Commercially available prosthetic hands are simple grippers with one or two degrees of freedom; these pinch type devices have two rigid fingers in opposition to a rigid thumb. This paper focuses on an innovative approach for the design of a myoelectric prosthetic hand. The new prosthesis features underactuated mechanisms in order to achieve a natural grasping behavior and a good distribution of...

Purpose – Passively compliant underactuated mechanisms are one way to obtain the gripper which could accommodate to any irregular and sensitive grasping object. The purpose of the underactuation is to use less active inputs than the number of degrees of freedom of the gripper mechanism to drive the open and close motion of the gripper. Another purpose of underaction is to reduce the number of c...

This paper discusses several design issues pertaining to the design of anthropomorphic underactuated robotic or prosthetic hands. The design of the underactuation mechanism that drives the fingers is first addressed. A double-stage mechanism is proposed that includes a lever arm to couple the motion of the thumb and the fingers as well as an additional pulley that amplifies the input force. The...

In this papera switching control strategy for robust stabilization of the 2nd-order non-holonornic 2-DOF SCARA robot Ft21)l is presented. The Ist joint is actuated by a direct drive motor, whereas the 2nd joint is equipped with a brake. The unactuated 2nd joint is controlled by non-collocated linearization and a PDcontroller. A stability region is den”ued and robustness is achieved by exploitin...

and Applied Analysis 3

This paper concerns a swing-up control problem for an n-link revolute robot in a vertical plane with its first joint being passive and the rest being active. The objectives of this paper are: 1) to design a controller under which the robot can be brought into any arbitrarily small neighborhood of the upright equilibrium point, where all links of the robot remain in their upright positions; 2) t...

We propose novel distributed exponentially-converging control frameworks for flocking and centroid trajectory tracking of multiple thrust-propelled vehicles (TPVs), which consist of the under-actuated translation dynamics on E(3) with one-dimensional thrust-force input and the fully-actuated attitude kinematics on SO(3) with angular-rates inputs; and evolves on a strongly-connected, yet, balanc...

This papers applies a recently developed ”generalized averaging theory” to construct stabilizing feedback control laws for underactuated driftless systems. These controls exponentialy stabilize in the average. Conditions relating the properties of the averaged and unaveraged systems are given. An example validates the theory, demonstrating its utility.