This paper deals with a novel flying mechanism. Inspired from parallel manipulators, this flying robot is composed of three quadrotors linked by a rigid articulated architecture composed of three legs and a platform. Associating quadrotor co-manipulation and rigid bodies, this new design offers novel possibilities for aerial robotics and manipulation. Previous work leads to the design of a flying parallel robot with two quadrotors. However, this robot did not allow the full control of the six degrees of freedom of its end-effector. With an additional quadrotor, this study seeks to obtain a full control of the platform position and orientation. To prove this property, the kinematic constraints are verified through screw theory. Then, the dynamic model is established and a decoupling property leads to the design of a specific controller for the platform and legs configurations. ADAMS/SIMULINK co-simulations validate the theoretical developments.

This paper seeks insight into stabilization mechanisms for periodic walking gaits in 3D bipedal robots. Based on this insight, a control strategy based on virtual constraints, which imposes coordination between joints rather than a temporal evolution, will be proposed for achieving asymptotic convergence toward a periodic motion. For planar bipeds with one degree of underactuation, it is known that a vertical displacement of the center of mass-with downward velocity at the step transitioninduces stability of a walking gait. This paper concerns the qualitative extension of this type of property to 3D walking with two degrees of underactuation. It is shown that a condition on the position of the center of mass in the horizontal plane at the transition between steps induces synchronization between the motions in the sagittal and frontal planes. A combination of the conditions for self-synchronization and vertical oscillations leads to stable gaits. The algorithm for self-stabilization of 3D walking gaits is first developed for a simplified model of a walking robot (an inverted pendulum with variable length legs), and then it is extended to a complex model of the humanoid robot Romeo using the notion of Hybrid Zero Dynamics. Simulations of the model of the robot illustrate the efficacy of the method and its robustness.