Amy Briggs | Middlebury College (original) (raw)

Papers by Amy Briggs

We consider the problem of planning sensor strategies that enable a sensor to be automatically co... more We consider the problem of planning sensor strategies that enable a sensor to be automatically configured for robot tasks. In this paper we present robust and efficient algorithms for computing the regions from which a sensor has unobstructed or partially obstructed views of a target in a goal. We apply these algorithms to the Error Detection and Recovery problem of recognizing whether a goal or failure region has been achieved. Based on these methods and strategies for visually-cued camera control, we have built a robot surveillance system in which one mobile robot navigates to a viewing position from which it has an unobstructed view of a goal region, and then uses visual recognition to detect when a specific target has entered the room. 1 Introduction This paper introduces a computational framework in which to study the problem of sensor configuration, and develops combinatorially precise algorithms for computing partial and complete visibility maps. A primary motivation for this...

This paper presents a new method for feature matching between pairs of one-dimensional panoramic ... more This paper presents a new method for feature matching between pairs of one-dimensional panoramic images for use in navigation and localization by a mobile robot equipped with an omnidirectional camera. We extract locally scale-invariant feature points from the scale space of such images, and collect color information and shape properties of the scale-space surface in a feature descriptor. We define a matching cost based on these descriptors, and present a novel dynamic programming method to establish globally optimal feature correspondences between images taken by a moving robot. Our method can handle arbitrary rotations and large numbers of missing features. It is also robust to significant changes in lighting conditions and viewing angle, and in the presence of some occlusion.

this paper we propose a new method for reliable vision-based navigation in an unmodeled dynamic e... more this paper we propose a new method for reliable vision-based navigation in an unmodeled dynamic environment. Artificial landmarks are used as visual cues for navigation. Our system builds a visibility graph among landmark locations during an exploration phase and then uses that graph for navigation. To deal with temporary occlusion of landmarks, long-term changes in the environment, and inherent uncertainties in the landmark detection process, we use a probabilistic model of landmark visibility. Based on the history of previous observations made, each visibility edge in the graph is annotated with an estimated probability of landmark detection. To solve a navigation task, our algorithm computes the expected shortest paths between all landmarks and the specified goal, by solving a special instance of a Markov decision process. The paper presents both the probabilistic expected shortest path planner and the landmark design and detection algorithm, which finds landmark patterns under g...

1. Summary The Advanced Placement (AP) Computer Science program is intended to reflect enough of ... more 1. Summary The Advanced Placement (AP) Computer Science program is intended to reflect enough of a common core of a first semester or year of university-level computer science so that placement or credit can be awarded for work done before college. The SIGCSE symposia have a long history of providing forums for discussing the evolution of the AP program from its inception [1] to the transition in languages from Pascal to C++ to Java [2,3,5,7,8,9]. In [15] a report on the beginning of the project we report on here was presented. This proposed special session is a report on a new direction, with the potential for widespread adoption, for a new course in computer science for high schools and colleges; a course with the potential to be a new AP course attracting a larger and more diverse audience than typical introductory programming courses. In this session we will report on the process that has led to this new direction, the potential for piloting the new course, and the need for comp...

Students and faculty alike at all education levels are clearly spending much more of their time i... more Students and faculty alike at all education levels are clearly spending much more of their time interacting with computing and communication tools than with each other. Is this good? Are all uses of computational technology in education helpful, and ...

The CS Principles Project is a collaborative effort to develop a new introductory course in compu... more The CS Principles Project is a collaborative effort to develop a new introductory course in computer science, accessible to all students. Computer Science educators at all levels have worked together on the development of the new curriculum under the direction of the College Board with support from the National Science Foundation. This special session provides an opportunity for the CS Principles project leaders to report on recent updates and new directions, and to engage in discussion on all aspects of the project with SIGCSE participants

ACM Inroads, 2012

The Computer Science Principles project is part of a national effort to reach a wide and diverse ... more The Computer Science Principles project is part of a national effort to reach a wide and diverse audience of students and share with them the deep and rich intellectual and practical contributions of computing. Members of the CS Principles community are building a new course⎯designed to be an introductory college--level course for everyone⎯a course rich in computer science content and exciting in its pedagogy. The course provides an academic foundation for understanding these contributions and for emphasizing the intellectual, practical, and creative aspects of the field of computer science.

ACM Inroads, 2012

ABSTRACT Welcome to the third installment of EduBits, your quarterly pipeline to new and exciting... more ABSTRACT Welcome to the third installment of EduBits, your quarterly pipeline to new and exciting happenings in the world of ACM education. Starting with this March issue of ACM Inroads, we are introducing a new thread that will highlight principal educational ...

Proceedings of the 1994 IEEE International Conference on Robotics and Automation, 1994

We consider the problem of planning the con guration of a sensor within the context of a robotic ... more We consider the problem of planning the con guration of a sensor within the context of a robotic task. In this paper, we focus on geometrically speci ed tasks in the plane, and give algorithms for computing the regions from which an idealized point-and-shoot sensor can detect a polygonal robot. Our main algorithm allows sensor con gurations from which the robot may be partially obstructed, and computes the regions from which the robot can be detected as it translates through the goal at a known orientation. This algorithm runs in time O(kmn 3 (n + m)) for an environment of complexity n, a robot of complexity m, and a goal of complexity k. The regions constructed can be used by an active sensing system to con gure sensors that are guaranteed to observe the robot as it enters the goal.

Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065), 2000

We propose a new system for vision-based mobile robot navigation in an unmodeled environment. Sim... more We propose a new system for vision-based mobile robot navigation in an unmodeled environment. Simple, unobtrusive arti cial landmarks are used as navigation and localization aids. The landmark patterns are designed so that they can be reliably detected in real-time in images taken with the robot's camera over a wide range of viewing con gurations. The code for the recognition algorithm is publicly available at

Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006

This paper presents a new method for navigation and localization of a mobile robot equipped with ... more This paper presents a new method for navigation and localization of a mobile robot equipped with an omnidirectional camera. We represent the environment using a collection of one-dimensional panoramic images formed by averaging the center scanlines of a cylindrical view. Such 1D images can be stored and processed with few resources, allowing a fairly dense sampling of the environment. Image matching proceeds in real time using dynamic programming on scale-invariant features extracted from each circular view. By analyzing the shape of the matching curve, the relative orientation of pairs of views can be recovered and utilized for navigation. When navigating, the robot continually matches its current view against stored reference views taken from known locations, and determines its location and heading from the properties of the matching results. Experiments show that our method is robust to occlusion, repeating patterns, and lighting variations.

Proceedings of the 46th ACM Technical Symposium on Computer Science Education - SIGCSE '15, 2015

Proceedings of the thirteenth annual symposium on Computational geometry - SCG '97, 1997

In this video, we use The Geometers SketchpodTM to d-scribe and animate a new polygon-offset dist... more In this video, we use The Geometers SketchpodTM to d-scribe and animate a new polygon-offset distance function, illustrating how offset polygons grow, how they differ born scaled polygons, how distance is measured using offset poly-gons, why the function does not ...

Computer Vision and Image Understanding, 2006

... There has been much recent work on invariant features in 2D images, including Lowe&am... more ... There has been much recent work on invariant features in 2D images, including Lowe&amp;amp;amp;#x27;s SIFT detector [1] and [10], and the invariant interest points by Mikolajczyk and Schmid [2] and [3] . Such features have been used for object recognition and image retrieval, as well as robot ...

This paper presents a new method for feature matching between pairs of one-dimensional panoramic ... more This paper presents a new method for feature matching between pairs of one-dimensional panoramic images for use in navigation and localization by a mobile robot equipped with an omnidirectional camera. We extract locally scaleinvariant feature points from the scale space of such images, and collect color information and shape properties of the scale-space surface in a feature descriptor. We define a matching cost based on these descriptors, and present a novel dynamic programming method to establish globally optimal feature correspondences between images taken by a moving robot. Our method can handle arbitrary rotations and large numbers of missing features. It is also robust to significant changes in lighting conditions and viewing angle, and in the presence of some occlusion.

A Vision-based mobile robot navigation requires robust methods for planning and executing tasks d... more A Vision-based mobile robot navigation requires robust methods for planning and executing tasks due to the unreliability of visual information. In this paper we propose a new method f o r r eliable vision-based navigation in an unmodeled dynamic environment. Arti cial landmarks are u s e d as visual cues for navigation. Our system builds a visibility graph among landmark locations during an exploration phase and then uses that graph for navigation. To d e al with temporary occlusion of landmarks, long-term changes in the environment, and inherent uncertainties in the landmark detection process, we use a probabilistic model of landmark visibility. Based on the history of previous observations made, each visibility edge in the graph is annotated with an estimated p r obability of landmark detection. To solve a navigation task, our algorithm computes the expected shortest paths between all landmarks and the speci ed goal, by solving a special instance of a Markov decision process. The paper presents both the probabilistic expected shortest path planner and the landmark design and detection algorithm, which nds landmark patterns under general a ne transformations in real-time.

ACM Inroads, 2012

Proceedings of the 1994 IEEE International Conference on Robotics and Automation, 1994

Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065), 2000

Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006

Proceedings of the 46th ACM Technical Symposium on Computer Science Education - SIGCSE '15, 2015

Proceedings of the thirteenth annual symposium on Computational geometry - SCG '97, 1997

Computer Vision and Image Understanding, 2006

This paper presents a new method for feature matching between pairs of one-dimensional panoramic ... more This paper presents a new method for feature matching between pairs of one-dimensional panoramic images for use in navigation and localization by a mobile robot equipped with an omnidirectional camera. We extract locally scaleinvariant feature points from the scale space of such images, and collect color information and shape properties of the scale-space surface in a feature descriptor. We define a matching cost based on these descriptors, and present a novel dynamic programming method to establish globally optimal feature correspondences between images taken by a moving robot. Our method can handle arbitrary rotations and large numbers of missing features. It is also robust to significant changes in lighting conditions and viewing angle, and in the presence of some occlusion.