Citation: de Gier, J.; Bergmans, J.;
Hildmann, H. Hierarchical Plan
Execution for Cooperative UxV
Missions. Robotics 2023, 12, 24.
https://doi.org/10.3390/
robotics12010024
Academic Editors: Xiaochun Cheng
and Daming Shi
Received: 28 December 2022
Revised: 26 January 2023
Accepted: 2 February 2023
Published: 4 February 2023
Copyright: © 2023 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Article
Hierarchical Plan Execution for Cooperative UxV Missions
Jan de Gier *, Jeroen Bergmans and Hanno Hildmann
Intelligent Autonomous Systems Group, Netherlands Organisation for Applied Scientific Research (TNO),
2597 AK The Hague, The Netherlands
* Correspondence: jan.degier@tno.nl
Abstract:
A generic reasoning approach for autonomous unmanned vehicle (
UxV
) mission execution
is presented. The system distinguishes (a) mission planning and (b) mission execution, treating these
as separate but closely interdependent stages. The context of the work is that of tactical military
operations, and the focus of the current (simulated) application is on ground-based platforms. The
reference behavior for the
UxV
s is defined by military doctrine. Two operational requirements are
met: (1) Mission plan and execution must be constructed such that they can be understood and
evaluated (prior to giving the go ahead for the platforms to commence the mission) by a decision
maker. (2) Mission plan and execution must account for both observations/information gathered
during execution (for example, the spotting of enemy units) and for foreseeable changes in the
internal and external situation (e.g., a sub-system failure, or changes in terrain or weather).
Keywords:
plan execution; multi-agent systems; coordination; autonomous weapon platforms; UxVs
1. Introduction
There has in recent years been a significant and rapid increase in the availability
and the use of unmanned systems in general. This is especially true in the context of
military operations. While this is not new (aerial systems have long been used by militaries
around the world; the earliest use of drones dates back to at least the Vietnam war [
1
,
2
]), the
attention this has received from research and the industrial sector has increased significantly.
Until recently, this was predominantly in the context of remote controlled or remote piloted
systems, that is, systems that are still controlled by a human operator. The benefits of this
include the safety of the operator, the ability to have a team of operators to take turns, etc.
In the civilian context, ground-based platforms have been remotely operated for, e.g.,
Search and Rescue (
SAR
) missions [
3
] and infrastructure inspection [
4
,
5
], for crime scene
inspection/material (bomb) removal (by civil defense units such as police) [
6
] or to inspect,
e.g., nuclear installations in the aftermath of a natural disaster [7].
At The Dutch Organization for Applied Scientific Research (
TNO
) we have researched
remotely operated systems since 1937 [
8
] (making
TNO
among the first in Europe to do
so). Due to advances in hardware and software and driven by the increasingly pervasive
nature of unmanned platforms [
9
], we are currently witnessing a paradigm shift from using
remote controlled systems to using autonomous systems.
In the military domain, the advent of loitering ammunition [
10
] (sometimes referred
to as kamikaze drones [
11
]) has had a massive impact on operations and is considered to
be a (tactical) game changer [
12
,
13
] (note that the authors are not fond of this term, as the
application and the application domain are not a game to those participating in it). The
conflict often mentioned in this context is the war between Armenia and Azerbaijan over
the disputed Nagorno-Karabakh region in 2020 [
14
], where Azerbaijan deployed drones
with devastating effect (for details we refer to this post by the Center for Strategic and
International Studies (2020): https://www.csis.org/analysis/air-and-missile-war-nagorno-
karabakh-lessons-future-strike-and-defense, accessed on 1 February 2023).
Robotics 2023, 12, 24. https://doi.org/10.3390/robotics12010024 https://www.mdpi.com/journal/robotics
