzzy controller was created using MATLAB 'Fuzzy Logic Toolbox, The control model and virtual prototype model were co-simulated through the medium of ADAMS/control, and then the steering characteristic of 4WS virtual prototype were comparative analyzed both yaw velocity feedback control and fuzzy control, as a result, fuzzy control take on both best robustness and manipulate stability.Lastly, the integration of 4WS technology and VDC technology were preliminary researched, as a result, the turn radius was reduced and turning flexibility was enhanced in high speed thought the conjunction of 4WS technology and brake turning technology,4WS automotive overall performance were advanced. The conjunction of 4WS and currently advanced automotive electronic technology have both prodigious develop space and engineering practical worth, as 4WS technology future trend were pointed out. |
PDF Full Text Request