The purpose of a collision avoidance system (CAS) is to relay critical roadway information to the driver in time to avoid a hazardous situation. The Intersection Collision Avoidance (ICA) countermeasure uses state-of-the-art technology to increase vehicle safety at intersections. Using a combination of radar and an integrated Global Positioning Satellite System and Geographic Information Systems (GPS/GIS), the ICA System (ICAS) notifies the driver when a threat vehicle is approaching the intersection on an intersecting path or when the driver is about to violate a traffic control stop requirement. ICAS uses a multi-modal driver vehicle interface (DVI) to provide warnings: (1) Visually, through a head-up display (HUD), (2) Aurally, using a pulsed tone, and (3) Haptically, by pulsing the brakes. Haptic brake pulsing, the focus of this paper, is accomplished using secondary brake calipers actuated by a hydraulic power unit and accumulator via computer controlled solenoid valves. The Haptic Warning System (HWS), as defined by the ICAS haptic warning design guidelines, is presented, together with challenges encountered during the design process and recently acquired shakedown test results. (A*)
Abstract