SUBMITTED FOR REVIEW 1
Joint Optimization of Deployment and Trajectory in
UAV and IRS-Assisted IoT Data Collection System
Li Dong, Zhibin Liu, Feibo Jiang and Kezhi Wang.
Abstract—Unmanned aerial vehicles (UAV) can be applied
in many Internet of Things (IoT) systems, e.g., smart farms,
as a data collection platform. However, the UAV-IoT wireless
channels may be occasionally blocked by trees or high-rise
buildings. Intelligent reflecting surface (IRS) can be applied to
improve the wireless channel quality by smartly reflecting the
signal via a large number of low-cost passive reflective elements.
This paper aims to minimize the energy consumption of the
system by jointly optimizing the deployment and trajectory of
the UAV. The problem can be formulated as a mixed-integer-
and-nonlinear-programming (MINLP), which is difficult to be
addressed by the traditional solution, which may be easily fall
into the local optimal. To address this issue, we propose a Joint
Optimization framework of depLoyment and Trajectory (JOLT),
where an adaptive whale optimization algorithm (AWOA) is
applied to optimize the deployment of the UAV, and an elastic
ring self-organizing map (ERSOM) is introduced to optimize the
trajectory of the UAV. Specifically, in AWOA, a variable-length
population strategy is applied to find the optimal number of
stop points, and a nonlinear parameter aand a partial mutation
rule are introduced to balance the exploration and exploitation.
In ERSOM, a competitive neural network is also introduced to
learn the trajectory of the UAV by competitive learning, and a
ring structure is presented to avoid the trajectory intersection.
Extensive experiments are carried out to show the effectiveness
of the proposed JOLT framework.
Index Terms—Deployment optimization; trajectory optimiza-
tion; UAV; IRS; adaptive whale optimization algorithm; elastic
ring self-organizing map
I. INTRODUCTION
Unmanned aerial vehicles (UAV) can be applied in many
Internet of Things (IoT) applications, e.g., smart farms [1],
as a data collection platform, due to its feature of flexibility
and easy to be deployed. Additionally, as the UAV can move
close to the IoT devices in the real environment, it can help
reduce the energy consumption of IoT devices. However,
UAVs usually have stringent constraints of size, weight, and
energy, which may limit their flight distance and time [2].
This work was supported in part by the National Natural Science Foundation
of China under Grant nos. 41904127, 41604117, 62002115. in part by the
Hunan Provincial Natural Science Foundation of China under Grant nos.
2020JJ4428, 2020JJ5105. in part by the Key Research and Development Plan
of Hunan Province under Grant no 2021NK2020. (Corresponding author:
Zhibin Liu)
Li Dong (Dlj2017@hunnu.edu.cn) is with Changsha Social Laboratory
of Artificial Intelligence, Hunan University of Technology and Business,
Changsha, China, Zhibin Liu (lzb2000@hunnu.edu.cn) is with Hunan Provin-
cial Key Laboratory of Intelligent Computing and Language Informa-
tion Processing, Hunan Normal University, Changsha, China, Feibo Jiang
(jiangfb@hunnu.edu.cn) is with Hunan Provincial Key Laboratory of In-
telligent Computing and Language Information Processing, Hunan Normal
University, Changsha, China, Kezhi Wang (kezhi.wang@northumbria.ac.uk)
is with the department of Computer and Information Sciences, Northumbria
University
Moreover, the line-of-sight (LoS) communication links may
be occasionally blocked by some obstacles, e.g., buildings or
trees. To address the above-mentioned issues and improve the
operation efficiency of the UAV system, intelligent reflecting
surfaces (IRS) can be applied as a promising solution [3] to
help reflect and enhance the communication signal between
UAV and the IoT devices. IRS is composed of a number of
reflective elements, which can reflect the signal by adjusting
their phase shift. IRS can be mounted on several places such as
the walls/facades of buildings, which can significantly improve
the quality of the communication links.
Based on the above background, we aim to optimize the
UAV’s deployment and trajectory by minimizing the energy
consumption of the whole system including the UAV and IoT
devices. To achieve this goal, we propose a Joint Optimiza-
tion framework of depLoyment and Trajectory (JOLT) which
consists of an adaptive whale optimization algorithm (AWOA)
and an elastic ring self-organizing map (ERSOM). The main
contributions can be summarized as follows:
(1) The UAV and IRS-assisted IoT data collection system
is proposed, where the UAV is introduced to collect the data
and the IRS is applied to enhance the communication links
between the UAV and the IoT devices. We formulate the
optimization problem to minimize the energy consumption of
the UAV and all the IoT devices by jointly optimizing the
deployment and trajectory of the UAV.
(2) Then, the joint optimization framework named JOLT
is proposed to solve the optimization problem efficiently, in
which AWOA is presented to find the optimal deployment of
the UAV, and ERSOM is applied to optimize the trajectory of
the UAV.
(3) For the deployment design of the UAV, the optimal
number of stop points is unknown and the problem is non-
convex. Hence, a variable-length population strategy in the
AWOA is presented to find the optimal number of stop points,
and a nonlinear parameter aand a partial mutation rule are
introduced to balance the exploration and exploitation of the
AWOA for searching the locations of the stop points.
(4) For the trajectory planning of the UAV, ERSOM is
applied as a competitive neural network which can learn the
trajectory of the UAV by competitive learning between the
neurons. We also introduce a ring structure in the ERSOM to
avoid the trajectory intersection of the UAV.
The rest of our work is organized as follows. Section II
surveys the related studies. The system model and problem
formulation are introduced in Section III. Section IV describes
the proposed JOLT framework. The simulation results and dis-
cussions are given in Section V. Finally, Section VI concludes
arXiv:2210.15203v1 [cs.NE] 27 Oct 2022