Adapting an articulated vehicle to its drivers

A yaw plane model with limited roll-DOF of a five-axle tractor semitrailer is developed to study the open-loop directional dynamics of the vehicle. A driver model incorporating path preview, low and high frequency compensator y gains and time delays, and prediction of the vehicle state, is developed and integrated with the vehicle model. The coupled model is analyzed to inv estigate the vehicle design, which could he best adapted in view of the con trol limits of different driver, which are identified in terms of preview d istance, reaction time and compensatory gain. A performance index based upo n the vehicle path tracking, directional response characteristics and the d river's steering effort is formulated and minimized using Gauss-Newton meth od to derive the desirable ranges of vehicle parameters, that could be adap ted for drivers with varying skills. It is concluded that the adaptability and thus the directional performance of the vehicle call be enhanced throug h variations in the weights and dimensions, and compliant properties of the suspension, tire and the fifth wheel. The results of the study suggest tha t a driver with superior driving skill can easily adapt a vehicle with rela tively large she, soft suspension and higher degree of oversteer. The resul ts further show that the driver-adapted vehicle yields up to 33 percent red uction in the steering effort demand posed on the driver, while the roll an gle and yaw rate response decrease by up to 40 percent.