A new sensor based homing integrated guidance and control law is presented to drive an underactuated autonomous underwater vehicle (AUV) towards a fixed target, in the horizontal plane, using the information provided by an Ultra-Short Base Line (USBL) positioning system. Almost global asymptotic stability (AGAS) is achieved, both in the absence of external disturbances and in the presence of co...

The development of universal grippers able to pick up unfamiliar objects of widely varying shapes and surfaces is a very challenging task. Passively compliant underactuated mechanisms are one way to obtain the gripper which could accommodate any irregular and sensitive grasping object. The purpose of the underactuation is to use the power of one actuator to drive the opening and closing motion ...

A recent approach to the control of underactuated systems is to look for control laws which will induce some speci3ed structure on the closed loop system. In this paper, we describe one matching condition and an approach for 3nding all control laws that 3t the condition. After an analysis of the resulting control laws for linear systems, we present the results from an experiment on a nonlinear ...

This paper presents a new sensor based integrated guidance and control law to solve the homing problem of an underactuated autonomous underwater vehicle (AUV), in the horizontal plane, using the information provided by an Ultra-Short Base Line (USBL) positioning system. Global asymptotic stability (GAS) is achieved in the presence (and absence) of constant known ocean currents and simulation re...

In this paper, the model-based robotic control problem with disturbance attenuation (or robotic H∞ control problem), presented in Chen et all (1994), is extended to underactuated manipulators. The dynamic coupling between the links is used to control all manipulator’s free joints. A global explicit solution is found solving a minimax Bellman-Isaacs equation, generated via differential game theo...

This is the second in a series of papers that exploit the physical coupling of tethered spacecraft to derive a propellant-free spin-up and attitude control strategy. We take a nonlinear control approach to underactuated tethered formation flying spacecraft, whose lack of full state feedback linearizability, along with their complex nonholonomic behavior, characterizes the difficult nonlinear co...

We introduce a decentralized attitude control strategy that can dramatically reduce the usage of propellant, by taking full advantage of the physical coupling of the tether. Motivated by a controllability analysis, indicating that both spin-up and relative attitudes are fully controllable by the reaction wheels, we report the first propellant-free underactuated linear and nonlinear control resu...

This paper introduces the iRobot-Harvard-Yale (iHY) Hand, an underactuated hand driven by 5 actuators that is capable of performing a wide range of grasping and in-hand repositioning tasks. This hand was designed to address the need for a durable, inexpensive, moderately dexterous hand suitable for use on mobile robots. The primary focus of this paper will be on the novel simplified design of t...

With the goal of improving 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. This paper identifies unique behaviors in the hand’s response as a function of the coupling mechanism and the actuation mode the hand is operated in. Specifically, we show that i...