Underactuated systems are those processing fewer actuators than degrees of freedom. But generally they are difficult to control. In this paper we realize crawling motion by an underactuated robot. By changing the location of the fixed point of the robot to the environment, the constraint of the system is changed. Local accessibility of the system with changing the constraints as a nonhoronomic ...

This paper presents a design framework for the stabilization of a class of underactuated mechanical systems. By utilizing nonregular static state feedbacks, these systems are transformed into a class of nonlinear systems with chain structures. Then, controller design is presented by applying the backstepping design technique. The design procedure is applied to an underactuated robotic system an...

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...

By exploiting centrifugal and Coriolis forces, simple, lowdegree-of-freedom robots can control objects with more degrees-of-freedom. For example, by allowing the object to roll and slip, a one-degree-of-freedom revolute robot can take a planar object to a full-dimensional subset of its state space. We present a dynamic manipulationplanner that finds manipulator trajectories to move an object fr...

This paper investigates the leader–follower formation tracking control of underactuated surface vessels (USVs) with input saturation. Each vessel is subject to uncertainties induced by model and environmental disturbances. First, an event-triggered extended-state observer (ETESO) used recover velocity, yaw rate uncertainties. Then, estimator estimate velocity leader. An controller (ETC) constru...

A horizontally mounted two-link manipulator is considered. We assume that only the first joint is actuated, while the second joint is passive and frictionless. The system exposes challenging properties, e. g. it is not controllable in the equilibrium points. We transform the equations of motion in Byrnes-Isidori normal form and consider the projection into the subspace spanned by the velocity-l...

In this paper, we present a control algorithm to control underactuated mechanical systems that evolve in the configuration space with the fiber bundle structure. We show that by using the geometric tools such as symmetric product, and small amplitude periodic forcing, we can develop unique techniques to control the underactuated dynamic system, such as an unmanned blimp.

Neurology shows that human controls dozens of muscles for hand poses in a coordinated manner and such coordination is referred as to a postural synergy. The concept of postural synergies was recently adopted in the control of robotic hands. With the synergies implemented digitally in a controller, all the motors in an anthropomorphic robotic hand can be controlled via a few synergy inputs. Aimi...

We present a collaborative team of two under-actuated autonomous surface vessels (ASVs) that performs a cooperative navigation task while satisfying a communication constraint. Our approach is based on the use of a hierarchical control structure where a supervisory module commands each vessel to perform prioritized elementary tasks, a behavior-based controller generates motion directives to ach...