Stability of adaptive cruise control systems taking account of vehicle response time and delay

The region of string stability of a platoon of adaptive cruise control vehicles, taking into account the delay and response of the vehicle powertrain, is found. An upper bound on the explicit delay time as a function the first-order powertrain response time constant is determined. The system is characterized by a headway time constant, a sensitivity parameter, relative (to the vehicle immediately in front) velocity control, and delayed-velocity feedback or acceleration feedback.

► I find the region of stability for a realistic adaptive cruise control system.
► Vehicle response time and explicit delay are included in the analysis.
► Delayed-feedback enlarges the parameter space that gives string stability.