Abstract
This paper compares design approaches for achieving a headway control functionality for trucks and buses. The approaches considered are fuzzy logic, H-Infinity, and a strategy based on headway range and its derivative (range-rate). For heavy vehicles, the control unit has a number of nonlinearities to compensate for, including full accelerator saturation, engine characteristics, and a limited deceleration capability as may be influenced by rolling resistance, aerodynamic drag, and retarder capabilities. Performance properties of the controllers are derived from simulations of basic operational situations such as closing-in on a preceding vehicle that is traveling at a slower speed or following a vehicle whose speed varies. (A)