LiU Electronic Press

Author:

Title:

Optimal placement of communications relay nodes

Department:

Linköping University, Department of Computer and Information Science, KPLAB - Knowledge Processing Lab

Linköping University, Department of Mathematics, Optimization

Linköping University, The Institute of Technology

Publication type:

Report (Other (popular science, discussion, etc.))

Language:

English

Place of publ.:
Linköping
Publisher:
Linköpings universitet

Pages:

21

Series:

LiTH-MAT-R, ISSN 0348-2960; 2009:3

Year of publ.:

2009

URI:

urn:nbn:se:liu:diva-51094

Permanent link:

http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51094

Subject category:

Mathematics

SVEP category:

MATHEMATICS

Abstract(en)
:

We consider a constrained optimization problem with mixed integer and real variables. It models optimal placement of communications relay nodes in the presence of obstacles. This problem is widely encountered, for instance, in robotics, where it is required to survey some target located in one point and convey the gathered information back to a base station located in another point. One or more unmanned aerial or ground vehicles (UAVs or UGVs) can be used for this purpose as communications relays. The decision variables are the number of unmanned vehicles (UVs) and the UV positions. The objective function is assumed to access the placement quality. We suggest one instance of such a function which is more suitable for accessing UAV placement. The constraints are determined by, firstly, a free line of sight requirement for every consecutive pair in the chain and, secondly, a limited communication range. Because of these requirements, our constrained optimization problem is a difficult multi-extremal problem for any fixed number of UVs. Moreover, the feasible set of real variables is typically disjoint. We present an approach that allows us to efficiently find a practically acceptable approximation to a global minimum in the problem of optimal placement of communications relay nodes. It is based on a spatial discretization with a subsequent reduction to a shortest path problem. The case of a restricted number of available UVs is also considered here. We introduce two label correcting algorithms which are able to take advantage of using some peculiarities of the resulting restricted shortest path problem. The algorithms produce a Pareto solution to the two-objective problem of minimizing the path cost and the number of hops. We justify their correctness. The presented results of numerical 3D experiments show that our algorithms are superior to the conventional Bellman-Ford algorithm tailored to solving this problem.

Available from:

2009-10-16

Created:

2009-10-16

Last updated:

2013-08-29

Statistics:

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