Planning algorithms are impacting technical disciplines and industries around the world, including robotics, computer-aided design, manufacturing, computer graphics, aerospace applications, drug design, and protein folding. This coherent and comprehensive book unifies material from several sources, including robotics, control theory, artificial intelligence, and algorithms. The treatment is centered on robot motion planning but integrates material on planning in discrete spaces. A major part of the book is devoted to planning under uncertainty, including decision theory, Markov decision processes, and information spaces, which are the “configuration spaces” of all sensor-based planning problems. The last part of the book delves into planning under differential constraints that arise when automating the motions of virtually any mechanical system. Developed from courses taught by the author, the book is intended for students, engineers, and researchers in robotics, artificial intelligence, and control theory as well as computer graphics, algorithms, and computational biology.

Planning Algorithms: Introductory Material

http://ee.sharif.edu/~miap/Files/A%20Survey%20of%20Medical%20Image%20Registration.pdf

A survey of medical image registration.

A survey of models, analysis tools and compensation methods for the control of machines with friction

Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

Pursuing prosthetic electronic skin.

Human-Robot Interaction (HRI) has recently received considerable attention in the academic community, in labs, in technology companies, and through the media. Because of this attention, it is desirable to present a survey of HRI to serve as a tutorial to people outside the field and to promote discussion of a unified vision of HRI within the field. The goal of this review is to present a unified treatment of HRI-related problems, to identify key themes, and discuss challenge problems that are likely to shape the field in the near future. Although the review follows a survey structure, the goal of presenting a coherent "story" of HRI means that there are necessarily some well-written, intriguing, and influential papers that are not referenced. Instead of trying to survey every paper, we describe the HRI story from multiple perspectives with an eye toward identifying themes that cross applications. The survey attempts to include papers that represent a fair cross section of the universities, government efforts, industry labs, and countries that contribute to HRI, and a cross section of the disciplines that contribute to the field, such as human, factors, robotics, cognitive psychology, and design.

/pdf/human-robot-interaction-a-survey-4q8yi606a9.pdf

Human-Robot Interaction: A Survey

The thesis of the paper is that a passive robotic wrist, of fixed mechanical design, can be programmed to execute a wide range of force control laws of potential use in automated assembly. The authors conduct a systematic study to characterize the range of control laws (given by admittance matrices) implementable by passive programmable mechanical devices. The authors electrical network theory results to identify the admittance matrices which are attainable in the joint-space of the wrist. They then project these matrices in the task-space and compare the range of task-space matrices with a known class of matrices in an attempt to quantify the versatility of passive devices. >

A task-space formulation of passive force control

Recent work in human-robot interaction has re- vealed the need for compliant, human-friendly devices. One such device, known as the MARIONET, is a cable-driven single joint actuator with the intended applications of physical rehabilitation and assistive devices. In this work, the stability of the nonlinear system is determined in regards to its equilibria in a wide variety of configurations. In certain configurations, the canonical version of this mechanism experiences an interesting mathematical behavior known as "catastrophes". This behavior may be disadvantageous toward control or even safety. Several cases are thoroughly investigated, two cases where each of two degrees of freedom loses control, and the final case explores the use of a mechanical advantage such as a block and tackle. The study concludes that for a range of design options, the MARIONET does not suffer from any catastrophes. However, the unique behaviors such as a unidirectional bifurcation produced by certain configurations may have use outside of our objectives, perhaps as a type of switch or valve. Tensioner keeps the tension of the cable at a constant value. The torque on the elbow is a function of the moment arm exerted by the length of cable from the Link to the Pulley (LLP ). This paper will explore the equilibria of the MARIONET under several different conditions. The first condition con- siders where the Pulley is under position control (a non- backdrivable Rotator). It is determined that the Link in this case will converge to the Pulley position in every configu- ration except for minute singularities. The second condition simulates a loss of control of the Pulley with the user rigidly controlling the Link (backdrivable Rotator). It is found that in certain portions of the workspace, the Pulley will settle to either of two equilibria, neither posing any danger to the user. The final portion of the analysis takes the second condition and investigates the effects of using different mechanical advantages on LLP . The mechanical advantage, physically realized as a block and tackle, can cause interesting motions in the Rotator known as "catastrophes" (defined below). These motions could potentially cause control issues, but at the level of mechanical advantage of the MARIONET, poses no threat. We conclude that while the MARIONET in its present state has virtually no instabilities in its workspace, the unique type of catastrophe described may be able to be used in other applications. The following work has been inspired by analysis on a very similar mechanism known as a Zeeman Catastrophe Machine (1), (2). The Zeeman Machine experiences a specific type of catastrophe, defined as a large change in internal configuration caused by a small change in external circumstances. While in everyday life, the term "catastrophe" has a negative connotation, it can be used for many useful applications. Examples of catastrophes include ski boot latches, buttons on a keyboard, and even the freezing of water. A catastrophe may be thought of as

/pdf/catastrophe-and-stability-analysis-of-a-cable-driven-5drke2dgqt.pdf

Catastrophe and Stability Analysis of a Cable-Driven Actuator

Our key motivation is the rehabilitation of individuals recovering from stroke or other neurological insult. The torque exerted by a cable-driven joint is the cross product of the line of action of the cable, known as the moment arm, and its tension. The subject of this article delves into this latter, less-studied quantity associated with torque. The concept of moment arm manipulation of a cable-driven joint is introduced, developed, formalized, and then examined with experiments on a physical, single-joint device. This method of moment arm manipulation, referred to as the moment arm manipulation for remote induction of net effective torque (MARIONET), is found to have distinct advantages that make it feasible for home rehabilitation as well as potential outside of the field.

Pulling your strings

Cobots are a class of robots that use continuously variable transmissions to develop high fidelity programmable constraint surfaces. Cobots consume very little electrical power even when providing high output forces, and their transmissions are highly efficient across a broad range of transmission ratios. Cobotic transmissions also have the ability to act either as a brake or to become entirely free. The design and performance of the cobotic hand controller, a recently developed six-degree-of-freedom haptic display, is reviewed. This device illustrates the high dynamic range and low power consumption achievable by cobots. A thorough comparison of the power efficiency of a cobotic system versus a conventional electro-mechanical system is provided.

High performance Cobotics

The origin of friction reduction on an ultrasonically vibrating plate has been the subject of debate. Recent work suggests that friction may be reduced due to intermittent contact caused by bouncing upon the vibrating surface [1], leaving the question of whether other phenomena such as levitation on a squeeze film of air also play a role. To probe the contribution of squeeze film levitation, we investigated the dependence of the friction reduction effect upon air pressure. An artificial finger was placed inside a vacuum chamber, touching an ultrasonic friction reduction device composed of a glass plate vibrated by piezo-actuators. Friction between the finger and the glass was measured by rotating the finger with a motor, and measuring the motor's torque load. Decreased friction is signaled by decreased motor current. Compared to atmospheric pressure, a 98% vacuum inside the chamber was observed to markedly diminish the friction reduction effect, suggesting that squeeze film levitation does indeed play a substantial role in ultrasonic friction reduction.

/pdf/the-contribution-of-air-to-ultrasonic-friction-reduction-19epod755w.pdf

Michael A. Peshkin

Papers

A task-space formulation of passive force control

Catastrophe and Stability Analysis of a Cable-Driven Actuator

Pulling your strings

High performance Cobotics

The contribution of air to ultrasonic friction reduction