Actuators

24 pages, 2860 KB

Open AccessArticle

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

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)

23 pages, 3539 KB

Open AccessArticle

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

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, 1785 KB

Open AccessArticle

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

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)

20 pages, 5464 KB

Open AccessArticle

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

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

Open AccessArticle

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 68

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

Open AccessArticle

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 68

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

Open AccessArticle

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 123

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

Open AccessArticle

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 56

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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30 pages, 2358 KB

Open AccessArticle

Model-Based Reinforcement Learning for Containing Malware Propagation in Wireless Radar Sensor Networks

by Haitao Lin, Can Tian, Linman Chen, Daizhi Liao, Yunbo Wang and Yubo Hua

Actuators 2025, 14(9), 434; https://doi.org/10.3390/act14090434 - 2 Sep 2025

Viewed by 112

Abstract

To address malware containment challenges in WRSNs—where traditional integer-order models neglect propagation memory effects and standard reinforcement learning (RL) suffers from slow trial-and-error limitations—we propose the following: (1) a fractional-order VCISQ epidemic model capturing temporal dependencies for higher accuracy, and (2) a model-based [...] Read more.

To address malware containment challenges in WRSNs—where traditional integer-order models neglect propagation memory effects and standard reinforcement learning (RL) suffers from slow trial-and-error limitations—we propose the following: (1) a fractional-order VCISQ epidemic model capturing temporal dependencies for higher accuracy, and (2) a model-based Soft Actor–Critic (MBSAC) method, which integrates a learned transition model into an actor–critic architecture to predict future states from limited data, accelerating learning. Experiments confirm MBSAC outperforms RL baselines by reducing control overhead, hastening convergence, and enhancing robustness. It alleviates the rigidity of the traditional method and establishes a reward-driven safeguard for WRSNs. Full article

(This article belongs to the Special Issue Intelligent Sensing, Control and Actuation in Networked Systems)

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18 pages, 3794 KB

Open AccessArticle

Augmented Recursive Sliding Mode Observer Based Adaptive Terminal Sliding Mode Controller for PMSM Drives

by Qiankang Hou, Bin Ma, Yan Sun, Bing Shi and Chen Ding

Actuators 2025, 14(9), 433; https://doi.org/10.3390/act14090433 - 2 Sep 2025

Viewed by 98

Abstract

Time-varying lumped disturbance and measurement noise are primary obstacles that restrict the control performance of permanent magnet synchronous motor (PMSM) drives. To tackle these obstacles, an adaptive nonsingular terminal sliding mode (ANTSM) algorithm is combined with augmented recursive sliding mode observer (ARSMO) for [...] Read more.

Time-varying lumped disturbance and measurement noise are primary obstacles that restrict the control performance of permanent magnet synchronous motor (PMSM) drives. To tackle these obstacles, an adaptive nonsingular terminal sliding mode (ANTSM) algorithm is combined with augmented recursive sliding mode observer (ARSMO) for PMSM speed regulation system in this paper. Generally, conventional nonsingular terminal sliding mode (NTSM) controller adopts a fixed and conservative control gain to suppress the time-varying disturbance, which will lead to unsatisfactory steady-state performance. Without requiring any information of the time-varying disturbance in advance, a novel barrier function adaptive algorithm is utilized to adjust the gain of NTSM controller online according to the amplitude of disturbance. In addition, the ARSMO is emoloyed to estimate the total disturbance and motor speed simultaneously, thereby alleviating the negative impact of measurement noise and excessive control gain. Comprehensive experimental results verify that the proposed enhanced ANTSM strategy can optimize the dynamic performance of PMSM system without sacrificing its steady-state performance. Full article

(This article belongs to the Section Control Systems)

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16 pages, 11849 KB

Open AccessArticle

A Modular Soft Gripper with Embedded Force Sensing and an Iris-Type Cutting Mechanism for Harvesting Medium-Sized Crops

by Eduardo Navas, Kai Blanco, Daniel Rodríguez-Nieto and Roemi Fernández

Actuators 2025, 14(9), 432; https://doi.org/10.3390/act14090432 - 2 Sep 2025

Viewed by 236

Abstract

Agriculture is facing increasing challenges due to labor shortages, rising productivity demands, and the need to operate in unstructured environments. Robotics, particularly soft robotics, offers promising solutions for automating delicate tasks such as fruit harvesting. While numerous soft grippers have been proposed, most [...] Read more.

Agriculture is facing increasing challenges due to labor shortages, rising productivity demands, and the need to operate in unstructured environments. Robotics, particularly soft robotics, offers promising solutions for automating delicate tasks such as fruit harvesting. While numerous soft grippers have been proposed, most focus on grasping and lack the capability to detach fruits with rigid peduncles, which require cutting. This paper presents a novel modular hexagonal soft gripper that integrates soft pneumatic actuators, embedded mechano-optical force sensors for real-time contact monitoring, and a self-centering iris-type cutting mechanism. The entire system is 3D-printed, enabling low-cost fabrication and rapid customization. Experimental validation demonstrates successful harvesting of bell peppers and identifies cutting limitations in tougher crops such as aubergine, primarily due to material constraints in the actuation system. This dual-capability design contributes to the development of multifunctional robotic harvesters capable of adapting to a wide range of fruit types with minimal requirements for perception and mechanical reconfiguration. Full article

(This article belongs to the Special Issue Soft Actuators and Robotics—2nd Edition)

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22 pages, 2508 KB

Open AccessArticle

Intelligent Vehicle Driving Decisions and Longitudinal–Lateral Trajectory Planning Considering Road Surface State Mutation

by Yongjun Yan, Chao Du, Yan Wang and Dawei Pi

Actuators 2025, 14(9), 431; https://doi.org/10.3390/act14090431 - 1 Sep 2025

Viewed by 141

Abstract

In an intelligent driving system, the rationality of driving decisions and the trajectory planning scheme directly determines the safety and stability of the system. Existing research mostly relies on high-definition maps and empirical parameters to estimate road adhesion conditions, ignoring the direct impact [...] Read more.

In an intelligent driving system, the rationality of driving decisions and the trajectory planning scheme directly determines the safety and stability of the system. Existing research mostly relies on high-definition maps and empirical parameters to estimate road adhesion conditions, ignoring the direct impact of real-time road status changes on the dynamic feasible domain of vehicles. This paper proposes an intelligent driving decision-making and trajectory planning method that comprehensively considers the influence factors of vehicle–road interaction. Firstly, real-time estimation of road adhesion coefficients was achieved based on the recursive least squares method, and a dynamic adhesion perception mechanism was constructed to guide the decision-making module to restrict lateral maneuvering behavior under low-adhesion conditions. A multi-objective lane evaluation function was designed for adaptive lane decision-making. Secondly, a longitudinal and lateral coupled trajectory planning framework was constructed based on the traditional lattice method to achieve smooth switching between lateral trajectory planning and longitudinal speed planning. The planned path is tracked based on a model predictive control algorithm and dual PID algorithm. Finally, the proposed method was verified on a co-simulation platform. The results show that this method has good safety, adaptability, and control stability in complex environments and dynamic adhesion conditions. 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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31 pages, 14518 KB

Open AccessArticle

A Novel Laminar Jamming Mechanism for Variable-Stiffness Robotic Arms

by Freddy Caro, Marc G. Carmichael and Jinchen Ji

Actuators 2025, 14(9), 430; https://doi.org/10.3390/act14090430 - 1 Sep 2025

Viewed by 223

Abstract

A central problem in human–robot interaction is the risk of severe injury in humans in the event of a collision with a rigid robot arm. The introduction of variable stiffness into a robot arm mitigates the effects of impact and generates a safe [...] Read more.

A central problem in human–robot interaction is the risk of severe injury in humans in the event of a collision with a rigid robot arm. The introduction of variable stiffness into a robot arm mitigates the effects of impact and generates a safe interaction in its compliant state. An approach to vary the stiffness of members in a robotic arm is Laminar Jamming. In this article, a new lock/unlock mechanism for Laminar Jamming is proposed. The solution consists of a pneumatic actuator that drives a trapezoidal pin to interfere mechanically with the layers, and, in turn, changing the stiffness of the Laminar Jamming Structure. Additionally, frames are placed along the structure to avoid local buckling of the layers. Experiments and finite element simulations were carried out to study the mechanical performance of this new mechanism. Experiments show that the proposed mechanism reached a maximum stiffness ratio of 3.65, which is 15% higher than the stiffness ratio of an equivalent flat clamp mechanism. Experiments also demonstrate that the proposed mechanism does not show the stick-slip phenomenon that exists in the flat clamp mechanism. Computational case studies were carried out to investigate the effects of the angle of the trapezoidal pin, the number of frames, the direction of the transverse force and the behavior at high deflections. Simulations show that the 30° trapezoidal pin has the highest stiffness for pressures larger than 500 kPa, three frames placed along the Laminar Jamming generate the maximum stiffness ratio, the stiffness slightly varies when the transverse force changes direction, and the stiffness decreases with increasing deflection. Full article

(This article belongs to the Special Issue Mechanical, Optical, and Acoustic Metamaterials and Anisotropic Design for Dynamic Control in Actuators and Sensors)

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21 pages, 7257 KB

Open AccessArticle

A Study on the Transient Performance of Compensated PLL-Type Estimators for Sensorless IPMSMs

by Dongwoo Lee

Actuators 2025, 14(9), 429; https://doi.org/10.3390/act14090429 - 31 Aug 2025

Viewed by 147

Abstract

The transient performance of sensorless control for interior permanent magnet synchronous motors (IPMSMs), based on back-electromotive force (back-EMF) estimation, is a critical factor in ensuring the high reliability of motor drive systems. Although rotor speed and position can be accurately estimated under steady-state [...] Read more.

The transient performance of sensorless control for interior permanent magnet synchronous motors (IPMSMs), based on back-electromotive force (back-EMF) estimation, is a critical factor in ensuring the high reliability of motor drive systems. Although rotor speed and position can be accurately estimated under steady-state conditions, estimation errors tend to increase during transient states such as acceleration, deceleration, and load torque variations. The enhancement of transient stability is closely related to the overshoot in the estimated position and speed errors. In this paper, the maximum overshoot of the estimated position and speed errors during transient operation is analyzed. Furthermore, compensation strategies are proposed to reduce the magnitude of these overshoots. The effectiveness of the proposed sensorless control method is validated through comparative analysis with existing approaches. Full article

(This article belongs to the Section Control Systems)

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19 pages, 8125 KB

Open AccessArticle

Flow Separation Delay Mechanism and Aerodynamic Enhancement via Optimized Flow Deflector Configurations

by Shengguan Xu, Siyi Wang, Hongquan Chen, Jianfeng Tan, Wei Li and Shuai Yin

Actuators 2025, 14(9), 428; https://doi.org/10.3390/act14090428 - 31 Aug 2025

Viewed by 179

Abstract

This study explores the critical role of the flow deflector in suppressing boundary layer separation and enhancing aerodynamic efficiency through systematic geometric parameterization and computational analysis. By defining eight key design variables, this research identifies optimal configurations that significantly delay flow separation at [...] Read more.

This study explores the critical role of the flow deflector in suppressing boundary layer separation and enhancing aerodynamic efficiency through systematic geometric parameterization and computational analysis. By defining eight key design variables, this research identifies optimal configurations that significantly delay flow separation at high angles of attack. Computational Fluid Dynamics (CFD) simulations reveal that optimized deflector geometries enhance suction peaks near the airfoil leading edge, redirect separated flow toward the upper surface, and inject momentum into the boundary layer to generate a more positive lift coefficient. The numerical results demonstrate that the optimized design achieves a 58.4% increase in lift coefficient and an 83.3% improvement in the lift–drag ratio by effectively mitigating large-scale vortical structures inherent in baseline configurations. Sensitivity analyses further highlight threshold-dependent “sudden-jump” behaviors in lift coefficients for parameters such as element spacing and deflection angles, while thickness exhibits minimal influence. Additionally, pre-stall optimizations show that strategically aligned deflectors preserve baseline performance with a 0.4% lift gain, whereas misaligned configurations degrade aerodynamic efficiency by up to 9.1%. These findings establish a direct correlation between deflector-induced flow redirection and separation suppression, offering actionable insights for passive flow control in stalled regimes. This research advances fundamental understanding of flow deflector-based separation management and provides practical guidelines for enhancing aerodynamic performance in aerospace applications. Full article

(This article belongs to the Special Issue Active Flow Control: Recent Advances in Fundamentals and Applications—3rd Edition)

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21 pages, 1415 KB

Open AccessArticle

Vibration Reduction and Stability Investigation of Van Der Pol–Mathieu–Duffing Oscillator via the Nonlinear Saturation Controller

by Ashraf Taha EL-Sayed, Rageh K. Hussein, Yasser A. Amer, Sara S. Mahmoud, Sharif Abu Alrub and Taher A. Bahnasy

Actuators 2025, 14(9), 427; https://doi.org/10.3390/act14090427 - 31 Aug 2025

Viewed by 172

Abstract

This study investigates the effect of a nonlinear saturation controller (NSC) on the van der Pol–Mathieu–Duffing oscillator (VMDO). The oscillator is a single degree of freedom (DOF) system. It is driven by an external force. It is described by a nonlinear differential equation [...] Read more.

This study investigates the effect of a nonlinear saturation controller (NSC) on the van der Pol–Mathieu–Duffing oscillator (VMDO). The oscillator is a single degree of freedom (DOF) system. It is driven by an external force. It is described by a nonlinear differential equation (DE). The multiple-scale perturbation method (MSPT) is applied. It gives second-order analytical solutions. The first indirect Lyapunov method is used. It provides the frequency–response equation. It also shows the stability conditions. Internal resonance is included. The analysis considers steady-state responses. It studies simultaneous primary resonance with a 1:2 internal resonance (

Λ_{1} ≅ ϖ_{1}

and

ϖ_{1} ≅ 2 ϖ_{2}

). Time–response simulations are presented. They show controlled and uncontrolled systems. Numerical solutions (NSs) are obtained with the fourth-order Runge–Kutta method (RK-4). They are compared with the approximate analytical solution (AS). The agreement is strong. It confirms the perturbation method. It shows that the method captures the main system dynamics. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Nonlinear Control and Dynamics for MEMS)

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19 pages, 4016 KB

Open AccessArticle

Multibody Dynamics Simulation of Upper Extremity Rehabilitation Exoskeleton During Task-Oriented Exercises

by Piotr Falkowski and Krzysztof Zawalski

Actuators 2025, 14(9), 426; https://doi.org/10.3390/act14090426 - 30 Aug 2025

Viewed by 289

Abstract

Population aging intensifies the demand for rehabilitation services, which are already suffering from staff shortages. In response to this challenge, the implementation of new technologies in physiotherapy is needed. For such a task, rehabilitation exoskeletons can be used. While designing such tools, their [...] Read more.

Population aging intensifies the demand for rehabilitation services, which are already suffering from staff shortages. In response to this challenge, the implementation of new technologies in physiotherapy is needed. For such a task, rehabilitation exoskeletons can be used. While designing such tools, their functionality and safety must be ensured. Therefore, simulations of their strength and kinematics must meet set criteria. This paper aims to present a methodology for simulating the dynamics of rehabilitation exoskeletons during activities of daily living and determining the reactions in the construction’s joints, as well as the required driving torques. The methodology is applied to the SmartEx-Home exoskeleton. Two versions of a multibody model were developed in the Matlab/Simulink environment—a rigid-only version and one with deformable components. The kinematic chain of construction was reflected with the driven rotational joints and modeled passive sliding open bearings. The simulation outputs include the driving torques and joint reaction forces and the torques for various input trajectories registered using IMU sensors on human participants. The results obtained in the investigation show that in general, to mobilize shoulder flexion/extension or abduction/adduction, around 30 Nm of torque is required in such a lightweight exoskeleton. For elbow flexion/extension, around 10 Nm of torque is needed. All of the reactions are presented in tables for all of the characteristic points on the passive and active joints, as well as the attachments of the extremities. This methodology provides realistic load estimations and can be universally used for similar structures. The presented numerical results can be used as the basis for a strength analysis and motor or force sensor selection. They will be directly implemented for the process of mass minimization of the SmartEx-Home exoskeleton based on computational optimization. Full article

(This article belongs to the Special Issue Advances in Intelligent Control of Actuator Systems)

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16 pages, 4547 KB

Open AccessArticle

Semi-Active Vibration Controllers for Magnetorheological Fluid-Based Systems via Frequency Shaping

by Young T. Choi, Norman M. Wereley and Gregory J. Hiemenz

Actuators 2025, 14(9), 425; https://doi.org/10.3390/act14090425 - 30 Aug 2025

Viewed by 160

Abstract

This study introduces novel semi-active vibration controllers for magnetorheological (MR) fluid-based vibration control systems, specifically a band-pass frequency-shaped semi-active control (FSSC) and a narrow-band FSSC. These algorithms are designed without requiring an accurate damper model or system identification for control current input. Unlike [...] Read more.

This study introduces novel semi-active vibration controllers for magnetorheological (MR) fluid-based vibration control systems, specifically a band-pass frequency-shaped semi-active control (FSSC) and a narrow-band FSSC. These algorithms are designed without requiring an accurate damper model or system identification for control current input. Unlike active controllers, the FSSC algorithms treat the MR damper as a semi-active dissipative device, and their control signal is a control current, not a control force. The performance of both FSSC algorithms is evaluated through simulation using a single-degree-of-freedom (SDOF) MR fluid-based engine mount system. A comparative analysis with the classical semi-active skyhook control demonstrates the advantages of the proposed FSSC algorithms. Full article

(This article belongs to the Special Issue Advances in Electrorheological and Magnetorheological Materials: Material Design, Control and Industrial Applications)

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18 pages, 6348 KB

Open AccessArticle

A Study on Reducing Loss in PCB Motor Stator Using Multi-Via Structure

by Su-Bin Jeon, Do-Hyeon Choi, Hyung-Sub Han, Yun-Ha Song and Won-Ho Kim

Actuators 2025, 14(9), 424; https://doi.org/10.3390/act14090424 - 29 Aug 2025

Viewed by 261

Abstract

This study proposes a multi-via structure as a loss-reduction design technique to mitigate current crowding in a slotless axial flux permanent magnet motor (AFPM) equipped with printed circuit board (PCB) stators. The PCB stator enables high current density operation through parallel copper-foil stacking [...] Read more.

This study proposes a multi-via structure as a loss-reduction design technique to mitigate current crowding in a slotless axial flux permanent magnet motor (AFPM) equipped with printed circuit board (PCB) stators. The PCB stator enables high current density operation through parallel copper-foil stacking and supports an ultra-compact structural configuration. However, current concentration in the via regions can increase copper loss and phase resistance. In this work, the via position and diameter were defined as design variables to perform a sensitivity analysis of current distribution and phase resistance variation. The effects of current density dispersion and the potential for copper loss reduction were evaluated using three-dimensional finite-element analysis (FEA). The results confirm that adopting a multi-via structure improves current path uniformity and reduces electrical losses, thereby enhancing overall efficiency. Furthermore, the analysis shows that excessive via enlargement or overuse does not necessarily yield optimal results and, in certain cases, may lead to localized current peaks. These findings demonstrate that the multi-via structure is an effective and appropriate design strategy for PCB stators and highlight the importance of optimized via placement tailored to each stator configuration. Full article

(This article belongs to the Special Issue Recent Developments in Precision Actuation Technologies)

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19 pages, 4270 KB

Open AccessArticle

Fast Terminal Sliding Mode Control Based on a Novel Fixed-Time Sliding Surface for a Permanent Magnet Arc Motor

by Qiangren Xu, Gang Wang and Shuhua Fang

Actuators 2025, 14(9), 423; https://doi.org/10.3390/act14090423 - 29 Aug 2025

Viewed by 166

Abstract

A fast terminal sliding mode control based on a fixed-time sliding surface is proposed for a permanent magnet arc motor (PMAM), effectively improving speed response, control accuracy, and disturbance rejection capability. Due to its piecewise structure and advanced logarithmic characteristics, a PMAM is [...] Read more.

A fast terminal sliding mode control based on a fixed-time sliding surface is proposed for a permanent magnet arc motor (PMAM), effectively improving speed response, control accuracy, and disturbance rejection capability. Due to its piecewise structure and advanced logarithmic characteristics, a PMAM is subject to high-frequency disturbances. Additionally, it is also influenced by external disturbances. To address this, a sliding mode reaching law that combines terminal terms, linear terms, and switching terms is designed to reduce chattering and enhance robustness. Furthermore, to improve the convergence speed of the sliding mode and disturbance rejection ability, a novel fixed-time converging sliding surface based on a variable exponent terminal term is introduced. Numerical simulations verify the convergence and disturbance rejection capabilities of the proposed sliding surface. Stability based on the Lyapunov theorem is strictly proven. Experimental results validate the effectiveness and superiority of the proposed algorithm. Full article

(This article belongs to the Special Issue High-Performance Control of Electromechanical Servo System Based on Motor/Hydraulic Actuator)

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35 pages, 10401 KB

Open AccessArticle

Dynamics Study of Multi-Supports Rotor Systems with Bearing Clearance Considering Angular Deflections

by Qiyao Dai, Zhefu Yang, Cun Wang, Yanhong Ma, Yongfeng Wang, Zhihong Song and Jie Hong

Actuators 2025, 14(9), 422; https://doi.org/10.3390/act14090422 - 29 Aug 2025

Viewed by 154

Abstract

Bearing clearance, prevalent in multi-supports rotor systems of aero engines, exerts a significant influence on the dynamics of rotor systems, actuators, and aero engines. The essence of it lies in the complex mechanical effects between the bearing and support. These effects become more [...] Read more.

Bearing clearance, prevalent in multi-supports rotor systems of aero engines, exerts a significant influence on the dynamics of rotor systems, actuators, and aero engines. The essence of it lies in the complex mechanical effects between the bearing and support. These effects become more complicated when significant relative angular deflections between the bearing and support exist, which is rarely considered in previous studies. In this paper, a model of support structure with bearing clearance considering angular deflections is proposed, and a mechanical model of the multi-supports rotor system with bearing clearance is developed. The dynamic response of the multi-supports rotor system with bearing clearance is investigated by numerical calculation and experimental verification. The results indicate that, in addition to the rotational frequency, remarkable harmonic frequency components occur in the response, which are generated by the relative movement and periodical collision between the bearing and support, and the relative angular deflections between the bearing and support have a significant impact on the amplitude of them; reducing the bearing clearance or increasing the misalignment both leads to a notable increase in the amplitudes of the harmonic frequency components. Full article

(This article belongs to the Section High Torque/Power Density Actuators)

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21 pages, 6240 KB

Open AccessArticle

Real-Time Gain Scheduling Controller for Axial Piston Pump Based on LPV Model

by Alexander Mitov, Tsonyo Slavov and Jordan Kralev

Actuators 2025, 14(9), 421; https://doi.org/10.3390/act14090421 - 29 Aug 2025

Viewed by 300

Abstract

This article is devoted to the design of a real-time gain scheduling (adaptive) proportional–integral (PI) controller for the displacement volume regulation of a swash plate-type axial piston pump. The pump is intended for open circuit hydraulic drive applications without “secondary control”. In this [...] Read more.

This article is devoted to the design of a real-time gain scheduling (adaptive) proportional–integral (PI) controller for the displacement volume regulation of a swash plate-type axial piston pump. The pump is intended for open circuit hydraulic drive applications without “secondary control”. In this type of pump, the displacement volume depends on the swash plate swivel angle. The swash plate is actuated by a hydraulic-driven mechanism. The classical control device is a hydro-mechanical type, which can realize different control laws (by pressure, flow rate, or power). In the present development, it is replaced by an electro-hydraulic proportional spool valve, which controls the swash plate-actuating mechanism. The designed digital gain scheduling controller evaluates control signal values applied to the proportional valve. The digital controller is based on the new linear parameter-varying mathematical model. This model is estimated and validated from experimental data for various loading modes by an identification procedure. The controller is implemented by a rapid prototyping system, and various real-time loading experiments are performed. The obtained results with the gain scheduling PI controller are compared with those obtained by other classical PI controllers. The developed control system achieves appropriate control performance for a wide working mode of the axial piston pump. The comparison analyses of the experimental results showed the advantages of the adaptive PI controller and confirmed the possibility for its implementation in a real-time control system of different types of variable displacement pumps. Full article

(This article belongs to the Special Issue Advances in Fluid Power Systems and Actuators)

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22 pages, 1165 KB

Open AccessArticle

Decentralized Sliding Mode Control for Large-Scale Systems with Actuator Failures Using Dynamic Event-Triggered Adaptive Dynamic Programming

by Yuling Liang, Xiao Mao, Kun Zhang, Lei Liu, He Jiang and Xiangmin Chen

Actuators 2025, 14(9), 420; https://doi.org/10.3390/act14090420 - 28 Aug 2025

Viewed by 212

Abstract

This study develops a new integral sliding mode-based method to address the decentralized adaptive fault-tolerant guaranteed cost control (GCC) problem via a dynamic event-triggered (DET) adaptive dynamic programming (ADP) approach. Firstly, integral sliding mode control technology is applied to eliminate the influence of [...] Read more.

This study develops a new integral sliding mode-based method to address the decentralized adaptive fault-tolerant guaranteed cost control (GCC) problem via a dynamic event-triggered (DET) adaptive dynamic programming (ADP) approach. Firstly, integral sliding mode control technology is applied to eliminate the influence of actuator faults, which can guarantee that the large-scale system states stay on the sliding mode surface. Secondly, the ADP algorithm based on DET mode is employed to improve the control performance for equivalent sliding mode surface and reduce computational and communication overhead. Meanwhile, the GCC method is introduced to ensure that the performance cost function is less than an upper bound while maintaining system stability. Then, through Lyapunov stability analysis, it is proven that the presented DET-GCC method based on ADP algorithm can guarantee that all signals are uniformly ultimately bounded. Finally, the validity of the developed approach is confirmed through the simulation results. Full article

(This article belongs to the Section Control Systems)

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24 pages, 3447 KB

Open AccessArticle

Stability Optimization of an Oil Sampling Machine Control System Based on Improved Sparrow Search Algorithm PID

by Pan Zhang, Changwei Yang, Min Liao, Junmin Li, Simon X. Yang, Peisong Jiang, Yangxin Teng and Xiaolong Wu

Actuators 2025, 14(9), 419; https://doi.org/10.3390/act14090419 - 28 Aug 2025

Viewed by 277

Abstract

This paper presents an automatic oil sampling system designed for vertical cylindrical oil tanks on land, focusing primarily on the structural design and control optimization for oil level measurement and liquid sampling inside the tank. First, the key structure and control architecture of [...] Read more.

This paper presents an automatic oil sampling system designed for vertical cylindrical oil tanks on land, focusing primarily on the structural design and control optimization for oil level measurement and liquid sampling inside the tank. First, the key structure and control architecture of the automatic sampler are introduced, explaining the collaborative working principles of its components to ensure good stability in system structure and motion control. On this basis, an improved Sparrow Search Algorithm (CSSA) is proposed, which integrates the Coati Optimization Algorithm (COA) and the traditional Sparrow Search Algorithm (SSA). This algorithm is used to optimize the parameters of the Proportional–Integral–Derivative (PID) control system in the oil sampler, aiming to address issues such as response delay, large overshoot, and insufficient stability that commonly occur in traditional PID control under complex conditions. This method achieves consistent response behavior over time and adaptiveness in the control process by dynamically adjusting the PID parameters in real time. To verify the effectiveness of the proposed control strategy, system simulations were conducted in the MATLAB 2024B environment, and a physical experimental platform was built for testing. The simulation compares the CSSA-PID controller with traditional PID, COA-PID, and SSA-PID control methods. In addition, a load disturbance was introduced at 300 ms to perform anti-interference comparative simulations. The results show that under CSSA-PID control, the system response time was shortened by up to 112 ms, the convergence speed improved by 72.3%, the global optimization capability was significantly enhanced, and the anti-interference ability was stronger. In the actual tests, the average error was reduced by approximately 45.3%. These results indicate that CSSA-PID can significantly enhance the stability and response speed of the control system. The efficient control of the automatic oil sampler will greatly enhance the intelligence and efficiency of oil level detection in tanks and reduce labor costs, having significant implications for the development of the grain and oil storage industry. Full article

(This article belongs to the Section Control Systems)

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17 pages, 28985 KB

Open AccessArticle

Design, Performance Testing, and Experimental Validation of Modular Soft Robots Based on Thin-Film Actuators

by Anqi Guo, Zhiwei Ji, Siqi Yu, Wenlong Xie, Xiangchen He and Guoqing Jin

Actuators 2025, 14(9), 418; https://doi.org/10.3390/act14090418 - 27 Aug 2025

Viewed by 306

Abstract

Currently, soft robots face challenges such as low motion efficiency, susceptibility to damage in traditional silicone materials, and difficulty in achieving reproducible manufacturing. To address these issues, we integrate flexible film materials with modular design principles and apply them to soft robotics. Based [...] Read more.

Currently, soft robots face challenges such as low motion efficiency, susceptibility to damage in traditional silicone materials, and difficulty in achieving reproducible manufacturing. To address these issues, we integrate flexible film materials with modular design principles and apply them to soft robotics. Based on the concept of modularity, this study simplifies and decomposes the robot’s motion into three fundamental modules: a thin-film elongation actuator module, a thin-film deflection actuator module, and a connection module. Inspired by the Miura-fold origami technique and traditional lantern contraction, the elongation actuator is designed to produce axial extension of varying lengths under different air pressures. The deflection actuator is modeled after the head expansion mechanism of the pelican eel, enabling deflection movement. The connection module integrates the elongation and deflection modules into a unified structure. The research results show that the elongation actuator achieves an extension length of 118 mm under 50 kPa and can pull a 500 g load during horizontal contraction. The two-layer deflection actuator achieves a deflection angle of 56° at 40 kPa, while the three-layer version reaches 98°. For further demonstration, we subsequently conducted peristaltic soft robot experiments and obstacle avoidance experiments. This study holds significant potential for the development of next-generation multifunctional soft robots. Full article

(This article belongs to the Section Actuators for Robotics)

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14 pages, 1776 KB

Open AccessArticle

A Fluid Elastomeric Actuator Design for Soft Robots

by Dennis Els, Theo van Niekerk, Paolo Mercorelli and Jacques Welgemoed

Actuators 2025, 14(9), 417; https://doi.org/10.3390/act14090417 - 25 Aug 2025

Viewed by 378

Abstract

The field of robotics faces significant challenges in creating adaptable and flexible end-effectors. Soft robotics, specifically soft robotic end-effectors, offer an innovative solution. This paper focuses on designing fluid elastomeric actuators (FEAs) for soft robotic end-effectors. The study presents key design considerations and [...] Read more.

The field of robotics faces significant challenges in creating adaptable and flexible end-effectors. Soft robotics, specifically soft robotic end-effectors, offer an innovative solution. This paper focuses on designing fluid elastomeric actuators (FEAs) for soft robotic end-effectors. The study presents key design considerations and evaluates the use of Finite Element Method (FEM) simulations for optimizing FEA performance. The study then concludes by proposing design guidelines for developing application-specific fluid elastomeric actuators. Full article

(This article belongs to the Special Issue Actuator Technologies and Control: Materials, Devices and Applications)

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15 pages, 5053 KB

Open AccessArticle

Master Cylinder Pressure Control Based on Piecewise-SMC in Electro-Hydraulic Brake System

by Cong Liang, Xing Xu, Hui Deng, Chuanlin He, Long Chen and Yan Wang

Actuators 2025, 14(9), 416; https://doi.org/10.3390/act14090416 - 24 Aug 2025

Viewed by 275

Abstract

This paper focuses on enhancing master cylinder pressure control in pressure-sensorless Electro-Hydraulic Brake (EHB) systems. A novel control strategy is developed, integrating a Piecewise Sliding Mode Controller (Piecewise-SMC) with an Extended Sliding Mode Observer (ESMO) based on a newly derived pressure–position–velocity model that [...] Read more.

This paper focuses on enhancing master cylinder pressure control in pressure-sensorless Electro-Hydraulic Brake (EHB) systems. A novel control strategy is developed, integrating a Piecewise Sliding Mode Controller (Piecewise-SMC) with an Extended Sliding Mode Observer (ESMO) based on a newly derived pressure–position–velocity model that accounts for rack position and velocity effects. To handle external disturbances and parameter uncertainties, the ESMO provides accurate pressure estimation. The nonlinear EHB model is approximated piecewise linearly to facilitate controller design. The proposed Piecewise-SMC regulates motor torque to achieve precise pressure tracking. Experimental validation under step-change braking conditions demonstrates that the Piecewise-SMC reduces response time by 31.8%, overshoot by 35.8%, and tracking root mean square error by 9.6% compared to traditional SMC, confirming its effectiveness and robustness for pressure-sensorless EHB applications. 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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24 pages, 1538 KB

Open AccessArticle

Intelligent Fault Diagnosis for Rotating Machinery via Transfer Learning and Attention Mechanisms: A Lightweight and Adaptive Approach

by Zhengjie Wang, Xing Yang, Tongjie Li, Lei She, Xuanchen Guo and Fan Yang

Actuators 2025, 14(9), 415; https://doi.org/10.3390/act14090415 - 23 Aug 2025

Viewed by 364

Abstract

Fault diagnosis under variable operating conditions remains challenging due to the limited adaptability of traditional methods. This paper proposes a transfer learning-based approach for bearing fault diagnosis across different rotational speeds, addressing the critical need for reliable detection in changing industrial environments. The [...] Read more.

Fault diagnosis under variable operating conditions remains challenging due to the limited adaptability of traditional methods. This paper proposes a transfer learning-based approach for bearing fault diagnosis across different rotational speeds, addressing the critical need for reliable detection in changing industrial environments. The method trains a diagnostic model on labeled source-domain data and transfers them to unlabeled target domains through a two-stage adaptation strategy. First, only the source-domain data are labeled to reflect real-world scenarios where target-domain labels are unavailable. The model architecture combines a convolutional neural network (CNN) for feature extraction with a self-attention mechanism for classification. During source-domain training, the feature extractor parameters are frozen to focus on classifier optimization. When transferring to target domains, the classifier parameters are frozen instead, allowing the feature extractor to adapt to new speed conditions. Experimental validation on the Case Western Reserve University bearing dataset (CWRU), Jiangnan University bearing dataset (JNU), and Southeast University gear and bearing dataset (SEU) demonstrates the method’s effectiveness, achieving accuracies of 99.95%, 99.99%, and 100%, respectively. The proposed method achieves significant model size reduction compared to conventional TL approaches (e.g., DANN and CDAN), with reductions of up to 91.97% and 64%, respectively. Furthermore, we observed a maximum reduction of 61.86% in FLOPs consumption. The results show significant improvement over conventional approaches in maintaining diagnostic performance across varying operational conditions. This study provides a practical solution for industrial applications where equipment operates under non-stationary speeds, offering both computational efficiency and reliable fault detection capabilities. Full article

(This article belongs to the Section Actuators for Manufacturing Systems)

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21 pages, 3369 KB

Open AccessArticle

Event-Triggered Fixed-Time Consensus Tracking Control for Uncertain Nonlinear Multi-Agent Systems with Dead-Zone Input

by Zian Wang, Yixiang Gu, Jiarui Liu, Yue Zhang, Kai Feng, Jietao Dai and Guoxiong Zheng

Actuators 2025, 14(9), 414; https://doi.org/10.3390/act14090414 - 22 Aug 2025

Viewed by 350

Abstract

This study explores the issue of fixed-time dynamic event-triggered consensus control for uncertain nonlinear multi-agent systems (MASs) within directed graph frameworks. In practical applications, the system encounters multiple constraints such as unknown time-varying parameters, unknown external disturbances, and input dead zones, which may [...] Read more.

This study explores the issue of fixed-time dynamic event-triggered consensus control for uncertain nonlinear multi-agent systems (MASs) within directed graph frameworks. In practical applications, the system encounters multiple constraints such as unknown time-varying parameters, unknown external disturbances, and input dead zones, which may increase the communication burden of the system. Therefore, achieving fixed-time consensus tracking control under the aforementioned conditions is challenging. To address these issues, an adaptive fixed-time consensus tracking control method based on boundary estimation and fuzzy logic systems (FLSs) is proposed to achieve online compensation for the input dead zone. Additionally, to optimize the utilization of communication resources, a periodic adaptive event-triggered control (PAETC) is designed. The mechanism dynamically adjusts the frequency at which the trigger is updated in real time, reducing communication resource usage by responding to changes in the control signal. Finally, the efficacy of the proposed approach is confirmed via theoretical evaluation and simulation. Full article

(This article belongs to the Special Issue Analysis and Design of Linear/Nonlinear Control System)

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27 pages, 8503 KB

Open AccessArticle

Design and Implementation of an Autonomous Intelligent Fertigation System for Cross-Regional Applications

by Ruizhi Tang, Hanhong Hu, Hai Lin, Jiahao Li, Zian Wang, Guanquan Zhu, Ziyou Mei and Jietao Dai

Actuators 2025, 14(9), 413; https://doi.org/10.3390/act14090413 - 22 Aug 2025

Viewed by 391

Abstract

Conventional fertigation systems suffer from limited cross-regional adaptability, mainly due to unstable fertilizer flow from fixed-aperture units, poor terrain adaptability, and an inadequate response to environmental heterogeneity. This study proposes an autonomous, cross-regional intelligent fertigation system based on an STM32F1 microcontroller and UART [...] Read more.

Conventional fertigation systems suffer from limited cross-regional adaptability, mainly due to unstable fertilizer flow from fixed-aperture units, poor terrain adaptability, and an inadequate response to environmental heterogeneity. This study proposes an autonomous, cross-regional intelligent fertigation system based on an STM32F1 microcontroller and UART communication protocols. The system integrates a mechanically adjustable iris fertilizer delivery unit, a dual-axis fertigation module, a data interconnection unit, and comprehensive control software with dynamic calibration capabilities. Prototype evaluations conducted on both sloped terrain (up to 38°) and flat surfaces demonstrate a stable performance, achieving fertilizer flow control errors below 3%, irrigation deviation under 5%, and fertilization deviation within 2%. Real-time data acquisition, remote monitoring, and intelligent operation are supported by a YOLOv5s-based visual recognition system, which attains an mAP@0.5 of 92.5%. This integrated solution offers a robust approach to precision agriculture across diverse environmental conditions. Full article

(This article belongs to the Special Issue Adaptive Fault-Tolerant Control Strategies for Uncertain Nonlinear Systems: Mitigating Actuator Faults)

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Actuators, Volume 14, Issue 9 (September 2025) – 30 articles

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