Lateral stability analysis of the tractor-semitrailer vehicle in severe situations

The lateral stability for the tractor-semitrailer vehicle which consists of the tractor and the semitrailer is much more complex compared with the individual 2-axle vehicle. ´Jackknife´ and ´lateral sway´ are the typical lateral destabilizations in server situations. Considering the strong nonlinear property of tyre force in severe situations, nonlinear system method is used here to study the lateral stability of the tractor-semitrailer vehicle. The mechanism of ´jackknife´ and ´lateral sway´ is studied based on the concept of main component of eigenvector (MCE). The result is that ´jackknife´ and ´lateral sway´ are much related to the state variation of hitch angle and hitch angular rate. The study given in this paper can provide a powerful means to the design of stability control system for the tractor-semitrailer vehicle.