Research Of Four-wheel-steering Vehicle Control Strategy Based On Differential Game

As an important research direction of the vehicle chassis control field, thefour-wheel-steering technology can reduce vehicle’s turning radius at low speed and decreasevehicle’s side slip angle at high speed. Therefore, this technology can improve vehicle’shandling stability especially in changing lane and overtaking. The following contents areresearched according to this technology.Firstly, the theory and characteristics of four-wheel-steering and the current researchsituation and methods are stated. Based on this, the research significance and contents of thispaper are determined. At the same time, the virtual simulation software ADAMS andscientific calculation software MATLAB are introduced, which will be used in this paper.Then, the differential game theory and optimum control theory are introduced, especiallyfor the multiple non-cooperative differential game and linear quadratic regulator optimumcontrol theory. Based on this, the differential game control four-wheel-steering vehicle, theoptimum control four-wheel-steering vehicle and the optimum control front-wheel-steeringvehicle models are built. The simulation and comparison analysis are conducted on MATLABunder high speed ISO lance change, high speed sine change, and low speed circular motionconditions.At last, the virtual prototype model of four-wheel-steering vehicle is built inADAMS/Car. By building control strategy in MATLAB/Simulink, the co-simulation isconducted in MATLAB/Simulink and ADAMS/Car.The simulation results show that the differential game algorithm has high accuracy andgreat handling stability in path tracking of four-wheel-steering vehicle. In according to theoptimum control algorithm, the differential game algorithm inputs lower control energy tovehicle at the same characteristics and control effect. Applying the Differential Game theoryto four-wheel-steering control can improve the handling stability and turning flexibility ofvehicle effectively.