Underactuated biped robots control is one of the interesting topics in robotics. The main difficulties are its highly nonlinear dynamics, open-loop instability, and discrete event at the end of the gait. One of the methods to control underactuated systems is the partial feedback linearization, but it is not robust against uncertainties and disturbances that restrict its performance to control b...

In this paper we develop a robust controller based on variable structure systems (VSS) control theory for the stabilization of a class of Underactuated Mechanical Systems. This controller is based on a noncollocated partial feedback linearization of the underactuated system with a particular choice of the additional control for which the design is made using the sliding mode approach. Simulatio...

Underactuated robotic hands are favorable for some applications due to its simplicity in mechanism and control compared with fully actuated hand. Incorporating sensors makes it possible for a hand to accomplish low level task autonomously. This project aims at analyzing pinch quality of an underactuated hand that was developed for underwater teleoperation with 8 sensor channels on each finger, ...

For a class of second order underactuated mechanical systems, a robust finite time control strategy is developed in this paper. The robust finite time controller is to drive the tracking error to be zero at the fixed final time. In order to assure system stability, we present a generalized Lyapunov stability proof for the second order underactuated mechanical system. By utilizing a Lyapunov sta...

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...

In an attempt to improve the performance of underactuated robotic hands in grasping, we investigate the influence of the underlying coupling mechanism on the robustness of underactuated hands to external disturbance. The coupling mechanisms used in underactuated mechanisms can be divided into two main classes based on the self-adaptive transmission used to route actuation to the degrees of free...

This paper presents motion planning algorithms for underactuated systems evolving on rigid rotation and displacement groups. Motion planning is transcribed into (low-dimensional) combinatorial selection and inversekinematic problems. We present a catalog of solutions for all underactuated systems on SE(2), SO(3) and SE(2) × R classified according to their controllability properties.

Problem statement: Underactuated finger mechanism is beneficial in the anthropomorphic applications in which it reduces the finger size, weight and power consumption due to the less number of actuators compared to its number of Degree Of Freedom (DOF). However, the currently existing underactuated finger is limited to grasping operations only and unable to pinch with the finger tip. Moreover, t...

Problem statement: Underactuated finger mechanism is beneficial in the anthropomorphic applications in which it reduces the finger size, weight and power consumption due to the less number of actuators compared to its number of Degree Of Freedom (DOF). However, the currently existing underactuated finger is limited to grasping operations only and unable to pinch with the finger tip. Moreover, t...

The research on underwater systems has gained an immense interest during the last decades with applications taken place in many fields such as exploration, investigation, repair, construction, etc. Hereby, control of underwater systems has emerged as a growing field of research. Underwater vehicles, in fact, accounted for 21% of the total number of service robots by the end of 2004, and are the...