Abstract: A method for estimating a flight time of a hydrogen fuel cell UAV (unmanned aerial vehicle) includes multiple steps performed by a controller: obtaining an internal pressure of a hydrogen tank by a pressure sensor installed on the hydrogen tank, calculating a remaining hydrogen volume according to the internal pressure and a capacity of the hydrogen tank, obtaining a reaction current value of the fuel cell, calculating a first hydrogen consumption rate according to the reaction current value, the number of a set of membrane electrodes connected in series and a Faraday constant, obtaining a second hydrogen consumption rate of a purge operation of an anode of the full cell; obtaining a hydrogen leakage rate of a stack of the fuel cell, and calculating the flight time according to the remaining hydrogen volume, the first hydrogen consumption rate, the second hydrogen consumption rate and the hydrogen leakage rate.

Abstract: A shock isolation system for electronic devices includes a first baseboard, a second baseboard and a plurality of helical springs interposed transversely between the first baseboard and the second baseboard. The helical springs can deform horizontally and vertically to isolate horizontal and vertical vibration-impact on the electronic devices. The first baseboard and the second baseboard further are bridged by a plurality of damping elements, which have damping characteristics to dissipate kinetic energy and reduce the vibration amplitude and instantaneous acceleration between the first baseboard and the second baseboard, thereby to enhancing the composite effect. The first baseboard further has a plurality of buffer struts to separate the first baseboard and the second baseboard, and prevent the second baseboard from directly hitting the first baseboard.