Multi Agents’ Multi Targets Mission Under Uncertainty Using
Probability Navigation Function
Shlomi Hacohen
1
Shraga Shoval
2
and Nir Shvalb
2
Abstract— In this paper we consider the problem of co-
operative control of a swarm of autonomous heterogeneous
mobile agents that are required to intercept a group of
moving targets while avoiding contacts with dynamic obstacles.
Traditionally these type of problems are solved by decomposing
the solution into several sub problems: targets assignments,
coordinated interception control, motion planning and motion
control. In this paper we present a simultaneous solution to
these problems based on the Probabilistic Navigation Function
(PNF). The proposed solution considers uncertainties in the
targets and obstacles locations. such that the locations and
geometries of the targets and obstacles are given by Gaussian
probability distributions. These probabilities are convoluted
with the agents’, obstacles’ and targets’ geometries to provide a
Global Probability Navigation Function - ϕ . The PNF provides
an analytic solution, and guarantees a simultaneous interception
of all targets while limiting the risk of the agents to a given
value. The complexity of the solution is linear with the number
of targets and agents, and therefore is not limited to small
problems. Although the solution provided by the PNF is not
optimal, it provides simple and efficient solution, making it
suitable for a large range of real time applications.
I. I NTRODUCTION
The complexity of many environments and missions may
require capabilities that are not feasible for a single agent.
Additionally, time and process constraints may require the
use of multiple agents working simultaneously on different
aspects of the mission in order to successfully accomplish
the objectives in time. To achieve the level of autonomy and
flexibility in a large variety of scenarios, teams of agents
must be assembled, so they can work together to accom-
plish the specific missions that no individual agent alone
can. The difficulties in designing a cooperative team are
significant [1]; how to formulate, decompose, and allocate
tasks among a group of heterogeneous intelligent agents,
how to enable agents to communicate and interact, how
to ensure that agents act coherently in their actions and
many more. Previous research in distributed heterogeneous
agents cooperation includes [2], who proposes a three-
layered control architecture for a robotic swarm that consists
of a planner level, a control level, and a functional level.
Caloud et al., [3] propose an architecture that includes a task
planner, a task allocator, a motion planner, and an execution
monitor. Asama et al., [4] describe an architecture called
ACTRESS that utilizes a negotiation framework to allow
agents to recruit help when needed. Kumar et al. [5] use a
1
Department of Mecanical Engineering Ariel University, Israel
2
Department of Industrial and Management Engineering Ariel University,
Israel
hierarchical division of authority to perform cooperative fire-
fighting. Cooperation can be defined as how the components
of a system work together to achieve the global emerging
properties. In cooperative teams, individual members that
appear to be independent, work together to create a highly
complex performance, greater-than-the-sum-of-its-parts. The
behavior of a team is often hard to predict as the number of
interactions between the team members increases combina-
torically. The interactions, or interfaces between the members
are often the most susceptible elements, as the members do
not necessarily ”speak the same language”. As a result, the
performance of the team can be lower-than-the-sum-of-its-
parts. The traditional assignment problem of agents to tasks
is considered to be one of the fundamental combinatorial
optimization problems. The mathematical formulation of the
traditional assignment problem is:
Given two sets, Agents A and Tasks T , and a
weight function C : A × T → R . Find a bijection
function f : A → T such that the cost function
∑
a∈A
C (a, f (a)) is minimized or maximized.
The Hungarian algorithm [6] is one of the first algorithms
suggested for solving the linear assignment problem within
time bounded by a polynomial expression of the number of
agents. There have been several more studies on efficient so-
lutions to the assignment problem. Most algorithms proposed
for the assignment problem are for static environments, e.g.,
the graph matching algorithm [7], network simplex algorithm
[8], distributed auction algorithm [9], genetic algorithm [10],
agent based algorithm [11], dynamic Tabu search algorithm
[12], and an adaptive task assignment algorithm in a dynamic
environment [13].
In this paper we consider a scenario where a team of
autonomous mobile agents are required to intercept a group
of dynamic targets while avoiding collisions with obstacles
that are scattered in the environment. Due to imperfect
information (e.g. limited capabilities of sensors, noisy en-
vironment etc.), the locations of the agents, the targets and
the obstacles are given by a probabilistic distribution function
as illustrated in 1. In the scenario shown, there are 2 agents
denoted by A
1
and A
2
, 3 targets denoted by T
1
, T
2
and T
3
,
and 2 obstacles (O
1
and O
2
). The shaded areas around the
objects represent their Probability Density Function (PDF)
such that a darker shade represents higher probability for
the objects to be at a certain location. Notice that the targets
and the obstacles may have different geometries, resulting in
different PDFs.
2017 13th IEEE International Conference on Control & Automation (ICCA)
July 3-6, 2017. Ohrid, Macedonia
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