The main function of aircraft ejection system is that it separates the store from the aircraft. The ejection force is important for the safety of the aircraft when the store is ejected, because the store can be lifted by air flow affected by the aircraft’s speed. If the ejection force is low, the aircraft can be damaged by the floating store. The ejection force of the suspension system should be designed in order to release the store safely. In this study, the ejection force of the pyrotechnic suspension using the cartridge to eject the store was researched. This research was performed, based on the precedent study about the over-center linkage mechanism and the pressure drop by the orifice. The ejection force was calculated, after analyzing mathematical fundamentals about the pressure in the system of the suspension and analyzed through AutoDyn and ADAMS software. Finally, the theoretical results were compared with the ejection test results of the suspension system.

In this study, slip phenomenon that occurs during trajectory tracking motion of an omni-directional mobile robot based on Mecanum wheels was analyzed. Mecanum wheels which generate the omni-directionality to the mobile robot comprise a centered rim wheel and passive sub-rollers. In forward and backward motion, they function like usual wheels to enable rolling along the ground. However, in sideways motion, they create lateral motion of the mobile robot from the rotational actuation using their peculiar structural configuration, during which slip of the sub-rollers occurs. Unnecessary over-slip of the sub-rollers causes tracking errors of the mobile robot motion. To analyze the properties and reasons for the slip phenomenon, squared and circular trajectory tacking experiments were performed. From the experiments, it was observed that sideways motion generated respectively larger tracking errors than forward and backward motion. The geometric analysis regarding the tracking error generation was discussed using the Mecanum wheel structure. Finally, it was confirmed that suspension mechanism to provide four Mecanum wheels of the mobile robot with even reaction forces on the ground is necessary.