Abstract:The differential equations of 2 DOF linear models for arbitrary steer axis vehicle were derived, based on the two-axis ear basic steer theory. The steady state response to angle input of multi-steering wheels was analyzed. The steady state response expression and three different steer types were obtained. The relationship between the axle distance and vehicle handling stability is discussed, which provides useful information for the layout of whole vehicle. A special 8-axis vehicle was analyzed by the 2 DOF linear models and simulated by dynamic analysis soflware-SIMPACK. The result shows that the 8-axis vehicle has under steer characteristics and better steady-state response. 2 DOF linear models are verified.