Innovative concept of unfoldable wheel with an active contact adaptation mechanism

In this paper, an original expandable mechanism for unfolding wheels is proposed. This mechanism combines two elementary mechanisms. One allows the deployment of the rim while the other one ensures the contact shape adaptation. In the first section, we analyse the different deployment mechanisms already proposed in the literature. Then, the design of the rim expansion mechanism is described and two complementary versions are proposed. Last, based on terramechanics models, a contact surface adaptation mechanism is proposed. This system allows to adapt the wheelground interaction properties and make the wheel ables to improve its traction and steering performance on soft soil.