Organizational Unit:

Institute for Robotics and Intelligent Machines (IRIM)

Permanent Link

https://hdl.handle.net/1853/70657

Includes Organization(s)

Organizational Unit

Biorobotics and Human Modeling Lab

Organizational Unit

Humanoid Robotics Laboratory

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Publication Search Results

Now showing 1 - 9 of 9

Generating Human-like Motion for Robots

(Georgia Institute of Technology, 2013-07) Gielniak, Michael J. ; Liu, C. Karen ; Thomaz, Andrea L.

Action prediction and fluidity are key elements of human-robot teamwork. If a robot’s actions are hard to understand, it can impede fluid HRI. Our goal is to improve the clarity of robot motion by making it more humanlike. We present an algorithm that autonomously synthesizes human-like variants of an input motion. Our approach is a three stage pipeline. First we optimize motion with respect to spatio-temporal correspondence (STC), which emulates the coordinated effects of human joints that are connected by muscles. We present three experiments that validate that our STC optimization approach increases human-likeness and recognition accuracy for human social partners. Next in the pipeline, we avoid repetitive motion by adding variance, through exploiting redundant and underutilized spaces of the input motion, which creates multiple motions from a single input. In two experiments we validate that our variance approach maintains the human-likeness from the previous step, and that a social partner can still accurately recognize the motion’s intent. As a final step, we maintain the robot’s ability to interact with it’s world by providing it the ability to satisfy constraints. We provide experimental analysis of the effects of constraints on the synthesized human-like robot motion variants.
Robots for Humanity: A Case Study in Assistive Mobile Manipulation

(Georgia Institute of Technology, 2013-03) Chen, Tiffany L. ; Ciocarlie, Matei ; Cousins, Steve ; Grice, Phillip M. ; Hawkins, Kelsey ; Hsiao, Kaijen ; Kemp, Charles C. ; King, Chih-Hung ; Lazewatsky, Daniel A. ; Nguyen, Hai ; Paepcke, Andreas ; Pantofaru, Caroline ; Smart, William D. ; Takayama, Leila

Assistive mobile manipulators have the potential to one day serve as surrogates and helpers for people with disabilities, giving them the freedom to perform tasks such as scratching an itch, picking up a cup, or socializing with their families. This article introduces a collaborative project with the goal of putting assistive mobile manipulators into real homes to work with people with disabilities. Through a participatory design process in which users have been actively involved from day one, we are identifying and developing assistive capabilities for the PR2 robot. Our approach is to develop a diverse suite of open source software tools that blend the capabilities of the user and the robot. Within this article, we introduce the project, describe our progress, and discuss lessons we have learned.
A Visualization Framework for Team Sports Captured using Multiple Static Cameras

(Georgia Institute of Technology, 2013) Hamid, Raffay ; Kumar, Ramkrishan ; Hodgins, Jessica K. ; Essa, Irfan

We present a novel approach for robust localization of multiple people observed using a set of static cameras. We use this location information to generate a visualization of the virtual offside line in soccer games. To compute the position of the offside line, we need to localize players' positions, and identify their team roles. We solve the problem of fusing corresponding players' positional information by finding minimum weight K-length cycles in a complete K-partite graph. Each partite of the graph corresponds to one of the K cameras, whereas each node of a partite encodes the position and appearance of a player observed from a particular camera. To find the minimum weight cycles in this graph, we use a dynamic programming based approach that varies over a continuum from maximally to minimally greedy in terms of the number of graph-paths explored at each iteration. We present proofs for the efficiency and performance bounds of our algorithms. Finally, we demonstrate the robustness of our framework by testing it on 82,000 frames of soccer footage captured over eight different illumination conditions, play types, and team attire. Our framework runs in near-real time, and processes video from 3 full HD cameras in about 0.4 seconds for each set of corresponding 3 frames.
Terrain Reconstruction of Glacial Surfaces via Robotic Surveying Techniques

(Georgia Institute of Technology, 2012-12) Williams, Stephen ; Parker, Lonnie T. ; Howard, Ayanna M.

The capability to monitor natural phenomena using mobile sensing is a benefit to the Earth science community given the potentially large impact that we, as humans, can have on naturally occurring processes. Observable phenomena that fall into this category of interest range from static to dynamic in both time and space (i.e. temperature, humidity, and elevation). Such phenomena can be readily monitored using networks of mobile sensor nodes that are tasked to regions of interest by scientists. In our work, we hone in on a very specific domain, elevation changes in glacial surfaces, to demonstrate a concept applicable to any spatially distributed phenomena. Our work leverages the sensing of a vision-based SLAM odometry system and the design of robotic surveying navigation rules to reconstruct scientific areas of interest, with the goal of monitoring elevation changes in glacial regions. We validate the output from our methodology and provide results that show the reconstructed terrain error complies with acceptable mapping standards found in the scientific community.
Robust 3D Visual Tracking Using Particle Filtering on the Special Euclidean Group: A Combined Approach of Keypoint and Edge Features

(Georgia Institute of Technology, 2012-03-07) Choi, Changhyun ; Christensen, Henrik I.

We present a 3D model-based visual tracking approach using edge and keypoint features in a particle filtering framework. Recently, particle filtering based approaches have been proposed to integrate multiple pose hypotheses and have shown good performance, but most of the work has made an assumption that an initial pose is given. To ameliorate this limitation, we employ keypoint features for initialization of the filter. Given 2D-3D keypoint correspondences, we randomly choose a set of minimum correspondences to calculate a set of possible pose hypotheses. Based on the inlier ratio of correspondences, the set of poses are drawn to initialize particles. After the initialization, edge points are employed to estimate inter-frame motions. While we follow a standard edge-based tracking, we perform a refinement process to improve the edge correspondences between sampled model edge points and image edge points. For better tracking performance, we employ a first order autoregressive state dynamics, which propagates particles more effectively than Gaussian random walk models. The proposed system re-initializes particles by itself when the tracked object goes out of the field of view or is occluded. The robustness and accuracy of our approach is demonstrated using comparative experiments on synthetic and real image sequences.
Using Haptic and Auditory Interaction Tools to Engage Students with Visual Impairments in Robot Programming Activities

(Georgia Institute of Technology, 2012-01) Howard, Ayanna M. ; Park, Chung Hyuk ; Remy, Sekou

The robotics field represents the integration of multiple facets of computer science and engineering. Robotics-based activities have been shown to encourage K-12 students to consider careers in computing and have even been adopted as part of core computer-science curriculum at a number of universities. Unfortunately, for students with visual impairments, there are still inadequate opportunities made available for teaching basic computing concepts using robotics-based curriculum. This outcome is generally due to the scarcity of accessible interfaces to educational robots and the unfamiliarity of teachers with alternative (e.g., nonvisual) teaching methods. As such, in this paper, we discuss the use of alternative interface modalities to engage students with visual impairments in robotics-based programming activities. We provide an overview of the interaction system and results on a pilot study that engaged nine middle school students with visual impairments during a two-week summer camp.
Force reflecting teleoperation with adaptive impedance control

(Georgia Institute of Technology, 2004-02) Love, Lonnie J. ; Book, Wayne J.

Experimentation and a survey of the literature clearly show that contact stability in a force reflecting teleoperation system requires high levels of damping on the master robot. However, excessive damping increases the energy required by an operator for commanding motion. The objective of this paper is to describe a new force reflecting teleoperation methodology that reduces operator energy requirements without sacrificing stability. We begin by describing a new approach to modeling and identifying the remote environment bf the teleoperation system. We combine a conventional Multi-Input, Multi-Output Recursive Least Squares (MIMO-RLS) system identification, identifying in real-time the remote environment impedance, with a discretized representation 'of the remote environment. This methodology generates a time-varying, position dependent representation of the remote environment dynamics. Next, we adapt the target impedance of the master robot with respect to the dynamic model of the remote environment. The environment estimation and impedance adaptation are execute simultaneously and in real time. We demonstrate, through experimentation, that this approach significantly reduces the energy required by an operator to execute remote tasks while simultaneously providing sufficient damping to ensure contact stability.
Control Techniques and Programming Issues for Time Delayed Internet Based Teleoperation

(Georgia Institute of Technology, 2003-06) Munir, Saghir ; Book, Wayne J.

This article focuses on Internet-based real time control, such as remote bilateral teleoperation. In such applications it is required that the control loop be closed around a time delayed network. Although various researchers have worked on this problem, this paper focuses on two control strategies (based on wave variables and a time forward observer), bandwidth issues, and some related programming details. Experimental results of bilateral teleoperation via the Ethernet between Atlanta and Tokyo are given. The system used was a two degree of freedom haptic interface, bilaterally coupled to simulation (implemented on a windows NT based computer) of a similar system.
Alternatives in the generation of time domain models of fluid lines using frequency domain techniques

(Georgia Institute of Technology, 2000-10) Watson, Cody ; Book, Wayne J.

By converting from frequency domain models to time domain models, nonlinear behavior and linear distributed behavior can both be effectively represented. Three methods are presented to convert fluid line models from the frequency domain to the time domain. Comparison shows that combining components in the frequency domain has advantages in accuracy and efficiency in many practical cases. Methods of finding model poles and residues and ways to avoid numerical difficulties with poles at the origin are discussed.