Conception d'un robot sauteur dedie a l'exploration planetaire et utilisant les fluctuations de temperature quotidiennes comme source de puissance

Planetary exploration is as much a current subject for agencies directly dealing in space as well as for the general public. However, the costs related to this type of mission are extremely steep and many space agencies attempt to participate without having the means to finance megamissions to which past missions have accustomed us. Hence, it is mainly for this reason that the Canadian Space Agency (CSA) has decided to turn to micromissions. Canada sees in these less elaborate missions, an opportunity to more actively engage in the discovery of other planets while reducing costs.; The present work deals with mechanical design of a hopping robot prototype destined to the exploration of planets with a low gravitational environment (Mars for instance). This robot uses extensive variations of temperature at Mars' surface as a source of energy. In order to do this, we proceeded in a systematic approach by establishing design requirements. Furthermore, a state-of-the-art study was done on the subject and assessed various potentials concepts. Once the most promising concept was established, the different sub-systems were dissected in minute detail and development started with those which had the most impact on the final design. The most risky or important mechanisms were manufactured and tested prior to continuing the design of the other elements.; We have thus designed the main mechanisms required to the locomotion of the robot as well as the structural parts. An "innovative" cylindrical mechanism with scissors used to transfer the energy needed by the robot's jump was designed, manufactured and tested. Moreover, an actuator with shape memory alloy (SMA's) working with the sun's heat was designed, while a prototype was tested. The robot's design shows the following characteristics: a unique actuator is used to load the energy needed for the jump into torsion springs and to reposition the robot back on its feet after having hopped. The robot's structure, in the shape of tetrahedron, is confined into a 300 mm edge lengthen cubic envelop which corresponds to a status of "micro" robot. The proposed concept takes advantage of the Martian environment. In fact, the low gravity and the low atmospheric density favors the jump as a means of locomotion, while the important gradient of temperature (day versus night) at the surface of Mars enables the elongation of the SMA. Consequently, jumping lets us cover longer distances while crossing the numerous rocks that cover the hazardous surface of Mars.; This thesis, based on experimental development, covers the important elements of a preliminary mechanical design without, however, dealing with the aspects that a final and complete design would need. Thus, to pursue this work, one should look closer into the structural analysis to verify how all elements can tolerate the impact upon landing. One should also verify the effect of thermo-elastic distortion in the mechanisms and simulate more precisely the friction in the joints and optimize the whole structure to reduce the total mass of the system.