TRACKING AND STABILITY OF MULTI-UNIT TRUCK COMBINATIONS

This report presents pertinent information for developing truck combinations that possess improved tracking and greater dynamic stability. It examines how geometric parameters and tire characteristics influence conflicting performance requirements for tracking and articulation stability. It also explores the benefits of kinematically steered wheels on full trailers. Trailer wheels that steer in response to draw bar angles are shown to provide good tracking in selected designs, but such a steering arrangement tends to reduce articulation stability. The analysis indicates that, at highway speeds, rapid steering efforts (such as required in a sudden maneuver to avoid an unexpected obstacle) can lead to amplified motions of full trailers equipped with steering arrangements designed to provide excellent low-speed tracking.