 | Planning Motion in Environments with Similar Obstacles papers: to appear in RSS 2009 In this work, we investigate solutions to the following question: Given two motion planning problems X and Y with the same robot and similar obstacles, can we reuse the computation from X to solve Y more efficiently? While the answer to this question can find many practical applications, all current motion planners ignore the correspondences between similar environments. Our study shows that by carefully storing and reusing the computation we can gain significant efficiency. |
 | Interactive Shepherd Computing papers: AAAI SS 2009 Planning motion to solve the shepherding problem is intractable. We propose an interactive motion planning which combines user input and motion planning strategies to improve the efficiency and accuracy of the planner. |
 | 3D Minkowski Sum Made Simple papers: WAFR 2008 Computing the Minkowski sum of two general polyhedra is known to be difficult. We propose a simple strategy to compute the Minkowski sums efficiently. |
 | DYMSUM: Dynamic Minkowski Sum video: divx 84MB (SoCG 2008) We developed a method that efficiently computes the Minkowski sums of rotating convex polyhedra. It is well known that the Minkowski sum of two polyhedra can be dramatically different from the Minkowski sum of the same polyhedra after rotation. We show that we can efficiently update, without complete re-computation, the Minkowski sums. |
 | Minkowski Sum Based Motion Planners papers: RSS 2008 In this work, we provide an investigation to the following question: Is there a motion planner that behaves like a deterministic planner for lower dimensional motion planning problems and behaves like a probabilistic planner for higher dimensional problems? Such a planner should have the advantages of both deterministic and probabilistic motion planners. |
 | Point-Based Minkowski Sum papers: Pacific Graphics 2007 Minkowski sum is a fundamental operation in many geometric applications, including robotics, penetration depth estimation, solid modeling, and virtual prototyping. In this work, we propose to represent the boundary of the Minkowski sum approximately using only points. Our results show that this point-based representation can be generated efficiently. An important feature of our method is its straightforward implementation and parallelization. |
 | Approximate Star Shape Decomposition papers: Point-Based Graphics 2007 A* decomposition of a point set : Decomposing a point set into a set of star-shaped subsets. |
 | Compressing Tele-immersion Data papers: Distributed Smart Cameras 2007, ISVC 2007 Data captured by a Tele-Immersion (TI) system can be very large. Compression is usually needed to ensure real-time data transmission. Our compression method takes advantage of prior knowledge of objects, e.g. human figures, in the TI environments and represents their motions using just a few parameters. |
 | Approximate Convex Decomposition papers: SoCG 2004, CGTA 2006 (2D), SPM 2007 (3D) While decomposition into convex components results in pieces that are easy to process, such decompositions can be costly to construct and often result in representations with an unmanageable number of components. We propose an alternative partitioning strategy that decomposes a given model (in 2D or 3D) into "approximately convex" pieces. |
 | Skeleton Extraction papers: SPM 2006 We present a novel skeleton extraction method using the approximate convex decomposition. Unlike traditional image-based methods which uniformly process all grids, our method saves time in the easy area and concentrates on refining the "difficult" area, e.g., the highly twisted area. Moreover, our method is robust in terms of shape description, e.g., less sensitive to boundary noise. |
 | Deformable Object Motion Planning papers: ICRA 2002, ICRA 2006 Though motion planning has been studied extensively for rigid and articulated robots, motion planning for deformable objects is an area that has received far less attention. |
 | Simulating Shepherding Behaviors papers: ICRA 2004 (single shepherd),ICRA 2005 (multiple shepherds) Shepherding behaviors are one class of flocking behaviors in which one or more external agents (called shepherds) attempt to control the motion of another group of agents (called flock) by exerting repulsive forces from shepherds to the flock. |
 | General Medial Axis Based PRM papers: ICRA 2003 \We propose a general framework for sampling the configuration space in which randomly generated configurations, free or not, are retracted onto the medial axis of the free space. In particular, our framework supports methods that retract a given configuration exactly or approximately onto the medial axis. |
 | Simulation of Coordinated Groups papers: Pacific Graphics 2002, Alife 2002, WAFR 2002 In our research, we investigate how to plan motion in dynamic/uncertain environments along with integrating adaptive roadmaps with traditional flocking techniques to generate complex global behaviors that are difficult to generate using traditional emergent approaches such as flocking. An adaptive roadmap is a roadmap (graph) containing representative paths in the environment whose edge values can be updated according to information gathered by the flock members. |
 | Mapping Cortical Network papers: Neurocomputing 2003 The brain has extraordinary computational power to represent and interpret complex natural environments. These natural computations are essentially determined by the topology and geometry of the brain's architectures. We present a framework to construct a 3D model of a cortical network using probabilistic roadmap methods. Our ultimate goal is to map and understand the connectivity and geometry of the cortical network. |
 | VR Navigation papers: CA 1999 After the introduction of VRML, 3D web browsing has become a popular form of networked virtual reality. However, it is still a great challenge for a novice user equipped with a regular desktop PC to navigate in most virtual worlds of moderate complexity. We consider an alternative metaphor of allowing a user to specify locations of interests on a 2D-layout map and let the system automatically generate the animation of guided tours in virtual architectural environments. We describe an auto-navigation system, in which several efficient path-planning algorithms adapted from robotics are used. This system has been implemented in Java and adopts common VRML browsers as its 3D interface. |