| dc.description.abstract | To improve the directional performance of multitrailer articulated heavy vehicles (MTAHVs), the
model-based active safety systems, including the active trailer steering, trailer differential braking
and the active roll control are developed. The active safety systems are integrated and coordinated
for optimal overall performance. The coordinated control system is designed in a modular,
hierarchical and multilevel approach. At the upper level, a moment controller is designed to
stabilize the yaw and the roll dynamics. At the intermediate level, an allocator is designed to
distribute the demanded moments to the actuating systems. At the lower level, the active
suspension system realizes the demanded roll moment, and the active trailer steering and the trailer
differential braking share the demanded yaw moment. The directional performance of the MTAHV
with the coordinated control system is evaluated in closed-loop simulations. A unified driver
model for road vehicles is developed to ‘drive’ the vehicle in the closed-loop simulations.
Considering the characteristics of the single unit and the multiunit vehicle drivers, a set of design
parameters are introduced to govern the characteristics of the driver model to mimic human drivers
in driving single unit and multiunit road vehicles, especially to simulate MTAHV drivers’ driving
performance under a high-speed evasive and a low-speed path-following maneuvers, respectively.
The directional performance of the MTAHV with the coordinated control system and the driver
model may be valuated and optimized using a genetic algorithm with the performance measures
in the time-domain and the frequency-domain, thanks to the introduction of the automated
frequency response measuring method (AFRM) into the articulated heavy vehicle dynamics. The
proposed design methods/techniques and findings derived from the research will contribute to the
advancement of active safety systems for MTAHVs. | en |
