2,161 research outputs found
Multilayer Graph-Based Trajectory Planning for Race Vehicles in Dynamic Scenarios
Trajectory planning at high velocities and at the handling limits is a
challenging task. In order to cope with the requirements of a race scenario, we
propose a far-sighted two step, multi-layered graph-based trajectory planner,
capable to run with speeds up to 212~km/h. The planner is designed to generate
an action set of multiple drivable trajectories, allowing an adjacent behavior
planner to pick the most appropriate action for the global state in the scene.
This method serves objectives such as race line tracking, following, stopping,
overtaking and a velocity profile which enables a handling of the vehicle at
the limit of friction. Thereby, it provides a high update rate, a far planning
horizon and solutions to non-convex scenarios. The capabilities of the proposed
method are demonstrated in simulation and on a real race vehicle.Comment: Accepted at The 22nd IEEE International Conference on Intelligent
Transportation Systems, October 27 - 30, 201
Adaptive Smoothing for Trajectory Reconstruction
Trajectory reconstruction is the process of inferring the path of a moving
object between successive observations. In this paper, we propose a smoothing
spline -- which we name the V-spline -- that incorporates position and velocity
information and a penalty term that controls acceleration. We introduce a
particular adaptive V-spline designed to control the impact of irregularly
sampled observations and noisy velocity measurements. A cross-validation scheme
for estimating the V-spline parameters is given and we detail the performance
of the V-spline on four particularly challenging test datasets. Finally, an
application of the V-spline to vehicle trajectory reconstruction in two
dimensions is given, in which the penalty term is allowed to further depend on
known operational characteristics of the vehicle.Comment: 25 pages, submitte
Geodesic Models with Convexity Shape Prior
The minimal geodesic models based on the Eikonal equations are capable of
finding suitable solutions in various image segmentation scenarios. Existing
geodesic-based segmentation approaches usually exploit image features in
conjunction with geometric regularization terms, such as Euclidean curve length
or curvature-penalized length, for computing geodesic curves. In this paper, we
take into account a more complicated problem: finding curvature-penalized
geodesic paths with a convexity shape prior. We establish new geodesic models
relying on the strategy of orientation-lifting, by which a planar curve can be
mapped to an high-dimensional orientation-dependent space. The convexity shape
prior serves as a constraint for the construction of local geodesic metrics
encoding a particular curvature constraint. Then the geodesic distances and the
corresponding closed geodesic paths in the orientation-lifted space can be
efficiently computed through state-of-the-art Hamiltonian fast marching method.
In addition, we apply the proposed geodesic models to the active contours,
leading to efficient interactive image segmentation algorithms that preserve
the advantages of convexity shape prior and curvature penalization.Comment: This paper has been accepted by TPAM
Grouping Boundary Proposals for Fast Interactive Image Segmentation
Geodesic models are known as an efficient tool for solving various image
segmentation problems. Most of existing approaches only exploit local pointwise
image features to track geodesic paths for delineating the objective
boundaries. However, such a segmentation strategy cannot take into account the
connectivity of the image edge features, increasing the risk of shortcut
problem, especially in the case of complicated scenario. In this work, we
introduce a new image segmentation model based on the minimal geodesic
framework in conjunction with an adaptive cut-based circular optimal path
computation scheme and a graph-based boundary proposals grouping scheme.
Specifically, the adaptive cut can disconnect the image domain such that the
target contours are imposed to pass through this cut only once. The boundary
proposals are comprised of precomputed image edge segments, providing the
connectivity information for our segmentation model. These boundary proposals
are then incorporated into the proposed image segmentation model, such that the
target segmentation contours are made up of a set of selected boundary
proposals and the corresponding geodesic paths linking them. Experimental
results show that the proposed model indeed outperforms state-of-the-art
minimal paths-based image segmentation approaches
Generalized fast marching method for computing highest threatening trajectories with curvature constraints and detection ambiguities in distance and radial speed
Work presented at the 9th Conference on Curves and Surfaces, 2018, ArcachonWe present a recent numerical method devoted to computing curves that globally minimize an energy featuring both a data driven term, and a second order curvature penalizing term. Applications to image segmentation are discussed. We then describe in detail recent progress on radar network configuration, in which the optimal curves represent an opponent's trajectories
- …