Key Takeaways & Executive Findings
- •• A novel foldable and deployable capture mechanism for AUV launch and recovery is proposed, achieving both enveloping and grasping movements with a single actuation. • Screw theory analysis reveals the degrees of freedom for enveloping and grasping movements are 6 and 2, respectively, enabling versatile capture adaptability. • Kinematic simulation confirms smooth displacement and velocity curves without interference, and vibration tests validate the mechanism's reliability. • The design offers a valuable reference for developing efficient and adaptable AUV capture equipment, reducing manual dependence and improving operational safety.
Abstract
The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle (AUV) retrieval and release. This study aims to develop a capture mechanism for the launch and recovery of AUV and elucidate its kinematic characteristics. Initially, based on the principles of deployment and retraction for AUV capture movements, a design scheme for a novel foldable and deployable capture mechanism is proposed. Subsequently, a detailed analysis of the Degrees of Freedom (DoFs) for enveloping and grasping movements is conducted according to screw theory. Additionally, the structural design of the actuation units for the capture mechanism is thoroughly discussed. Motion screw topology diagram is utilized to construct the kinematic model. On this basis, kinematic simulation verification of the capture mechanism is performed. The theoretical analysis revealed that the DoF for enveloping and grasping movements are 6 and 2, respectively. By appropriately configuring the actuation mechanism, enveloping and grasping movements can be achieved with a single actuation. The displacement and velocity curves of the capture mechanism were smooth, with no interference occurring. Vibration test results validate the reliability of the capture mechanism. The research work provides a valuable reference for the development of novel capture equipment for AUVs.
1. Introduction
With the increasing importance of marine strategy and ocean economy, autonomous underwater vehicles (AUVs) have become an important medium for the understanding and development of marine resources. Recovery, as a key link in the completion of marine exploration and military reconnaissance tasks by AUVs, often relies on manually completing the hooking process, which is very likely to cause personnel and property damage in poor sea conditions. At present, the recovery of AUVs still poses problems such as strong manual dependence, insufficient adaptability and low operational efficiency, so there is an urgent need to improve the working efficiency of AUV retrieval and release equipment [1].
Due to the diversity of marine operating environments and underwater exploration missions, there are significant differences in the shape, size and weight of AUVs. According to the design specifications for AUVs, the designs of AUVs that have been implemented are categorized into three caliber sizes: 180, 324, and 533 mm. Many types of AUV retrieval and release systems have been developed at home and abroad, and the typical retrieval and release systems include: crane boom type, chute type, hanger type and so on. It's of great significance to study the capture mechanism of AUVs with strong adaptability and good versatility.
Regarding the research on the capture mechanism of AUV, related scholars mainly focus on the configuration design of the capture mechanism, docking control technology and experimental research. For example, Li et al. [2] developed a funnel-type AUV retrieval and release system based on visual navigation and completed pool capture experiments. At the same time, Du et al. [3] proposed a multi degree of freedom (DoF) funnel-type AUV capture device and developed an underwater hydraulic actuation system. On this basis, Sarda et al. [4] proposed an autonomous navigated surface catamaran system for AUV deployment and recovery and carried out recovery experiments at sea. Lin et al. [5] proposed a submarine suspended charging station docking scheme for underwater robot energy replenishment, and completed the system design and experimental testing. Meanwhile, Palomeras et al. [6, 7] designed an underwater docking device to solve the AUV docking problem, and developed long-distance and close-distance docking algorithms, in which the close-distance docking used active optical beacons to assist in accomplishing the localization docking task. At the same time, Li et al. [8] realized the docking navigation and localization of AUV based on binocular vision, and the pool experimental results showed that the system had high capture efficiency. Lin et al. [9] proposed an underwater electromagnetically guided docking method based on a magnetic dipole model for AUV capture challenges and comp
Loading authentic research manuscript (Pages 1–5)...
Guoxing Zhang, Renjie Luo, Jinwei Guo, Jie Wang, Xinlu Xia (2025). Motion Characteristics Analysis of a Novel Autonomous Underwater Vehicle Deployable Capture Mechanism. Chinese Journal of Mechanical Engineering. https://doi.org/10.1186/s10033-025-01259-x
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the main contribution of this paper?
The paper proposes a novel foldable and deployable capture mechanism for AUV launch and recovery, analyzes its degrees of freedom using screw theory, and validates its motion characteristics through simulation and vibration tests, demonstrating high adaptability and reliability.
How many degrees of freedom does the capture mechanism have?
The enveloping movement has 6 degrees of freedom, while the grasping movement has 2 degrees of freedom, as determined by screw theory analysis.
Can the capture mechanism be actuated with a single actuator?
Yes, by appropriately configuring the actuation mechanism, both enveloping and grasping movements can be achieved with a single actuation, simplifying the design and control.
What are the typical applications of this capture mechanism?
The mechanism is designed for the launch and recovery of autonomous underwater vehicles (AUVs), improving operational efficiency and safety in marine environments.
What validation was performed in the study?
Kinematic simulation verified smooth displacement and velocity curves without interference, and vibration tests confirmed the reliability of the capture mechanism.
Related Technical Papers & Translations
Direct Repair of the Crystal Structure and Coating Surface of Spent LiFePO4 Materials Enables Superfast Li-Ion Migration
The rapid accumulation of spent LiFePO4 (LFP) cathodes from retired lithium-ion batteries necessitates the development of effective and environmental-friendly recycling strategies. In this context, direct regeneration has emerged as a promising approach for reclaiming LFP cathode materials, offering a streamlined pathway to restore their electrochemical functionality. We report an integrated regeneration protocol that simultaneously repairs the degraded crystal structure and reconstructs the damaged carbon coating in spent LFP. The regenerated cathode material had superfast lithium-ion diffusion kinetics and a stable cathode–electrolyte interface, giving a remarkable rate capability with specific capacities of 122 mAh g−1 at 5C and 106 mAh g−1 at 10C (1C = 170 mA g−1). It also maintained capacities of 110.7 mAh g−1 (5C) and 84.1 mAh g−1 (10C) after 400 cycles. It could be used in harsh environments and could be stably cycled at subzero temperatures (−10 and −20 °C) and in solid-state electrolyte batteries. Life cycle assessment combined with economic evaluation using the EverBatt model reveals that this direct regeneration approach has high economic and environmental benefits.
Oxide Semiconductor for Advanced Memory Architectures: Atomic Layer Deposition, Key Requirement and Challenges
Oxide semiconductors (OSs), introduced by the Hosono group in the early 2000s, have evolved from display backplane materials to promising candidates for advanced memory and logic devices. The exceptionally low leakage current of OSs and compatibility with three-dimensional (3D) architectures have recently sparked renewed interest in their use in semiconductor applications. This review begins by exploring the unique material properties of OSs, which fundamentally originate from their distinct electronic band structure. Subsequently, we focus on atomic layer deposition (ALD), a core technique for growing excellent OS films, covering both basic and advanced processes compatible with 3D scaling. The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced. Furthermore, material design strategies, such as cation selection, crystallinity control, anion doping, and heterostructure engineering, are discussed. We also highlight challenges in memory applications, including contact resistance, hydrogen instability, and lack of p-type materials, and discuss the feasibility of ALD-grown OSs as potential solutions. Lastly, we provide an outlook on the role of ALD-grown OSs in memory technologies. This review bridges material fundamentals and device-level requirements, offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
Laser powder bed fusion of biodegradable Zn-4Cu alloy: Processing, microstructure and properties
Zn's natural degradability and biocompatibility make it a promising candidate for implants, however, its mechanical properties remain insufficient for bone applications. In this study, the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion (LPBF). Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed. Under optimized conditions of 100 W and 100 mm/s, high-density (99.58%) Zn-Cu alloys with improved hardness (68.2HV) and yield strength (160 MPa) were achieved. These improvements are attributed to solid solution strengthening, segregation strengthening, and grain refinement. The Zn-Cu alloys also demonstrated favorable degradation behavior, with a rate of 0.16 mm/year. This degradation is primarily driven by micro-galvanic corrosion between the CuZn5 phase and Zn matrix, along with refined grains and increased grain boundary density. This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.