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Actuators
Volume 14
Issue 9
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Actuators, Volume 14, Issue 9 (September 2025) – 52 articles

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86 pages, 4498 KB  
Review
Autonomous Driving in Agricultural Machinery: Advancing the Frontier of Precision Agriculture
by Qingchao Liu, Ruohan Yu, Haoda Suo, Yingfeng Cai, Long Chen and Haobin Jiang
Actuators 2025, 14(9), 464; https://doi.org/10.3390/act14090464 - 22 Sep 2025
Viewed by 976
Abstract
Increasing global food production to address challenges from population growth, labor shortages, and climate change necessitates a significant enhancement of agricultural sustainability. Autonomous agricultural machinery, a recognized application of precision agriculture, offers a promising solution to boost productivity, resource efficiency, and environmental sustainability. [...] Read more.
Increasing global food production to address challenges from population growth, labor shortages, and climate change necessitates a significant enhancement of agricultural sustainability. Autonomous agricultural machinery, a recognized application of precision agriculture, offers a promising solution to boost productivity, resource efficiency, and environmental sustainability. This study presents a systematic review of autonomous driving technologies for agricultural machinery based on 506 rigorously selected publications. The review emphasizes three core aspects: navigation reliability assurance, motion control mechanisms for both vehicles and implements, and actuator fault-tolerance strategies in complex agricultural environments. Applications in farmland, orchards, and livestock farming demonstrate substantial potential. This study also discusses current challenges and future development trends. It aims to provide a reference and technical guidance for the engineering implementation of intelligent agricultural machinery and to support sustainable agricultural transformation. Full article
(This article belongs to the Special Issue Actuator Fault Diagnosis, State Detection and Fault Tolerant Control for Ground and Rail Vehicles)
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16 pages, 4282 KB  
Article
A Fast Response, High Flow Rate, Low Power Consumption Pneumatic Proportional Valve for Medical Ventilators Driven by a Piezoelectric Bimorph
by Shuai Ren, Junling Chen, Tao Wang and Bingbing Ma
Actuators 2025, 14(9), 463; https://doi.org/10.3390/act14090463 - 22 Sep 2025
Viewed by 289
Abstract
In recent years, pneumatic proportional valves have become increasingly prevalent in ventilators, particularly proportional solenoid valves. However, these traditional valves face challenges, including a slow response, being prone to overheating from long-term work, and high power consumption. This study presents the development of [...] Read more.
In recent years, pneumatic proportional valves have become increasingly prevalent in ventilators, particularly proportional solenoid valves. However, these traditional valves face challenges, including a slow response, being prone to overheating from long-term work, and high power consumption. This study presents the development of a fast response, high flow rate, and low power consumption pneumatic proportional valve specifically designed for medical ventilators. Utilizing a piezoelectric bimorph as the actuator, we innovatively eliminate movable components such as springs while ensuring effective sealing of the valve. A support structure was designed to enhance the mechanical performance of the piezoelectric bimorph. A testing platform was established to rigorously assess the valve’s performance. The results indicate that the valve can achieve a maximum output flow rate of approximately 130 L/min at an input pressure of 4 bar, with a hysteresis rate of 25.3%, a response time of under 10 ms, and a power consumption of just 0.07 W. Furthermore, a comparative analysis with existing commercial proportional solenoid valves demonstrated that it has superior performance in terms of response speed, flow rate, and power efficiency. The piezoelectric proportional valve developed in this study holds the potential to replace conventional proportional solenoid valves, significantly enhancing the response speed of ventilators, reducing their overall power consumption, and facilitating the development of portable ventilators. Full article
(This article belongs to the Section Actuators for Medical Instruments)
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22 pages, 5174 KB  
Article
Pre-Processing Optimisation of Robot Control to Reduce Energy Consumption
by Petr Vavruska, Strahinja Protić and Tomas Kratena
Actuators 2025, 14(9), 462; https://doi.org/10.3390/act14090462 - 22 Sep 2025
Viewed by 284
Abstract
The huge growth in the utilisation of six-axis robots in various technological applications in production calls for a detailed focus on the process of preparing Numerical Control (NC) programmes for effective robot control. Considerable attention is currently being paid to optimisation by increasing [...] Read more.
The huge growth in the utilisation of six-axis robots in various technological applications in production calls for a detailed focus on the process of preparing Numerical Control (NC) programmes for effective robot control. Considerable attention is currently being paid to optimisation by increasing stiffness, but there is also a need to focus on reducing energy consumption in robot control. Focusing on reducing energy consumption is highly justified given the widespread adoption of robotic systems across diverse manufacturing technologies and the significant potential for application. This is particularly relevant today, when minimising production costs is a critical industrial objective. A redundant degree of freedom—which is the possibility to rotate around the end-effector axis and thus influence the adjustment of the rotation of the individual robot joints—can be used for this purpose. Therefore, this paper exploits this redundant degree of freedom to set up a proper robot configuration that reduces energy consumption. The user-friendly solution, including the algorithm design and processing through a function, could be effectively implemented within an industry-standard post-processor solution for generating NC programmes for robots. This solution is unique as it is used for the optimisation of the working section of the toolpaths, where continuous control of the end-effector movement during manufacturing operations occurs. The solution was verified on a KUKA KR60 HA robot; however, it is applicable to any industrial six-axis robot. Substantial energy savings were obtained in multi-axis toolpath operations, with a 7.5% reduction in total energy consumption when using the optimised NC programme. Full article
(This article belongs to the Special Issue Motion Planning, Trajectory Prediction, and Control for Robotics)
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24 pages, 2157 KB  
Article
Research on Aerodynamic Force/Thrust Vector Combined Trajectory Optimization Method for Hypersonic Drones Based on Deep Reinforcement Learning
by Zijun Zhang, Yunfan Zhou, Leichao Yang, Wenzhong Jin and Jun Wang
Actuators 2025, 14(9), 461; https://doi.org/10.3390/act14090461 - 22 Sep 2025
Viewed by 379
Abstract
This paper addresses the cruise range maximization problem for hypersonic drones by proposing a combined aerodynamic force/thrust vector trajectory optimization method. A novel continuous linear parameterization strategy for trajectory optimization is innovatively developed, achieving continuous thrust vector trajectory optimization throughout the entire flight [...] Read more.
This paper addresses the cruise range maximization problem for hypersonic drones by proposing a combined aerodynamic force/thrust vector trajectory optimization method. A novel continuous linear parameterization strategy for trajectory optimization is innovatively developed, achieving continuous thrust vector trajectory optimization throughout the entire flight using only 21 parameters through recursive linear function design. This approach reduces parameter dimensionality and effectively addresses sparse rewards and training difficulties in reinforcement learning. The study integrates the Deep Deterministic Policy Gradient (DDPG) algorithm with deep residual networks for trajectory optimization, systematically exploring the impact mechanisms of different aerodynamic force and thrust vector combination modes on range performance. Through collaborative trajectory optimization of thrust vectors and flight height, simulation results demonstrate that the combined trajectory optimization strategy achieves a total range enhancement of approximately 146.14 km compared to pure aerodynamic control, with continuous linearly parameterized thrust vector trajectory optimization providing superior performance over traditional segmented methods. These results verify the significant advantages of the proposed trajectory optimization approach and the effectiveness of the deep reinforcement learning framework. Full article
(This article belongs to the Section Aerospace Actuators)
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32 pages, 4787 KB  
Review
Performance Comparison of Mechanical and Ferrofluidic Micropumps: Structural and Operational Perspectives
by Xing Zhou, Zhenggui Li, Baozhu Han, Qinkui Guo and Zhichao Qing
Actuators 2025, 14(9), 460; https://doi.org/10.3390/act14090460 - 20 Sep 2025
Viewed by 634
Abstract
Since the successful implementation of microfluidic technology in biomedical applications, research on micropumps—the central component of these systems—has gained significant momentum. Benefiting from advancements in pump materials and corresponding fabrication methods, micropumps have evolved from structurally complex mechanical designs to simpler non-mechanical configurations. [...] Read more.
Since the successful implementation of microfluidic technology in biomedical applications, research on micropumps—the central component of these systems—has gained significant momentum. Benefiting from advancements in pump materials and corresponding fabrication methods, micropumps have evolved from structurally complex mechanical designs to simpler non-mechanical configurations. This paper reviews well-developed mechanical micropumps, discussing their diaphragms, pump chambers, materials, and other aspects to outline their developmental trajectory and current applications, while also highlighting their limitations. After identifying the shortcomings of traditional micropumps, we introduce the concept of ferrofluid-based micropumps, emphasizing their structural simplicity, self-sealing capability, and recoverability. Previous research on ferrofluidic micropumps is summarized, demonstrating their superior performance in certain aspects. Finally, we provide an outlook on their potential applications in biomedicine and specialized fields. Full article
(This article belongs to the Section Miniaturized and Micro Actuators)
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24 pages, 102794 KB  
Article
Agentic AI for Real-Time Adaptive PID Control of a Servo Motor
by Tariq Mohammad Arif and Md Adilur Rahim
Actuators 2025, 14(9), 459; https://doi.org/10.3390/act14090459 - 20 Sep 2025
Viewed by 789
Abstract
This study explores a novel approach of using large language models (LLMs) in the real-time Proportional–Integral–Derivative (PID) control of a physical system, the Quanser QUBE-Servo 2. We investigated whether LLMs, used with an Artificial Intelligence (AI) agent workflow platform, can participate in the [...] Read more.
This study explores a novel approach of using large language models (LLMs) in the real-time Proportional–Integral–Derivative (PID) control of a physical system, the Quanser QUBE-Servo 2. We investigated whether LLMs, used with an Artificial Intelligence (AI) agent workflow platform, can participate in the live tuning of PID parameters through natural language instructions. Two AI agents were developed: a control agent that monitors the system performance and decides if tuning is necessary, and an Optimizer Agent that updates PID gains using either a guided system prompt or a self-directed free approach within a safe parameter range. The LLM integration was implemented through Python programming and Flask-based communication between the AI agents and the hardware system. Experimental results show that LLM-based tuning approaches can effectively reduce standard error metrics, such as IAE, ISE, MSE, and RMSE. This study presents one of the first implementations of real-time PID tuning powered by LLMs, and it has the potential to become a novel alternative to classical control, as well as machine learning or reinforcement learning-based approaches. The results are promising for using agentic AI in heuristic-based tuning and the control of complex physical systems, marking the shift toward more human-centered, explainable, and adaptive control engineering. Full article
(This article belongs to the Special Issue Advanced Technologies in Actuators for Control Systems)
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30 pages, 9701 KB  
Article
Lightweight Adaptive Feature Compression and Dynamic Network Fusion for Rotating Machinery Fault Diagnosis Under Extreme Conditions
by Kaiyi Zhang, Xuling Liu, Guohua Yang, Kun Zhai, Gaofei An, Yusong Zhang and Chaofeng Peng
Actuators 2025, 14(9), 458; https://doi.org/10.3390/act14090458 - 19 Sep 2025
Viewed by 470
Abstract
Reliable fault diagnosis of rotating machines under extreme conditions—strong speed, load variation, intense noise, and severe class imbalance—remains a critical industrial challenge. We develop an ultra-light yet robust framework to accurately detect weak bearing, and gear faults when less than 5% labels, 10 [...] Read more.
Reliable fault diagnosis of rotating machines under extreme conditions—strong speed, load variation, intense noise, and severe class imbalance—remains a critical industrial challenge. We develop an ultra-light yet robust framework to accurately detect weak bearing, and gear faults when less than 5% labels, 10 dB noise, 100:1 imbalance and plus or minus 20% operating-point drift coexist. Methods: The proposed Adaptive Feature Module–Conditional Dynamic GRU Auto-Encoder (AFM-CDGAE) first compresses 512 d spectra into 32/48 d “feature modules” via K-means while retaining 98.4% fault energy. A workload-adaptive multi-scale convolution with spatial attention and CPU-aware λ-scaling suppresses noise and adapts to edge–device load. A GRU-based auto-encoder, enhanced by self-attention, is trained with balanced-subset sampling and minority-F1-weighted voting to counter extreme imbalance. On Paderborn (5-class) and CWRU (7-class) benchmarks, the 0.87 M-parameter model achieves 99.12% and 98.83% Macro-F1, surpassing five recent baselines by 3.1% under normal and 5.4% under the above extreme conditions, with only 1.5 to 1.8% F1 drop versus 6.7% for baselines. AFM-CDGAE delivers state-of-the-art accuracy, minimal footprint and strong robustness, enabling real-time deployment at the edge. Full article
(This article belongs to the Section Actuators for Manufacturing Systems)
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22 pages, 3892 KB  
Article
Adaptive Sliding Mode Control for Unmanned Surface Vehicle Trajectory Tracking Based on Event-Driven and Control Input Quantization
by Zhihui Li, Mengyuan Li, Xinrui Jing, Changfu Yuan and Kai Wang
Actuators 2025, 14(9), 457; https://doi.org/10.3390/act14090457 - 18 Sep 2025
Viewed by 409
Abstract
This primary study aims to optimize network resource utilization efficiency in marine control systems. A novel event-triggering condition is proposed to significantly reduce communication traffic, where the error norm is squared while the input norm remains linear. To simulate realistic environmental disturbances, bounded [...] Read more.
This primary study aims to optimize network resource utilization efficiency in marine control systems. A novel event-triggering condition is proposed to significantly reduce communication traffic, where the error norm is squared while the input norm remains linear. To simulate realistic environmental disturbances, bounded unknown parameters are incorporated. Within the networked transmission architecture, input quantization is introduced, enabling the design of a quantized feedback controller without prior knowledge of quantization parameters. By integrating the event-triggering mechanism with sliding mode control, a quantized feedback control system is developed. The closed-loop system’s stability is rigorously proven via Lyapunov theory, with guaranteed boundedness of trajectory tracking errors. Numerical simulations validate the effectiveness of the proposed method for marine vehicle trajectory control under environmental disturbances. Full article
(This article belongs to the Special Issue Control System of Autonomous Surface Vehicle)
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22 pages, 4299 KB  
Article
Motion Control of Gallium-Based Liquid Metal Droplets in Abrasive Suspensions Within a Flow Channel
by Yapeng Ma, Baoqi Feng, Kaixiang Li and Lei Zhang
Actuators 2025, 14(9), 456; https://doi.org/10.3390/act14090456 - 18 Sep 2025
Viewed by 369
Abstract
Gallium-based room-temperature liquid metal is a promising multifunctional material for microfluidics and precision machining due to its high mobility and deformability. However, precise motion control of gallium-based liquid metal droplets, especially in abrasive particle-laden fluids, remains challenging. This study presents a hybrid control [...] Read more.
Gallium-based room-temperature liquid metal is a promising multifunctional material for microfluidics and precision machining due to its high mobility and deformability. However, precise motion control of gallium-based liquid metal droplets, especially in abrasive particle-laden fluids, remains challenging. This study presents a hybrid control framework for regulating droplet motion in a one-dimensional PMMA channel filled with NaOH-based SiC abrasive suspensions. A dynamic model incorporating particle size and concentration effects on the damping coefficient was established. The system combines a setpoint controller, high-resolution voltage source, and vision feedback to guide droplets to target positions with high accuracy. Experimental validation and MATLAB simulations confirm that the proposed dynamic damping control strategy ensures stable, rapid, and precise positioning of droplets, minimizing motion fluctuations. This approach offers new insights into the manipulation of gallium-based liquid metal droplets for targeted material removal in micro-manufacturing, with potential applications in microelectronics and high-precision surface finishing. Full article
(This article belongs to the Section Control Systems)
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17 pages, 1898 KB  
Article
Prescribed-Performance-Bound-Based Adaptive Fault-Tolerant Control for Rigid Spacecraft Attitude Systems
by Zixuan Chen, Teng Cao, Shaohua Yang and Yang Cao
Actuators 2025, 14(9), 455; https://doi.org/10.3390/act14090455 - 17 Sep 2025
Viewed by 322
Abstract
This paper investigates the attitude control problems of spacecraft subject to external disturbances and compound actuator faults, including both additive and multiplicative components. To address these problems, an improved learning observer (ILO) is proposed. Compared to traditional learning observers (TLOs), the improved learning [...] Read more.
This paper investigates the attitude control problems of spacecraft subject to external disturbances and compound actuator faults, including both additive and multiplicative components. To address these problems, an improved learning observer (ILO) is proposed. Compared to traditional learning observers (TLOs), the improved learning observer incorporates the previous-step state estimation error as an iterative term. Based on the observer’s outputs, a robust adaptive fault-tolerant attitude control scheme is developed using the backstepping method, under a prescribed performance bound (PPB). This control framework guarantees that the attitude tracking error adheres to prescribed transient performance specifications, such as bounded overshoot and accelerated convergence. Unlike conventional control schemes, the proposed approach ensures that system trajectories remain strictly within the desired bound throughout the transient process. A comprehensive Lyapunov-based analysis rigorously demonstrates the global uniform ultimate boundedness of all closed-loop signals. Numerical simulations substantiate the efficacy of the proposed approach, highlighting the enhanced disturbance estimation capability of the ILO in comparison to the TLO, as well as the superior transient tracking performance of the PPB-based control strategy relative to existing methods. Full article
(This article belongs to the Section Aerospace Actuators)
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19 pages, 1722 KB  
Article
Global-Initialization-Based Model Predictive Control for Mobile Robots Navigating Nonconvex Obstacle Environments
by Seung-Mok Lee
Actuators 2025, 14(9), 454; https://doi.org/10.3390/act14090454 - 17 Sep 2025
Viewed by 477
Abstract
This paper proposes a nonlinear model predictive control (MPC) framework initialized using an initial-guess particle swarm optimization (IG-PSO) algorithm for mobile robots navigating in environments with nonconvex obstacles. The proposed method is designed to address the local minimum problem inherent in conventional optimization-based [...] Read more.
This paper proposes a nonlinear model predictive control (MPC) framework initialized using an initial-guess particle swarm optimization (IG-PSO) algorithm for mobile robots navigating in environments with nonconvex obstacles. The proposed method is designed to address the local minimum problem inherent in conventional optimization-based MPC by incorporating a PSO-based global search method to generate effective initial guesses. In addition, a grid-based representation of the nonconvex obstacles is implemented to systematically define the collision avoidance constraints within the MPC formulation. The proposed method was validated in real-time simulations using the Robot Operating System (ROS) and the Gazebo physics simulator. The results demonstrate that the proposed MPC initialized by IG-PSO generates collision-free trajectories that avoid local minima and track the desired reference trajectory in environments with nonconvex obstacles. Compared with conventional IPOPT-based MPC, the proposed method exhibited improved performance in the tested scenario. The proposed method also maintains real-time control capabilities by selectively activating the IG-PSO algorithm only as required. The findings of this study demonstrate the potential of the proposed framework for robust and efficient trajectory planning in complex, nonconvex obstacle environments. Full article
(This article belongs to the Section Actuators for Robotics)
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20 pages, 5120 KB  
Article
Fast Fourier Transform-Based Activation and Monitoring of Micro-Supercapacitors: Enabling Energy-Autonomous Actuators
by Negar Heidari, Parviz Norouzi, Alireza Badiei and Ebrahim Ghafar-Zadeh
Actuators 2025, 14(9), 453; https://doi.org/10.3390/act14090453 - 16 Sep 2025
Viewed by 399
Abstract
This work provides the first demonstration of FFTCCV as a dual-purpose method, serving both as a real-time diagnostic tool and as a phase- and morphology-engineering strategy. By adjusting the scan rate, FFTCCV directs the crystallographic evolution of Ni (OH)2 on Ni foam—stabilizing [...] Read more.
This work provides the first demonstration of FFTCCV as a dual-purpose method, serving both as a real-time diagnostic tool and as a phase- and morphology-engineering strategy. By adjusting the scan rate, FFTCCV directs the crystallographic evolution of Ni (OH)2 on Ni foam—stabilizing α-nanoflakes at 0.7 V·s−1 and β-platelets at 0.007 V·s−1—while simultaneously enabling electrode-resolved ΔQ tracking and predictive state-of-health (SoH) monitoring. This approach enabled the precise regulation of electrode morphology and phase composition, yielding high areal capacitance (546.5 mF·cm−2 at 5 mA·cm−2) with ~75% retention after 3000 cycles. These improvements advance the development of high-performance micro-supercapacitors, facilitating their integration into wearable and miniaturized devices where compact and durable energy storage is required. Beyond performance enhancement, FFTCCV also enabled continuous monitoring of capacitance during extended operation (up to 40,000 s). By recording both anodic and cathodic responses, the method provided time-resolved insights into device stability and revealed characteristic signatures of electrode degradation, phase transitions, and morphological changes. Such detection allows recognition of early failure pathways that are not accessible through conventional testing. This monitoring capability functions as an embedded health sensor, offering a pathway for predictive diagnosis of supercapacitor failure. Such functionality is particularly important for energy-driven actuators and smart materials, where uninterrupted operation and preventive maintenance are critical. FFTCCV therefore provides a scalable strategy for developing energy-autonomous microsystems with improved performance and real-time state-of-health monitoring. Full article
(This article belongs to the Section Miniaturized and Micro Actuators)
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27 pages, 12457 KB  
Article
Research on Dual-Motor Redundant Compensation for Unstable Fluid Load of Control Valves
by Zhisheng Li, Yudong Xie, Jiazhen Han and Yong Wang
Actuators 2025, 14(9), 452; https://doi.org/10.3390/act14090452 - 15 Sep 2025
Viewed by 366
Abstract
Control valves are widely applied in nuclear power, offshore oil/gas extraction, and chemical engineering, but suffer from issues like pressure oscillation, flow control accuracy degradation, and motor overload due to unstable fluid loads (e.g., nuclear reactions in power plants and complex marine climates). [...] Read more.
Control valves are widely applied in nuclear power, offshore oil/gas extraction, and chemical engineering, but suffer from issues like pressure oscillation, flow control accuracy degradation, and motor overload due to unstable fluid loads (e.g., nuclear reactions in power plants and complex marine climates). This paper proposes a dual-motor redundant compensation method to address these challenges. The core lies in a control strategy where a single main motor drives the valve under normal conditions, while a redundant motor intervenes when load torque exceeds a preset threshold—calculated via the valve core’s fluid load model. By introducing excess load torque as positive feedback to the current loop, the method coordinates torque output between the two motors. AMESim and Matlab/Simulink joint simulations compare single-motor non-compensation, single-motor compensation, and dual-motor schemes. Results show that under inlet pressure step changes, the dual-motor compensation scheme shortens the stabilization time of the valve’s controlled variable by 40%, reduces overshoot by 65%, and decreases motor torque fluctuation by 50%. This redundant design enhances fault tolerance, providing a novel approach for reliability enhancement of deep-sea oil/gas control valves. Full article
(This article belongs to the Section Control Systems)
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23 pages, 2128 KB  
Article
Fully-Distributed Bipartite Consensus for Linear Multiagent Systems with Dynamic Event-Triggered Mechanism Under Signed Topology Network
by Han Sun, Xiaogong Lin and Dawei Zhao
Actuators 2025, 14(9), 451; https://doi.org/10.3390/act14090451 - 13 Sep 2025
Viewed by 350
Abstract
This article investigates the bipartite consensus control problem of general linear multiagent systems over an antagonistic interaction topology using a dynamic event-triggered mechanism. Primarily, for each agent, a distributed dynamic event-triggered control scheme is proposed based on a signed cooperative–competitive communication graph. Controller [...] Read more.
This article investigates the bipartite consensus control problem of general linear multiagent systems over an antagonistic interaction topology using a dynamic event-triggered mechanism. Primarily, for each agent, a distributed dynamic event-triggered control scheme is proposed based on a signed cooperative–competitive communication graph. Controller updates and triggering condition monitoring are executed only when a specified event is triggered, thereby reducing communication overhead. Subsequently, by integrating the time-varying control gain into the presented control strategy, a fully distributed bipartite controller architecture is defined without using global topology information. As a result, the influence of coupling weights on each agent can be restrained, enabling the realization of bipartite consensus for multiagent systems. Moreover, the proposed dynamic event-triggered control protocol is rigorously proven to exclude Zeno behavior over the entire time horizon. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed method. Full article
(This article belongs to the Special Issue Advanced Technologies in Actuators for Control Systems)
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19 pages, 4083 KB  
Article
Design and Analysis of a Dual-Screw Propelled Robot for Underwater and Muddy Substrate Operations in Agricultural Ponds
by Yan Xu, Pengchao Dai, Mingjin Xin, Liyan Wu and Yuqiu Song
Actuators 2025, 14(9), 450; https://doi.org/10.3390/act14090450 - 12 Sep 2025
Viewed by 510
Abstract
Conventional underwater vehicles, which are typically equipped with oscillating fins or standard propellers, are incapable of effective locomotion within the viscous, high-resistance environment of muddy substrates common in agricultural ponds. To address this operational limitation, this paper presents a compact dual-screw propelled robot [...] Read more.
Conventional underwater vehicles, which are typically equipped with oscillating fins or standard propellers, are incapable of effective locomotion within the viscous, high-resistance environment of muddy substrates common in agricultural ponds. To address this operational limitation, this paper presents a compact dual-screw propelled robot capable of traversing both the water column and soft substrate layers. The robot’s locomotion is driven by two optimized helical screw propellers, while depth control and roll stability are actively managed by a control fin. A dynamic model of the robot–fluid interaction was developed to optimize the screw configuration that achieves a maximum theoretical thrust of 40 N with a calculated 16% slippage rate in mud. Computational fluid dynamics simulations were employed to determine the optimal angle for the control fin, which was found to be 9°, maximizing the lift-to-drag ratio at 12.09 for efficient depth maneuvering. A cable-free remote control system with a response time of less than 0.5 s governs all operations. Experimental validation in a controlled tank environment confirmed the robot’s performance, demonstrating stable locomotion at 0.4 m/s in water and 0.3 m/s in a simulated mud substrate. This dual-screw propelled robot represents a promising technological solution for comprehensive monitoring and operational tasks in agricultural pond environments. Full article
(This article belongs to the Special Issue Design and Control of Agricultural Robotics)
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21 pages, 12614 KB  
Article
Research on Inertial Force Suppression Control for Hydraulic Cylinder Synchronization of Shield Tunnel Segment Erector Based on Sliding Mode Control
by Fangao Zhang, Zhaoqiang Wang, Xiaori Zhang, Xiaoqiang Wang and Xiaoxi Hu
Actuators 2025, 14(9), 449; https://doi.org/10.3390/act14090449 - 11 Sep 2025
Viewed by 413
Abstract
As a critical component in tunnel construction, the segment erector of shield tunneling machines critically influences segment assembly quality and construction efficiency, largely determined by its dual-cylinder synchronization control. Addressing challenges such as dynamic coupling, nonlinear disturbances, and significant inertial force fluctuations inherent [...] Read more.
As a critical component in tunnel construction, the segment erector of shield tunneling machines critically influences segment assembly quality and construction efficiency, largely determined by its dual-cylinder synchronization control. Addressing challenges such as dynamic coupling, nonlinear disturbances, and significant inertial force fluctuations inherent in hydraulic cylinder synchronization under large-inertia loads and variable working conditions, this study proposes an optimized inertial force suppression strategy utilizing an improved sliding mode control (SMC). Mechanical and hydraulic dynamic models of the dual-cylinder lifting mechanism were established to analyze load distribution and force-arm variation patterns, thereby elucidating the influence of inertial forces on synchronization accuracy. Based on this analysis, an adaptive boundary-layer SMC, incorporating real-time inertial force compensation, was designed. This design effectively suppresses system chattering and enhances robustness. Simulation and experimental results demonstrate that the proposed method achieves synchronization errors within ±0.5 mm during step responses, reduces inertial force peaks by 50%, and exhibits significantly superior anti-interference performance compared to conventional PID control. This research provides theoretical foundations and practical engineering insights for high-precision synchronization control in shield tunneling, demonstrating substantial application value. Full article
(This article belongs to the Section Control Systems)
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24 pages, 840 KB  
Article
Adaptive Event-Triggered Full-State Constrained Control of Multi-Agent Systems Under Cyber Attacks
by Jinxia Wu, Pengfei Cui, Juan Wang and Yuanxin Li
Actuators 2025, 14(9), 448; https://doi.org/10.3390/act14090448 - 11 Sep 2025
Viewed by 394
Abstract
For multi-agent systems under Denial-of-Service (DoS) attacks, a relative threshold strategy for event triggering and a state-constrained control method with prescribed performance are proposed. Within the framework of combining graph theory with the leader–follower approach, coordinate transformation is utilized to decouple the multi-agent [...] Read more.
For multi-agent systems under Denial-of-Service (DoS) attacks, a relative threshold strategy for event triggering and a state-constrained control method with prescribed performance are proposed. Within the framework of combining graph theory with the leader–follower approach, coordinate transformation is utilized to decouple the multi-agent system. Inspired by the three-way handshake technology of TCP communication, a DoS detection system is designed based on event-triggering. This system is used to detect DoS attacks, prevent the impacts brought by DoS attacks, and reduce the update frequency of the controller. Fuzzy logic systems are employed to approximate the unknown nonlinear functions within the system. By using a first-order filter to approximate the derivative of the virtual controller, the computational complexity issue in the backstepping method is addressed. Furthermore, The Barrier Lyapunov Function (BLF) possesses unique mathematical properties. When the system state approaches the pre-set boundary, it can exhibit a special variation trend, thereby imposing a restrictive effect on the system state. The Prescribed Performance Function (PPF), on the other hand, defines the expected performance standards that the system aims to achieve in the tracking task, covering key indicators such as tracking accuracy and response speed. By organically integrating these two functions, the system can continuously monitor and adjust its own state during operation. When there is a tendency for the tracking error to deviate from the specified range, the combined function mechanism will promptly come into play. Through the reasonable adjustment of the system’s control input, it ensures that the tracking error always remains within the pre-specified range. Finally, through Lyapunov analysis, the proposed control protocol ensures that all closed-loop signals remain bounded under attacks, with the outputs of all followers synchronizing with the leader’s output in the communication graph. Full article
(This article belongs to the Special Issue Advanced Technologies in Actuators for Control Systems)
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38 pages, 5009 KB  
Article
An Adaptive Estimation Model for the States and Loads in Electro-Hydraulic Actuation Systems
by Dimitar Dichev, Borislav Georgiev, Iliya Zhelezarov, Tsanko Karadzhov and Hristo Hristov
Actuators 2025, 14(9), 447; https://doi.org/10.3390/act14090447 - 11 Sep 2025
Viewed by 309
Abstract
In this study, we introduce an advanced framework for state estimation in electro-hydraulic systems, utilizing a structurally adapted Kalman filter. The proposed model was designed to enhance estimation accuracy and robustness under dynamic load variations and evolving measurement conditions. A notable feature of [...] Read more.
In this study, we introduce an advanced framework for state estimation in electro-hydraulic systems, utilizing a structurally adapted Kalman filter. The proposed model was designed to enhance estimation accuracy and robustness under dynamic load variations and evolving measurement conditions. A notable feature of the approach is the algebraic resolution of one system state during each iteration, enabling the seamless inclusion of variables that are otherwise difficult to measure, without disrupting the model’s linear formulation. In addition, the dynamics of the load torque are empirically characterized through a regression-based model derived from experimental observations. The framework integrates adaptive mechanisms for updating the model and measurement error covariance matrices, facilitating the real-time accommodation of system nonlinearities and environmental changes. Experimental results are presented in different operating modes, reflecting characteristic dynamic movements. They show that the method reduced the root mean square error (RMSE) when estimating angular velocity between five and more than six times, depending on the mode. When evaluating the load torque, even in modes with a sharply changing load, the RMSE value remains stable below 0.05 Nm, which indicates the absence of systematic drift and high stability of the estimates. This confirms the stable operation of the algorithm in dynamic conditions and its applicability in real systems. Full article
(This article belongs to the Section Control Systems)
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14 pages, 1256 KB  
Article
Application-Oriented Analysis of Hexaglide Pose Accuracy in Through-Hole Assembly of Electronic Components
by Mikhail Polikarpov, Yousuf Mehmood and Jochen Deuse
Actuators 2025, 14(9), 446; https://doi.org/10.3390/act14090446 - 9 Sep 2025
Viewed by 370
Abstract
Hexaglide parallel manipulators are characterized by high accuracy and dynamic performance, which makes them suitable for industrial high-precision assembly tasks such as placement of electronic THT components on printed circuit boards. In this paper we describe an assembly system that comprises a Hexaglide [...] Read more.
Hexaglide parallel manipulators are characterized by high accuracy and dynamic performance, which makes them suitable for industrial high-precision assembly tasks such as placement of electronic THT components on printed circuit boards. In this paper we describe an assembly system that comprises a Hexaglide manipulator with vertical ball screws, moving printed circuit boards relative to stationary THT components. We evaluate the effects of the manufacturing tolerances of machine parts, such as bar length tolerance, ball screw axis position uncertainty, and ball screw axis orientation uncertainty, on Hexaglide end-effector pose accuracy using a geometric simulation study based on stochastic tolerance sampling. In the investigated configuration and under standard industrial tolerances, bar length inaccuracy and axis position uncertainty lead to significant position and rotation deviations for the Hexaglide end-effector in the horizontal plane that need to be compensated for by control algorithms to enable THT assembly using the Hexaglide prototype. The geometric simulation method applied in this paper can be used by designers of Hexaglide machines to study and evaluate different machine configurations. Full article
(This article belongs to the Special Issue Industrial and Biomechanical Applications of Actuators and Robots and Eco-Sustainability)
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17 pages, 3584 KB  
Article
Developing an Energy-Efficient Electrostatic-Actuated Micro-Accelerometer for Low-Frequency Sensing Applications
by Umar Jamil, Muhammad Sohaib Zahid, Nouman Ghafoor, Faisal Nawaz, Jose Raul Montes-Bojorquez and Mehboob Alam
Actuators 2025, 14(9), 445; https://doi.org/10.3390/act14090445 - 8 Sep 2025
Viewed by 914
Abstract
Micro-accelerometers are in high demand across many due to their compact size, low energy consumption, and excellent precision. Since gravity causes a large movement when the device is positioned vertically, measuring low gravitational acceleration is challenging. This study examines the intrinsic relationship between [...] Read more.
Micro-accelerometers are in high demand across many due to their compact size, low energy consumption, and excellent precision. Since gravity causes a large movement when the device is positioned vertically, measuring low gravitational acceleration is challenging. This study examines the intrinsic relationship between applied voltage levels and displacement in micro-accelerometers. The study introduces a novel design that integrates hybrid flexures, comprising both linear and angular configurations, with an out-of-plane overlap varying (OPOV) electrostatic actuation mechanism. This design aims to measure the micro-accelerometer’s movement and low frequency response. The proposed device with silicon material is designed and simulated using the IntelliSuite® software, considering its small dimensions and 25 µm thickness. The norm value of 28.0916 μN from gravity’s reaction forces on the body, a resonant frequency of 179.668 Hz at the first desired mode, and a maximum stress of 24.7 MPa were obtained through the electro-mechanical analysis. A comparison of the proposed design was conducted with other configurations, measuring a frequency of 179.668 Hz at a minimum downward displacement of 7.69916 µm under the influence of gravity without electrostatic mechanisms. Following this, an electrostatic actuation mechanism was introduced to minimize displacement by applying different voltage levels, including 1 V, 1.5 V, and 3 V. At 3 V, a significant improvement in displacement reduction was observed compared to the other applied voltages. Additionally, dynamic and sensitivity analyses were carried out to validate the performance of the proposed design further. Full article
(This article belongs to the Special Issue Recent Advances in the Design and Applications for Magnetoelastic and Electroelastic Actuators)
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14 pages, 2638 KB  
Article
The Impact of Pump Cavity Gaps on the Flow Characteristics of Helical Mixed-Flow Pumps
by Wei Han, Yucheng Chen, Tongqing Xue and Pengzheng Lei
Actuators 2025, 14(9), 444; https://doi.org/10.3390/act14090444 - 8 Sep 2025
Viewed by 407
Abstract
The performance of pump-jet propulsion systems is critically important in defense and marine applications. However, their optimization has encountered bottlenecks due to a lack of theoretical understanding of underlying flow mechanisms. This study investigates the influence of the pump cavity gap on the [...] Read more.
The performance of pump-jet propulsion systems is critically important in defense and marine applications. However, their optimization has encountered bottlenecks due to a lack of theoretical understanding of underlying flow mechanisms. This study investigates the influence of the pump cavity gap on the flow characteristics and performance of a helical mixed-flow pump using numerical simulations. The gap size is non-dimensionalized as a gap coefficient—defined as the ratio of pump cavity gap to blade thickness—with the inlet ring gap fixed at 0.2 mm. Results demonstrate that the gap coefficient significantly affects internal flow stability and energy loss. A gap coefficient of 0.15 effectively suppresses leakage and vortex formation, improving efficiency (peak efficiency reaches 75%) and head (1.9 m) under low-flow conditions. This configuration also promotes uniform pressure distribution on the impeller shaft surface and reduces turbulent kinetic energy and axial vorticity. In contrast, a smaller gap coefficient (0.125) exacerbates flow separation at high flow rates, while a larger value (0.2) increases leakage losses and degrades performance. The study elucidates correlations between the pump cavity gap and vortex evolution, pressure gradient, and turbulence distribution, providing theoretical support for the optimized design of helical mixed-flow pumps. Full article
(This article belongs to the Special Issue Advanced Actuators and Magnetic Fluid Systems: Design, Control, and Applications)
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19 pages, 1539 KB  
Article
Design and Evaluation of a Torque-Controlled Ankle Exoskeleton Using the Small-Scale Hydrostatic Actuator: miniHydrA
by Kyrian Staman and Herman van der Kooij
Actuators 2025, 14(9), 443; https://doi.org/10.3390/act14090443 - 8 Sep 2025
Viewed by 808
Abstract
A small-scale electro-hydrostatic actuator, termed miniHydrA, was developed based on biomechanical requirements for gait and integrated into an ankle exoskeleton. The key advantage of this actuator concept lies in its compact size and the low mass of its output stage, combined with the [...] Read more.
A small-scale electro-hydrostatic actuator, termed miniHydrA, was developed based on biomechanical requirements for gait and integrated into an ankle exoskeleton. The key advantage of this actuator concept lies in its compact size and the low mass of its output stage, combined with the ability to deliver high support torques, sufficient for full human assistance. During development, hydraulic cylinder leakage and friction were identified as key challenges. To address control requirements, a dedicated control strategy was proposed and implemented. The prototype exoskeleton was evaluated for joint torque tracking performance across a range of torques (0–120 Nm), both in benchtop tests and during treadmill walking trials. In benchtop experiments, zero-torque tracking was achieved with a mean absolute error ranging from 0.03 to 2.26 Nm across frequencies from 0 to 5 Hz. During treadmill walking, torque tracking errors ranged from 0.70 to 0.95 Nm, with no observable deviations in ankle joint kinematics among the three test subjects. These results show the feasibility of the miniHydrA for remote actuation. Compared to Bowden cables, commonly used in exoskeletons and exosuits, the proposed actuator concept offers two key advantages: it is better suited for high-torque applications, and its friction characteristics can be more accurately predicted and modeled, enabling more effective feedforward control. Full article
(This article belongs to the Special Issue Control of Hydraulic Robotic Manipulators)
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23 pages, 4098 KB  
Article
Modeling of the Dynamic Characteristics for a High-Load Magnetorheological Fluid-Elastomer Isolator
by Yu Tao, Wenhao Chen, Feifei Liu and Ruijie Han
Actuators 2025, 14(9), 442; https://doi.org/10.3390/act14090442 - 5 Sep 2025
Viewed by 353
Abstract
To meet the vibration isolation requirements of engines under diverse operating conditions, this paper proposes a novel magnetorheological fluid-elastomer isolator with high load and tunable parameters. The mechanical and magnetic circuit structures of the isolator were designed and optimized through theoretical calculations and [...] Read more.
To meet the vibration isolation requirements of engines under diverse operating conditions, this paper proposes a novel magnetorheological fluid-elastomer isolator with high load and tunable parameters. The mechanical and magnetic circuit structures of the isolator were designed and optimized through theoretical calculations and finite element simulations, achieving effective vibration isolation within confined spaces. The dynamic performance of the isolator was experimentally evaluated using a hydraulic testing system under varying excitation amplitudes, frequencies, initial positions, and magnetic fields. Experimental results indicate that the isolator achieves a static stiffness of 3 × 106 N/m and a maximum adjustable compression load range of 105.4%. In light of the asymmetric nonlinear dynamic behavior of the isolator, an improved nine-parameter Bouc–Wen model is proposed. Parameter identification performed via a genetic algorithm demonstrates a model accuracy of 95.0%, with a minimum error reduction of 28.8% compared to the conventional Bouc–Wen model. Full article
(This article belongs to the Section Precision Actuators)
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23 pages, 3539 KB  
Article
Synchronous Leveling Control Method of Crane Vehicle Platform Based on Position–Force Coordination
by Feixiang Xu, Haichao Hu, Shiyong Feng and Chen Zhou
Actuators 2025, 14(9), 441; https://doi.org/10.3390/act14090441 - 5 Sep 2025
Viewed by 378
Abstract
Leveling of the crane support platform plays a vital role in operational safety and lifting efficiency; it requires both precise horizontal positioning and the rational distribution of outrigger load. However, the current synchronous leveling methods mainly focus on displacement synchronization leveling while neglecting [...] Read more.
Leveling of the crane support platform plays a vital role in operational safety and lifting efficiency; it requires both precise horizontal positioning and the rational distribution of outrigger load. However, the current synchronous leveling methods mainly focus on displacement synchronization leveling while neglecting the control of outrigger load, resulting in the problem of individual outrigger overloading. To address this problem, a synchronous leveling control method with variable load constraints (SLCM-VLC) is proposed in this paper based on the framework of model predictive control. Firstly, the proposed method conducts independent outrigger modeling and decoupling of outriggers through adjacent cross-coupling; then a displacement synchronization controller (DSC) is designed to ensure efficient synchronous leveling. Secondly, a collaborative controller of displacement and force (DFCC) under variable load constraints is designed to overcome the limitations of traditional independent optimization. Subsequently, an extended state observer (ESO) is introduced to compensate for environmental disturbances and control deviations. Finally, the effectiveness of the proposed method is verified through a co-simulation using Matlab, Adams, and Solidworks. The results show that, compared with existing leveling control methods, the proposed method can achieve high precision and rapid leveling under smaller peak load, thereby extending the service life of the platform’s electric cylinders. Full article
(This article belongs to the Section Control Systems)
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16 pages, 2759 KB  
Article
Research on Linear Active Disturbance Rejection Control of Electrically Excited Motor for Vehicle Based on ADP Parameter Optimization
by Heping Ling, Junzhi Zhang and Hua Pan
Actuators 2025, 14(9), 440; https://doi.org/10.3390/act14090440 - 4 Sep 2025
Viewed by 369
Abstract
In the three-motor hybrid architecture, the auxiliary drive uses electrically excited synchronous motor (EESM), which has the advantages of high torque density, wide speed range and strong anti-demagnetization ability. However, the strong electromagnetic coupling between the field winding and the armature winding leads [...] Read more.
In the three-motor hybrid architecture, the auxiliary drive uses electrically excited synchronous motor (EESM), which has the advantages of high torque density, wide speed range and strong anti-demagnetization ability. However, the strong electromagnetic coupling between the field winding and the armature winding leads to the difficulty of current control, and the traditional PID has limitations in dynamic response and immunity. In order to solve this problem, a linear active disturbance rejection control (LADRC) method for the rotor of EESM is proposed in this paper, linear extended state observer (LESO) is used to estimate and compensate the system internal and external disturbances (such as winding coupling and parameter perturbation) in real time. The method only uses the input and output of the system and does not depend on any mechanical parameters, so that the torque response is improved by 50%, and the steady-state fluctuation is reduced by 10.2%. In addition, an adaptive dynamic programming (ADP) parameter optimization strategy is proposed to solve the bandwidth parameter tuning problem of LADRC algorithm in complex operating conditions, and the related mathematical analysis of optimality properties is given. Finally, the proposed method is compared with the traditional PI controller in several operating conditions of EESM, and the effectiveness of the proposed method is validated by the corresponding results. Full article
(This article belongs to the Section Control Systems)
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20 pages, 5464 KB  
Article
Simulation-Based Testing of Autonomous Robotic Systems for Surgical Applications
by Jun Lin, Tiantian Sun, Rihui Song, Di Zhu, Lan Liu, Jiewu Leng, Kai Huang and Rongjie Yan
Actuators 2025, 14(9), 439; https://doi.org/10.3390/act14090439 - 4 Sep 2025
Viewed by 692
Abstract
Autonomous surgery involves surgical tasks performed by a robot with minimal or no human involvement. Thanks to its precise automation, surgical robotics offers significant benefits in enhancing the consistency, safety, and quality of procedures, driving its growing popularity. However, ensuring the safety of [...] Read more.
Autonomous surgery involves surgical tasks performed by a robot with minimal or no human involvement. Thanks to its precise automation, surgical robotics offers significant benefits in enhancing the consistency, safety, and quality of procedures, driving its growing popularity. However, ensuring the safety of autonomous surgical robotic systems remains a significant challenge. To address this, we propose a simulation-based validation method to detect potential safety issues in the software of surgical robotic systems, complemented by a digital twin to estimate the gap between simulation and reality. The validation framework consists of a test case generator and a monitor for validating properties and evaluating the performance of the robotic system during test execution. Using a robotic arm for needle insertion as a case study, we present a systematic test case generation method that ensures effective coverage measurement for a three-dimensional, irregular model. Since no simulation can perfectly replicate reality due to differences in sensing and actuation, the digital twin bridges the gap between simulation and the physical robotic arm. This integration enables us to assess the discrepancy between virtual simulations and real-world operations by verifying whether the data from the simulation accurately predicts real-world outcomes. Through extensive experimentation, we identified several flaws in the robotic software. Co-simulation within the digital twin framework has highlighted these discrepancies that should be considered. Full article
(This article belongs to the Section Actuators for Robotics)
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15 pages, 1796 KB  
Article
Second- and Third-Order Stability Bounds for High-Order Linear Consensus on Directed Graph Topologies with Partial Relative State Information and Global/Local Gains
by Eric A. Butcher and Mohammad Maadani
Actuators 2025, 14(9), 438; https://doi.org/10.3390/act14090438 - 3 Sep 2025
Viewed by 399
Abstract
A general high-order linear consensus protocol is proposed for coupling topologies defined by directed graphs with partial relative state information and a reference model with lobal/local gains. Necessary and sufficient second-order stability bounds for the cases of relative position feedback with reference velocity [...] Read more.
A general high-order linear consensus protocol is proposed for coupling topologies defined by directed graphs with partial relative state information and a reference model with lobal/local gains. Necessary and sufficient second-order stability bounds for the cases of relative position feedback with reference velocity and relative position and velocity feedback are then reviewed. Next, new necessary and sufficient stability bounds are obtained for third-order consensus for three cases of feedback of full and partial relative state information. The stability bounds obtained, unlike in prior studies, allow for the gains to be conveniently selected in a sequential manner and are shown to utilize those for second-order consensus. Comparisons with conservative stability bounds from previous studies are shown, and illustrative examples of the proposed consensus protocols and the obtained stability bounds are provided. Full article
(This article belongs to the Special Issue New Control Schemes for Actuators—2nd Edition)
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28 pages, 2429 KB  
Article
Neural Network Disturbance Observer-Based Adaptive Fault-Tolerant Attitude Tracking Control for UAVs with Actuator Faults, Input Saturation, and External Disturbances
by Yan Zhou, Ye Liu, Jiaze Li and Huiying Liu
Actuators 2025, 14(9), 437; https://doi.org/10.3390/act14090437 - 3 Sep 2025
Viewed by 387
Abstract
A dual-loop fault-tolerant control scheme is investigated for UAV attitude control systems subject to actuator faults, input saturation, and external disturbances in this paper. In the outer loop of attitude angles, a nonlinear dynamic inversion controller is developed as baseline controller for fast [...] Read more.
A dual-loop fault-tolerant control scheme is investigated for UAV attitude control systems subject to actuator faults, input saturation, and external disturbances in this paper. In the outer loop of attitude angles, a nonlinear dynamic inversion controller is developed as baseline controller for fast response and is augmented by a neural network disturbance observer to enhance the adaptability and robustness. Considering input saturation, actuator faults, and external disturbances in the inner loop of attitude angle velocities, the unbalanced input saturation is first converted into a time-varying system with unknown parameters and disturbances using a nonlinear function approximation method. An L1 adaptive fault-tolerant controller is then introduced to compensate for the effects of lumped uncertainties including system uncertainties, actuator faults, external disturbances, and approximation errors, and the stability and performance boundaries are verified by Lyapunov theorem and L1 reference system. Some simulation examples are carried out to demonstrate its effectiveness. Full article
(This article belongs to the Section Control Systems)
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11 pages, 1251 KB  
Article
AI-Enhanced Model for Integrated Performance Prediction and Classification of Vibration-Reducing Gloves for Hand-Transmitted Vibration Control
by Yumeng Yao, Wei Xiao, Alireza Moezi, Marco Tarabini, Paola Saccomandi and Subhash Rakheja
Actuators 2025, 14(9), 436; https://doi.org/10.3390/act14090436 - 3 Sep 2025
Viewed by 452
Abstract
This study presents a human-centric, data-driven modeling framework for the intelligent evaluation and classification of vibration-reducing (VR) gloves used in hand-transmitted vibration environments. Recognizing the trade-offs between protection and functionality, the integrated performance assessment incorporates three critical and often conflicting metrics: manual dexterity, [...] Read more.
This study presents a human-centric, data-driven modeling framework for the intelligent evaluation and classification of vibration-reducing (VR) gloves used in hand-transmitted vibration environments. Recognizing the trade-offs between protection and functionality, the integrated performance assessment incorporates three critical and often conflicting metrics: manual dexterity, grip strength, and distributed vibration transmissibility at the palm and fingers. Three independent experiments involving fifteen participants were conducted to evaluate the individual performance of ten commercially available VR gloves fabricated from air bladders, polymers, and viscoelastic gels. The effects of VR gloves on manual dexterity, grip strength, and distributed vibration transmission were investigated. The resulting experimental data were used to train and tune seven different machine learning models. The results suggested that the AdaBoost model demonstrated superior predictive performance, achieving 92% accuracy in efficiently evaluating the integrated performance of VR gloves. It is further shown that the proposed data-driven model could be effectively applied to classify the performances of VR gloves in three workplace conditions based on the dominant vibration frequencies (low-, medium-, and high-frequency). The proposed framework demonstrates the potential of AI-enhanced intelligent actuation systems to support personalized selection of wearable protective equipment, thereby enhancing occupational safety, usability, and task efficiency in vibration-intensive environments. Full article
(This article belongs to the Special Issue Human-Centric Intelligent Actuation Systems: Innovations in Control, Sensing, and Multidisciplinary Applications)
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24 pages, 1435 KB  
Article
Robust Sliding Mode Motion Control for an Integrated Hydromechatronic Actuator
by Dom Wilson, Andrew Plummer and Ioannis Georgilas
Actuators 2025, 14(9), 435; https://doi.org/10.3390/act14090435 - 3 Sep 2025
Viewed by 357
Abstract
Electro-hydraulic servoactuators have great potential in mobile robotics due to their robustness, high bandwidth and power density, but compared with electromechanical actuators, they can be inefficient and more difficult to integrate into systems. The Integrated Smart Actuator (ISA) developed by Moog Controls Ltd. [...] Read more.
Electro-hydraulic servoactuators have great potential in mobile robotics due to their robustness, high bandwidth and power density, but compared with electromechanical actuators, they can be inefficient and more difficult to integrate into systems. The Integrated Smart Actuator (ISA) developed by Moog Controls Ltd. is a hydromechatronic device that aims to address these issues by combining a novel efficient servovalve, cylinder, sensors and control electronics into a single component. The aim of this work was to develop a robust motion control algorithm that can make integration of the ISA into a robotic system straightforward by requiring minimal controller set-up despite variations in the load characteristics. The proposed controller is a sliding mode controller with a varying boundary layer that contains two robustness parameters and a single bandwidth parameter that defines the response. The controller outperforms a conventional high-performance linear controller in terms of tracking performance and its robustness to variations in the load mass and fluid bulk modulus. The response when the system was subject to some unachievable demand trajectories, such as large step demands, was found to be poor, and an online velocity, acceleration and jerk limited trajectory filter was demonstrated to rectify this issue. The successful implementation of a robust motion controller enables this highly novel integrated actuator to live up to its ‘smart’ epithet. Full article
(This article belongs to the Special Issue Intelligent and Precision Control for Mechatronic/Electro-Hydraulic Systems—Second Edition)
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