This paper considers underwater propulsion that is generated by variations in body shape. We summarize and extend some of the emerging approaches for the uniform modeling and control of such underactuated systems. Two examples illustrate these ideas.

This note describes a method for generating an infinite-dimensional family of nonlinear control laws for underactuated systems. For a ball and beam system, the entire family is found explicitly. Copyright c © 2000 IFAC

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...

Two-wheeled mobile robots (2WMRs) with lower center of gravity exhibit more practicality and operability because their mass center locates on the bottom of the configuration center. By analyzing motion behaviors of the vehicle body, we present the underactuated property and give the dynamics equation of this kind of robot. The system matrices and nonholonomic constraint change drastically becau...

We propose a constructive control design for stabilization of non-periodic trajectories of underactuated mechanical systems. An important example of such a system is an underactuated “dynamic walking” biped robot walking over rough terrain. The proposed technique is to compute a transverse linearization about the desired motion: a linear impulsive system which locally represents dynamics about ...

This paper presents an Internal Model Control (IMC) structure designed for a class of continuous linear underactuated systems. The study treats the case of Minimum Phase (MP) systems and those whose zero dynamics are not necessarily stable. The proposed IMC structure is based on a specific controller which is obtained by the realization of an approximate inverse of the model plant. It is shown ...

Machine-mediated training of dynamic task completion is typically implemented with passive intervention via virtual fixtures or active assist by means of record and replay strategies. During interaction with a real dynamic system however, the user relies on both visual and haptic feedback real-time in order to elicit desired motions. This work investigates human performance in a Fitts’ type tar...

In this paper we discuss the control of underactuated mechanical systems. Underactuated mechanical systems have fewer control inputs than degrees of freedom and arise in applications, such as space and undersea robots, mobile robots, exible robots, walking, brachiating, and gymnastic robots. The Lagrangian dynamics of these systems may contain feedforward nonlinearities, non-minimum phase zero ...

Force rendering is important in underactuated haptic systems. Underactuation means that some force directions at the contacts cannot be rendered because of the lack of actuation. In this paper we propose to exploit the knowledge of the task to mitigate the effect of the underactuation. The simulation of a grasp is considered and two alternative algorithms are proposed to improve the sensitivity...

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...