A parallel manipulator of STEWART GOUGH (SG) type consists of a platform and a base, which are connected via six spherical-prismatic-spherical legs, where all prismatic joint are active (actuated) and all spherical joints are passive (non-actuated). If we fix the prismatic joints, the SG platform is generically rigid, but under particular geometric conditions the manipulator can perform a n-dim...

Robot manipulators, in general, are required to have the same number of actuators as the number of joints to obtain full control. In the case of under-actuated robots, this condition is not satisfied which make the behavior of that class of robots very difficult to be predicted. Under-actuated robots can be a better design choice for robots in space and other industrial applications, their adva...

It will be shown how to generate under-actuated manipulators by substituting non-holonomic spherical pairs (nS pairs) for (holonomic) spherical pairs (S pairs) in fully-parallel manipulators (FPMs). Through this pair substitution, an under-actuated manipulator, previously proposed by one of the authors, will be demonstrated to be generated from an inversion of the 6-3 FPM. Moreover, the kinetos...

This paper presents the main simulation and experimental results from studies of the robustness of a proposed new control strategy for the under-actuated robot RABBIT. The disturbances studied include modifications of the characteristics of the foot/ground interaction and the application of external forces to the trunk of the robot. These two kinds of disturbance correspond to those most freque...

This work studies a stabilization problem of flapping-wing flying robots (FWFRs) before take-off phase while robot is on branch. The claw the FWFR grasps branch with enough friction to hold system steady in stationary condition. Before take-off, opens itself and between vanishes. At that moment, mechanical model turns into an under-actuated multi-link (serial configuration) robotic where first ...

Upper limbs of human beings are extremely special and significant, which obtain crucial function to achieve manipulations intelligently and dexterously. Gesture-Changeable Under-Actuated (GCUA) grasping function is presented to improve the capability of robotic hands to achieve humanoid manipulations with low dependence on control and sensor feedback systems, which includes traditional under-ac...