A new effective nonlinear strategy for lateral stability increment of an articulated vehicle rigid cargo

Abstract

In this paper, the effects of the most important parameters on directional dynamics of a tractor-semitrailer vehicle are examined. Initially, a three DOF dynamic model of a tractor-semitrailer vehicle is proposed. Then, the developed model is validated by means of TruckSim software during a standard maneuver. In order to analyze the system stability, the Lyapunov method has been used and the stability conditions have been extracted based on Routh criterion. The most important parameters are selected based on the articulation angle gain. Among the studied parameters, the semitrailer mass, the distance of the tractor unit center of mass and its front axle, and the tires cornering stiffness exhibited more effective behavior on the vehicle’s stability. The simulation results show that as the tractor center of mass moves toward its rear axle, the probability of the jackknifing increases. Moreover, an increment in the semitrailer mass leads to a turn of the semitrailer with respect to the tractor. Also, the understeer specification of the vehicle strengthens due to the tire cornering stiffness increment. Moreover, in order to increase the maneuverability of the articulated vehicle a new active steering controller is proposed using two different control methods. The controller is developed using the simplified dynamic model and the basis of feedback linearization method using dynamic sliding mode control method. In this system, the yaw rate and the lateral velocity of the tractor unit as well as articulation angle are studied as state variables which are targeted to track their desired references. Then, the vehicle dynamic performance is investigated during standard maneuvers. A more investigation shows that the track of the desired values of the vehicle state variables leads to eliminate off-tracking path.