2015 |
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Sung, Cynthia; Rus, Daniela Foldable joints for foldable robots (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021012, 2015. @article{sung2015foldable, Print-and-fold manufacturing has the potential to democratize access to robots with robots that are easier to fabricate using materials that are easier to procure. Unfortunately, a lack of understanding about how motion can be achieved by folding hinders the scope of print-and-fold robots. In this paper, we show how the basic joints used in robots can be constructed using print-and-fold. Our patterns are parameterized so that users not only get the desired degrees of freedom but can also specify the joint's range of motion. The joints can be combined with each other to achieve higher degrees of freedom or with rigid bodies to produce foldable linkages. We have folded our basic joints and measured their force–displacement curves. We have composed them into joints with higher degrees of freedom and into foldable mechanisms and found that they achieve the expected kinematics. We have also added actuators and control circuitry to our joints and mechanisms, showing that it is possible to print and fold entire robots with many different kinematics using a uniform process. | |
Miyashita, Shuhei; DiDio, Isabello; Ananthabhotla, Ishwarya; An, Byoungkwon; Sung, Cynthia; Arabagi, Slava; Rus, Daniela Folding angle regulation by curved crease design for self-assembling origami propellers (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021013, 2015. @article{miyashita2015folding, This paper describes a method for manufacturing complex three-dimensional curved structures by self-folding layered materials. Our main focus is to first show that the material can cope with curved crease self-folding and then to utilize the curvature to predict the folding angles. The self-folding process employs uniform heat to induce self-folding of the material and shows the successful generation of several types of propellers as a proof of concept. We further show the resulting device is functional by demonstrating its levitation in the presence of a magnetic field applied remotely. | |
2014 |
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Sung, Cynthia; Rus, Daniela Foldable joints for foldable robots (Conference) International Symposium on Experimental Robotics (ISER), 2014. @conference{Sung2014, Print-and-fold approaches to robot fabrication allow entire robots to be produced using a single uniform process: fabricating them in-plane and then folding them into their 3-D forms. Current efforts to design print-and-fold robots have been limited by a lack of understanding of what motions can be achieved by folding. In this paper, we introduce fold patterns for three basic joints commonly used in robots, and we show how the patterns can be changed to accommodate user-specified ranges of motion. The joints are composed with each other to produce joints with higher degrees of freedom and with rigid bodies to produce entire foldable linkage mechanisms. We have folded our basic joints and composed mechanisms, and they achieve the expected kinematics. We have also printed control circuitry on and attached actuators directly to three of our designs, demonstrating that it possible to print and fold robots with many different kinematics. | |
2013 |
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Feldman, Dan; Sugaya, Andrew; Sung, Cynthia; Rus, Daniela iDiary: From GPS signals to a text-searchable diary (Conference) 11th ACM Conference on Embedded Networked Sensor Systems (SenSys), ACM, 2013. @conference{feldman2013idiary, This paper describes a system that takes as input GPS data streams generated by users' phones and creates a searchable database of locations and activities. The system is called iDiary and turns large GPS signals collected from smartphones into textual descriptions of the trajectories. The system features a user interface similar to Google Search that allows users to type text queries on their activities (e.g., "Where did I buy books?") and receive textual answers based on their GPS signals. iDiary uses novel algorithms for semantic compression (known as coresets) and trajectory clustering of massive GPS signals in parallel to compute the critical locations of a user. Using an external database, we then map these locations to textual descriptions and activities so that we can apply text mining techniques on the resulting data (e.g. LSA or transportation mode recognition). We provide experimental results for both the system and algorithms and compare them to existing commercial and academic state-of-the-art. This is the first GPS system that enables text-searchable activities from GPS data. | |
Sung, Cynthia; Demaine, Erik D.; Demaine, Martin L.; Rus, Daniela Edge-compositions of 3-D surfaces (Journal Article) In: ASME Journal of Mechanical Design, vol. 135, no. 11, pp. 111001, 2013. @article{sung2013edge, Origami-based design methods enable complex devices to be fabricated quickly in plane and then folded into their final 3D shapes. So far, these folded structures have been designed manually. This paper presents a geometric approach to automatic composition of folded surfaces, which will allow existing designs to be combined and complex functionality to be produced with minimal human input. We show that given two surfaces in 3D and their 2D unfoldings, a surface consisting of the two originals joined along an arbitrary edge can always be achieved by connecting the two original unfoldings with some additional linking material, and we provide a polynomial-time algorithm to generate this composite unfolding. The algorithm is verified using various surfaces, as well as a walking and gripping robot design. | |
Sung, Cynthia; Demaine, Erik D.; Demaine, Martin L.; Rus, Daniela Joining unfoldings of 3-D surfaces (Conference) ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDETC/CIE), ASME, 2013. @conference{sung2013joining, Origami-based design methods enable complex devices to be fabricated quickly in plane and then folded into their final 3-D shapes. So far, these folded structures have been designed manually. This paper presents a geometric approach to automatic composition of folded surfaces, which will allow existing designs to be combined and complex functionality to be produced with minimal human input. We show that given two surfaces in 3-D and their 2-D unfoldings, a surface consisting of the two originals joined along an arbitrary edge can always be achieved by connecting the two original unfoldings with some additional linking material, and we provide an algorithm to generate this composite unfolding. The algorithm is verified using various surfaces, as well as a walking and gripping robot design. | |
Sung, Cynthia; Ayanian, Nora; Rus, Daniela Improving the performance of multi-robot systems by task switching (Conference) IEEE International Conference on Robotics and Automation (ICRA), IEEE, 2013. @conference{sung2013improving, We consider the problem of task assignment for a multi-robot system where each robot must attend to one or more queues of tasks. We assume that individual robots have no knowledge of tasks in the environment that are not in their queue. Robots in communication with each other may share information about active tasks and exchange queues to achieve lower cost for the system. We show that allowing this kind of task switching causes tasks to be completed more efficiently. In addition, we present conditions under which queues can be guaranteed to make progress, and we support these claims with simulation and experimental results. This work has potential applications in manufacturing, environmental exploration, and pickup-delivery tasks. | |
Wu, Cathy; Feldman, Dan; Sung, Cynthia; Rus, Daniela Using coresets for map making for long-term operation of robots (Workshop) IEEE International Conference on Robotics and Automation (ICRA), Workshop on Long-Term Autonomy, 2013. (BibTeX) @workshop{wu2013using, | |
2012 |
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Feldman, Dan; Sung, Cynthia; Rus, Daniela The single pixel GPS: Learning big data signals from tiny coresets (Conference) 20th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (GIS 2012), ACM, 2012. @conference{feldman2012single, We present algorithms for simplifying and clustering patterns from sensors such as GPS, LiDAR, and other devices that can produce high-dimensional signals. The algorithms are suitable for handling very large (e.g. terabytes) streaming data and can be run in parallel on networks or clouds. Applications include compression, denoising, activity recognition, road matching, and map generation. We encode these problems as (k, m)-segment mean problems. Formally, we provide (1 + ε)-approximations to the k-segment and (k, m)-segment mean of a d-dimensional discrete-time signal. The k-segment mean is a k-piecewise linear function that minimizes the regression distance to the signal. The (k,m)-segment mean has an additional constraint that the projection of the k segments on Rd consists of only m ≤ k segments. Existing algorithms for these problems take O(kn2) and nO(mk) time respectively and O(kn2) space, where n is the length of the signal. Our main tool is a new coreset for discrete-time signals. The coreset is a smart compression of the input signal that allows computation of a (1 + ε)-approximation to the k-segment or (k,m)-segment mean in O(n log n) time for arbitrary constants ε,k, and m. We use coresets to obtain a parallel algorithm that scans the signal in one pass, using space and update time per point that is polynomial in log n. We provide empirical evaluations of the quality of our coreset and experimental results that show how our coreset boosts both inefficient optimal algorithms and existing heuristics. We demonstrate our results for extracting signals from GPS traces. However, the results are more general and applicable to other types of sensors. | |
Sung, Cynthia; Feldman, Dan; Rus, Daniela Trajectory clustering for motion prediction (Conference) IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2012. @conference{sung2012trajectory, We investigate a data-driven approach to robotic path planning and analyze its performance in the context of interception tasks. Trajectories of moving objects often contain repeated patterns of motion, and learning those patterns can yield interception paths that succeed more often. We therefore propose an original trajectory clustering algorithm for extracting motion patterns from trajectory data and demonstrate its effectiveness over the more common clustering approach of using k-means. We use the results to build a Hidden Markov Model of a target's motion and predict movement. Our simulations show that these predictions lead to more effective interception. The results of this work have potential applications in coordination of multi-robot systems, tracking and surveillance tasks, and dynamic obstacle avoidance. |
Publications
2015 |
|
Foldable joints for foldable robots (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021012, 2015. | |
Folding angle regulation by curved crease design for self-assembling origami propellers (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021013, 2015. | |
2014 |
|
Foldable joints for foldable robots (Conference) International Symposium on Experimental Robotics (ISER), 2014. | |
2013 |
|
iDiary: From GPS signals to a text-searchable diary (Conference) 11th ACM Conference on Embedded Networked Sensor Systems (SenSys), ACM, 2013. | |
Edge-compositions of 3-D surfaces (Journal Article) In: ASME Journal of Mechanical Design, vol. 135, no. 11, pp. 111001, 2013. | |
Joining unfoldings of 3-D surfaces (Conference) ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDETC/CIE), ASME, 2013. | |
Improving the performance of multi-robot systems by task switching (Conference) IEEE International Conference on Robotics and Automation (ICRA), IEEE, 2013. | |
Using coresets for map making for long-term operation of robots (Workshop) IEEE International Conference on Robotics and Automation (ICRA), Workshop on Long-Term Autonomy, 2013. | |
2012 |
|
The single pixel GPS: Learning big data signals from tiny coresets (Conference) 20th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (GIS 2012), ACM, 2012. | |
Trajectory clustering for motion prediction (Conference) IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2012. |