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Proceedings ArticleDOI

A two level fuzzy PRM for manipulation planning

01 Jan 2000-Vol. 3, pp 1716-1721
TL;DR: An algorithm which extends the probabilistic roadmap (PRM) framework to handle manipulation planning by using a two level approach, a PRM of PRMs, made possible by the introduction of a new kind of roadmap, called the fuzzy roadmap.
Abstract: This paper presents an algorithm which extends the probabilistic roadmap (PRM) framework to handle manipulation planning. This is done by using a two level approach, a PRM of PRMs. The first level builds a manipulation graph, whose nodes represent stable placements of the manipulated objects while the edges represent transfer and transit actions. The actual motion planning for the transfer and transit paths is done by PRM planners at the second level. The approach is made possible by the introduction of a new kind of roadmap, called the fuzzy roadmap. The fuzzy roadmap contains edges which are not verified by a local planner during construction. Instead, each edge is assigned a number which represents the probability that it is feasible. Later, if the edge is part of a solution path, the edge is checked for collisions. The overall effect is that our roadmaps evolve iteratively until they contain a solution. The use of fuzzy roadmaps in both levels of our manipulation planner offers many advantages. At the first level, a fuzzy roadmap represents the manipulation graph and addresses the problem of having probabilistically complete planners at the second level. At the second level, fuzzy roadmaps drastically reduce the number of collision checks. The paper contains experimental results demonstrating the feasibility and efficiency of our scheme.

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Citations
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Proceedings ArticleDOI
06 May 2013
TL;DR: The effectiveness of Lazy Toggle PRM in a wide range of scenarios, including those with narrow passages and high descriptive complexity, is demonstrated, concluding that it is more effective than existing methods in solving difficult queries.
Abstract: Probabilistic RoadMaps (PRMs) are quite successful in solving complex and high-dimensional motion planning problems. While particularly suited for multiple-query scenarios and expansive spaces, they lack efficiency in both solving single-query scenarios and mapping narrow spaces. Two PRM variants separately tackle these gaps. Lazy PRM reduces the computational cost of roadmap construction for single-query scenarios by delaying roadmap validation until query time. Toggle PRM is well suited for mapping narrow spaces by mapping both Cfree and Cobst, which gives certain theoretical benefits. However, fully validating the two resulting roadmaps can be costly. We present a strategy, Lazy Toggle PRM, for integrating these two approaches into a method which is both suited for narrow passages and efficient single-query calculations. This simultaneously addresses two challenges of PRMs. Like Lazy PRM, Lazy Toggle PRM delays validation of roadmaps until query time, but if no path is found, the algorithm augments the roadmap using the Toggle PRM methodology. We demonstrate the effectiveness of Lazy Toggle PRM in a wide range of scenarios, including those with narrow passages and high descriptive complexity (e.g., those described by many triangles), concluding that it is more effective than existing methods in solving difficult queries.

26 citations


Cites background or methods from "A two level fuzzy PRM for manipulat..."

  • ...Lazy strategies, such as Lazy PRM [3], Fuzzy PRM [17], and Customizable PRM [21], aim to reduce the computational cost of PRMs by delaying evaluation of vertices and edges of the roadmap until validation is absolutely necessary, i....

    [...]

  • ...Fuzzy PRM [17] performs a two-level construction of roadmaps associating edges with their corresponding probabilities of collision....

    [...]

  • ...Lazy PRM [3], [17], [21] remedies this by delaying validity tests as long as possible....

    [...]

Journal ArticleDOI
TL;DR: This survey focuses on robotics-inspired methods designed to obtain efficient representations of structure spaces of molecules in isolation or in assemblies for the purpose of characterizing equilibrium structure and dynamics.
Abstract: More than fifty years of research in molecular biology have demonstrated that the ability of small and large molecules to interact with one another and propagate the cellular processes in the living cell lies in the ability of these molecules to assume and switch between specific structures under physiological conditions. Elucidating biomolecular structure and dynamics at equilibrium is therefore fundamental to furthering our understanding of biological function, molecular mechanisms in the cell, our own biology, disease, and disease treatments. By now, there is a wealth of methods designed to elucidate biomolecular structure and dynamics contributed from diverse scientific communities. In this survey, we focus on recent methods contributed from the Robotics community that promise to address outstanding challenges regarding the disparate length and time scales that characterize dynamic molecular processes in the cell. In particular, we survey robotics-inspired methods designed to obtain efficient representations of structure spaces of molecules in isolation or in assemblies for the purpose of characterizing equilibrium structure and dynamics. While an exhaustive review is an impossible endeavor, this survey balances the description of important algorithmic contributions with a critical discussion of outstanding computational challenges. The objective is to spur further research to address outstanding challenges in modeling equilibrium biomolecular structure and dynamics.

24 citations


Cites background from "A two level fuzzy PRM for manipulat..."

  • ...When making use of complex local planners, a prioritized path sampling scheme is needed to prioritize the application of these computationallydemanding planners on the most promising paths in order to control computational cost (Nielsen & Kavraki, 2000)....

    [...]

  • ...The latter idea is borrowed from the similarly challenging setting of motion planning for manipulators, where linear interpolation is also not effective (Nielsen & Kavraki, 2000)....

    [...]

Patent
05 Jun 2008
TL;DR: In this article, the feasibility and utility of transition configurations of two adjacent modes are precomputed to exclude non-feasible transition configurations in the most constrained mode from being sampled, and then bias sampling of the transition configuration so that transition configurations with higher utility are sampled with higher probability.
Abstract: Multi-modal planning method and system that search a path for the most constrained mode first, and then expands the searches for path in a less constrained mode. By searching the path for the most constrained mode first, less resource are wasted on searching for paths that does not result in a feasible path in the most constrained mode. Multi-modal planning is performed by precomputing feasibility and utility of transition configurations of two adjacent modes. The feasibility is used to exclude non-feasible transition configurations in the most constrained mode from being sampled. The utility is used to bias sampling of the transition configuration so that transition configurations with higher utility are sampled with higher probability. Paths of configurations with higher utility and efficiency are obtained by biasing the sampling of the transition configurations.

24 citations

Proceedings ArticleDOI
01 May 2020
TL;DR: This paper presents a general layered planning approach to multi-modal planning that uses a discrete " lead" to bias search towards useful mode transitions and demonstrates the planner on complex scenes and shows that significant performance improvements are tied to both the authors' discrete "lead" and their continuous representation.
Abstract: Robotic manipulation problems are inherently continuous, but typically have underlying discrete structure, e.g., whether or not an object is grasped. This means many problems are multi-modal and in particular have a continuous infinity of modes. For example, in a pick-and-place manipulation domain, every grasp and placement of an object is a mode. Usually manipulation problems require the robot to transition into different modes, e.g., going from a mode with an object placed to another mode with the object grasped. To successfully find a manipulation plan, a planner must find a sequence of valid single-mode motions as well as valid transitions between these modes. Many manipulation planners have been proposed to solve tasks with multi-modal structure. However, these methods require mode-specific planners and fail to scale to very cluttered environments or to tasks that require long sequences of transitions. This paper presents a general layered planning approach to multi-modal planning that uses a discrete "lead" to bias search towards useful mode transitions. The difficulty of achieving specific mode transitions is captured online and used to bias search towards more promising sequences of modes. We demonstrate our planner on complex scenes and show that significant performance improvements are tied to both our discrete "lead" and our continuous representation.

24 citations


Cites background or methods from "A two level fuzzy PRM for manipulat..."

  • ...There are other manipulation planners [4]– [6], that are layered planning approaches; a “higher-level” planner finds what transitions to take, which then informs a “lower-level” planner that searches for feasible motions....

    [...]

  • ...g, [4], [24]), but if the discretization is not fine enough a plan will not be found....

    [...]

  • ...This is similar to the weighting done in [4], but for continuously...

    [...]

Book ChapterDOI
24 Sep 2006
TL;DR: An APF guided ACO algorithm is proposed, which shows some good features in searching for the optimal path solution and can always be achieved with the proposed hybrid algorithm in different obstacles environment from simulation results.
Abstract: This paper investigates the problem of robot planning with ant colony optimization and artificial potential filed algorithms. Robot planning is to find a feasible path from a source to a goal while avoiding obstacles in configuration space. Artificial potential field (APF) is verified as an efficient method to find a path by following the maximum potential field gradient. But it suffers from the local minima. However, ant colony optimization (ACO) is characterized as powerful probabilistic search ability, which is thought to be fit for solving such local minima problems. By the combination of both merits, an APF guided ACO algorithm is proposed, which shows some good features in searching for the optimal path solution. The length optimal path solution can always be achieved with the proposed hybrid algorithm in different obstacles environment from simulation results.

23 citations


Cites methods from "A two level fuzzy PRM for manipulat..."

  • ...The problem has been widely investigated, and some famous methods have been proposed, such as artificial potential field (APF) [1-6], probabilistic roadmap planner (PRM) [7-8], sensor-based method [9], etc....

    [...]

  • ...The PRM is fit for planning the robot with multiple degrees of freedom, but hard to be extended in dynamic environment....

    [...]

References
More filters
Journal ArticleDOI
01 Aug 1996
TL;DR: Experimental results show that path planning can be done in a fraction of a second on a contemporary workstation (/spl ap/150 MIPS), after learning for relatively short periods of time (a few dozen seconds).
Abstract: A new motion planning method for robots in static workspaces is presented. This method proceeds in two phases: a learning phase and a query phase. In the learning phase, a probabilistic roadmap is constructed and stored as a graph whose nodes correspond to collision-free configurations and whose edges correspond to feasible paths between these configurations. These paths are computed using a simple and fast local planner. In the query phase, any given start and goal configurations of the robot are connected to two nodes of the roadmap; the roadmap is then searched for a path joining these two nodes. The method is general and easy to implement. It can be applied to virtually any type of holonomic robot. It requires selecting certain parameters (e.g., the duration of the learning phase) whose values depend on the scene, that is the robot and its workspace. But these values turn out to be relatively easy to choose, Increased efficiency can also be achieved by tailoring some components of the method (e.g., the local planner) to the considered robots. In this paper the method is applied to planar articulated robots with many degrees of freedom. Experimental results show that path planning can be done in a fraction of a second on a contemporary workstation (/spl ap/150 MIPS), after learning for relatively short periods of time (a few dozen seconds).

4,977 citations

Proceedings Article
01 Aug 1998
TL;DR: This paper presents a new class of randomized path planning methods, known as Probabilistic Roadmap Methods (prms), which use randomization to construct a graph of representative paths in C-space whose vertices correspond to collision-free con gurations of the robot.
Abstract: Recently, a new class of randomized path planning methods, known as Probabilistic Roadmap Methods (prms) have shown great potential for solving complicated high-dimensional problems. prms use randomization (usually during preprocessing) to construct a graph of representative paths in C-space (a roadmap) whose vertices correspond to collision-free con gurations of the robot and in which two vertices are connected by an edge if a path between the two corresponding con gurations can be found by a local planning method.

533 citations

Proceedings Article
01 Aug 1998
TL;DR: Y@lBEDGF HEIKJ L„DzMPORQSIUT MV@CW2X >A@CBEDGF HeIKJRX\[^]\X,L>z]  ~Uw ’Nw2x  “eUfa3Vx=
Abstract: .0/2143658709;:=A@CBEDGF HEIKJ L DNMPORQSIUT MV@CW2X >Y@CBEDZF HEIUJRX\[^]\X,L=>N] _?`N5a3P/(b-cYd,/21aeZ/Rfa3CN] vpw /Rxzy;{ |6/R:Y54w}_=/R~Kp€(‚wƒ<‚>Y@lBEDGF HEIUJ L„DNMPO QSI…T MV@lWmX >Y@lBEDGF HEIKJRX\[^]†XsL=>N] ‡†/ ˆ‰w2w21‹ŠŒp~‰Ž/ xN3CY@lBEDGF HEIKJ L„DzMPORQSIUT MV@CW2X >A@CBEDGF HEIKJRX\[^]\X,L>z]  ~Uw ‘N’Nw2x  “eUfa3Vx=Y@lBEDGF HEIKJ L„DzMPORQSIUT MV@CW2X >A@CBEDGF HEIKJRX\[^]\X,L>z]

364 citations

Proceedings Article
12 May 1995
TL;DR: This paper addresses the motion planning problem for a robot in presence of movable objects with an overview of a general approach which consists in building a manipulation graph whose connected components characterize the existence of solutions.
Abstract: This paper addresses the motion planning problem for a robot in presence of movable objects. Motion planning in this context appears as a constrained instance of the coordinated motion planning problem for multiple movable bodies. Indeed, a solution path in the configuration space of the robot and all movable objects is a sequence of transit paths where the robot moves alone and transfer paths where a movable object follows the robot. A major problem is to find the set of configurations where the robot has to grasp or release objects. The paper gives an overview of a general approach which consists in building a manipulation graph whose connected components characterize the existence of solutions. Two planners developed at LAAS-CNRS illustrate how the general formulation can be instantiated in specific cases.

175 citations

Proceedings Article
12 May 1995

160 citations