It is often suggested that hand prostheses and robot grippers must possess a kinematic structure that is similar to those of the natural human hand [1-4]. Such structure allows better adaptation of the gripper to the size and the shape of the grasped object and better cosmetic effect. Anthropomorphic hands with a large number of joints are highly dexterous, but their independent joint control r...

The control of underactuated mechanical system is very complex for the loss of its control inputs. The model of underactuated mechanical systems in a potential field is built with Lagrangian method and its structural properties are analyzed in detail. A genetic algorithm (GA)based stable control approach is proposed for the class of underactuated mechanical systems. The Lyapunov stability theor...

In this paper, we introduce cascade normal forms for underactuated mechanical systems that are convenient for control design. These normal forms are partially linear which results from a well-known fact that underactuated systems can be partially linearized using a change of control [12]. The difficulty arises when the new control appears both in the linear and nonlinear subsystems. We introduc...

For more than a decade underactuated manipulators have been under investigation, cf. [1]. Investigation of underactuated manipulators is of interest because both path planning and control is possible only if the nonlinear dynamic couplings between the links are taken into account. From a practical point of view, major benefits of underactuated manipulation systems are reduction of weight, costs...

In this paper, we address nonlinear control and reduction of two classes of high-order underactuated mechanical systems with kinetic symmetry called Class-II and Class-III systems. Class-II systems are underactuated systems with unactuated shape variables, decoupled inputs, and integrable normalized momentums (all to be defined). We show that all Class-II underactuated systems can be transforme...

In this paper, a stability control strategy for underactuated biped robots is proposed based on imbalance degree. The dynamic models of single-leg support of underactuated biped robots are firstly illustrated. Based on the external disturbance force strength of the system, the motion process of an underactuated biped robot is partitioned into three stages according to the imbalance degree. In d...

Abstract—The dynamic control of a 3R underactuated robot is investigated in this paper. The second order nonholonomic dynamic equation of the robot is derived. An intelligent control method is proposed for the position control of underactuated manipulator based on genetic algorithm. A new fuzzy controller for motion control of underactuated robot is presented, in which the joint angular errors ...

A new concept for controlling of underactuated robot manipulators is presented by using switching computed torque method. One fundamental feature of the present approach is to use the partly stable controllers (PSCs) in order to fulfill the ultimate control objective. Dynamic model of an underactuated robot system is directly analyzed to synthesize partly stable, computed torque controllers wit...

We introduce the notion of kinematic controllability for second-order underactuated mechanical systems. For systems satisfying this property, the problem of planning fast collision-free trajectories between zero velocity states can be decoupled into the computationally simpler problems of path planning for a kinematic system followed by time-optimal time scaling. While this approach is well kno...

Underactuated manipulators are a class of robotic mechanisms where passive joints are present. By controlling only the motion of the active joints, it is possible to control the entire system. Our goal is to develop control schemes using both classical nonlinear and modern learning techniques for underactuated manipulators. To examine the validity of the approaches, we developed an experimental...