Zachary Dodds

AAAI Conference 2011 Conference Paper

Can Quadrotors Succeed as an Educational Platform?

• Zachary Dodds

AAAI Conference 2010 Conference Paper

Model AI Assignments

• Todd Neller
• John DeNero
• Dan Klein
• Sven Koenig
• William Yeoh
• Xiaoming Zheng
• Kenny Daniel
• Alex Nash

ICRA Conference 2007 Conference Paper

Evaluating the Roomba: A low-cost, ubiquitous platform for robotics research and education

• Ben Tribelhorn
• Zachary Dodds

This paper presents the iRobot corporation's Roomba vacuum as a low-cost resource for robotics research and education. Sensor and actuation models for unmodified Roombas are presented in the context of both special- and general-purpose spatial-reasoning algorithms, including Monte Carlo Localization and FastSLAM. Further tests probe the feasibility of sensor extensions to the platform. Results demonstrate that, with some caveats, the Roomba is a viable foundation for both classroom and laboratory use, especially for work seeking to leverage robots to other ends, as well as robotics per se with a computational focus.

AAAI Conference 2006 Conference Paper

Erdos: Cost-Effective Peripheral Robotics for AI Education

• Zachary Dodds

This work combines hardware, software, and curricula in order to create robots capable enough to advance the field of AI yet inexpensive enough to be widely accessible. Costs are kept low by pairing iRobot’s roombas with existing laptop or palmtop computers and their accessories. The result is a sub-$200 untethered physical platform capable of running and testing state-of-the-art AI algorithms.

IROS Conference 2003 Conference Paper

Handling discontinuities in stereovisual alignment tasks

• Zachary Dodds
• Gregory D. Hager

For more than a decade the capabilities of incompletely calibrated stereo systems have been formally characterized. These characterizations provide theoretical limits on the tasks that visually guided robotic systems can achieve. Within these limits there are several feature-alignment tasks whose image-space representations are inherently discontinuous, including collinearity and coplanarity. This paper presents smooth, locally convergent image-space approximations for such tasks. In addition, we propose the general notion of a "safe" image-based approximation to spatial tasks, in which complete image-space characterization is sacrificed in return for partial characterization along with local controllability. As a result, this article bridges the gap between theoretically specifiable tasks and locally controllable tasks for common stereovisual servoing systems.

ICRA Conference 2000 Conference Paper

On Specifying and Performing Visual Tasks with Qualitative Object Models

• Gregory D. Hager
• Zachary Dodds

Vision-based control has aimed to develop general-purpose, high accuracy systems for manipulating objects. While much of the scientific and technological infrastructure needed to accomplish this aim is now in place, several stumbling blocks still remain. One continuing issue is accuracy, and its relationship to system calibration. We describe a generative task structure for vision-based control of motion that admits a simple, geometric approach to task specification. At the same time, this approach allows one to state precisely what types of miscalibration lead to errors in task performance. A second hurdle has been the programmability of hand-eye systems. However, we argue that a structured object representation sufficient for flexible hand-eye coordination is a possibility. The result is a high-level, object-centered language for expressing hand-eye tasks.

ICRA Conference 1999 Conference Paper

Task Specification and Monitoring for Uncalibrated Hand/Eye Coordination

• Zachary Dodds
• Gregory D. Hager
• A. Stephen Morse
• João P. Hespanha 0001

Most of the work in robotic manipulation and visual servoing has emphasized how to specify and perform particular tasks. Recent results have formally shown what tasks are possible with uncalibrated imaging systems. This paper extends those results by characterizing in a constructive manner the set of tasks which can be performed with different types of uncalibrated camera models. The tasks resulting structure provides a principle foundation both for a specification language and for automatic execution monitoring in uncalibrated environments.

ICRA Conference 1998 Conference Paper

What Can Be Done with an Uncalibrated Stereo System?

• João P. Hespanha 0001
• Zachary Dodds
• Gregory D. Hager
• A. Stephen Morse

Over the last several years, there has been an increasing appreciation of the impact of control architecture on the accuracy of visual servoing systems. In particular, it is generally acknowledged that so-called image-based methods provide the highest guarantees of accuracy on inaccurately calibrated hand-eye systems. Less clear is the impact of the control architecture on the set of tasks which the system can perform. In this article, we present a formal analysis of control architectures for hand-eye coordination. Specifically, we first state a formal characterization of what makes a task performable under three possible encoding methods. Then, for the specific case of cameras modeled using projective geometry, we relate this characterization to notions of projective invariance and demonstrate the limits of achievable performance in this regard.

AAAI Conference 1997 Conference Paper

A Color Interest Operator for Landmark-Based Navigation

• Zachary Dodds

Landmark-based approaches to robot navigation require an “interest operator” to estimate the utility of a particular image region as an effective representative for a scene. This paper presents a color interest operator consisting of a weighted combination of heuristic scores. The operator selects those image regions (landmarks) likely to be found again, even under a different viewing geometry and/or diRerent illumination conditions. These salient regions yield a robust representation for recognition of a scene. Experiments showing the reproduceability of the regions selected by this operator demonstrate its use as a hedge against environment al uncertainties.