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.

在本文中，研究了最重要的参数对半挂牵引车车辆方向动力学的影响。最初，提出了一种半自动半挂牵引车的三自由度动力学模型。然后，在标准操作过程中通过TruckSim软件验证开发的模型。为了分析系统稳定性，使用了Lyapunov方法，并根据Routh准则提取了稳定性条件。根据关节角度增益选择最重要的参数。在研究的参数中，半挂车质量，牵引车质量中心与其前轴的距离以及轮胎的转弯刚度对车辆的稳定性表现出更有效的表现。仿真结果表明，随着拖拉机质心向后轴移动，劫机的可能性增加。此外，半挂车质量的增加导致半挂车相对于拖拉机的转向。此外，由于轮胎转弯刚度增加，车辆的转向不足规范也得到了加强。此外，为了提高铰接车辆的可操纵性，提出了一种使用两种不同控制方法的新型主动转向控制器。该控制器是使用简化的动态模型开发的，并且是使用动态滑模控制方法的反馈线性化方法的基础。在该系统中，牵引器单元的横摆率和横向速度以及铰接角作为状态变量进行了研究，旨在跟踪其所需的参考值。然后，在标准操纵过程中研究车辆的动态性能。