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Podeu consultar la versió en castellà a: http://hdl.handle.net/11703/10236

Development of compliance displaying device using pneumatic parallel manipulator

The goal of this study is to develop a mechanical system that can display elastic characteristic of an object aiming at the application in the field of virtual reality. Pneumatic parallel manipulator is introduced as a driving mechanism, which, consequently, brings capability of minute force displaying property owing to the air compressibility. Compliance displaying scheme based on the contact force and contact point detection is proposed. The validity of the proposed scheme is verified experimentally. </p

Object Exploration Using a Parallel Jaw Gripper

In this paper we present a system for tactile object exploration. The system is built using a gripper with two parallel fingers, each equipped with a tactile array and a force/torque sensor. We have designed and implemented a set of exploratory procedures for acquiring the following properties: weight, shape, texture, and hardness. The system is successful at extracting these properties from a limited domain of objects. We present a detailed evaluation of the system and the causes of its limitations. The manipulation, motion, and, sensing primitives we have developed in the process of this work could be used for a variety of other tasks, such as model-based recognition, tool manipulation, and assembly

A survey of dextrous manipulation

technical reportThe development of mechanical end effectors capable of dextrous manipulation is a rapidly growing and quite successful field of research. It has in some sense put the focus on control issues, in particular, how to control these remarkably humanlike manipulators to perform the deft movement that we take for granted in the human hand. The kinematic and control issues surrounding manipulation research are clouded by more basic concerns such as: what is the goal of a manipulation system, is the anthropomorphic or functional design methodology appropriate, and to what degree does the control of the manipulator depend on other sensory systems. This paper examines the potential of creating a general purpose, anthropomorphically motivated, dextrous manipulation system. The discussion will focus on features of the human hand that permit its general usefulness as a manipulator. A survey of machinery designed to emulate these capabilities is presented. Finally, the tasks of grasping and manipulation are examined from the control standpoint to suggest a control paradigm which is descriptive, yet flexible and computationally efficient1

A friendly teaching system for dexterous manipulation tasks of multi-fingered hands.

by Lam Pak Chio.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.Includes bibliographical references (leaves 101-105).Abstract also in Chinese.Abstract --- p.iiAcknowledgements --- p.vContentsChapter 1 --- Introduction --- p.1Chapter 1.1 --- Background --- p.1Chapter 1.2 --- Problem Definition and Approach --- p.3Chapter 1.3 --- Outline --- p.5Chapter 2 --- Algorithm Outline --- p.7Chapter 2.1 --- Introduction --- p.7Chapter 2.2 --- Assumptions --- p.7Chapter 2.3 --- Object Model --- p.8Chapter 2.4 --- Hand Model --- p.9Chapter 2.5 --- Measurement Data --- p.11Chapter 2.6 --- Algorithm Outline --- p.12Chapter 3 --- Calculation of Contact States --- p.14Chapter 3.1 --- Introduction --- p.14Chapter 3.2 --- Problem Analysis --- p.15Chapter 3.3 --- Details of Algorithm --- p.17Chapter 3.3.1 --- Calculation of Contact Points --- p.18Chapter 3.3.2 --- Calculation of Object Position and Orientation --- p.26Chapter 3.3.2.1 --- The Object Orientation --- p.26Chapter 3.3.2.2 --- The Object Position --- p.28Chapter 3.3.3 --- Contact Points on Other Fingers --- p.32Chapter 4 --- Calculation of Contact Motion --- p.34Chapter 4.1 --- Introduction --- p.34Chapter 4.2 --- Search-tree --- p.34Chapter 4.3 --- Cost Function --- p.36Chapter 4.4 --- Details of Algorithm --- p.37Chapter 4.4.1 --- Calculation of the Next Instant Contact States --- p.39Chapter 4.4.1.1 --- Contact Region Estimation --- p.41Chapter 4.4.1.2 --- Contact Point Calculation --- p.45Chapter 4.4.1.3 --- Object Position and Orientation Calculation --- p.48Chapter 4.4.1.4 --- Contact Motion Calculation --- p.50Chapter 5 --- Implementation --- p.56Chapter 5.1 --- Introduction --- p.56Chapter 5.2 --- Architecture of Friendly Teaching System --- p.56Chapter 5.2.1 --- CyberGlove --- p.57Chapter 5.2.2 --- CyberGlove Interface Unit --- p.57Chapter 5.2.3 --- Host Computer --- p.58Chapter 5.2.4 --- Software --- p.58Chapter 5.3 --- Algorithm Implementation --- p.59Chapter 5.4 --- Examples for Calculation of Contact Configuration --- p.59Chapter 5.5 --- Simulation --- p.68Chapter 5.6 --- Experiments --- p.82Chapter 5.6.1 --- Translation of an Object --- p.82Chapter 5.6.2 --- Rotation of an Object --- p.90Chapter 6 --- Conclusions --- p.98References --- p.101Appendix --- p.10

Tactile mapping of harsh, constrained environments, with an application to oil wells

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. [110]-114).This work develops a practical approach to explore rough environments when time is critical. The harsh environmental conditions prevent the use of range, force/torque or tactile sensors. A representative case is the mapping of oil wells. In these conditions, tactile exploration is appealing. In this work, the environment is mapped tactilely, by a manipulator whose only sensors are joint encoders. The robot autonomously explores the environment collecting few, sparse tactile data and monitoring its free movements. These data are used to create a model of the surface in real time and to choose the robot's movements to reduce the mapping time. First, the approach is described and its feasibility demonstrated. Real-time impedance control allows a robust robot movement and the detection of the surface using a manipulator mounting only position sensors. A representation based on geometric primitives describes the surface using the few, sparse data available. The robustness of the method is tested against surface roughness and different surrounding fluids. Joint backlash strongly affect the robot's precision, and it is inevitable because of the thermal expansion in the joints. Here, a new strategy is developed to compensate for backlash positioning errors, by simultaneously identifying the surface and the backlash values. Second, an exploration strategy to map a constraining environment with a manipulator is developed. To maximize the use of the acquired data, this work proposes a hybrid approach involving both workspace and configuration space. The amount of knowledge of the environment is evaluated with an approach based on information theory, and the robot's movements are chosen to maximize the expected increase of such knowledge. Since the robot only possesses position sensors, the location along the robot where contact with the surface occurs cannot be determined with certainty. Thus a new approach is developed, that evaluates the probability of contact with specific parts of the robot and classifies and uses the data according to the different types of contact. This work is validated with simulations and experiments with a prototype manipulator specifically designed for this application.by Francesco Mazzini.Ph.D

Contact sensing--a sequential decision approach to sensing manipulation contact features

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1995.Includes bibliographical references (p. 179-186).by Brian Scott Eberman.Ph.D