a process for triggering a passive safety device for vehicle occupants inside a vehicle , in particular airbags , pretensioning systems , buckle switches , and roll - over bars , where -- by means of electric sensors , an evaluation circuit evaluating the acceleration signals of these sensors , and triggering agents -- the safety devices are triggered if the acceleration signals indicate a vehicle condition which may be potentially hazardous for the vehicle occupants . according to the invention , sensor signal characteristics will be generated from quantified sensor signals by means of an evaluation function ; these sensor signal characteristics will then be differentiated and fed into an amount calculation function . the up - integrated values of these amounts will then be compared to a trigger threshold so that safety devices can be triggered , if necessary . the process according to the invention allows vehicle crash events to be fully classified whilst at the same time being easy to implement in terms of actual hardware and software requirements .