Automakers are introducing rollover protection systems at a time when interest in them has never, arguably, been higher.

The harsh reality remains that while today's vehicles are equipped with safety features such as sensors, air bags and restraint systems, the 9% of accidents that result in rollover are responsible for a disproportionate number of fatalities.

The key to preventing rollover fatalities is understanding them. That involves thorough knowledge of vehicle dynamics as well as crash dynamics, say Madana Gopal and Edward Wallner of Delphi Automotive Systems.

Attempts to model such a crash requires sensors able to distinguish between no-roll and roll conditions. They must also be able to recognize body roll as part of normal driving.

Technology such as tilt switches to detect when the vehicle is on a dangerous angle can be slow to deploy and don't always work when a vehicle is airborne, says Mr. Wallner.

An alternative is satellite rollover sensors that use an angle rate sensor that measures roll through yaw and pitch rates. The future success of such a sensor will require the ability to factor in speed, steering, information gleaned from smart tires and more, says Mr. Wallner.