Next Issue
Volume 15, April
Previous Issue
Volume 15, February
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.3
2.3
Journals
Actuators
Volume 15
Issue 3
share announcement

Actuators, Volume 15, Issue 3 (March 2026) – 46 articles

Cover Story (view full-size image): Spasticity is an involuntary increase in muscle tone frequently experienced by stroke survivors. To heal spasticity, they complete rehabilitation sessions where they perform repetitive movements of the affected joints. Accessing specialized equipment and medical support for rehabilitation is a frequent struggle for patients. Offering orthoses suitable for use outside of clinical settings is required to limit the involvement of healthcare personnel and reduce patient transport to hospitals. Such orthoses must be designed to be portable and to tolerate the erratic motions of spasms without breaking or injuring patients. This paper presents the use of magnetorheological actuators to design an elbow orthosis, improving the weight, reactivity, and transparency necessary for effective rehabilitation of spastic patients. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
22 pages, 9224 KB  
Article
Extending Inflatable Actuator with Spool Mechanism Incorporating Air Supply Tubes Within Its Body
by Yuki Satake and Shinichi Hirai
Actuators 2026, 15(3), 176; https://doi.org/10.3390/act15030176 - 22 Mar 2026
Viewed by 313
Abstract
Soft actuators provide a wide range of motion capabilities, allowing for the advancement of novel mobile robots. However, soft actuators that possess the capability required to achieve three-dimensional movement are limited. In addition, the presence of air supply tubes poses a challenge to [...] Read more.
Soft actuators provide a wide range of motion capabilities, allowing for the advancement of novel mobile robots. However, soft actuators that possess the capability required to achieve three-dimensional movement are limited. In addition, the presence of air supply tubes poses a challenge to utilizing pneumatic actuators as mobile robot components. This study presents a long inflatable actuator with a novel structure in which air supply tubes are arranged within its body. This structure enables the extension of the inflatable tube with minimal deformation. The proposed actuator comprises an inflatable tube and a spool mechanism. The length of the actuator is controlled by a motor. The performance of the actuator was evaluated experimentally, validating its alignment with our proposed models. The results showed that the proposed actuator exerted extension and contraction forces of 28 N and 87 N, respectively. Furthermore, the proposed actuator can be equipped with a gripper at its tip, enhancing its functionality. In a demonstration, this gripper-equipped actuator successfully extended to grasp a bar at a height of 1.3 m and contracted while lifting a 1.0 kg base. This demonstration indicated that the proposed actuator could provide the required arm motions of a bi-arm climbing robot. Full article
(This article belongs to the Special Issue Soft Actuators and Robotics—2nd Edition)
►▼ Show Figures

Figure 1

37 pages, 1661 KB  
Article
Control Strategies for DC Motor Systems Driving Nonlinear Loads in Mechatronic Applications
by Asma Al-Tamimi, Fadwa Al-Momani, Mohammad Salah, Suleiman Banihani and Ahmad Al-Jarrah
Actuators 2026, 15(3), 175; https://doi.org/10.3390/act15030175 - 20 Mar 2026
Viewed by 333
Abstract
DC motors are widely used in mechatronic systems; however, their performance degrades significantly in the presence of nonlinear mechanical loads, parameter variations and sensing uncertainties. This paper proposes three control strategies (i.e., PID, optimal, and hybrid controllers) for discrete-time DC motor systems to [...] Read more.
DC motors are widely used in mechatronic systems; however, their performance degrades significantly in the presence of nonlinear mechanical loads, parameter variations and sensing uncertainties. This paper proposes three control strategies (i.e., PID, optimal, and hybrid controllers) for discrete-time DC motor systems to overcome the disturbances caused by nonlinear mechanical loads and parameter variations. Optimal control of nonlinear discrete-time systems is formally characterized by the Hamilton–Jacobi–Bellman (HJB) equation, whose analytical solution is generally intractable. To address this challenge, a learning-based optimal control strategy based on the Heuristic Dynamic Programming (HDP) framework is developed to approximate the HJB equation, supported by a formal convergence proof. For that purpose, Neural Networks (NNs) are employed to approximate both the cost function and the optimal control policy, enabling near-optimal performance with manageable computational complexity. Although the resulting optimal control achieves fast convergence, it may introduce overshoot and steady-state offset under nonlinear disturbances. To address this limitation, a hybrid control framework is proposed, where nonlinear optimal corrections are integrated with the robustness and adaptability of Proportional–Integral–Derivative (PID) control through error-dependent gating and gain-scheduling mechanisms. A structured evaluation framework is conducted, including nominal analysis, motor-parameter stress testing across nine nonlinear scenarios, controller-design sensitivity analysis, and stochastic measurement-noise assessment under filtered sensing conditions. Results demonstrate that the hybrid controller preserves transient speeds within 5–10% of the optimal controller while effectively eliminating overshoot and steady-state offset under nominal conditions. The hybrid design reduces the accumulated tracking error by more than 95% compared to the optimal controller, while incurring only negligible additional control effort. Under aggressive supply-sag disturbances, the hybrid controller significantly limits peak deviation and reduces accumulated tracking error by over 90%, while maintaining comparable control cost. Overall, the hybrid framework provides a convergence-proven and practically deployable control solution that combines near-optimal convergence speed with robust, overshoot-free performance for intelligent motion-control and robotics applications. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Graphical abstract

25 pages, 5357 KB  
Article
A Quasi-3D Parameterized Equivalent Magnetic Network for the Electromagnetic Analysis of Hybrid-Flux High-Speed Switched Reluctance Motors with High Torque Density
by Lukuan Qiao and Aimin Liu
Actuators 2026, 15(3), 174; https://doi.org/10.3390/act15030174 - 20 Mar 2026
Viewed by 230
Abstract
To reduce the computational burden of 3D finite element analysis for hybrid-flux high-speed switched reluctance motors (HFHSRMs), a quasi-3D parameterized equivalent magnetic network (EMN) is proposed. A parameterized radial–circumferential cross-grid is used to discretize the stator, air-gap, and rotor regions, and axial coupling [...] Read more.
To reduce the computational burden of 3D finite element analysis for hybrid-flux high-speed switched reluctance motors (HFHSRMs), a quasi-3D parameterized equivalent magnetic network (EMN) is proposed. A parameterized radial–circumferential cross-grid is used to discretize the stator, air-gap, and rotor regions, and axial coupling branches are introduced to represent key 3D flux paths. Rotor rotation and rotor dislocation are implemented through a circumferential node-shift mapping, thereby avoiding topology reconstruction at different rotor positions. Core nonlinearity is incorporated using a piecewise fit of measured B–H data, and sparse-matrix assembly is adopted to improve solution efficiency. Based on the proposed EMN, key electromagnetic quantities are evaluated, including air-gap flux density, static characteristics, and dynamic characteristics. The results are validated against 3D finite element method (FEM) and prototype experiments. In the prototype experiments, the EMN prediction errors of key quantities are within 6%. In addition, computational efficiency is significantly improved compared with the 3D FEM, enabling rapid parameter iteration and early-stage design evaluation for HFHSRMs. Full article
(This article belongs to the Section High Torque/Power Density Actuators)
►▼ Show Figures

Figure 1

23 pages, 7102 KB  
Article
Positional Pneumatic Actuator Development for a Coordinate Mechanism with Long-Stroke Movements and Improved Operational Characteristics
by Daniil A. Korotych, Vyacheslav I. Grishchenko and Alexey N. Beskopylny
Actuators 2026, 15(3), 173; https://doi.org/10.3390/act15030173 - 19 Mar 2026
Viewed by 465
Abstract
This paper presents an original positional pneumatic actuator for long-stroke coordinate mechanisms. The design integrates a rodless pneumatic cylinder, a jet control system, and an external braking device. It achieves a positioning accuracy of 200 microns, a discrete step of 2 mm, and [...] Read more.
This paper presents an original positional pneumatic actuator for long-stroke coordinate mechanisms. The design integrates a rodless pneumatic cylinder, a jet control system, and an external braking device. It achieves a positioning accuracy of 200 microns, a discrete step of 2 mm, and an average speed of 0.15 m/s over a maximum stroke of 6 m. This solution offers a two-fold improvement in technical, economic, and operational performance compared to electromechanical drives. A mathematical model of the drive was developed using SimInTech software and validated with a custom-built experimental stand. The discrepancy between calculated and experimental data does not exceed 18%. The study established the dependence of positioning accuracy on the load and kinematic characteristics of the drive, which helps reduce design time for coordinate mechanisms. As a result of the research, a new scheme of a positional pneumatic actuator has been developed and experimentally confirmed, which allows for a two-fold improvement in technical and economic indicators compared to electromechanical analogs due to the original combination of a rodless cylinder, a jet control system, and an external braking device. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Figure 1

15 pages, 4144 KB  
Article
Static Performance Analysis and Optimization of High-Speed Solenoids Integrated with Permanent Magnets and Annular Flanges
by Peng Liu, Wenwen Quan, Jiecheng Wang and Zhida Gao
Actuators 2026, 15(3), 172; https://doi.org/10.3390/act15030172 - 19 Mar 2026
Viewed by 206
Abstract
To enhance the performance of high-speed solenoids (HSSs) in control systems, two improved structural designs incorporating a permanent magnet (PM) and an annular flange (AF) are proposed based on the parallel magnetic circuit principle. Their static electromagnetism performances were thoroughly investigated by the [...] Read more.
To enhance the performance of high-speed solenoids (HSSs) in control systems, two improved structural designs incorporating a permanent magnet (PM) and an annular flange (AF) are proposed based on the parallel magnetic circuit principle. Their static electromagnetism performances were thoroughly investigated by the finite element method. Furthermore, multi-objective optimization combined with the response surface method and NSGA-II was carried out. The results indicate that the electromagnetic energy conversion efficiency and electromagnetic force of HSSs can be promoted by applying a PM and an AF: for the first improvement design just employing a PM, increasing the PM height improves energy conversion efficiency and mitigates magnetic saturation within the main pole, and for the second improvement design employing both a PM and an AF, the electromagnetic energy conversion efficiency and electromagnetic force of HSS can be further promoted. In the end, based on the Pareto optimal solution set, the optimized design increases the net electromagnetic force by 18.8% and reduces the peak current by 18.8%. This is the result of applying the optimization scheme, which is beneficial for increasing the dynamic response speed of the HSS valve and reduce its energy loss. Full article
(This article belongs to the Special Issue Advanced Theory and Application of Magnetic Actuators—3rd Edition)
►▼ Show Figures

Figure 1

29 pages, 3356 KB  
Review
Comparative Analysis of Actuation Methods in Flexible Upper-Limb Exoskeleton Robots
by Cuizhi Fei, Zheng Deng, Chongyu Wang, Shuai Wang and Hui Li
Actuators 2026, 15(3), 171; https://doi.org/10.3390/act15030171 - 18 Mar 2026
Viewed by 331
Abstract
The flexible upper-limb exoskeleton robot (exosuit) is composed of fabrics, soft actuators and compliant force-transmitting structures, which provides assistance or rehabilitation training for the shoulders, elbows, wrists and hands. By realizing human–robot collaboration, this kind of system has the advantages of comfort, light [...] Read more.
The flexible upper-limb exoskeleton robot (exosuit) is composed of fabrics, soft actuators and compliant force-transmitting structures, which provides assistance or rehabilitation training for the shoulders, elbows, wrists and hands. By realizing human–robot collaboration, this kind of system has the advantages of comfort, light weight and portability, thus promoting motor function recovery and neural plasticity. This review establishes a classification and comparison framework for flexible upper-limb exoskeletons based on the actuation modalities and systematically summarizes the research progress under different actuation modalities. The relevant literature published from 2015 to 2025 was retrieved from the EI, IEEE Xplore, PubMed and Web of Science databases. After screening according to the preset inclusion and exclusion criteria, a total of 64 original research papers meeting the criteria were finally included for analysis. According to the actuation modalities, the flexible upper-limb exoskeleton robot is classified, and all kinds of systems are summarized and compared. Motor–cable/tendon actuation and pneumatic/hydraulic actuation have advanced substantially and are approaching technical maturity for flexible upper-limb exoskeletons. Meanwhile, designs based on passive/hybrid mechanisms (e.g., elastic energy storage elements and clutches) and new intelligent material actuations are showing a diversified development trend. In the future, the development is expected to further focus on lightweight and compliance, and by integrating multimodal sensing and feedback control, motion intention recognition and human–robot interaction theories, actuation systems will be developed towards modularization, intelligence and high-power density, in order to achieve more comfortable, lighter and more effective flexible upper-limb exoskeleton systems. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

27 pages, 7208 KB  
Article
Real-Time HILS Comparison of Full-State Feedback and LQ-Servo Tracking Control for a Wheeled Bipedal Robot
by Sooyoung Noh, Gu-sung Kim, Cheong-Ha Jung and Changhyun Kim
Actuators 2026, 15(3), 170; https://doi.org/10.3390/act15030170 - 17 Mar 2026
Viewed by 253
Abstract
Wheeled bipedal robots are promising for industrial mobility because they combine tight turning, agile balancing, and efficient rolling. Their inherently unstable and underactuated dynamics make reliable reference tracking challenging, particularly in the presence of sustained external disturbances and modeling errors. This paper presents [...] Read more.
Wheeled bipedal robots are promising for industrial mobility because they combine tight turning, agile balancing, and efficient rolling. Their inherently unstable and underactuated dynamics make reliable reference tracking challenging, particularly in the presence of sustained external disturbances and modeling errors. This paper presents a systematic modeling and control study using a three-degrees-of-freedom sagittal plane representation derived from the original six-degrees-of-freedom dynamics. Two linear tracking controllers are designed and compared: a full state feedback tracking controller and a linear quadratic servo controller with integral action. Practical performance is validated through real-time hardware in the loop simulation, where the controller runs on embedded hardware and the plant is executed on a real-time target including discrete time-sampling effects and analog input output communication noise associated with signal transmission. The results show that both controllers achieve stabilization, while the comparative HILS results reveal a trade-off rather than a uniformly superior controller. The full state feedback controller often yields lower finite-horizon position tracking errors, whereas the linear quadratic servo controller provides tighter body-pitch regulation and the more reliable removal of steady-state offset under sustained constant disturbances. These results demonstrate the feasibility of optimal servo control on cost-effective embedded platforms and indicate that controller selection should depend on the desired balance, considering tracking accuracy, disturbance rejection, convergence behavior, and actuator usage. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

20 pages, 4312 KB  
Article
Design and Analysis of a Compact Self-Tuning High-Voltage Controller for MFC
by Qiong Zhu, Qiang Zhang, Hongli Ji and Jinhao Qiu
Actuators 2026, 15(3), 169; https://doi.org/10.3390/act15030169 - 17 Mar 2026
Viewed by 235
Abstract
In aerospace applications, the vibration of aircraft structures results in a reduction in their fatigue life. Vibration-suppression technology utilizing macro fiber composite (MFC) materials constitutes a significant research direction. Aiming at the specific requirements of the MFC actuator operating in the asymmetric high-voltage [...] Read more.
In aerospace applications, the vibration of aircraft structures results in a reduction in their fatigue life. Vibration-suppression technology utilizing macro fiber composite (MFC) materials constitutes a significant research direction. Aiming at the specific requirements of the MFC actuator operating in the asymmetric high-voltage range of −500 V to 1500 V and the miniaturization of the drive system for aircraft, this study designs a compact self-tuning digital high-voltage controller which adopts a discontinuous conduction mode (DCM) flyback topology as the fundamental model for the switching power supply high-voltage controller, uses the STM32G431 chip as the main controller, and incorporates a Type-II digital compensator designed to enhance the system stability under constant parameters. A Backpropagation (BP) neural network is proposed to enable dynamic adjustment of the digital compensator control parameters, thereby achieving self-tuning, while also supporting program download and real-time data transmission. The high-voltage controller effectively addresses the size and weight constraints in vibration active control systems. Laboratory tests demonstrated its excellent transient response and robust load-driving capability. Vibration-suppression experiments on a high-aspect-ratio UAV wing achieved a 74% vibration attenuation rate, validating the effectiveness of the proposed high-voltage controller. Full article
(This article belongs to the Section Aerospace Actuators)
►▼ Show Figures

Figure 1

23 pages, 4693 KB  
Article
Dynamic Tribological Behavior of Surface-Textured Bushings in External Gear Pumps: A CFD Investigation
by Masoud Hatami Garousi, Paolo Casoli, Massimo Rundo and Seyed Mojtaba Hejazi
Actuators 2026, 15(3), 168; https://doi.org/10.3390/act15030168 - 16 Mar 2026
Viewed by 304
Abstract
This study investigates the dynamic behavior of the suction-side lubrication gap between bushing and gear in external gear pumps (EGPs), with emphasis on how surface texturing and bushing micromotion influence the effective stiffness and damping of the oil film. A three-dimensional CFD model [...] Read more.
This study investigates the dynamic behavior of the suction-side lubrication gap between bushing and gear in external gear pumps (EGPs), with emphasis on how surface texturing and bushing micromotion influence the effective stiffness and damping of the oil film. A three-dimensional CFD model of a lubrication gap between bushing and gear is developed to resolve the coupled sliding–squeezing hydrodynamics arising under realistic suction-side operating conditions. Steady-state simulations are used to determine the nonlinear static force–gap height relationship and extract the hydrodynamic stiffness, while transient simulations with harmonic perturbations are post-processed to evaluate the damping coefficient through acceleration-based filtering. The results show that both stiffness and damping increase sharply as the gap height decreases due to the strong confinement of the lubricant in the small-clearance region. Increasing the textured area slightly enlarges the effective gap height and reduces the hydrodynamic load capacity, leading to lower stiffness and damping values; this behavior highlights that the choice of an appropriate texturing configuration is a critical design parameter. Overall, the study provides a comprehensive dynamic characterization of textured bushing–gear lubrication films in EGP and offers quantitative data for developing lumped parameter models of EGP with textured bushings. Full article
(This article belongs to the Special Issue Innovations and Advanced Control in Fluid Power Actuation Systems)
►▼ Show Figures

Figure 1

24 pages, 4975 KB  
Article
Disturbance Observer-Based Actor–Critic Reinforcement Learning with Adaptive Reward for Energy-Efficient Control of Robotic Manipulators
by Le Thi Minh Tam, Nguyen Viet Ngu, Duc Hung Pham and V. T. Mai
Actuators 2026, 15(3), 167; https://doi.org/10.3390/act15030167 - 16 Mar 2026
Viewed by 360
Abstract
Reinforcement learning controllers for robot manipulators depend strongly on reward tuning, and fixed weights may yield poor trade-offs under uncertainty and disturbances. This paper proposes a disturbance observer-based actor–critic RL (DOB–ACRL) with adaptive multi-objective reward shaping for a torque-saturated 2-DOF manipulator, where the [...] Read more.
Reinforcement learning controllers for robot manipulators depend strongly on reward tuning, and fixed weights may yield poor trade-offs under uncertainty and disturbances. This paper proposes a disturbance observer-based actor–critic RL (DOB–ACRL) with adaptive multi-objective reward shaping for a torque-saturated 2-DOF manipulator, where the reward weights are updated online using normalized indicators of tracking error, control energy, and effort. A Lyapunov analysis guarantees the uniform ultimate boundedness of closed-loop signals. The simulations show improved learning and performance over a static reward actor–critic baseline, reducing the RMS tracking error by up to 22.8%, the control energy by ~4.6%, the control effort by 1.9%, and the settling time by up to 29.2%. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

22 pages, 526 KB  
Review
Learning Nonlinear Motor Control: How Integrating Machine Learning and Nonlinear Dynamics Reveals Structure, Adaptation, and Control in Human Movement
by Armin Hakkak Moghadam Torbati, Yavar Shiravand and Armin Mazinani
Actuators 2026, 15(3), 166; https://doi.org/10.3390/act15030166 - 16 Mar 2026
Viewed by 434
Abstract
Human movement emerges from complex interactions between neural processes, musculoskeletal dynamics, and environmental constraints, resulting in behavior that is inherently nonlinear. Therefore, nonlinear dynamical systems approaches have been widely used to characterize variability, stability, and coordination in motor behavior. However, despite their conceptual [...] Read more.
Human movement emerges from complex interactions between neural processes, musculoskeletal dynamics, and environmental constraints, resulting in behavior that is inherently nonlinear. Therefore, nonlinear dynamical systems approaches have been widely used to characterize variability, stability, and coordination in motor behavior. However, despite their conceptual value, these methods are often applied post hoc and remain limited in their ability to support prediction, control, and integration of high-dimensional multimodal data. Artificial intelligence (AI) provides a complementary modeling framework capable of addressing these limitations. Yet many current AI applications treat motor signals primarily as feature sets for classification or regression, leaving the underlying dynamical structure of movement underexplored. This review synthesizes recent research that integrates AI with nonlinear motor control analysis to model, interpret, and control human movement across neural, biomechanical, and behavioral domains. We organize related studies according to the type of nonlinear motor control problem addressed, including input–output mappings, temporal dynamics, and adaptive control policies under conditions of partial observability and nonstationarity. Across these examples, we show that AI becomes scientifically informative when constrained and evaluated by nonlinear dynamical constructs such as attractors, phase relationships, manifolds, and stability structures. Finally, we discuss current limitations and outline future directions toward theory-informed, explainable, and closed-loop AI models for motor control and human–actuator interaction. Full article
(This article belongs to the Special Issue Analysis and Design of Linear/Nonlinear Control System—2nd Edition)
►▼ Show Figures

Figure 1

27 pages, 8343 KB  
Article
Modeling Human–Robot Impact Dynamics in Collaborative Applications
by Alessio Caneschi, Matteo Bottin and Giulio Rosati
Actuators 2026, 15(3), 165; https://doi.org/10.3390/act15030165 - 12 Mar 2026
Viewed by 376
Abstract
This study presents an integrated experimental and modeling framework to investigate human–robot collision dynamics involving a collaborative manipulator (KUKA LBR iiwa 14 R820). A dedicated impact test prototype was developed to reproduce controlled contact scenarios between the robot and human body analogues under [...] Read more.
This study presents an integrated experimental and modeling framework to investigate human–robot collision dynamics involving a collaborative manipulator (KUKA LBR iiwa 14 R820). A dedicated impact test prototype was developed to reproduce controlled contact scenarios between the robot and human body analogues under various dynamic conditions. The experimental setup enables the acquisition of synchronized force, velocities, and displacement signals during contact events. These data are used to calibrate and validate a set of contact models, ranging from classical formulations such as Hertz and Hunt–Crossley to more recent supervised machine learning models. The proposed methodology allows a quantitative assessment of model accuracy and physical consistency in replicating real collision phenomena. Furthermore, the effective mass of the robot along its kinematic chain is estimated to compute impact energy and predict the interaction severity according to ISO 10218-1/2:2025 safety limits. The results highlight the trade-off between model complexity and predictive capability, offering alternative guidelines for collision severity evaluation in collaborative robotics applications. Full article
(This article belongs to the Special Issue Human-Centered Actuation: Algorithms, Design, and Robotic Applications)
►▼ Show Figures

Figure 1

13 pages, 690 KB  
Article
Discriminating Vibrotactile Signals: The Relative Roles of Amplitude and Frequency
by Ivan Makarov, Árni Kristjánsson and Runar Unnthorsson
Actuators 2026, 15(3), 164; https://doi.org/10.3390/act15030164 - 12 Mar 2026
Viewed by 349
Abstract
Vibrotactile interfaces commonly encode information using changes in stimulus amplitude and frequency, yet it remains unclear how reliably these parameters can be distinguished when spatial cues are unavailable. The present study examined discrimination of vibrotactile signals that differed in amplitude, frequency, or both, [...] Read more.
Vibrotactile interfaces commonly encode information using changes in stimulus amplitude and frequency, yet it remains unclear how reliably these parameters can be distinguished when spatial cues are unavailable. The present study examined discrimination of vibrotactile signals that differed in amplitude, frequency, or both, with sequential stimulation delivered to a single location on the wrist. Vibrotactile stimuli were presented through a wearable actuator, and participants judged whether pairs of signals were the same or different. Discrimination performance was high when stimuli differed in amplitude, whereas signals differing only in frequency were difficult to distinguish and often produced performance near chance. Importantly, adding frequency differences to amplitude differences did not improve discrimination beyond amplitude differences alone. These findings indicate that, under non-spatial and sequential presentation conditions, amplitude provides a robust cue for vibrotactile signal discrimination, whereas frequency modulations on their own offer limited benefits for perceptual discrimination. The results highlight basic constraints on vibrotactile perception that are relevant for the design of wearable tactile interfaces and sensory substitution devices. Full article
(This article belongs to the Special Issue Actuators for System Identification, Vibration Analysis, and Control—2nd Edition)
►▼ Show Figures

Figure 1

23 pages, 628 KB  
Article
Adaptive Formation Control for Multi-UAV Swarms in Cluttered Environments with Communication Delays Under Directed Switching Topologies
by Yingzheng Zhang and Zhenghong Jin
Actuators 2026, 15(3), 163; https://doi.org/10.3390/act15030163 - 12 Mar 2026
Viewed by 308
Abstract
This paper addresses distributed formation control for multiple unmanned aerial vehicles (UAVs) operating in obstacle-dense environments under directed switching communication topologies. A leader–follower architecture is adopted, wherein the leader performs online trajectory replanning while followers rely on delayed and intermittently available neighbor information. [...] Read more.
This paper addresses distributed formation control for multiple unmanned aerial vehicles (UAVs) operating in obstacle-dense environments under directed switching communication topologies. A leader–follower architecture is adopted, wherein the leader performs online trajectory replanning while followers rely on delayed and intermittently available neighbor information. To simultaneously tackle collision avoidance, formation feasibility under narrow passages, and communication intermittency, we propose an integrated deformable formation navigation framework. The framework couples Safe Flight Corridor (SFC)-constrained Bézier trajectory planning with a dynamic formation scaling mechanism, allowing the swarm to adaptively shrink or expand its geometric configuration when traversing constricted spaces, thereby ensuring all agents remain within certified collision-free corridors. A nonlinear distributed consensus-based estimator is designed to propagate leader reference states under directed switching graphs with bounded delays. Using a max-min contraction analytical approach, we establish guaranteed practical convergence for both leader tracking and inter-follower agreement without requiring persistent connectivity. Extensive simulations in complex cluttered environments demonstrate that the proposed approach enables flexible and real-time formation reshaping, enhancing navigational safety and robustness while maintaining cohesive swarm behavior under challenging communication and spatial constraints. Full article
(This article belongs to the Section Aerospace Actuators)
►▼ Show Figures

Figure 1

47 pages, 13253 KB  
Review
Shape Memory Alloy Actuators in Robotics
by Jaroslav Romančík, Ľubica Miková, Patrik Šarga, Tatiana Kelemenová and Michal Kelemen
Actuators 2026, 15(3), 162; https://doi.org/10.3390/act15030162 - 11 Mar 2026
Cited by 1 | Viewed by 792
Abstract
Shape memory alloys (SMAs) are materials that, when used as actuators, can generate deformation and force that can be used to perform mechanical work. This actuation capability is driven by temperature variation, which induces a reversible phase transformation between martensite (at low temperature) [...] Read more.
Shape memory alloys (SMAs) are materials that, when used as actuators, can generate deformation and force that can be used to perform mechanical work. This actuation capability is driven by temperature variation, which induces a reversible phase transformation between martensite (at low temperature) and austenite (at high temperature). Owing to their advantages, SMAs are widely applied as actuators and, in certain applications, can be more suitable than other actuation technologies. A thorough understanding of SMA actuator characteristics is therefore essential for their effective implementation in practical applications. This article provides an overview of the most important properties of SMA actuators. In addition, it reviews the application potential of SMA actuators in robotics. Based on the survey of the literature, perspectives for further research and development in this field are also presented. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

25 pages, 4285 KB  
Article
A Simulation Study on Wear Monitoring and Prognosis in Electro-Mechanical Brakes for a Small Passenger Aircraft
by Riccardo Achille, Andrea De Martin, Antonio Carlo Bertolino, Giovanni Jacazio and Massimo Sorli
Actuators 2026, 15(3), 161; https://doi.org/10.3390/act15030161 - 11 Mar 2026
Viewed by 305
Abstract
The evolution towards “more-electric” aircraft has accelerated in the last decade, motivated by environmental concerns and the development of new market frontiers such as urban air mobility. This transition is affecting both propulsion and aircraft systems, with electro-mechanical brakes (E-Brakes) representing a promising [...] Read more.
The evolution towards “more-electric” aircraft has accelerated in the last decade, motivated by environmental concerns and the development of new market frontiers such as urban air mobility. This transition is affecting both propulsion and aircraft systems, with electro-mechanical brakes (E-Brakes) representing a promising alternative to traditional hydraulic solutions. While E-Brakes offer advantages such as reduced system complexity and elimination of hydraulic leakage issues, they remain a relatively unproven technology in civil aviation. In this context, the development of Prognostics and Health Management (PHM) solutions aligns with the need for continuous monitoring of novel components while also providing the benefits typically associated with prognostic techniques. This paper presents the preliminary stages of the development of a PHM framework for an E-Brake intended for future executive-class aircraft. Since experimental activities are not yet available, the analysis was carried out on simulated data generated through a high-fidelity model of the system. The study focuses on brake pad wear as the primary degradation mechanism and proposes a particle-filtering approach to estimate the health state and predict the Remaining Useful Life (RUL). Early results obtained from simulated fault-to-failure trajectories prove the ability of the algorithm to track degradation and to provide reliable prognostic forecasts, paving the way for future validation with real-world data. Full article
(This article belongs to the Section Aerospace Actuators)
►▼ Show Figures

Figure 1

19 pages, 8208 KB  
Article
Research on Dual-Motor Cross-Coupled Synchronous Control of Flexographic Printing Pressure Integrating Hertz Theory and Fuzzy PI
by Shuqin Wu, Jiashu Huang, Shuyuan Wei, Jialin Li, Jiajie Kang, Qiang Da, Yu Yao, Xinru Dong, Shubo Shi and Chengwen Chai
Actuators 2026, 15(3), 160; https://doi.org/10.3390/act15030160 - 10 Mar 2026
Viewed by 294
Abstract
This study addresses key challenges in high-precision industrial motion control, including dynamic load disturbances, nonlinear parameter coupling, and degradation in synchronization accuracy. A dual-motor cross-coupled synchronous control strategy is proposed, integrating Hertzian contact theory with an adaptive fuzzy PI control algorithm. First, a [...] Read more.
This study addresses key challenges in high-precision industrial motion control, including dynamic load disturbances, nonlinear parameter coupling, and degradation in synchronization accuracy. A dual-motor cross-coupled synchronous control strategy is proposed, integrating Hertzian contact theory with an adaptive fuzzy PI control algorithm. First, a precise pressure measurement model for the printing contact zone is established based on Hertzian contact theory. The model quantitatively characterizes the relationship between structural parameters and pressure distribution. Key parameters include cylinder radius and plate thickness. This provides a theoretical foundation for precise regulation. Subsequently, a fuzzy PI controller with parameter self-tuning capability is incorporated into the motor speed loop, enabling real-time adjustment of control parameters to effectively compensate for system nonlinearities and time-varying disturbances. Furthermore, a cross-coupled synchronization architecture is designed to enable bidirectional compensation between the two motors, significantly improving synchronization accuracy under complex operating conditions. Simulations were performed in MATLAB/Simulink. The tests covered typical operational scenarios, including load start-up, single-motor disturbance, and multi-disturbance conditions. The results demonstrate that the proposed system achieves high performance: dual-motor speed synchronization accuracy reaches 99.5%; the response time for disturbance compensation is within 0.3 s; and printing-pressure fluctuation is confined to ±0.8%. This performance represents a 62.5% improvement in stability over conventional single-motor control systems. This research not only resolves the long-standing issue of pressure non-uniformity in flexographic printing but also provides a generalizable framework for multi-motor synchronous control in precision manufacturing. The findings offer substantial academic insight and practical value for advancing intelligent industrial measurement and control technologies. Full article
(This article belongs to the Section Actuators for Manufacturing Systems)
►▼ Show Figures

Figure 1

18 pages, 11342 KB  
Article
A Novel Multi-Dimensional Synergistic Optimization Control Strategy for Enhanced Performance of Mining Dump Truck Hydro-Pneumatic Suspensions
by Mingsen Zhao, Lin Yang and Hao Cui
Actuators 2026, 15(3), 159; https://doi.org/10.3390/act15030159 - 10 Mar 2026
Viewed by 305
Abstract
Aiming at the challenge of simultaneously controlling ride comfort and wheel grounding performance for mining dump trucks, this paper proposes a multi-dimensional synergistic optimization control (MDSOC) strategy based on model predictive control (MPC) for active hydro-pneumatic suspension. First, an accurate hydro-pneumatic suspension and [...] Read more.
Aiming at the challenge of simultaneously controlling ride comfort and wheel grounding performance for mining dump trucks, this paper proposes a multi-dimensional synergistic optimization control (MDSOC) strategy based on model predictive control (MPC) for active hydro-pneumatic suspension. First, an accurate hydro-pneumatic suspension and hinged mining truck full-vehicle-dynamics model is established, and the model accuracy is validated through actual vehicle testing. Subsequently, an MDSOC-MPC for active hydro-pneumatic suspension is constructed to minimize the mean square root of the three-axis acceleration of the body, pitch angle, roll angle, and wheel dynamic tire load. Comparative analysis is performed with traditional single-MPC longitudinal, lateral, and vertical control, and the simulation results showed: under emergency braking conditions, the root mean square (RMS) value of the pitch angle is reduced by 18.2%; under single and double-shift conditions, the RMS values of the roll angle are reduced by 40.4% and 30%, respectively; under D-class random road, the RMS values of the longitudinal, lateral, and vertical body acceleration are significantly reduced by 22%, 21.5%, and 21.2%, respectively, while the RMS values of pitch angle and roll angle are reduced by 22.5%, and 20.2%, respectively, systematically improving riding comfort, vehicle wheel contact, and driving safety. This study provides a theoretical basis and feasible engineering methods for the active control of hydro-pneumatic suspension systems in heavy engineering vehicles. Full article
(This article belongs to the Section Actuators for Surface Vehicles)
►▼ Show Figures

Figure 1

14 pages, 2451 KB  
Article
Design of an Elbow Magnetorheological Rehabilitation Orthosis for Patients with Spasticity
by Henri Pagé, Carolane Guay-Tanguay, François Michaud, Dominic Létourneau, David Orlikowski, Gilbert Pradel, Sébastien Charles and Jean-Sébastien Plante
Actuators 2026, 15(3), 158; https://doi.org/10.3390/act15030158 - 10 Mar 2026
Viewed by 374
Abstract
Stroke survivors with spasticity, an involuntary increase in muscle tone, often struggle to access specialized equipment and medical support for their rehabilitation. Rehabilitation exercises are daily routines requiring patients to perform repetitive movements of their spastic joints. To reduce patient mobilization within hospitals, [...] Read more.
Stroke survivors with spasticity, an involuntary increase in muscle tone, often struggle to access specialized equipment and medical support for their rehabilitation. Rehabilitation exercises are daily routines requiring patients to perform repetitive movements of their spastic joints. To reduce patient mobilization within hospitals, offering orthoses suitable for use in home settings, outside of clinical environments, is required to limit the involvement of healthcare personnel in the treatment of hemiparesis for patients. Such orthoses must be designed to be portable and be able to tolerate the erratic motions of spasms without breaking or injuring patients. This paper presents the use of magnetorheological actuators to design an elbow orthosis, improving weight, reactivity, and transparence necessary for effective rehabilitation of spastic patients. A prototype is designed, built, and characterized experimentally. Results suggest that the technology is lightweight and highly transparent to erratic motion, and thus well-suited for spastic patients. Full article
(This article belongs to the Special Issue Advances in Electrorheological and Magnetorheological Materials: Material Design, Control and Industrial Applications)
►▼ Show Figures

Figure 1

27 pages, 3634 KB  
Article
4-DOF Full-Speed Range Vibration Suppression of an Active–Passive Supported Flywheel Rotor Based on Inverse System Decoupling
by Mingming Hu, Yuan Zeng, Da Li, Hao Luo, Jingbo Wei and Kun Liu
Actuators 2026, 15(3), 157; https://doi.org/10.3390/act15030157 - 8 Mar 2026
Viewed by 240
Abstract
Flywheel energy storage systems exhibit superior performance in electric vehicle regenerative braking, railway traction power supply, and grid frequency regulation due to their high instantaneous power and fast dynamic response. However, systems supported by conventional mechanical bearings face severe radial structural coupling; unbalanced [...] Read more.
Flywheel energy storage systems exhibit superior performance in electric vehicle regenerative braking, railway traction power supply, and grid frequency regulation due to their high instantaneous power and fast dynamic response. However, systems supported by conventional mechanical bearings face severe radial structural coupling; unbalanced excitation and gyroscopic effects drastically amplify vibrations during critical speed traversal, undermining operational reliability and engineering scalability. To tackle this challenge, this paper proposes a full-speed vibration suppression scheme for active–passive supported flywheel energy storage systems integrated with a damping ring, combined with an inverse system decoupling controller to eliminate structural coupling, unbalance-induced vibration, and gyroscopic effects. A dynamic model of the integrated system is established using Lagrange’s equations, and four-degree of freedom decoupling expressions are derived to achieve complete radial decoupling. A speed-stage-based control strategy is further developed for full-speed adaptation. Comprehensive simulations validate the scheme’s decoupling performance, vibration suppression efficacy, and robustness. Results demonstrate that the proposed controller achieves full radial decoupling, reducing the average steady-state tracking error by 99.86%. The segmented control enables stable operation across 100–20,000 rpm and cuts critical speed resonance peaks by 81.23%. Compared with pure mechanical and magnetic bearing systems, the integrated active–passive support reduces resonance peaks by 94.72% and 42.25%, respectively. Under current perturbation and parameter variation, the scheme reduces the average steady-state error by 75.89% relative to the coupled system, confirming its strong engineering applicability. Full article
(This article belongs to the Special Issue Vibration Control Based on Intelligent Actuators and Sensors)
►▼ Show Figures

Figure 1

17 pages, 3749 KB  
Article
Research on a Two-Degree-of-Freedom Pneumatic Vibroactuator
by Laura Gegeckienė, Darius Pauliukaitis, Ingrida Venytė and Kęstutis Vaitasius
Actuators 2026, 15(3), 156; https://doi.org/10.3390/act15030156 - 7 Mar 2026
Viewed by 315
Abstract
A two-degree-of-freedom, self-exciting pneumatic vibroactuator was investigated. The feature of this vibroactuator is that, along with the sliding-reciprocating movement of the working body along the axis, it also rotates about this axis. A new mathematical model of this vibroactuator is presented and solved [...] Read more.
A two-degree-of-freedom, self-exciting pneumatic vibroactuator was investigated. The feature of this vibroactuator is that, along with the sliding-reciprocating movement of the working body along the axis, it also rotates about this axis. A new mathematical model of this vibroactuator is presented and solved using numerical methods. Comparisons of the results of numerical and experimental studies are described. The analyzed vibroactuator, supplemented with extended functional capabilities, is established for use in intensifying technological production processes. Full article
(This article belongs to the Section Actuators for Manufacturing Systems)
►▼ Show Figures

Figure 1

32 pages, 10783 KB  
Article
A Collaborative Robot-Based Approach for Automated 3D Shape Inspection of Complex Parts
by Keqing Lu, Kaifu Wang, Junhua Lu, Chuanyong Wang, Zhanfeng Chen and Wen Wang
Actuators 2026, 15(3), 155; https://doi.org/10.3390/act15030155 - 7 Mar 2026
Viewed by 402
Abstract
As manufacturing progresses, the demand for precision inspection of complex parts has intensified. To guarantee functionality and sensory performance, high-efficiency 3D shape measurement is required. In this paper, a collaborative robot-based approach for efficient and high-precision 3D shape inspection of complex parts is [...] Read more.
As manufacturing progresses, the demand for precision inspection of complex parts has intensified. To guarantee functionality and sensory performance, high-efficiency 3D shape measurement is required. In this paper, a collaborative robot-based approach for efficient and high-precision 3D shape inspection of complex parts is proposed. The system employs a collaborative robot to drive the scanner along optimized trajectories. First, the configuration of the inspection system is presented, and the ideal measurement mode for the sensor is analyzed. Subsequently, adaptive viewpoints are generated through parametric discretization based on surface geometric features. For inter-region scanning path planning, the problem is modeled as the Shortest Path Problem (SPP) within the framework of the Traveling Salesman Problem (TSP) and solved by constructing a Successive Approximation Algorithm (SAA). Furthermore, a Modified Denavit-Hartenberg (MDH) method is applied to establish the precise kinematic model of the collaborative robot. Inverse kinematics solutions are derived to convert planned viewpoints into target joint configurations, thereby achieving precise end-effector pose control. Simulation and experimental results on an engine cover and a cylinder head demonstrate that the proposed approach enables comprehensive 3D shape inspection of complex parts in a single setup and achieves higher efficiency and accuracy compared to existing methods. This work offers a viable solution for integrating robotic actuation and active sensing in the automated inspection of complex geometries. Full article
(This article belongs to the Special Issue Actuation and Sensing of Intelligent Soft Robots—2nd Edition)
►▼ Show Figures

Figure 1

22 pages, 1977 KB  
Article
Design Characteristics of Continuum Robots Based on TSA Variable Stiffness Method
by Gang Chen, Yutong Wu, Zhixin Zhang, Jianxiao Zheng, Shiying Liu, Jiwei Yuan, Mingrui Luo and En Li
Actuators 2026, 15(3), 154; https://doi.org/10.3390/act15030154 - 4 Mar 2026
Viewed by 437
Abstract
To address the contradiction between high flexibility and low stiffness in continuum robots, as well as the problems of complex structure, slow response, and narrow stiffness adjustment range in existing variable stiffness methods, this paper proposes a variable stiffness approach based on Twisted [...] Read more.
To address the contradiction between high flexibility and low stiffness in continuum robots, as well as the problems of complex structure, slow response, and narrow stiffness adjustment range in existing variable stiffness methods, this paper proposes a variable stiffness approach based on Twisted Multi-String Actuators (hereinafter referred to as TSA) for bionic spine-like continuum robots. Firstly, a bionic spine-like configuration was designed to support the force-locking variable stiffness mechanism. Secondly, the proposed TSA-based variable stiffness method was analyzed theoretically from the perspectives of geometric relationships and stiffness characteristics, laying a foundation for establishing other mathematical models such as that of string-twisting behavior. Finally, an experimental prototype was fabricated and subjected to flexibility tests. Furthermore, TSA variable stiffness experiments were conducted under two-strand, three-strand, and four-strand configurations to investigate the retraction and stiffness performance under different torsion turns and external loads. The results demonstrate that the stiffness of the robot is effectively enhanced by the TSA method, and increasing the number of string strands raises the failure load of the robot. Characteristic curves confirm that the proposed design and model exhibit superior performance to the traditional single-cable force-locking scheme. The design features a simple structure, fast response, and wide stiffness adjustment range, which provides a valuable reference for the stiffness modulation research of continuum robots. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

16 pages, 5007 KB  
Article
Dynamic Response Control of Dual Active Bridge Converters Incorporating Current Stress Optimization
by Hao Yang, Kunhui Xu, Song Qiu and Qingxiang Liu
Actuators 2026, 15(3), 153; https://doi.org/10.3390/act15030153 - 4 Mar 2026
Viewed by 423
Abstract
In microgrid systems, due to the strong intermittency and randomness exhibited by solar energy and wind energy, significant challenges are posed to the stable power supply and normal operation of actuators. Thus, bidirectional DC-DC converters are required to possess excellent steady-state characteristics and [...] Read more.
In microgrid systems, due to the strong intermittency and randomness exhibited by solar energy and wind energy, significant challenges are posed to the stable power supply and normal operation of actuators. Thus, bidirectional DC-DC converters are required to possess excellent steady-state characteristics and dynamic response performance. This paper presents an active disturbance rejection control (ADRC) method for dual active bridge (DAB) converters incorporating current stress optimization, centering on the analysis and investigation of the integrated technique of current stress optimization and ADRC for DAB converters under triple-phase-shift (TPS) control. Based on TPS modulation, the optimal current stress strategies corresponding to different operating modes are deduced. Meanwhile, an ADRC closed-loop is established, where the extended state observer (ESO) performs real-time estimation of system states and compensates for system disturbances. Furthermore, a unified control model is constructed, facilitating flexible trade-off between control complexity and performance. Finally, a simulation scheme is designed to compare the performance of different control schemes, and the simulation results verify the feasibility and superiority of the proposed strategy. Full article
(This article belongs to the Special Issue Design, Hydrodynamics, and Control of Valve Systems)
►▼ Show Figures

Figure 1

17 pages, 6553 KB  
Article
Multi-Degree-of-Freedom Backstepping Control for Magnetic Levitation Actuators in Laser Cutting Applications
by Qinwei Zhang, Chuan Zhao, Ling Tong, Feng Liu, Fangchao Xu, Honglei Sha and Feng Sun
Actuators 2026, 15(3), 152; https://doi.org/10.3390/act15030152 - 4 Mar 2026
Viewed by 260
Abstract
During laser processing, optimizing the cutting performance by adjusting the angle or off-axis displacement between the auxiliary gas flow and the laser beam is an effective approach to improving processing quality and efficiency. However, traditional electromechanical actuators suffer from inherent limitations in compactness [...] Read more.
During laser processing, optimizing the cutting performance by adjusting the angle or off-axis displacement between the auxiliary gas flow and the laser beam is an effective approach to improving processing quality and efficiency. However, traditional electromechanical actuators suffer from inherent limitations in compactness and multi-degree-of-freedom cooperative control, which restrict their applicability in high-speed and high-precision laser cutting systems. To address these limitations, this paper presents a five-degree-of-freedom magnetic levitation actuator for laser cutting lens control and proposes a multi-degree-of-freedom cooperative control strategy based on backstepping control (BC) to cope with the system’s strong coupling, nonlinearity, and model uncertainty. First, a dynamic model of the actuator system is established, and a corresponding BC is designed. Subsequently, a centralized control framework is developed, and comparative simulations and experiments are carried out between the proposed BC and a conventional PID controller. The experimental results demonstrate that the proposed BC method outperforms the PID controller in terms of multi-degree-of-freedom cooperative control capability and dynamic response, thereby significantly enhancing the overall control performance of the system. Full article
(This article belongs to the Special Issue Magnetic Levitation and Actuator Integration: From Fundamental Research to Emerging Applications)
►▼ Show Figures

Figure 1

27 pages, 2269 KB  
Article
Long-Stroke Reluctance Magnetic Levitation Systems: Characteristic Analysis and Gain Scheduling Positioning Control
by Wenzhe Pei, Chuan Zhao, Koichi Oka, Feng Sun, Junjie Jin and Xiaoyou Zhang
Actuators 2026, 15(3), 151; https://doi.org/10.3390/act15030151 - 4 Mar 2026
Viewed by 301
Abstract
With inherent negative stiffness and nonlinearity, reluctance magnetic levitation systems struggle to sustain satisfactory control performance across a long stroke. To address this issue, theoretical analysis, control strategy design, and experiments are performed. First, the magnetic and dynamic behavior are analyzed, and the [...] Read more.
With inherent negative stiffness and nonlinearity, reluctance magnetic levitation systems struggle to sustain satisfactory control performance across a long stroke. To address this issue, theoretical analysis, control strategy design, and experiments are performed. First, the magnetic and dynamic behavior are analyzed, and the corresponding mathematical model is derived. Then, the control system analysis is conducted, and the feedback properties are described from a physically intuitive perspective. Moreover, with a standard PD/PID compensator, a clear trade-off emerges between robustness at small air gaps and tracking performance at large air gaps. Subsequently, a control strategy combining feedforward compensation with gain scheduling PD is designed. It is directly mapped from the reluctance actuator parameters without relying on engineering experience and can be flexibly configured to meet performance requirements. Finally, time-domain and frequency-domain experiments are conducted. The positioning control results show that the proposed strategy effectively shortens the settling time of long-stroke step responses and improves the uniformity of the dynamic performance. The frequency response evidence shows a more uniform response over the full stroke and simultaneous improvements in robustness and tracking, effectively resolving the long-stroke conflict. Full article
(This article belongs to the Special Issue Magnetic Bearings and Actuators: From Theory to Industrial Innovations)
►▼ Show Figures

Figure 1

14 pages, 1352 KB  
Article
Finite-Time Prescribed Performance Neural Network Force Control of Electro-Hydraulic Proportional Load Simulator with Output Feedback
by Zhenle Dong, Chao Li, Pengxiang Zhang, Yilong Jia, Jianyong Yao and Long Liu
Actuators 2026, 15(3), 150; https://doi.org/10.3390/act15030150 - 4 Mar 2026
Viewed by 271
Abstract
This paper focus on the high accuracy force control of electro-hydraulic proportional load simulator (EHPLS). Firstly, to weaken the influence of the unknown dead zone of the proportional valve, a mathematic model with a smooth inverse dead zone was constructed. Then, finite-time prescribed [...] Read more.
This paper focus on the high accuracy force control of electro-hydraulic proportional load simulator (EHPLS). Firstly, to weaken the influence of the unknown dead zone of the proportional valve, a mathematic model with a smooth inverse dead zone was constructed. Then, finite-time prescribed performance function, of which the desired steady-state value can be achieved within finite time, is defined to impose constraints on the tracking error, while the neural network feedback is introduced to compensate for the unknown dynamic, which can ensure the tracking accuracy further improved for the entire tracking process in the presence of unknown dead-zone parameters, unknown system parameters and disturbance. Finally, through design modification, the proposed control technologies are realized based on the output feedback signal. Comparative simulations under two desired force trajectories are carried out to verify the effectiveness of the proposed controller. Full article
(This article belongs to the Special Issue High-Performance Control of Electromechanical Servo System Based on Motor/Hydraulic Actuator)
►▼ Show Figures

Figure 1

22 pages, 2865 KB  
Article
Theoretical Analysis of IGAO-Fuzzy PID Fault-Tolerant Control and Performance Optimization for Electro-Hydraulic Active Suspensions Under Internal Leakage Faults
by Haiwu Zheng, Hao Xiong, Dingxuan Zhao, Yufei Zhao, Yinying Ren, Yao Xiao and Yi Han
Actuators 2026, 15(3), 149; https://doi.org/10.3390/act15030149 - 4 Mar 2026
Viewed by 287
Abstract
To address performance degradation and control instability in electro-hydraulic servo active suspension systems due to internal leakage faults arising from wear and aging of hydraulic components, this paper proposes an innovative fuzzy PID fault-tolerant controller based on the Improved Giant Armadillo Optimization (IGAO) [...] Read more.
To address performance degradation and control instability in electro-hydraulic servo active suspension systems due to internal leakage faults arising from wear and aging of hydraulic components, this paper proposes an innovative fuzzy PID fault-tolerant controller based on the Improved Giant Armadillo Optimization (IGAO) algorithm. Specifically, to overcome the limitations of the standard Giant Armadillo Optimization (GAO), which is prone to local optima and exhibits poor convergence performance when handling multi-constraint parameter optimization problems, this study introduces a nonlinear dynamic inertia weight mechanism and a random reflection strategy for out-of-bounds particles to improve the original algorithm’s performance. These enhancements significantly enhance its ability to balance global exploration and local exploitation. Furthermore, this research develops a comprehensive performance evaluation fitness function by quantifying key performance indicators such as body acceleration, suspension dynamic deflection, and tire dynamic load. A quarter-car model incorporating an internal leakage fault was established as a simulation validation platform to demonstrate the reliability of the proposed method. Simulation results indicate that under various road excitation conditions, the proposed IGAO algorithm can rapidly and stably converge to superior parameters for the fuzzy PID controller. Compared to the Particle Swarm Optimization (PSO) and standard GAO algorithm, the control system optimized by IGAO not only significantly more effectively suppresses body vibration and reduces shock amplitude but also exhibits stronger dynamic recovery performance and control robustness under varying degrees of internal leakage faults. This research provides a robust control approach for addressing internal parameter uncertainties in hydraulic systems and offers a new approach to theoretical modeling for enhancing the reliability of design and fault-tolerant control capabilities of active suspension systems. Full article
(This article belongs to the Special Issue Advanced Actuation and Control Technologies for Vehicle Driving Systems—2nd Edition)
►▼ Show Figures

Figure 1

21 pages, 5645 KB  
Article
Active Composite Plates with Embedded Shape-Memory Alloy Wires for Vibration Damping
by Aron Padilla, Peter L. Bishay and Maya Pishvar
Actuators 2026, 15(3), 148; https://doi.org/10.3390/act15030148 - 3 Mar 2026
Cited by 1 | Viewed by 347
Abstract
The integration of shape-memory alloy (SMA) wires into composite laminates offers a promising approach for active vibration damping. Towards this goal, this study investigates the damping behavior of hybrid random mat E-glass/epoxy composite plates with embedded SMA wires under electrically active and inactive [...] Read more.
The integration of shape-memory alloy (SMA) wires into composite laminates offers a promising approach for active vibration damping. Towards this goal, this study investigates the damping behavior of hybrid random mat E-glass/epoxy composite plates with embedded SMA wires under electrically active and inactive conditions. The composites are tested using a Laser Doppler Vibrometer (LDV) and an impact hammer to assess the effect of SMA wire activation on the natural frequencies and vibration behavior of composites. For a fixed number of active SMA wires, differences in vibration behavior are evaluated between outer- and inner-wire activation configurations in both two-ply and four-ply composite plates. The results show that SMA wire activation significantly affects damping behavior, while the mode shapes remain unchanged. The magnitude and frequency of the first natural frequency as well as the quality factor (Q-factor) decrease in composites with activated SMA wires compared to the inactive configuration, indicating enhanced energy dissipation. Under the fully active condition, a reduction in vibrational amplitude of approximately 42–60% and a frequency shift of approximately 10–17% are observed. Compared to outer-wire activation, inner-wire activation results in greater reductions in vibration magnitude, reaching approximately 7–13%. Full article
(This article belongs to the Special Issue Shape Memory Alloy (SMA) Actuators and Their Applications—2nd Edition)
►▼ Show Figures

Figure 1

18 pages, 4743 KB  
Article
Reinforcement Learning-Based Super-Twisting Sliding Mode Control for Maglev Guidance System
by Junqi Xu, Wenshuo Wang, Chen Chen, Lijun Rong, Wen Ji and Zijian Guo
Actuators 2026, 15(3), 147; https://doi.org/10.3390/act15030147 - 3 Mar 2026
Viewed by 343
Abstract
The high-speed Electromagnetic Suspension (EMS) maglev guidance system exhibits inherent characteristics of strong nonlinearity, parameter time-variation, and complex external disturbances. To further optimize and improve the control performance of the guidance system for high-speed maglev trains, a novel intelligent control strategy that integrates [...] Read more.
The high-speed Electromagnetic Suspension (EMS) maglev guidance system exhibits inherent characteristics of strong nonlinearity, parameter time-variation, and complex external disturbances. To further optimize and improve the control performance of the guidance system for high-speed maglev trains, a novel intelligent control strategy that integrates the Deep Deterministic Policy Gradient (DDPG) algorithm with Super-Twisting Sliding Mode Control (STSMC) is proposed. Focusing on a single-ended guidance unit with differential control of dual electromagnets, an STSMC controller is first designed based on a cascaded control framework. To overcome the limitation of offline parameter tuning in dynamic operational conditions, a reinforcement learning optimization framework employing DDPG is introduced. A multi-objective hybrid reward function is formulated, incorporating error convergence, sliding mode stability, and chattering suppression, thereby realizing the online self-tuning of core STSMC parameters via real-time interaction between the agent and the environment. Numerical simulations under typical disturbance conditions verify that the proposed DDPG-STSMC controller significantly reduces the amplitude of guidance gap variation and accelerates dynamic recovery compared to conventional PID control. Its superior performance in disturbance rejection, control accuracy, and operational adaptability is validated. This study, conducted through high-fidelity numerical simulations based on actual system parameters, provides a robust theoretical foundation for subsequent hardware-in-the-loop (HIL) experimentation. Full article
(This article belongs to the Special Issue Advanced Theory and Application of Magnetic Actuators—3rd Edition)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-46
Previous Issue
Next Issue
Back to TopTop