Networked Telerobotics: Systems, Collaborative Algorithms

• Demonstrate Demonstrate, commissioned by the Whitney Museum, set up a state-of-the-art robotic webcamera over UC Berkeley's Sproul Plaza, birthplace of the Free Speech Movement. For six weeks, the camera was accessible to anyone on the Internet. Online participants shared remote control of the camera, allowing them to zoom in to frame and photograph activity in the Plaza at any time of day or night.
• Sharecam We are developing network-based applications for education, journalism and entertainment where many users share control of a single physical resource. Our project, "Sharecam", is a single robotic pan, tilt, zoom digital camera. In this paper we describe algorithms for controlling the camera frame based on independent requests from online users.
• Tele-Actor Internet-based "online robots" now provide public access to remote locations such as museums and laboratories. The Tele-Actor is a collaborative online teleoperation system for distance learning that allows many students to simultaneously share control of a single mobile resource.
• Collaborative Control Collaborative Telerobotics (CT) is a novel approach to teleimmersion and teleworking. With CT, participants collaborate rather than compete for access to valuable resources such as historical and scientific sites. Collaboration is a crucial ingredient for education and teamwork. A scalable infrastructure for CT, compatible with the Internet, would allow large groups of students or researchers to simultaneously participate in remote experiences.
• Ouija 2000: Collaborative Teleoperation on the Internet We have created a system that allows a distributed group of users to simultaneously teleoperate an industrial robot arm via the Internet. A java applet at each client streams mouse motion vectors from up to 30 users; a server aggregates these inputs to produce a single control stream for the robot. Users receive visual feedback from a digital camera mounted above the robot arm.
• The Telegarden: An Interactive Installation on the WWW The TeleGarden is an art installation that allows web users to view and interact with a remote garden filled with living plants. Members can plant, water, and monitor the progress of seedlings via the tender movements of an industrial robot arm.
• Memento Mori Mori displays streaming seismographic data measured continuously from a site near the Hayward Fault above University of California at Berkeley. The earthquake detector is a Streckeisen STS-1 seismometer that measures vertical ground velocity. Data is collected by the Berkeley Seismological Laboratory and relayed to a server in the Alpha Lab.
• Shadow Server Dislocation of Intimacy is a net-based installation by Ken Goldberg, Bob Farzin, and the Alpha Lab. The installation is based on a sealed black box who's interior is accessible only via the Internet. The user selects from among five lights, clicks the button, and receives a surrealist and mysterious shadow, which arrives at the user's screen in gray-scale and without content.
• Eigentaste Eigentaste is a collaborative filtering algorithm that uses universal queries to elicit real-valued user ratings on a common set of items and applies principal component analysis (PCA) to the resulting dense subset of the ratings matrix. PCA facilitates dimensionality reduction for offline clustering of users and rapid computation of recommendations. Eigentaste was originally used in an online joke recommendation system called Jester, which recommends new jokes to users based on their ratings of an initial set. We are currently working on implementing a new application, Donation Dashboard, which recommends a portfolio of non-profits (including suggested donation dollar amounts for each).

Algorithmic Automation: Part Feeding, Fixturing

• Evaluating the Blade Primitive for Feeding Polygonal Parts with Vibratory Bowls: Simulation, Hardware, and Experiments This project involves the design of a test track, completion of quantitative physical experiments, development of theories to explain discrepancies between the blade algorithm and the experiments, and the exploration of software simulation.
• D-Space and Deform Closure We extend the form closure framework for rigid parts to holding a class of deformable parts. In this class, a part is a linearly elastic, frictionless polygon with a finite element mesh and given stiffness matrix.
• Grasping at Concavities A simple gripper with two vertical cylindrical jaws can make contact with external or internal concavities in polygonal and polyhedral parts to align and grip parts in form closure.
• Gripper Point Contacts for Part Alignment The initial resting pose of many industrial parts differs from the orientation desired for assembly. We show that it is possible to align parts during grasping using a standard parallel-jaw gripper.
• Gripper Linear Contacts for Part Alignment Assembly lines often require grippers. It is possible in many cases to compensate for the difference in part orientation using a parallel-jaw gripper with appropriate jaw design.
• Grasping at Part Edges We propose a new model for grasping parts with an industrial parallel-jaw gripper where two define candidate grasps that are resistant to slipping and torque about the part's center of mass.
• Trap Design for Vibratory Bowl Feeders The vibratory bowl feeder is the oldest and still most common approach to the automated feeding (orienting) of industrial parts. In this project we consider a class of vibratory bowl filters that can be described by removing polygonal sections from the track; we refer to this class of filters as traps.
• Pin Design for Part Feeding We consider a sensorless approach to feeding parts on a conveyor belt using pins (rigid barriers) to topple parts into desired orientations. Given the n-sided 2D convex projection of an extruded polygonal part, its center of mass (COM), and coefficients of friction, we develop an O(n2) algorithm to compute the toppling graph, a new data structure that represents the mechanics of toppling including rolling and jamming.
• "Unilateral" Fixturing of Sheet Metal Parts using Modular Jaws with Plane-Cone Contacts To fixture sheet metal parts for welding, we propose "unilateral fixtures" consisting of modular fixturing elements that lie almost completely on one side of the part. These are based on cylindrical jaws with conical grooves which provide the equivalent of 4 point contacts.
• Fixture-Based Industrial Robot Calibration for Silicon-Wafer Handling Semiconductor manufacturing industry requires highly accurate robot operation with short downtime. We develop a fast, low cost and easy-to-operate calibration system for wafer-handling robots. The system is defined by a fixture and a simple compensation algorithm. Given robot repeatability, endeffector uncertainties, and the tolerance requirements of wafer placement points, we derive fixture design and placement specifications based on worst-case and statistical tolerance models. We verify our resultant design by physical experiments in a factory-floor environment.
• FixtureNet: a Feasibility Study for Geometric CAD Evaluation via the WWW Fixturenet is an interactive Java applet that allows users to draw a part. Fixturenet then computes and displays all modular fixtures that will hold that part. Users can click and drag on the resulting displays to visualize reaction forces.

Medical Robotics: Steerable Needles, Dose Delivery

• Needle Insertion and Radioactive Seed Implantation in Human Tissues: Simulation and Sensitivity Analysis To facilitate training and planning for medical procedures such as prostate brachytherapy, we are developing an interactive simulation of needle insertion and radioactive seed implantation in soft tissues. We describe a new 2D dynamic FEM model based on a reduced set of scalar parameters such as needle friction, sharpness, and velocity, where the mesh is updated to maintain element boundaries along the needle shaft and the effect of needle tip and frictional forces are simulated.
• Image Registration for Prostate MR Spectroscopy We develop an image registration system based on biomechanical modeling of the prostate and surrounding tissues to register cancerous tumor locations for targeted prostate brachytherapy treatment planning. Cancerous tumors can be identified using magnetic resonance spectroscopy (MRS) imaging, which is acquired with an endorectal probe that causes significant nonlinear deformation of the prostate.

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