Open Access
Real-time modification of collision-free paths
Reads0
Chats0
TLDR
A novel algorithm for efficiently computing the distance between non-convex objects and a real-time algorithm for calculating a discrete approximation to the time-optimal parameterization of a path are developed and combined in a system that demonstrates the elastic band framework for a Puma 560 manipulator.Abstract:
The modification of collision-free paths is proposed as the basis for a new framework to close the gap between global path planning and real-time sensor-based robot control. A physically-based model of a flexible string-like object, called an elastic band, is used to determine the modification of a path. The initial shape of the elastic is the free path generated by a planner. Subjected to artificial forces, the elastic band deforms in real time to a short and smooth path that maintains clearance from the obstacles. The elastic continues to deform as changes in the environment are detected by sensors, enabling the robot to accommodate uncertainties and react to unexpected and moving obstacles. While providing a tight connection between the robot and its environment, the elastic band preserves the global nature of the planned path. The greater part of this thesis deals with the design and implementation of elastic bands, with emphasis on achieving real-time performance even for robots with many degrees of freedom. To achieve these goals, we propose the concept of bubbles of free-space---a region of free-space around a given configuration of the robot generated from distance information. We also develop a novel algorithm for efficiently computing the distance between non-convex objects and a real-time algorithm for calculating a discrete approximation to the time-optimal parameterization of a path. These various developments are combined in a system that demonstrates the elastic band framework for a Puma 560 manipulator.read more
Citations
More filters
Proceedings ArticleDOI
CHOMP: Gradient optimization techniques for efficient motion planning
TL;DR: This paper presents CHOMP, a novel method for continuous path refinement that uses covariant gradient techniques to improve the quality of sampled trajectories and relax the collision-free feasibility prerequisite on input paths required by those strategies.
Journal ArticleDOI
CHOMP: Covariant Hamiltonian optimization for motion planning
Matt Zucker,Nathan Ratliff,Anca D. Dragan,Mihail Pivtoraiko,Matthew Klingensmith,Christopher M. Dellin,J. Andrew Bagnell,Siddhartha S. Srinivasa +7 more
TL;DR: CHOMP (covariant Hamiltonian optimization for motion planning), a method for trajectory optimization invariant to reparametrization, uses functional gradient techniques to iteratively improve the quality of an initial trajectory, optimizing a functional that trades off between a smoothness and an obstacle avoidance component.
Journal ArticleDOI
Elastic Strips: A Framework for Motion Generation in Human Environments
Oliver Brock,Oussama Khatib +1 more
TL;DR: The elastic strip framework presented in this paper enables the execution of a previously planned motion in a dynamic environment for robots with many degrees of freedom, and encompasses methods to suspend task behavior when its execution becomes inconsistent with other constraints imposed on the motion.
Proceedings ArticleDOI
Multipartite RRTs for Rapid Replanning in Dynamic Environments
TL;DR: The multipartite RRT (MP-RRT), an RRT variant which supports planning in unknown or dynamic environments, is presented, by purposefully biasing the sampling distribution and re-using branches from previous planning iterations.
Journal ArticleDOI
Integrated online trajectory planning and optimization in distinctive topologies
TL;DR: A novel integrated approach for efficient optimization based online trajectory planning of topologically distinctive mobile robot trajectories by maintains and simultaneously optimizes a subset of admissible candidate trajectories of distinctive topologies and thus seeking the overall best candidate among the set of alternative local solutions.
References
More filters
Journal ArticleDOI
Optimization by Simulated Annealing
TL;DR: There is a deep and useful connection between statistical mechanics and multivariate or combinatorial optimization (finding the minimum of a given function depending on many parameters), and a detailed analogy with annealing in solids provides a framework for optimization of very large and complex systems.
Journal ArticleDOI
Snakes : Active Contour Models
TL;DR: This work uses snakes for interactive interpretation, in which user-imposed constraint forces guide the snake near features of interest, and uses scale-space continuation to enlarge the capture region surrounding a feature.
Book
A robust layered control system for a mobile robot
TL;DR: A new architecture for controlling mobile robots is described, building a robust and flexible robot control system that has been used to control a mobile robot wandering around unconstrained laboratory areas and computer machine rooms.
Book
Methods of Mathematical Physics
Richard Courant,David Hilbert +1 more
TL;DR: In this paper, the authors present an algebraic extension of LINEAR TRANSFORMATIONS and QUADRATIC FORMS, and apply it to EIGEN-VARIATIONS.
Journal ArticleDOI
A robust layered control system for a mobile robot
TL;DR: In this paper, a new architecture for controlling mobile robots is described, which is made up of asynchronous modules that communicate over low-bandwidth channels, each module is an instance of a fairly simple computational machine.