A device for controlling personal protection apparatus in a vehicle includes: at least one sensor unit that acquires at least one physical quantity; and evaluation and control unit which (i) produces, from the at least one acquired physical quantity, at least one signal curve that characterizes an impact, (ii) determines, as a function of an energy dissipation behavior of the vehicle, at least one temporal phase in the produced signal curve, and (iii) evaluates the at least one phase for crash classification and for a triggering decision for the personal protection apparatus. The evaluation and control unit retroactively calculates at least one feature of the energy dissipation based on a characteristic time in the signal curve that represents the end of a first temporal phase.