Optimal control of helicopter seat cushions for the reduction of spinal injuries

Abstract The theoretically optimal performance of a helicopter seat cushion for the reduction of spinal injuries during vertical crashes is investigated using a limiting performance analysis. The spinal dynamic response index and the maximum spinal compression load are used as the system performance indices to be minimized. Three types of seat cushions (passive, active, and pre-acting) are studied. A trade-off curve and the optimal control force for each type of cushion are obtained. Computational results indicate that for the prevention and reduction of spinal injuries, the pre-acting seat cushion is superior to the active non-pre-acting cushion, which is in turn superior to the passive cushion.