Optimization of Semi-Active Hydraulic Shock Absorbers Coping with Mass Variation

Abstract

We propose an optimization method of semi-active hydraulic shock absorbers for landing gears of aircrafts for cope with the problem that the vertical acceleration of aircrafts during landing varies due to variation of their masses. The maximum vertical acceleration of an aircraft is set as an objective function to be minimized. The design variables searched in the first step of this optimization for a semi-active shock absorber are discrete orifice areas made by the metering pin and a hole. And the design variable searched in the second step is a compensating orifice area that is controlled for the mass variation. As a result of the optimization, the optimum orifice areas of the semi-active shock absorber are obtained, and it is clarified that the shock absorber can cope with the mass variation of the aircraft as much better as an optimum passive one.