Optimal Crash Pulse for Minimization of Peak Occupant Deceleration in Frontal Impact

In automobile frontal impact, for given restraint characteristics and prescribed impact speed and crash deformation, what is the optimal vehicle crash pulse that produces the lowest peak occupant deceleration? In this paper, based on a lumped-parameter model of the occupant-vehicle system, the optimal kinematics of the occupant in frontal impact is studied first, and the optimal vehicle crash pulse is then investigated according to the optimal occupant kinematics. For linear restraint characteristics, the theoretical optimal crash pulse is found, and the relation of the peak occupant deceleration to the impact speed, crash deformation, and vehicle interior rattlespace is established. The optimal crash pulses for passive, active, and pre-acting restraint systems are discussed. Numerical optimization is formulated to find the optimal crash pulse for general restraint systems. The occupant responses under the constant-deceleration crash pulse and the half-sine crash pulse are analyzed for linear restraint systems. Comparisons are made between the optimal crash pulse and those two “non-optimal” crash pulses.