Novel jumping mechanism for asteroid lander
- Paper number
IAC-08.A3.I.2
- Author
Dr. Yoshiki Sugawara, Aoyamagakuin University, Japan
- Coauthor
Prof. Nobuyuki Kobayashi, Aoyama Gakuin University, Japan
- Year
2008
- Abstract
Several asteroid landers have been sent to asteroids and exploration of Itokawa has showed prominent results recent year. And sometimes such an exploration includes landing mission of asteroid lander and it is expected that they brings a lot of significant results than only remote observations from orbit. But it is not easy to make landers to land and explore asteroids successfully because of such an astral bodies like asteroids have two special features and some failures may arise due to the failures. One feature is that there is no air and it induces vacuum metalizing of metal slide member. The other feature is that their gravity is usually quite small and it induces bad controllability especially for landers with wheels which require enough frictional force between ground and wheels. Therefore, it is preferable for landers to use jump mechanism without slide member. Additionally, jump mechanism is superior to wheel mechanism because they have possibility to overcome obstacles which is so high that wheel mechanism can’t overcome. It can be shown numerically that change of rigidity of two-mass-spring system under vibration causes jump phenomenon. Suppose a beam which has a mass at the center of it and fixed at both end. It is not difficult to guess that such a mechanism can produce jump phenomenon in the same way with two-mass-spring system. But it is not so easy to realize such a variable rigidity system with high reliabilities by mechanical method under vibration. A beam of which piezoceramic plate is attached on the surface is sometimes used to control vibrations. Furthermore, to suppress vibrations in passive control method, piezoceramic plate is connected to shunt circuit which consists of resisters and inductances. In the method, performance of the vibration suppression can be changed by values of resistors and inductances. Connection of piezoceramic plate to shunt circuit realizes a virtual change of rigidity and viscous behavior. Therefore, mechanical properties can be changed electrically and such a system is generally more reliable than that of change by mechanical method. Moreover, mechanically variable system requires more physical spaces than electrically method. In the paper, some numerical simulations are carried out for simple principle model and validities of a proposed system are shown and the characteristics and the potentials of the system are analyzed. Furthermore, several designs of asteroid lander with proposed mechanism are shown.
- Abstract document
- Manuscript document
IAC-08.A3.I.2.pdf (🔒 authorized access only).
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