1. Introduction
The rapid advancement of the low-altitude economy has driven the widespread deployment of unmanned aerial vehicle (UAV) systems across sectors such as smart logistics [
1], precision agriculture [
2], and military operations [
3]. However, large-scale implementation faces significant technical challenges. According to the 2023 annual report of the International UAV Systems Association, the global commercial UAV market is projected to surpass USD 120 billion by 2025. Yet, limitations in current route-planning technologies hinder approximately 23% of potential applications. In complex environments—including urban canyons, mountainous terrain, and dynamically controlled airspace—conventional two-dimensional path-planning approaches, which rely on geometric constraints, exhibit critical shortcomings. These include inadequate three-dimensional spatial modeling and substantial delays in dynamic obstacle avoidance [
4].
Classical path-planning approaches predominantly rely on adaptations of the A* algorithm [
5] and the rapidly exploring random tree (RRT) framework [
6]. However, these methods encounter exponential increases in computational complexity when applied to high-dimensional continuous state-space planning. A paradigm shift toward intelligent optimization algorithms has provided a promising avenue to address this challenge.
Swarm intelligence techniques, including particle swarm optimization (PSO) [
7], genetic algorithms (GAs) [
8], and the whale optimization algorithm (WOA) [
9], have emerged as key research directions for UAV path planning. Considerable efforts have focused on refining these algorithms or integrating multiple swarm intelligence strategies to improve high-dimensional optimization and route efficiency. Liu et al. [
10] introduced a hybrid multi-strategy artificial rabbit optimization (HARO) algorithm for UAV path planning in complex environments. By integrating a dual exploration switching strategy with a population migration memory mechanism, HARO effectively balances exploration and exploitation, enhancing search efficiency and minimizing the likelihood of local optima. Jiang et al. [
11] proposed a UAV 3D path generation method combining a partially observable Markov decision process (POMDP) with an improved grey wolf optimizer (GWO), demonstrating enhanced convergence and constraint-handling capabilities. Liu et al. [
12] introduced a modified sparrow search algorithm, CASSA, incorporating chaotic mapping and adaptive inertia weighting to improve convergence speed. Comparative simulations indicated superior path-planning performance over conventional sparrow search algorithms. Yu et al. [
13] advanced PSO by integrating a simulated annealing (SA) mechanism, strengthening global optima updates and mitigating local convergence issues through dimension-based learning strategies. Wang et al. [
14] developed an enhanced Butterfly Algorithm featuring a population reset strategy and hybrid particle swarm optimization, validated through simulation. He et al. [
15] proposed the HIPSO-MSOS hybrid algorithm, integrating enhanced PSO with modified symbiotic search, yielding superior multi-objective optimization performance for multi-UAV 3D path planning. Similarly, Pan et al. [
16] introduced the dual-learning golden eagle optimizer (GEO-DLS), incorporating personal exemplar learning and mirror reflection mechanisms to improve global search efficiency, successfully addressing UAV path planning in power inspection scenarios.
Reinforcement learning has also demonstrated notable advantages in UAV navigation. Yu et al. [
17] developed a reinforcement learning-driven multi-strategy cuckoo search algorithm (RL-MCS), integrating adaptive strategy selection and dynamic parameter tuning to achieve superior optimization performance in both benchmark functions and complex 3D flight environments. Xie et al. [
18] employed deep reinforcement learning for 3D path planning, leveraging local information and relative distance instead of global data, achieving greater stability and learning efficiency compared to Deep Q-Network and Deep Recurrent Q-Network models. Alpdemir [
19] introduced a reinforcement learning framework tailored for tactical UAV navigation under dynamic radar threats, incorporating probabilistic engagement modeling and geometry-aware maneuver optimization to address sparse reward challenges in contested electromagnetic environments. Lin et al. [
20] proposed a fixed-horizon constrained reinforcement learning framework for decision-making and planning tasks. Experimental results demonstrate that the framework outperforms rule-based, imitation learning-based, and traditional reinforcement learning approaches, underscoring its effectiveness in handling complex planning scenarios.
Swarm intelligence algorithms have gained significant attention in global optimization, harnessing collective dynamics to address complex optimization challenges. In UAV path planning, these algorithms typically encode population individuals as a sequence of vector coordinates, representing both position and attitude to define the complete flight trajectory. However, as the number of path nodes increases, the dimensionality of the problem grows exponentially, leading to heightened computational complexity and making the pursuit of a globally stable optimal solution increasingly difficult. To address this challenge, the whale optimization algorithm (WOA) [
9] has emerged for its robust performance across low- to high-dimensional optimization tasks. Inspired by the hunting strategies of whales, including circling behavior and bubble-net foraging, WOA is computationally efficient, easy to implement, and has found widespread application across various fields. Despite its strengths, the WOA faces several limitations, such as susceptibility to local optima, slow convergence, and limited global search capacity. Overcoming these challenges is vital for improving WOA’s effectiveness in real-world applications, such as UAV path planning.
To overcome these limitations, researchers have proposed various enhancements to improve the performance of the WOA. Kaur et al. [
21] explored the incorporation of various chaotic mappings into the WOA, analyzing their impact on optimization performance. Qu et al. [
22] proposed the Spiral-Enhanced Whale Optimization Algorithm (SEWOA), introducing a nonlinear time-varying self-adaptive perturbation strategy alongside an Archimedean spiral structure, with experimental validation confirming its effectiveness. Sun et al. [
23] further refined the WOA by integrating a tent map and novel iteration-based update mechanisms for the convergence factor, inertia weight, and optimal feedback strategy, demonstrating superior performance in benchmark function tests. Similarly, Fan et al. [
24] enhanced the WOA with a tent map, adaptive inertia weighting, and an opposition-based learning mechanism, yielding improved adaptability to high-dimensional global optimization problems, as verified through numerical experiments.
Building on previous advancements, this study proposes an adaptive whale optimization algorithm enhanced with dung beetle optimization (DBO-AWOA). Compared to the standard WOA, DBO-AWOA improves the algorithm’s ability to escape local optima while enhancing convergence accuracy, making it particularly well suited for UAV path planning. The key enhancements introduced in DBO-AWOA include the following:
- (1)
The ICMIC chaotic mapping is employed to optimize initial population distributions, improving solution quality.
- (2)
A nonlinear convergence factor is introduced to dynamically balance exploration and exploitation.
- (3)
An adaptive inertia strategy is integrated into the spiral position updating mechanism, facilitating escape from local optima.
- (4)
Drawing on reproductive behaviors from the dung beetle optimization (DBO) algorithm, a novel optimization mechanism is designed to strengthen local search capability.
The structure of this paper is as follows:
Section 2 provides an overview of the WOA and details the update mechanisms introduced in DBO-AWOA.
Section 3 evaluates the algorithm’s performance through benchmark tests and simulations. Finally,
Section 4 presents the conclusions of the study.
4. Conclusions
The DBO-AWOA algorithm effectively addresses the exploration–exploitation trade-off in three-dimensional UAV path planning. By incorporating chaotic initialization of the ICMIC, adaptive inertia weights, and reproductive mechanisms inspired by dung beetles, the algorithm demonstrates faster convergence rates and enhanced global search capabilities. Benchmark tests on the CEC2017 suite highlight its superiority, especially in unimodal and composition scenarios, where it outperforms traditional whale optimization variants and other algorithms. In 3D path-planning simulations, DBO-AWOA excels in generating energy-efficient, collision-free trajectories, with significant improvements in path smoothness and altitude adherence. Despite its strengths, challenges remain in hybrid functions with tightly coupled subcomponents, where excessive global exploration can slightly compromise precision. These results affirm the robustness of DBO-AWOA as a solution for complex optimization tasks while underscoring the importance of context-aware parameter adaptation to enhance stability in dynamic environments.
For practical deployment in a UAV system, the DBO-AWOA algorithm should be integrated with on-board sensors, such as LiDAR, GPS, and vision systems to provide real-time environmental awareness and dynamic obstacle avoidance. The UAV’s computational system must be able to process the algorithm’s complexity in real time, ensuring efficiency within the system’s operational constraints. Furthermore, the algorithm must be seamlessly coupled to the UAV flight control system, enabling continuous trajectory adjustments based on the latest sensor data.