Hypovigilance warning system: A review on driver alerting techniques

In recent years, driver hypovigilance (drowsiness and inattentiveness) is one of the major causes for road accidents and it leads to severe traumas such as physical injuries, deaths, and economic losses. Several researchers have reported on driver drowsiness detection and only very few works have been reported on detecting the driver hypovigilance. The physiological signals and vision based approaches are mostly used for estimating the driver's hypovigilance. When the physical state of the driver is drowsy or inattentive, it is important to alert the driver through alerting methods to avoid the accidents. In this paper, we have reviewed various methods used to alert drivers and the issues involved in detecting the hypovigilance. There are many methods adopted for alerting the driver during hypovigilance such as alarms, visual effects, vibrations, etc. This present work discusses in detail about the different methods used for driver alertness system. The level of alertness is based on the hypovigilance level of the driver. The hypovigilance detection system should be designed in such a way to efficiently trigger the alert system only when the driver is in hypovigilance state.