Seminars by Visiting Scientists at I²R

Title: Human-Centered Robotics

Speaker: Professor Oussama Khatib
Artificial Intelligence Laboratory
Department of Computer Science
Stanford University

Visiting Scientist, I²R

Phone: +1 (650)723-9753
Fax:   +1 (650) 725-1449
http://robotics.stanford.edu/~ok/

Venue: Big-One, I²R

Time: 10-12, Tue, Nov 13, 2007

Chaired by: Dr Huang Zhiyong


Abstract

Robotics is rapidly expanding into human environments and vigorously engaged in its new emerging challenges. Interacting, exploring, and working with humans, the new generation of robots will increasingly touch people and their lives. The successful introduction of robots in human environments will rely on the development of competent and practical systems that are dependable, safe, and easy to use. This presentation focuses on our ongoing effort to develop human-friendly robotic systems that combine the essential characteristics of safety, human-compatibility, and performance. In the area of human-friendly robot design, our effort has focused on new design concepts for the development of intrinsically safe robotic systems that possess the requisite capabilities and performance to interact and work with humans. Robot design has traditionally relied on the use of rigid structures and powerful motor/gear systems in order to achieve fast motions and produce the needed contact forces. While suited for multitude of tasks in industrial robot applications, the resulting systems are certainly unsafe for human interaction, as they can lead to hazardous impact forces should the robot unexpectedly collide with its environment.

Our work on human-friendly robot design has led to a novel actuation approach that is based on the so-called Distributed Macro Mini (DM2) Actuation concept. DM2 combines the use of small motors at the joints with pneumatic, muscle-like actuators remotely connected by cables. With this hybrid actuation, the impedance of the resulting robot is decreased by an order of magnitude, making it substantially safer without sacrificing performance. To further increase the robot safety during its interactions with humans, we have developed an impact absorbent skin that covers its structure. In the area of human-motion synthesis, our objective has been to analyze human motion to unveil its underlying characteristics through the elaboration of its physiological basis, and to formulate general strategies for interactive whole-body robot control. Our exploration has employed models of human musculoskeletal dynamics and used extensive experimental studies of human subjects with motion capture techniques. This investigation has revealed the dominant role physiological characteristics play in shaping human motion. Using these characteristics we develop generic motion behaviors that efficiently and effectively encode some basic human motion behaviors. To implement these behaviors on robots with complex human-like structures, we developed a unified whole-body task-oriented control structure that addresses dynamics in the context of multiple tasks, multi-point contacts, and multiple constraints. The performance and effectiveness of this approach are demonstrated through extensive robot dynamic simulations and implementations on physical robots for experimental validation.

Biographical sketch

Dr. Khatib is Professor of Computer Science at Stanford University. He received his Ph.D. in 1980 from Sup'Aero, Toulouse, France. His current research is in human-centered robotics, haptic interactions, and human-friendly robot design. Professor Khatib was the Program Chair of ICRA2000 (San Francisco) and Editor of ``The Robotics Review'' (MIT Press). He served as the Director of the Stanford Computer Forum, an industry affiliate program. He is the President of the International Foundation of Robotics Research, IFRR, Editor of STAR, Springer Tracts in Advanced Robotics, and Editor of Springer Handbook of Robotics. Professor Khatib is an IEEE Fellow who served as a Distinguished Lecturer of IEEE, and is a recipient of the JARA Award.

Title: Vision-Realistic Rendering

Speaker: Professor Brian A. Barsky
Professor of Computer Science

Affiliate Professor of Optometry and Vision Science

University of California, Berkeley

Visiting Scientist, I²R

Phone: +1 (510) 642-9838

http://www.eecs.berkeley.edu/Faculty/Homepages/barsky.html

Venue: Big-One, I²R

Time: Tue 3-3:50, Aug 21, 2007

Chaired by: Dr Susanto Rahardja

Abstract

Vision-simulated imaging (VSI) is the computer generation of synthetic images to simulate a subject's vision, by incorporating the characteristics of a particular individual’s entire optical system. Using measured aberration data from a Shack-Hartmann wavefront aberrometry device, VSI modifies input images to simulate the appearance of the scene for the individual patient. Each input image can be a photograph, synthetic image created by computer, frame from a video, or standard Snellen acuity eye chart -- as long as there is accompanying depth information. An eye chart is very revealing, since it shows what the patient would see during an eye examination, and provides an accurate picture of his or her vision. Using wavefront aberration measurements, we determine a discrete blur function by sampling at a set of focusing distances, specified as a set of depth planes that discretize the three-dimensional space. For each depth plane, we construct an object-space blur filter. VSI methodolgy comprises several steps: (1) creation of a set of depth images, (2) computation of blur filters, (3) stratification of the image, (4) blurring of each depth image, and (5) composition of the blurred depth images to form a single vision-simulated image.

VSI provides images and videos of simulated vision to enable a patient's eye doctor to see the specific visual anomalies of the patient. In addition to blur, VSI could reveal to the doctor the multiple images or distortions present in the patient's vision that would not otherwise be apparent from standard visual acuity measurements. VSI could educate medical students as well as patients about the particular visual effects of certain vision disorders (such as keratoconus and monocular diplopia) by enabling them to view images and videos that are generated using the optics of various eye conditions. By measuring PRK/LASIK patients pre- and post-op, VSI could provide doctors with extensive, objective, information about a patient's vision before and after surgery. Potential candiates contemplating surgery could see simulations of their predicted vision and of various possible visual anomalies that could arise from the surgery, such as glare at night. The current protocol, where patients sign a consent form that can be difficult for a layperson to understand fully, could be supplemented by the viewing of a computer-generated video of simulated vision showing the possible visual problems that could be engendered by the surgery.

Biography

Brian A. Barsky is Professor of Computer Science and Affiliate Professor of Optometry and Vision Science at the University of California at Berkeley. He is a member of the Joint Graduate Group in Bioengineering, an interdisciplinary and inter-campus program, between UC Berkeley and UC San Francisco.

He was a Directeur de Recherches at the Laboratoire d'Informatique Fondamentale de Lille (LIFL) of l'Université des Sciences et Technologies de Lille (USTL). He has been a Visiting Professor of Computer Science at The Hong Kong University of Science and Technology in Hong Kong, at the University of Otago in Dunedin, New Zealand, in the Modélisation Géométrique et Infographie Interactive group at l'Institut de Recherche en Informatique de Nantes and l'Ecole Centrale de Nantes, in Nantes, and at the University of Toronto in Toronto. Prof. Barsky was a Distinguished Visitor at the School of Computing at the National University of Singapore in Singapore, an Attaché de Recherche Invité at the Laboratoire Image of l'Ecole Nationale Supérieure des Télécommunications in Paris, and a visiting researcher with the Computer Aided Design and Manufacturing Group at the Sentralinsitutt for Industriell Forskning (Central Institute for Industrial Research) in Oslo.

He attended McGill University in Montréal, where he received a D.C.S. in engineering and a B.Sc. in mathematics and computer science. He studied computer graphics and computer science at Cornell University in Ithaca, where he earned an M.S. degree. His Ph.D. degree is in computer science from the University of Utah in Salt Lake City. He is a Fellow of the American Academy of Optometry (F.A.A.O.).

He is a co-author of the book An Introduction to Splines for Use in Computer Graphics and Geometric Modeling, co-editor of the book Making Them Move: Mechanics, Control, and Animation of Articulated Figures, and author of the book Computer Graphics and Geometric Modeling Using Beta-splines. He has published 120 technical articles in this field and has been a speaker at many international meetings.

Dr. Barsky was a recipient of an IBM Faculty Development Award and a National Science Foundation Presidential Young Investigator Award. He is an area editor for the journal Graphical Models. He is the Computer Graphics Editor of the Synthesis digital library of engineering and computer science, published by Morgan & Claypool Publishers, and the Series Editor for Computer Science for Course Technology, part of Thomson Learning. He was the editor of the Computer Graphics and Geometric Modeling series of Morgan Kaufmann Publishers, Inc. from December 1988 to September 2004. He was the Technical Program Committee Chair for the Association for Computing Machinery / SIGGRAPH '85 conference.

His research interests include computer aided geometric design and modeling, interactive three-dimensional computer graphics, visualization in scientific computing, computer aided cornea modeling and visualization, medical imaging, and virtual environments for surgical simulation.

He has been working in spline curve/surface representation and their applications in computer graphics and geometric modeling for many years. He is applying his knowledge of curve/surface representations as well as his computer graphics experience to improving videokeratography and corneal topographic mapping, forming a mathematical model of the cornea, and providing computer visualization of patients' corneas to clinicians. This has applications in the design and fabrication of contact lenses, and in laser vision correction surgery. His current research, called Vision-Realistic Rendering is developing new three-dimensional rendering techniques for the computer generation of synthetic images that will simulate the vision of specific individuals based on their actual patient data using measurements from a instrument a Shack-Hartmann wavefront aberrometery device. This research forms the OPTICAL (OPtics and Topography Involving Cornea and Lens) project.