Recently, an adaptive variable structure controller was proposed in the above note1 to solve the set-point problem for underactuated robots. Specifically, a time-varying gain, denoted by k(t) 2 , was utilized in the control development and stability analysis which was generated via a discontinuous differential equation. Unfortunately, due to the discontinuous nature of the time derivative of k(...

in this paper, stability analysis of walking gaits and robustness analysis are developed for a five-link and four-actuator biped robot. stability conditions are derived by studying unactuated dynamics and using the poincarã© map associated with periodic walking gaits. a stable gait is designed by an optimization process satisfying physical constraints and stability conditions. also, considering...

Current prosthetic hands are basically simple grippers with one or two degrees of freedom, which barely restore the capability of the thumbindex pinch. Although most amputees consider this performance as acceptable 6r usual tasks, there is ample room for improvement by exploiting recent progresses in mechatronic design and technology. This paper focus on an innovative approach for the design an...

This paper deals with the full dynamic modelling and control of a flying architecture called parallel robot (FPR). architecture, which can be seen as whose actuators have been replaced by drones, offers novel possibilities for robotic aerial manipulation. Over last decade, many prototypes developed in field manipulation, like attaching gripper or manipulator to drone. Nevertheless, proposed app...

We study the stabilizability, via the method of energy shaping, of a given Lagrangian system with two degrees of underactuation and with n ≥ 4 degrees of freedom. By making use of the formal theory of PDEs, we derive an involutive system of PDEs which governs energy shapability, and thus deduce, for the first time, easily verifiable conditions under which energy shaping is guaranteed. We illust...

Standard quadrotor UAVs possess a limited mobility because of their inherent underactuation, i.e., availability of 4 independent control inputs (the 4 propeller spinning velocities) vs. the 6 dofs parameterizing the quadrotor position/orientation in space. As a consequence, the quadrotor pose cannot track arbitrary trajectories in space (e.g., it can hover on the spot only when horizontal). Sin...

A planar underactuated bipedal robot with an impulsive foot model is considered. The analysis extends previous work on a model with unactuated point feet of Westervelt et al. 1 to include the actuator model of Kuo . The impulsive actuator at each leg end is active only during the double support phase, which results in the model being identical to the model with unactuated point feet for the sin...

This note describes two problems related to the digital implementation of control laws in the infinite dimensional family of matching control laws, namely state estimation and sampled data induced error. The entire family of control laws is written for an inverted pendulum cart. Numerical simulations which include sampled data and a state estimator are presented for one of the control laws in t...