چكيده به لاتين
The current research investgates a new approach for the lateral stabilization of articulated heavy vehicles at handling limit. First, a review of the state of the art of technology was made to highlight the weakness and strongpoints of the available approaches. Then, as per the reviews made, a method was proposed to mitigate monotonic and oscillatory instabilities of semi-trailer in a tractor semi-trailer combination. Active Auxiliary Axle (ALA) is introduced as a system with reduced complexities ascompared to active trailer steering systems, with a fouces on stability improvement of AHVs at handling limit, and more effective utilization of tire lateral force generation potential. A linear three degree of freedom model was used for feasibility study both in time and frequency domain, and a nonlinear model constructed in truckSIM was employed as a full vehicle model.The active axle was constructed in the truckSIM with modified K&C properties to eliminate lateral force transfer between left and right wheels. A co-simulation of truckSIM with MatLab was performed to perform the analysis. The tire force-lateral slip generation was modified to obtain the required force generation properties. The fuzzy logic controller (FLC) was developed in the Simulink environment. Two test scenarios, a closed-loop driver in the model double lane change (DLC) and an open loop single lane change (SLC) were used to simulate vehicle behavior under diferent maneuvering conditions. The DLC maneuver was performed with the aim of studyng driver’s behavior under the actuation of active axle.The open loop maneuver was performed to identify vehicle behavior under obstacle avoidance situations. To amplify instability conditions induced to the vehicle, the forward speed was increased by 33 percent as compared to the standard speed identified in the vehicle simulation library. Additionally, a reduction of 30 percent in the friction coefficient was considered to study the effects of mu-reduced conditions. Results suggested that the intervention of active axle at the predefined instances reduces the overshoots in the semi-trailer yaw rate response by 45 percent. Additionally, the RWA was reduced down below one. A by-product of the active axle was the roll stability improvement. The double lane change maneuvers under high loading conditions revleaed a reduction in the whole roll angle response to one-third below the uncontrolled case. Additionally, it was demonstrated that this approach can show high potential for roll-over prevention in case proper tuning is applied to the controller.
Keywords:
Lateral Stablity, Articulated Heavy Vehice, Lateral Stability Control, Active Auxiliary Axle,
