| According to NHTSA's 2011 Traffic Safety Facts, large-truck occupant fatalities increased from 530 in 2010 to 635 in 2011, which is a 20% increase. This was a second consecutive year in which large truck fatalities have increased (9% increase from 2009 to 2010). There was also a 15% increase in large truck occupant injuries from 2010. Moreover, the fatal crashes involving large trucks increased by 1.9%, in contrast to other-vehicle-occupant fatalities that declined by 3.6% from 2010.;Given the high accident involvement rate of heavy trucks, the research presented in this dissertation focussed on methods of improving and testing heavy truck ESC performance. The first part of the research, aimed at estimating trailer parameters and states using sensors on the tractor to enhance the capabilities of the tractor based ESC unit. The mass of the vehicle and road grade are first estimated using recursive least square estimation. The trailer CG position is then estimated using the load on the tractor drive axels. This is followed by a planar model of an articulated vehicle to calculate the lateral acceleration, longitudinal acceleration and yaw rate of the trailer CG. Finally a Dual Extended Kalman Filter is developed to estimate trailer roll angle and roll parameters.;The second phase of the research involved the development of a state of the art Hardware in the Loop simulation setup to test heavy truck ESC systems. The design of the HIL system is briefly discussed followed by the modeling of the vehicles in TruckSim. This is followed by a rigorous validation of the vehicle models and the HIL setup. Finally some of the applications of the validated HIL setup is discussed. This includes an indepth study of the Sine with Dwell maneuver and effects of vehicle speed, surface friction and CG height on the vehicle stability. This is followed by the design of a steering controller which is used to study the advantages afforded by the ESC system in an actual crash scenario. |
