Next Issue
Volume 15, July
Previous Issue
Volume 15, May
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.3
2.4
Journals
Actuators
Volume 15
Issue 6
share announcement

Actuators, Volume 15, Issue 6 (June 2026) – 76 articles

Cover Story (view full-size image):  
  • 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, 4344 KB  
Article
Data-Based Youla Parameterization for Robust Disturbance Observer Design of VCM Motion Stage
by Beibei Hou, Lingchen Meng, Weipeng Zhang, Pengbo Liu and Peng Yan
Actuators 2026, 15(6), 355; https://doi.org/10.3390/act15060355 - 22 Jun 2026
Viewed by 199
Abstract
Robust disturbance rejection in voice coil motor (VCM) motion stages is often limited by model uncertainties and the difficulty of obtaining accurate plant inverses. To address this issue, this paper develops a data-based Youla parameterization method for designing a robust disturbance observer (DOB) [...] Read more.
Robust disturbance rejection in voice coil motor (VCM) motion stages is often limited by model uncertainties and the difficulty of obtaining accurate plant inverses. To address this issue, this paper develops a data-based Youla parameterization method for designing a robust disturbance observer (DOB) without relying on an analytical plant model. Frequency response data from the VCM stage are measured directly under multiple operating conditions. The Youla parameter Q is expanded using a Laguerre orthogonal basis, and its coefficients are optimized by solving a convex problem that enforces H∞ robust stability and H2 average tracking error constraints on a finite frequency grid. Experiments on a VCM motion stage demonstrate that the optimized Q filter effectively estimates and rejects electromagnetic noise and other disturbances. A total of 30 groups of data covering the full range of operating conditions were used for optimization, and 10 randomly designed experiments were conducted to validate the controller, with the maximum average error below 0.05%. Repetitive tests were carried out to verify the tracking performance for 1 Hz sinusoidal and triangular signals. The results show that the average RMSEs of the proposed method is 0.87% and 0.59%, respectively, which are lower than those of the ITAE-PID, ADRC and K0 controllers. Finally, the robustness of the proposed method is further verified by analyzing the sensitivity function of the closed-loop system. Full article
(This article belongs to the Special Issue Intelligent and Precision Control for Mechatronic/Electro-Hydraulic Systems—Second Edition)
►▼ Show Figures

Figure 1

23 pages, 5098 KB  
Article
On-Load Configurable Dual Active Bridge Converter for Wide Voltage Range and Multi-Port DC-DC Power Conversion
by Chandra Babu Guttikonda, P. Srinivasa Varma, M. Kiran Kumar, K. V. Govardhana Rao, Joon Ho Choi, E. Shiva Prasad and Ch. Rami Reddy
Actuators 2026, 15(6), 354; https://doi.org/10.3390/act15060354 - 22 Jun 2026
Viewed by 245
Abstract
This paper presents an on-load programmable configuration of individual dual active bridge modules on a single-core transformer for wide voltage range and multi-port DC-DC power conversion. The mathematical models of power delivery and control transfer functions are presented for the proposed configurable converter. [...] Read more.
This paper presents an on-load programmable configuration of individual dual active bridge modules on a single-core transformer for wide voltage range and multi-port DC-DC power conversion. The mathematical models of power delivery and control transfer functions are presented for the proposed configurable converter. The universal control structure to implement the programmable configuration, control parameter programming, and closed-loop current regulation is presented. Simulation of the proposed converter and control is implemented in MATLAB/SIMULINK 2026A. A reduced-scale hardware prototype is implemented to validate simulation results. The performance of the converter in terms of feasible on-load switching of configurations and simultaneous regulation of multiple loads are compared to existing topologies, which demonstrated stable operation of proposed converter and control scheme over the investigated voltage range. Full article
(This article belongs to the Special Issue Advanced Power Electronics and Intelligent Actuation for Next-Generation Energy Systems)
►▼ Show Figures

Figure 1

16 pages, 1639 KB  
Article
Multi-Link Kinematic Calibration with Photogrammetry
by Anton Vasilevich Gudym, Sergey Dmitrievich Borisov, Anna Sergeevna Kovtun and Alexander Pavlovich Sokolov
Actuators 2026, 15(6), 353; https://doi.org/10.3390/act15060353 - 20 Jun 2026
Viewed by 223
Abstract
Industrial robotic arms are fundamental components of modern automated production lines, executing critical tasks such as welding, painting, and assembly. Such high-precision operations often require careful manual tool positioning during the initial setup. To automate and refine this process, a highly accurate kinematic [...] Read more.
Industrial robotic arms are fundamental components of modern automated production lines, executing critical tasks such as welding, painting, and assembly. Such high-precision operations often require careful manual tool positioning during the initial setup. To automate and refine this process, a highly accurate kinematic model of the robot is essential. In this paper, the authors propose a novel algorithm for kinematic parameter calibration using photogrammetry to track multiple robot links simultaneously. The proposed multi-link calibration approach provides a more precise parameter estimation and introduces the practical possibility of continuous parameter refinement while the robot executes its primary operational tasks. The superior accuracy and robustness of the proposed methodology are confirmed through comprehensive simulation experiments, and the feasibility of the approach is successfully demonstrated on a real robotic arm. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

28 pages, 28462 KB  
Article
Integrated Control of EV Battery Chargers for Virtual Inertia and Vehicle-to-Grid Support Using Hybrid Energy Storage
by Chandra Babu Guttikonda, Pinni Srinivasa Varma, Malligunta Kiran Kumar, K. V. Govardhan Rao, Joon Ho Choi, E. Shiva Prasad and Ch. Rami Reddy
Actuators 2026, 15(6), 352; https://doi.org/10.3390/act15060352 - 19 Jun 2026
Viewed by 255
Abstract
The increasing penetration of renewable energy sources and converter-interfaced loads has intensified the need for fast and reliable grid-support services. Although electric vehicle (EV) battery chargers have emerged as promising resources for Vehicle-to-Grid (V2G) applications, existing solutions typically focus on individual services such [...] Read more.
The increasing penetration of renewable energy sources and converter-interfaced loads has intensified the need for fast and reliable grid-support services. Although electric vehicle (EV) battery chargers have emerged as promising resources for Vehicle-to-Grid (V2G) applications, existing solutions typically focus on individual services such as virtual inertia or frequency regulation, while limited attention has been given to the coordinated provision of multiple ancillary services within a unified framework. Furthermore, the use of batteries alone for fast frequency support may accelerate battery degradation due to frequent high-power transients. To address these challenges, this paper proposes a hybrid energy storage-based EV battery charger architecture and a coordinated multi-timescale control strategy capable of simultaneously providing virtual inertia support, long-term frequency regulation, reactive power compensation, and harmonic mitigation. The proposed approach utilizes a DC-link capacitor to deliver fast inertial response while the battery supplies sustained frequency support, thereby reducing battery stress and improving energy management efficiency. An enhanced frequency estimation method based on a phase-locked loop combined with a low-pass filter is also introduced to improve dynamic performance. Simulation results demonstrate the effectiveness of the proposed strategy under various grid disturbances. The system achieves an equivalent virtual inertia constant of approximately 1.85 s and delivers up to 786 W of transient inertial support within 80 ms during frequency events. The enhanced frequency estimation method significantly reduces transient overshoot, while harmonic compensation limits the grid current and voltage total harmonic distortion to 1.50% and 3.23%, respectively. In addition, the controller provides up to 400 VAR of reactive power support during voltage disturbances while maintaining stable battery operation. These results demonstrate that the proposed EV battery charger can function as a multifunctional grid-support resource, enhancing frequency stability, voltage regulation, power quality, and overall V2G capability in future smart grids. Full article
(This article belongs to the Special Issue Advanced Power Electronics and Intelligent Actuation for Next-Generation Energy Systems)
►▼ Show Figures

Figure 1

29 pages, 4734 KB  
Article
Research on Adaptive AGV Speed Control System Based on EKF State Estimation
by Zhengyang Liang, Changning Zhou, Penghui Chen and Yang Yang
Actuators 2026, 15(6), 351; https://doi.org/10.3390/act15060351 - 19 Jun 2026
Viewed by 279
Abstract
In order to improve the speed regulation accuracy, dynamic response and operation robustness of an automatic guided vehicle (AGV) in a complex road disturbance environment, this paper studies an adaptive AGV speed regulation system based on EKF state estimation on the basis of [...] Read more.
In order to improve the speed regulation accuracy, dynamic response and operation robustness of an automatic guided vehicle (AGV) in a complex road disturbance environment, this paper studies an adaptive AGV speed regulation system based on EKF state estimation on the basis of AGV dynamics modeling and adaptive control. Firstly, through the electrical-mechanical coupling modeling of the AGV drive system, state space construction and external unknown disturbance equivalent design, a unified electromechanical coupling simulation and physical verification environment is built, which lays a model foundation for the research of the speed control algorithm. Secondly, based on the optimal control model of PID and LQR with first-order lead compensation, an EKF adaptive speed regulation model is constructed by combining the extended Kalman filter and adaptive control to realize the online estimation and dynamic compensation of unknown disturbances. Finally, based on MATLAB/Simulink simulation platform and the STM32 embedded experimental platform, the rationality and robustness of the proposed speed control strategy are verified by speed-mutation conditions, load-disturbance condition and a physical verification experiment. The results show that the overshoot of the EKF adaptive control strategy is only 1.8%, which is 84.1% lower than that of PID control and 61.7% lower than that of LQR control. The rise time is 42% shorter than PID and 23% shorter than LQR. The recovery time under load disturbance is 58% shorter than that of PID and 31% shorter than that of LQR. EKF adaptive control is significantly better than PID and LQR in overshoot, rise time and control stability. The disturbance rejection ability and dynamic recovery speed are greatly improved, which can ensure the high robustness and smooth operation of the AGV speed control system under complex working conditions, effectively enhance the response and compensation ability of the system to sudden disturbances, and better meet the actual needs of AGV speed control in complex engineering scenarios. Full article
(This article belongs to the Section Actuators for Surface Vehicles)
►▼ Show Figures

Figure 1

21 pages, 1892 KB  
Article
Design of PI-P Controllers for a Class of Nonlinear Discrete Cascade Control Systems
by Wenting Jia and Zhaoping Du
Actuators 2026, 15(6), 350; https://doi.org/10.3390/act15060350 - 19 Jun 2026
Viewed by 172
Abstract
To address the parameter coordination and system integration issues in nonlinear discrete-time cascade control systems, this paper proposes, for the first time, a novel collaborative PI-P controller design method. First, an augmented state-space model for the PI-P controller is introduced, where the integral [...] Read more.
To address the parameter coordination and system integration issues in nonlinear discrete-time cascade control systems, this paper proposes, for the first time, a novel collaborative PI-P controller design method. First, an augmented state-space model for the PI-P controller is introduced, where the integral term is embedded into the state variables. Then, stability conditions are derived using Lyapunov stability theory, which are formulated as linear matrix inequality (LMI) constraints, enabling the simultaneous design of both primary and secondary controllers. The method is validated through simulations on a steam temperature control system. The results demonstrate that the proposed method outperforms conventional methods, achieving a faster response, reduced overshoot, and enhanced robustness. Moreover, the proposed method shows strong disturbance rejection capability and improved overall dynamic performance, further confirming its effectiveness and potential for application in nonlinear discrete-time cascade control systems. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Figure 1

11 pages, 1980 KB  
Article
Development of an Automatic Reagent Dispensing System for Micro Passive Pumps
by Katsuo Mogi, Reo Shimada, Naoki Takada and Hiroyuki Kimura
Actuators 2026, 15(6), 349; https://doi.org/10.3390/act15060349 - 18 Jun 2026
Viewed by 201
Abstract
A surface tension pump, a type of passive pumping method, can generate a gentle and low-flow liquid transport in microchannels without external equipment or tubing, even under microgravity conditions. However, its applicability is limited for long-term operation with large liquid volumes due to [...] Read more.
A surface tension pump, a type of passive pumping method, can generate a gentle and low-flow liquid transport in microchannels without external equipment or tubing, even under microgravity conditions. However, its applicability is limited for long-term operation with large liquid volumes due to its reliance on phenomena specific to small liquid volumes. To overcome this limitation, we developed an automatic reagent dispensing system enabling intermittent replenishment of the inlet reservoir in microfluidic devices. The system achieved high positional repeatability, with a maximum error below 781 µm, which was sufficient for operation within the inlet well used in this study. Initial flow-rate characterization demonstrated that the flow behavior could be adjusted through the dispensed droplet volume. The system was further evaluated through an 18 h automated cell-culture experiment, showing cell-retention performance comparable to that obtained by manual medium replenishment. These results demonstrate the feasibility of using automated intermittent replenishment to extend the operating duration of passive pumping systems. Full article
(This article belongs to the Section Miniaturized and Micro Actuators)
►▼ Show Figures

Figure 1

17 pages, 7689 KB  
Article
Design and Fabrication Method of a Soft Pneumatic Silicone Exosuit for Elbow Rehabilitation Assistance
by Zhirui Zhao, Dequan Deng, Xinyu Hou, Chun Xia, Xinyu Zeng, Dexing Shan, Lina Hao and Huicong Gao
Actuators 2026, 15(6), 348; https://doi.org/10.3390/act15060348 - 18 Jun 2026
Viewed by 182
Abstract
This study introduces the design process and fabrication method of a soft pneumatic silicone-based exosuit intended to assist human elbow extension and flexion movement for rehabilitation. First of all, an integrated fabrication method is developed to replace the step-by-step casting and cloth fiber [...] Read more.
This study introduces the design process and fabrication method of a soft pneumatic silicone-based exosuit intended to assist human elbow extension and flexion movement for rehabilitation. First of all, an integrated fabrication method is developed to replace the step-by-step casting and cloth fiber layer, using a 3D-printed PVA mold in silicone casting to ensure the airtightness of the silicone actuator, and a carbon fiber woven mesh is used as the base plate of the actuator to improve its bending performance. Then, the finite element analysis is used to optimize the geometric parameters, hardness, and the number of air chambers for the exosuit structure. The experimental evaluation confirms that the exosuit achieves a bending angle of 112 degrees without any load and 71 degrees with a load of 2 kg. Combining with the PI angular controller, the system limits the maximum absolute tracking error to 4.29 degrees. These results also suggest the proposed exosuit is a promising candidate for practical rehabilitation tasks. Full article
(This article belongs to the Topic Recent Advances in Smart Soft Materials: From Theory to Practice)
►▼ Show Figures

Figure 1

18 pages, 3436 KB  
Article
A Difference Equation Matrix Model Predictive Control Approach Applied to a Distillation Column
by Basil Mohammed Al-Hadithi, Javier Blanco Rico and Agustín Jiménez
Actuators 2026, 15(6), 347; https://doi.org/10.3390/act15060347 - 18 Jun 2026
Viewed by 235
Abstract
The Difference Equation Matrix Model (DEMM) is presented as an input–output Model Predictive Control (MPC) formulation derived from discrete difference equations. The proposed approach is compared with the widely used Dynamic Matrix Control (DMC) strategy from a structural perspective, highlighting differences in model [...] Read more.
The Difference Equation Matrix Model (DEMM) is presented as an input–output Model Predictive Control (MPC) formulation derived from discrete difference equations. The proposed approach is compared with the widely used Dynamic Matrix Control (DMC) strategy from a structural perspective, highlighting differences in model parameterization, identification requirements, and matrix dimensions. The analysis indicates that DEMM provides a more compact model representation than the DMC formulation considered in this work while preserving the predictive-control framework. Furthermore, the DEMM strategy is applied to a binary distillation column, a multivariable nonlinear process, to illustrate its implementation and closed-loop behavior under disturbance, noise, and setpoint-change scenarios. Simulation results demonstrate satisfactory disturbance-rejection and tracking performance for the considered operating conditions. Full article
(This article belongs to the Special Issue Analysis and Design of Linear/Nonlinear Control System—2nd Edition)
►▼ Show Figures

Figure 1

15 pages, 4294 KB  
Article
Comprehensive Analysis of the Electrical–Magneto–Mechanical Coupled Characteristics of AC Electromagnetic Actuators: A Case Study of Three-Phase AC Contactors
by Yubin He, Wanbin Ren, Zhihao Gu and Chao Zhang
Actuators 2026, 15(6), 346; https://doi.org/10.3390/act15060346 - 18 Jun 2026
Viewed by 308
Abstract
The motion of AC electromagnetic actuators exhibits complex electrical–magneto–mechanical coupling characteristics. A three-phase AC contactor is taken as the typical research object in this paper. Using the finite-element method (FEM) and mesh deformation technique, the commercial software COMSOL Multiphysics is adopted to analyze [...] Read more.
The motion of AC electromagnetic actuators exhibits complex electrical–magneto–mechanical coupling characteristics. A three-phase AC contactor is taken as the typical research object in this paper. Using the finite-element method (FEM) and mesh deformation technique, the commercial software COMSOL Multiphysics is adopted to analyze its static electromagnetic characteristics, together with the operational coil current response and movable core displacement. In addition, the static correlation between the magnetic force, air gap, and time-varying magnetic force curves in the movement process are obtained. An experimental platform is established to measure the magnetic force of electromagnetic actuators. The experiment results demonstrate the feasibility of the proposed simulation method. The normalized root mean square errors between simulated and measured static magnetic forces are below 8% under all tested coil voltages. Furthermore, the effect of coil voltage phase angle on dynamic operational characteristics is thoroughly investigated. Combined with the closing time and final velocity of the movable core, the recommended operating window and its corresponding phase angle are determined. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Figure 1

20 pages, 4288 KB  
Article
A Prompt-Driven Vision-Language Framework for Deictic Interpretation in Human-Robot Handover
by Jimin Byeon, Song Min Ryu and Kyu Min Park
Actuators 2026, 15(6), 345; https://doi.org/10.3390/act15060345 - 18 Jun 2026
Viewed by 274
Abstract
Recent advancements in Vision-Language Models (VLMs) have enabled robotic systems to leverage model-based understanding and reasoning over visual and linguistic inputs, offering a promising approach for interpreting user intent in human–robot interaction (HRI). In particular, deictic expressions commonly used in object handovers, such [...] Read more.
Recent advancements in Vision-Language Models (VLMs) have enabled robotic systems to leverage model-based understanding and reasoning over visual and linguistic inputs, offering a promising approach for interpreting user intent in human–robot interaction (HRI). In particular, deictic expressions commonly used in object handovers, such as “take this” and “give me that”, cannot be fully interpreted through language alone and require a comprehensive understanding of the speaker’s perspective and the environment. This study proposes a prompt-driven vision-language framework for deictic interpretation in human–robot handover. The system integrates a pre-trained VLM with a hierarchical prompt that decomposes reasoning into intent classification, spatio-temporal grounding, and output self-validation, enabling accurate identification of target objects and goal locations without model fine-tuning. Experimental results demonstrate 100% command interpretation accuracy across multiple interaction scenarios, including pick-and-place tasks, robot-to-human and human-to-robot handovers, and temporal deictic commands. Notably, the system operates under a prompt–command language mismatch, accurately interpreting Korean commands while being guided by English-based prompts. Analysis across progressive system configurations further demonstrates that structured prompting plays a critical role in reasoning performance. These results highlight the effectiveness of a prompt-driven approach for deictic interpretation and spatio-temporal grounding, providing a practical training-free framework for HRI. Full article
(This article belongs to the Special Issue Human-Centered Actuation: Algorithms, Design, and Robotic Applications)
►▼ Show Figures

Figure 1

26 pages, 5761 KB  
Article
Physics-Informed Modeling of Electrohydraulic Semi-Active Dampers Using LSTM, Transformer and Extended Hyperbolic Tangent Model
by Mert Büyükköprü, Muhammet Güven, Erdem Uzunsoy and Xavier Mouton
Actuators 2026, 15(6), 344; https://doi.org/10.3390/act15060344 - 17 Jun 2026
Viewed by 387
Abstract
This study investigates physics-informed and data-driven hybrid modeling strategies for an automotive-grade electrohydraulic (EH) semi-active damper system. Although deep sequence learning architectures such as Long Short-Term Memory (LSTM) networks and Transformers can provide high predictive accuracy, purely data-driven approaches may struggle to preserve [...] Read more.
This study investigates physics-informed and data-driven hybrid modeling strategies for an automotive-grade electrohydraulic (EH) semi-active damper system. Although deep sequence learning architectures such as Long Short-Term Memory (LSTM) networks and Transformers can provide high predictive accuracy, purely data-driven approaches may struggle to preserve physical consistency and maintain robustness under unseen operating conditions. These limitations become more pronounced for EH dampers, whose hysteretic characteristics exhibit highly nonlinear and non-proportional variations under different current and frequency excitations, unlike the more scalable behavior commonly observed in magnetorheological (MR) dampers. To address these challenges, two physics-informed integration strategies are investigated. The first strategy combines physical and data-driven models through parallel loss-function synthesis. The second strategy introduces a learnable physics layer (PINN-Hybrid), in which the coefficients of the extended hyperbolic tangent formulation are adaptively learned within the neural network architecture. In this framework, the physical model acts as a structural regularization mechanism that guides the learning process while preserving the flexibility of data-driven sequence modeling. The proposed models are evaluated under abrupt valve-control operating conditions. Comparative results indicate that the proposed physics-informed architectures improve hysteresis continuity, physical plausibility, and robustness compared with purely data-driven approaches, particularly in low-velocity and transition regions. The proposed framework therefore demonstrates the potential of physics-informed learning strategies for reliable real-time modeling of nonlinear automotive EH damper systems. Full article
(This article belongs to the Section Actuators for Surface Vehicles)
►▼ Show Figures

Figure 1

29 pages, 18303 KB  
Article
Design of Dual-Motor Drive Composite Control Strategy Based on Iterative Learning Feedforward Control and Super-Twisting Sliding Mode Observer
by Anning Wang, Xianying Feng, Hao Wang and Ming Yao
Actuators 2026, 15(6), 343; https://doi.org/10.3390/act15060343 - 17 Jun 2026
Viewed by 170
Abstract
Periodic and non-periodic disturbances significantly affect the tracking accuracy of servo systems. A dual-motor drive composite control strategy based on iterative learning feedforward control and super-twisting sliding mode observer is proposed. Initially, a novel reaching law capable of dynamically adjusting gain coefficients based [...] Read more.
Periodic and non-periodic disturbances significantly affect the tracking accuracy of servo systems. A dual-motor drive composite control strategy based on iterative learning feedforward control and super-twisting sliding mode observer is proposed. Initially, a novel reaching law capable of dynamically adjusting gain coefficients based on system states is introduced, leading to the design of a sliding mode controller with proven asymptotic stability. To address non-periodic total disturbances, a super-twisting sliding mode observer is developed, and Lyapunov stability theory is employed to demonstrate system stability and error convergence to zero. A resonant controller is designed to suppress medium- to high-frequency periodic disturbances. For periodic total disturbances, a parameterized feedforward controller based on iterative learning is devised, and an input-shaping filter is introduced to refine the input trajectory. The feedforward control parameters are iteratively updated using a data-driven approach. Experiments are conducted on a differential dual-drive servo system. The nut motor adopts the sliding mode controller with an observer. The screw motor employs the iterative learning feedforward controller. Results show effective suppression of the disturbances. Speed ripple is reduced, and tracking accuracy is significantly improved. The study demonstrates the feasibility and advantage of combining robust control with iterative learning in high-precision servo systems. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Figure 1

29 pages, 5190 KB  
Article
Kinematic Indicators as Complementary Performance Metrics for PID and Fuzzy Speed Controllers in Rover Actuators
by Juan David Guncay, Christian Salamea Palacios, Javier Viñanzaca and Michael Peralta
Actuators 2026, 15(6), 342; https://doi.org/10.3390/act15060342 - 17 Jun 2026
Viewed by 275
Abstract
This work presents an experimental comparison of three speed control strategies for a permanent magnet DC (PMDC) rover actuator implemented on a resource-constrained embedded microcontroller platform. The system operates under fixed-rate discrete control with quantized encoder velocity feedback, representative of low-cost embedded systems. [...] Read more.
This work presents an experimental comparison of three speed control strategies for a permanent magnet DC (PMDC) rover actuator implemented on a resource-constrained embedded microcontroller platform. The system operates under fixed-rate discrete control with quantized encoder velocity feedback, representative of low-cost embedded systems. The controllers evaluated are a classical PID, a PID controller designed via discrete pole placement, and a Mamdani fuzzy controller. Beyond conventional tracking and transient response metrics, the proposed evaluation framework incorporates jerk-based kinematic indicators to assess the mechanical activity induced by control actions under both nominal and mechanically disturbed operating conditions. Experimental validation was performed over a range of operating speeds using repeated trials, and the observed differences were evaluated through nonparametric statistical testing. The results show that controller rankings depend strongly on operating conditions: the classical PID provides smoother motion under nominal conditions, whereas the fuzzy and compensated PID controllers achieve superior disturbance rejection when external mechanical perturbations are introduced. These findings reveal a clear tradeoff between mechanical smoothness and tracking robustness, and demonstrate that controllers exhibiting better tracking performance do not necessarily produce the smoothest kinematic response. The principal contribution of this work is the experimental demonstration that jerk-based indicators provide essential complementary information to conventional performance metrics for the evaluation and selection of embedded speed controllers in mechatronic systems subject to variable mechanical loading. Full article
(This article belongs to the Special Issue Actuators for System Identification, Vibration Analysis, and Control—2nd Edition)
►▼ Show Figures

Graphical abstract

26 pages, 15210 KB  
Article
Structural Parameter Optimization for Synchronous Error of Gantry-Type Dual-Drive Feed System
by Hao Zheng, Junjie Ma, Zengao Zhang and Wentie Niu
Actuators 2026, 15(6), 341; https://doi.org/10.3390/act15060341 - 15 Jun 2026
Viewed by 191
Abstract
Gantry-type dual-drive feed systems are widely used in high-precision CNC machine tools, and their synchronization performance directly affects machining accuracy and operational stability. To reduce synchronization errors caused by load-position variation, nonuniform stiffness distribution, and inertia mismatch, this study proposes a structural parameter [...] Read more.
Gantry-type dual-drive feed systems are widely used in high-precision CNC machine tools, and their synchronization performance directly affects machining accuracy and operational stability. To reduce synchronization errors caused by load-position variation, nonuniform stiffness distribution, and inertia mismatch, this study proposes a structural parameter optimization method for a gantry-type dual-drive feed system. The novelty of this work lies in integrating position-dependent dynamic modeling, critical-position identification, sensitive structural-parameter selection, and response-surface-based optimization into a unified framework for synchronization-error reduction. First, a position-dependent dynamic model is established using modal reduction, spline interpolation, and substructure synthesis. The dynamic model is then coupled with a servo control model to construct an electromechanical coupling model, which is validated experimentally on a gantry-type dual-drive feed system. Next, the synchronization-error distribution over the entire workspace is evaluated, and the critical position with the poorest synchronization performance is identified. Based on sensitivity analysis, the key structural parameters affecting synchronization error are selected as design variables. A response surface surrogate model is then constructed, and particle swarm optimization is used to obtain the optimal structural-parameter combination. The results show that the synchronization error at the critical position is reduced by 20.5%, while the average synchronization error at the validation positions is reduced by 17.3%. These results demonstrate that the proposed method can effectively improve the synchronization accuracy of gantry-type dual-drive feed systems and provide practical guidance for the structural design of high-precision dual-drive machine tools. Full article
(This article belongs to the Section Actuators for Manufacturing Systems)
►▼ Show Figures

Figure 1

24 pages, 16109 KB  
Article
Broadband Simulation-Based EMC Modeling and EMI Assessment of a GaN-Based Phase-Shift Full-Bridge Converter for EV DC Powertrains
by Sofiane Khelladi, Nassim Rizoug, Cristina Morel and Abdelchafik Hadjadj
Actuators 2026, 15(6), 340; https://doi.org/10.3390/act15060340 - 13 Jun 2026
Viewed by 370
Abstract
Nowadays, numerical simulation methods are advanced and widely used in industry, enabling the modeling of complex systems from printed circuit boards (PCBs) to full power converters. Among many isolated topologies, the phase-shift full-bridge (PSFB) topology is a well-established solution for isolated DC–DC conversion [...] Read more.
Nowadays, numerical simulation methods are advanced and widely used in industry, enabling the modeling of complex systems from printed circuit boards (PCBs) to full power converters. Among many isolated topologies, the phase-shift full-bridge (PSFB) topology is a well-established solution for isolated DC–DC conversion in electric vehicles. Therefore, this paper proposes a broadband electromagnetic compatibility (EMC) modeling methodology for a custom-designed 1 kW gallium nitride (GaN)-based PSFB converter intended for an electric vehicle (EV) DC powertrain. Moreover, the approach combines full-wave electromagnetic simulation with circuit-level simulation, including parasitic effects from PCB layout, power harnesses, and discrete components. Thus, the virtual prototype is assessed within a complete virtual test bench compliant with the standard Comité International Spécial des Perturbations Radioélectriques (CISPR) 25 over the 150 kHz–108 MHz range to capture common-mode (CM) and differential-mode (DM) conducted electromagnetic interference (EMI). Results show that the converter achieves efficiencies of 97.26% in standalone mode and 97.03% when integrated into the full DC powertrain. However, the conducted EMI assessment reveals that both CM and DM emissions exceed CISPR 25 Class 2 limits across the entire spectrum, with excess levels reaching up to 72 dBµV. Therefore, power harnesses significantly increase EMI levels at low frequencies due to the distributed inductance and stray capacitance. Finally, this study demonstrates the value of virtual prototyping for simulation-based EMI prediction in early-stage power converter design. Full article
(This article belongs to the Special Issue Electrothermal and Electromagnetic Modeling of Actuator Power Cable Harnesses)
►▼ Show Figures

Figure 1

23 pages, 40386 KB  
Article
A Reconfigurable Design Approach for Hybrid Tendon–Pneumatic Continuum Robots Enabled by Soft Multi-Lumen Backbones
by Burak Ozdemir, Amman Chougle, Pietro Valdastri and James H. Chandler
Actuators 2026, 15(6), 339; https://doi.org/10.3390/act15060339 - 13 Jun 2026
Viewed by 366
Abstract
Continuum robots offer inherent compliance and dexterity for operation in confined and unstructured environments; however, achieving hybrid multi-segment functionality typically requires application-specific redesign and tightly coupled architectures. To address this limitation, this study proposes a reconfigurable hybrid continuum robot architecture based around a [...] Read more.
Continuum robots offer inherent compliance and dexterity for operation in confined and unstructured environments; however, achieving hybrid multi-segment functionality typically requires application-specific redesign and tightly coupled architectures. To address this limitation, this study proposes a reconfigurable hybrid continuum robot architecture based around a multi-lumen central integration backbone that supports multiple actuation modalities and robot configurations. The proposed design combines external tendon-driven disk modules for proximal actuation with a pneumatically actuated distal tip, while internal lumens allow routing of pneumatic lines and the insertion of optional stiffening elements without structural interference. The reconfigurability of the architecture is demonstrated through two configurations: Concept-1, a two-segment hybrid system, and Concept-2, a miniaturized three-segment configuration achieved by reducing the disk diameter and extending tendon actuation to the backbone. Experimental evaluations are conducted to characterize segment-wise actuation, coupled deformation behavior, and workspace capabilities, hysteresis response, tip contact force, and phantom-based target reachability. Results show that the integration of tendon-driven and pneumatic actuation significantly expands and reorients the reachable workspace. Additional functional tests showed repeatable loading–unloading behaviour of the tendon-driven segment, a maximum pneumatic tip contact force of approximately 0.45 N, and successful access to five representative targets within a stomach-like phantom using Concept-2. A kinematic model based on a constant-curvature formulation is validated against experimental data, yielding root-mean-square errors (RMSE) of 5.44 mm and 6.12 mm for Concept-1 and Concept-2, respectively. These results demonstrate consistent model accuracy across different configurations and scales. Overall, the proposed architecture enables modular, scalable, and reconfigurable hybrid continuum robots, providing a flexible framework for applications ranging from large-scale manipulation to gastroscopy-inspired minimally invasive procedures. Full article
(This article belongs to the Special Issue Soft Pneumatic Actuators: Recent Advances and Emerging Applications)
►▼ Show Figures

Figure 1

23 pages, 9007 KB  
Article
Modeling, Comparative Investigation and Compensation for Hysteresis Response of Actuator Using Nonlinear Transformation
by Zhisheng Ren, Yuguo Cui, Xingyang Xie, Pan Chen and Yang Yu
Actuators 2026, 15(6), 338; https://doi.org/10.3390/act15060338 - 13 Jun 2026
Viewed by 244
Abstract
Aiming at problems such as the reduced positioning accuracy and insufficient dynamic response caused by the inherent hysteresis nonlinearity of piezoelectric actuators, this paper proposes a hysteresis modeling and compensation method for piezoelectric actuators based on nonlinear transformation. The proposed NT hysteresis model [...] Read more.
Aiming at problems such as the reduced positioning accuracy and insufficient dynamic response caused by the inherent hysteresis nonlinearity of piezoelectric actuators, this paper proposes a hysteresis modeling and compensation method for piezoelectric actuators based on nonlinear transformation. The proposed NT hysteresis model utilizes the nonlinear characteristics of activation functions to describe the complex nonlinearity in the hysteresis response of piezoelectric actuators. On this basis, a feedforward compensation controller is further designed based on the proposed inverse NT hysteresis model. Moreover, a composite controller is constructed by combining it with PID feedback to improve the dynamic response speed and trajectory tracking accuracy of piezoelectric actuators. Based on experimental data, the fitting performance of the proposed model is compared with that of several common hysteresis models using evaluation indicators including RMSE, MAPE and SMAPE. Finally, the performance of the proposed control method is verified through step response and sinusoidal trajectory tracking experiments. Experimental results show that the proposed NT hysteresis model performs best in characterizing the hysteresis characteristics of piezoelectric actuators, and the feedforward compensation controller constructed based on its inverse model exhibits superior control performance. Full article
(This article belongs to the Section Actuator Materials)
►▼ Show Figures

Figure 1

27 pages, 11164 KB  
Article
Reduced-Order Nonlinear Dynamic Analysis and Lyapunov-Based Chaos Characterization of SMA Hybrid Composite Actuator Beams Under Thermo-Aeroelastic Excitation
by Fusong Jin and Jianghong Xue
Actuators 2026, 15(6), 337; https://doi.org/10.3390/act15060337 - 13 Jun 2026
Viewed by 222
Abstract
This study investigates the nonlinear dynamic response and chaos evolution of a shape memory alloy hybrid composite (SMAHC) actuator beam under coupled thermal, harmonic, and aerodynamic excitations. A reduced-order nonlinear dynamic model was developed by combining Euler–Bernoulli beam theory, von Karman geometric nonlinearity, [...] Read more.
This study investigates the nonlinear dynamic response and chaos evolution of a shape memory alloy hybrid composite (SMAHC) actuator beam under coupled thermal, harmonic, and aerodynamic excitations. A reduced-order nonlinear dynamic model was developed by combining Euler–Bernoulli beam theory, von Karman geometric nonlinearity, the Brinson SMA constitutive relation, and first-order piston-theory aerodynamics. The governing equations were derived from Hamilton’s principle, discretized by the weighted residual method, and solved using the Newmark-beta algorithm. Chaotic evolution was quantified using a largest Lyapunov exponent-based chaos intensity indicator rather than the exact Kolmogorov–Sinai entropy. The reduced-order model was compared with ABAQUS finite element simulations under representative coupled aerodynamic and harmonic loading. The MATLAB prediction and ABAQUS response gave a dominant frequency of approximately 9.50 Hz, close to the prescribed excitation frequency of 9.55 Hz, with peak displacement amplitudes of approximately 0.0285 mm and 0.0324 mm, respectively. A supplementary ABAQUS modal-frequency separation check supported the use of the two-mode reduced-order model for the dominant low-frequency response, while also clarifying its limitation for high-dimensional chaotic modal interactions. The parametric results showed that an increasing excitation amplitude and aerodynamic load promoted frequency broadening and chaotic transitions. The Lyapunov-based indicator rose near γ = 65 under λ* = 100 and near λ* = 328 under γ = 30. Temperature-dependent SMA recovery stress further shifted the transition threshold by modifying the effective stiffness and internal restoring action of the beam. These results provide a reduced-order framework for interpreting nonlinear response transitions in SMAHC actuator beams in thermo-aeroelastic environments. Full article
(This article belongs to the Section Actuator Materials)
►▼ Show Figures

Figure 1

27 pages, 65786 KB  
Article
Canopy-Adaptive TAD-IRRT* Algorithm for 3D Path Planning of 6-DOF Apple-Harvesting Robots in Dense Orchards
by Lu Han, Wei Chen, Tianzhong Fang and Yunpeng Sun
Actuators 2026, 15(6), 336; https://doi.org/10.3390/act15060336 - 13 Jun 2026
Viewed by 246
Abstract
This study proposes a canopy-adaptive TAD-IRRT* (target-biased sampling, artificial potential field, and dynamic step-size informed rapidly-exploring random tree star) algorithm to solve the collision-free 3D path-planning problem for a 6-DOF apple-harvesting robotic arm. To improve computational speed and search directionality, the method integrates [...] Read more.
This study proposes a canopy-adaptive TAD-IRRT* (target-biased sampling, artificial potential field, and dynamic step-size informed rapidly-exploring random tree star) algorithm to solve the collision-free 3D path-planning problem for a 6-DOF apple-harvesting robotic arm. To improve computational speed and search directionality, the method integrates target-biased sampling and a distance-regulated artificial potential field (APF) into the Informed-RRT* framework. Furthermore, an obstacle-distance-based dynamic step-size mechanism is introduced to optimize spatial exploration. The generated routes undergo greedy path pruning and cubic B-spline smoothing to ensure kinematic executability. The simulation results in complicated ROS-based scenarios demonstrate that the TAD-IRRT* algorithm achieves a 100% planning success rate, reducing the average computational time and joint-space path length by approximately 60.1% and 15.6%, respectively, compared to the standard Informed-RRT*. Kinematic analysis via Fourier curve fitting (R2=0.9849) confirms continuous angular velocity and acceleration without high-frequency chattering. Physical prototype experiments in the dense-obstacle scenarios show that the proposed method increases the path execution success rate by 36.7% and reduces the average execution time by 41% compared to the standard Informed-RRT* algorithm. The proposed approach effectively balances high-quality path generation with low computational overhead, providing a reliable and safe solution that significantly reduces mechanical wear. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

15 pages, 12932 KB  
Article
Voltage-Controlled Active Preload Adjustment of an Ultrasonic Traveling Wave Motor Under Thermal Vacuum Conditions
by Benediktas Ščiučka, Laurynas Šišovas and Andrius Čeponis
Actuators 2026, 15(6), 335; https://doi.org/10.3390/act15060335 - 12 Jun 2026
Viewed by 225
Abstract
This study presents numerical and experimental investigations of a voltage-controlled active preload adjustment system for an ultrasonic traveling wave piezoelectric motor intended for potential use in space-related systems. The proposed preload system consists of two ring-shaped piezoceramic elements driven by a DC voltage [...] Read more.
This study presents numerical and experimental investigations of a voltage-controlled active preload adjustment system for an ultrasonic traveling wave piezoelectric motor intended for potential use in space-related systems. The proposed preload system consists of two ring-shaped piezoceramic elements driven by a DC voltage of up to 300 VDC. The passive conical spring provides the nominal rotor preload, while the piezoelectric ring stack enables open-loop remote fine adjustment of the stator–rotor contact force by modifying the axial compression of the spring. Finite element simulations were performed over a temperature range from −25 °C to 55 °C to evaluate the electromechanical response and thermal sensitivity of the preload system. The numerical results indicated that the active preload system can generate a simulated preload force variation of approximately 0.47 N at 300 VDC, corresponding to approximately 21.4% of the nominal initial preload force of 2.2 N. Experimental tests were conducted in a thermal vacuum chamber at a pressure of 5.6 × 10−6 mbar. The measured displacement of the piezoceramic preload stack ranged from 0.33 µm to 2.36 µm and showed good agreement with the numerical displacement results. Motor speed measurements demonstrated that increasing the preload-control voltage from 0 to 300 VDC resulted in an average angular speed increase of approximately 17–20 RPM, depending on temperature. The results demonstrate that the proposed system can provide compact open-loop preload fine adjustment under thermal vacuum conditions, with preload force variation supported by FEM estimation and experimentally validated displacement response. Full article
(This article belongs to the Special Issue Advanced Control of Mechatronics Systems for Small Scale Robotics)
►▼ Show Figures

Figure 1

35 pages, 13090 KB  
Article
TD3-Enhanced MPC for Safe Braking of Overhead Cranes with Safety-Critical Region Prediction
by Wenshuai Zhang, Yifan Wang, Manlan Liu and Peng Lan
Actuators 2026, 15(6), 334; https://doi.org/10.3390/act15060334 - 12 Jun 2026
Viewed by 177
Abstract
To address the strong coupling between trolley motion and payload swing, as well as the difficulty of determining optimal braking timing during emergency operations of overhead cranes in complex environments, a model-predictive braking control method integrated with the Twin Delayed Deep Deterministic Policy [...] Read more.
To address the strong coupling between trolley motion and payload swing, as well as the difficulty of determining optimal braking timing during emergency operations of overhead cranes in complex environments, a model-predictive braking control method integrated with the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm is proposed. Within the Model Predictive Control (MPC) framework, payload swing angle constraints are explicitly incorporated, and an adaptive braking reference trajectory is constructed to achieve rapid and stable stopping while effectively suppressing load oscillations. Furthermore, the TD3 algorithm is employed for online adaptive optimization of key MPC parameters, enabling a dynamic trade-off between braking performance and swing suppression under varying operating conditions. In addition, a minimum braking distance prediction model based on Support Vector Regression (SVR) is developed, and a state-dependent safety-critical region prediction model is established to quantitatively determine optimal braking timing. Simulation results across multiple operating conditions demonstrate that the proposed TD3–MPC method outperforms conventional MPC in terms of braking efficiency, swing suppression capability, and system stability while satisfying swing angle constraints. Moreover, real-crane experimental results demonstrate the effectiveness of the proposed safety-critical region prediction method in determining appropriate braking trigger timing and achieving safe and smooth stopping of the overhead crane under obstacle-avoidance conditions. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Figure 1

29 pages, 6058 KB  
Article
Research on Robotic Force Control for Infant Hip Ultrasound
by Jianwei Cui, Xinyu Zhang, Yuxiang Dai and Wenyi Zhang
Actuators 2026, 15(6), 333; https://doi.org/10.3390/act15060333 - 11 Jun 2026
Viewed by 291
Abstract
The contact force between the ultrasound probe and human skin directly affects image quality, patient safety, and comfort. In infant developmental dysplasia of the hip (DDH) ultrasound examinations, higher force control precision is required, as infants have thin skin and soft cartilage that [...] Read more.
The contact force between the ultrasound probe and human skin directly affects image quality, patient safety, and comfort. In infant developmental dysplasia of the hip (DDH) ultrasound examinations, higher force control precision is required, as infants have thin skin and soft cartilage that are easily deformed under excessive probe pressure. This paper proposes a comprehensive force control method for DDH ultrasound robots. Firstly, an online gravity calibration approach is employed to estimate the installation tilt, sensor zero offset, and probe center of gravity, thereby improving force measurement accuracy. Then, a torque-based pose control algorithm is adopted to achieve conformal probe–skin contact. Finally, a variable admittance control strategy based on fuzzy neural network (FNN) is proposed, which adaptively regulates the damping coefficient based on the force error and its rate, enabling stable force control without explicit soft-tissue modeling. Experiments on an infant phantom and human skin show that the proposed method achieves force fluctuation amplitudes of 0.0984 ± 0.0012 N and 0.0976 ± 0.0014 N, respectively, with absolute steady-state force errors below 0.01 N. Compared with conventional admittance control, it significantly reduces force oscillations and improves tracking accuracy. In infant experiments, the method enables smooth convergence to the desired force and maintains relatively stable probe–skin interaction, which contributes to consistent ultrasound image acquisition and reduces tissue deformation. These results suggest that the proposed method can provide a feasible force control basis for stable and gentle robotic DDH ultrasound scanning. Full article
(This article belongs to the Section Actuators for Robotics)
►▼ Show Figures

Figure 1

23 pages, 2460 KB  
Article
Model-Based Control of Antagonistic Pair of Pneumatically Actuated Pouch Motors
by Syed Arshad Hussain and Enrico Franco
Actuators 2026, 15(6), 332; https://doi.org/10.3390/act15060332 - 11 Jun 2026
Viewed by 199
Abstract
Pneumatic pouch motors are soft actuators that contract when inflated. Their low cost and ease of fabrication make them ideal choices for disposable systems such as those used in robotic surgery. However, the dynamics of pouch motors are highly nonlinear, which complicates control. [...] Read more.
Pneumatic pouch motors are soft actuators that contract when inflated. Their low cost and ease of fabrication make them ideal choices for disposable systems such as those used in robotic surgery. However, the dynamics of pouch motors are highly nonlinear, which complicates control. In this paper, we investigate the position control of an antagonistic pair of soft pneumatic pouch motors. An analytical model of system dynamics, including the pressure dynamics in the pouches, is proposed. To compensate for uncertainties and disturbances, a nonlinear observer is constructed based on the Immersion and Invariance methodology. A new model-based nonlinear controller, constructed using a nested sliding variable, is designed for tracking tasks. Stability conditions are discussed, and the effectiveness of the new controller is demonstrated in simulations and experiments. The new controller is compared with a reduced-order version that neglects pressure dynamics. The results indicate that both controllers are effective in tracking tasks, with the new controller showing improved accuracy by up to 33.3% in experiments. Full article
(This article belongs to the Special Issue Advanced Mechanism Design and Sensing for Soft Robotics)
►▼ Show Figures

Figure 1

26 pages, 4257 KB  
Article
Predicted Adaptive Line-of-Sight Path Following Control for Underactuated USVs with Unknown Time-Varying Sideslip Angles
by Ming Yi and Yuchuang Wang
Actuators 2026, 15(6), 331; https://doi.org/10.3390/act15060331 - 11 Jun 2026
Viewed by 308
Abstract
The problem of path following control for underactuated Unmanned Surface Vehicles (USVs) is tackled in this work, and a scheme based on Predicted Adaptive Line-of-Sight (PALOS) is put forward. At the guidance level, prediction techniques and adaptive mechanisms are incorporated to eliminate the [...] Read more.
The problem of path following control for underactuated Unmanned Surface Vehicles (USVs) is tackled in this work, and a scheme based on Predicted Adaptive Line-of-Sight (PALOS) is put forward. At the guidance level, prediction techniques and adaptive mechanisms are incorporated to eliminate the inherent assumption of small sideslip angle in the conventional LOS methods, enabling online estimation and dynamic feedforward compensation of time-varying sideslip angles. On the control side, radial basis function neural networks are combined with virtual parameter learning techniques to achieve online approximation of the lumped uncertainties, which include modeling inaccuracies and external disturbances. An adaptive control scheme based on lifelong learning mechanisms is developed, wherein the historical knowledge is constructed and preserved through feedback terms to achieve knowledge retention and on-demand reuse, thereby enhancing control efficiency and mitigating catastrophic forgetting. Additionally, a self-triggered mechanism acts as a knowledge transfer instrument, reducing communication overhead, relaxing transmission conditions, and rigorously precluding Zeno behavior. Through theoretical derivations, one can prove that all closed-loop signals are uniformly ultimately bounded. Comprehensive numerical simulations based on the 1:70 CyberShip II scale-model ship dynamics under complex sea conditions verify the proposed approach to be both effective and practical. Full article
(This article belongs to the Special Issue Advanced Underwater Robotics)
►▼ Show Figures

Figure 1

34 pages, 101766 KB  
Article
Design of a Granular Media-Adaptable Bionic-Inspired Reconfigurable Foot Based on EDEM–Adams Coupling Simulation
by Zilei Ji, Feiyang Han, Yudong Xie, Jiazhen Han, Yong Wang and Yingying Zhang
Actuators 2026, 15(6), 330; https://doi.org/10.3390/act15060330 - 11 Jun 2026
Viewed by 274
Abstract
The foot structure plays a decisive role in the trafficability of legged robots on granular media. Traditional foot-ends (spherical, cylindrical, flat-bottomed) are prone to sinkage and slippage, resulting in unstable locomotion. To solve this problem, a novel bionic-inspired reconfigurable foot with active opening [...] Read more.
The foot structure plays a decisive role in the trafficability of legged robots on granular media. Traditional foot-ends (spherical, cylindrical, flat-bottomed) are prone to sinkage and slippage, resulting in unstable locomotion. To solve this problem, a novel bionic-inspired reconfigurable foot with active opening and closing adjustment capability is designed based on bionics, combining the stable phalangeal contour of goat hoof capsules and the high-adhesion feature of beetle foot-end spines. A coupled EDEM–Adams simulation model is established, and physical experiments combined with simulation inversion are used to calibrate contact parameters between particles and between particles and the foot, including the coefficient of restitution, static friction and rolling friction. A high-fidelity numerical platform for foot–ground dynamic interaction is thus constructed. By comparing and analyzing the differences in anti-sinkage and traction performance between the bionic-inspired foot and traditional foot-ends, this study systematically revealed the influence law of bionic morphology on the mechanical behavior of the foot, and clarified the intrinsic mechanism through which bionic design improves foot–ground interaction. The results demonstrate that the spine structures of the bionic-inspired foot reshape the mechanical constitutive relationship of granular media. By expanding the ground contact area and optimizing contact pressure distribution, the maximum reduction in foot sinkage depth reaches 70.11%, and the traction coefficient is increased by up to 37.13%. Full article
(This article belongs to the Special Issue Cutting-Edge Advancements in Robotics and Control Systems)
►▼ Show Figures

Figure 1

29 pages, 26501 KB  
Article
High-Precision Calibration of Dual 6-DOF Series-Parallel Robot Actuators for Precision Manufacturing Systems via a Hierarchical Decoupling Multi-Modal Fusion Algorithm
by Litong Zhang, Haonan Dai, Mingyang Liu and Lizhong Sun
Actuators 2026, 15(6), 329; https://doi.org/10.3390/act15060329 - 9 Jun 2026
Viewed by 269
Abstract
Dual 6 degrees of freedom (6-DOF) series-parallel cooperative robot actuators are core execution components in modern intelligent manufacturing systems, which are widely used in high-end manufacturing scenarios such as aerospace precision assembly, laser precision machining, and core component assembly of new energy vehicles. [...] Read more.
Dual 6 degrees of freedom (6-DOF) series-parallel cooperative robot actuators are core execution components in modern intelligent manufacturing systems, which are widely used in high-end manufacturing scenarios such as aerospace precision assembly, laser precision machining, and core component assembly of new energy vehicles. However, in actual manufacturing processes, the pose deviation between theoretical model prediction and actual motion execution of the actuator, caused by kinematic model mismatch, unquantified core parameters, incomplete error processing chain, and complex on-site environmental interference, severely restricts the assembly accuracy, product qualification rate and production efficiency of the manufacturing system. To address these critical pain points of robot actuators in precision manufacturing systems, this paper proposes a four-layer hierarchical decoupling multi-modal fusion calibration algorithm for high-precision pose control of dual series-parallel robot actuators. The algorithm integrates singular value decomposition (SVD) for cross-structure coordinate alignment of heterogeneous actuators, chaotic mapping-enhanced particle swarm optimization (PSO) for nonlinear error suppression of the actuator system, attention-enhanced deep residual network (DRN) for unmodeled residual learning of the actuator, and Kalman filter (KF) for dynamic noise reduction in the manufacturing process. Meanwhile, a full-chain error transfer model of the actuator system in the manufacturing process is constructed, and the core parameters of the algorithm are quantified via dimensional sensitivity analysis and orthogonal experiments. Experimental results show that the static position error of the actuator system after calibration reaches 1.4 ± 0.08 mm, and the static pose error reaches 0.0059 ± 0.0003 rad in the laboratory environment; in the engineering application of laser precision machining in an actual manufacturing line, the position error and pose error only increase by 8.6% and 6.8% respectively, maintaining high stability in industrial manufacturing scenarios. Compared with mainstream calibration methods, the proposed algorithm reduces the position error and pose error of the actuator by up to 55.7% and 17.9% respectively, with lower computational complexity and higher engineering reproducibility. This work constructs an end-to-end error suppression chain with quantitative parameter criteria for the series-parallel actuator system in manufacturing systems, which provides a reliable high-precision calibration solution for industrial dual-robot cooperative manufacturing and has important guiding significance for improving the motion accuracy and operation stability of actuators in precision manufacturing systems. Full article
(This article belongs to the Section Actuators for Manufacturing Systems)
►▼ Show Figures

Figure 1

33 pages, 28449 KB  
Article
Static and Dynamic Performance Optimization of the AC Rotary Head Based on Stiffness-Mass Matching
by Jiaming Liu, Qing Liu, Hao Zheng and Wentie Niu
Actuators 2026, 15(6), 328; https://doi.org/10.3390/act15060328 - 9 Jun 2026
Viewed by 193
Abstract
The AC rotary head, serving as a dual-axis direct-drive rotary actuation unit in five-axis CNC machine tools, integrates torque motors for A- and C-axis actuation, and its structural static and dynamic characteristics directly govern the actuation accuracy, dynamic response, and stability of the [...] Read more.
The AC rotary head, serving as a dual-axis direct-drive rotary actuation unit in five-axis CNC machine tools, integrates torque motors for A- and C-axis actuation, and its structural static and dynamic characteristics directly govern the actuation accuracy, dynamic response, and stability of the electromechanical system. Its complex spatial pose variations further complicate performance prediction. To overcome the difficulty of existing local optimization methods in balancing stiffness-mass matching for such complex actuation assemblies, this paper proposes a static and dynamic performance optimization method based on stiffness-mass matching. First, a pose-dependent semi-analytical dynamic model is established using dynamic condensation and component mode synthesis (CMS) to reveal performance distribution laws across the workspace and identify weak poses. Then, Sobol’ sensitivity analysis identifies key joints and structural components, and the NSGA-II algorithm optimizes their stiffness-mass matching. Finally, a surrogate model performs dimensional parameter optimization targeting the optimized matrices. Results show that the first-order natural frequency increases by 10.5%, translational static stiffness in the X and Y directions improves by over 20%, and other directions by 4.2–18.6%. The proposed method effectively enhances global static and dynamic performance, providing theoretical guidance for the structural design of direct-drive rotary actuators in electromechanical actuation systems. Full article
(This article belongs to the Section Actuators for Manufacturing Systems)
►▼ Show Figures

Figure 1

18 pages, 16525 KB  
Article
A Printed Circuit Board Stator Pattern for Loss Trade-Off Mitigation in Slotless Axial Flux Permanent Magnet Motors
by Ji-Won Moon, Hyung-Sub Han, Jung-Hoon Lee, Do-Hyeon Choi and Won-Ho Kim
Actuators 2026, 15(6), 327; https://doi.org/10.3390/act15060327 - 9 Jun 2026
Viewed by 283
Abstract
This study proposes a printed circuit board (PCB) stator pattern for alleviating the trade-off between DC copper loss and AC winding loss in a slotless axial flux permanent magnet motor (AFPM). The proposed pattern has a structure in which the width of the [...] Read more.
This study proposes a printed circuit board (PCB) stator pattern for alleviating the trade-off between DC copper loss and AC winding loss in a slotless axial flux permanent magnet motor (AFPM). The proposed pattern has a structure in which the width of the effective conductor region directly exposed to time-varying magnetic flux is reduced, and two additional conductors with the same width are placed within the available axial space and then connected in parallel through vias. Three-dimensional finite element analysis was performed while varying the effective conductor width ratio from 0.3 to 0.8, and an additional refined sweep was conducted in the range of α = 0.5–0.6, where the minimum total winding loss appeared in the initial sweep. Under the rated operating condition, the minimum total winding loss was obtained at α=0.53 based on the refined sweep results. Under this condition, the phase resistance, DC copper loss, AC winding loss, and total winding loss were reduced by 11.82%, 12.1%, 15.09%, and 12.48%, respectively. As a result, the efficiency increased from 81.53% to 83.5%, while the back electromotive force (BEMF), torque, and output were nearly unchanged. In addition, the AC winding loss distribution decreased in both the coil region closest to the magnets and the coil region farthest from the magnets. These results demonstrate that the proposed pattern is an effective design method for improving the winding loss characteristics of slotless PCB AFPM without meaningful degradation of the fundamental electromagnetic performance. Full article
(This article belongs to the Section High Torque/Power Density Actuators)
►▼ Show Figures

Figure 1

22 pages, 14217 KB  
Article
Control-Oriented Comparison of Electrode Placement Strategies in an Electrohydrodynamic Actuation System
by Itamar Goshen and Oded Medina
Actuators 2026, 15(6), 326; https://doi.org/10.3390/act15060326 - 8 Jun 2026
Viewed by 270
Abstract
This study investigates the controllability of a hovering platform based on ion thrust generated through the Biefeld–Brown effect. The primary objective is to examine the feasibility of stabilizing a triangular structure under laboratory conditions. To this end, three custom high-voltage power supplies were [...] Read more.
This study investigates the controllability of a hovering platform based on ion thrust generated through the Biefeld–Brown effect. The primary objective is to examine the feasibility of stabilizing a triangular structure under laboratory conditions. To this end, three custom high-voltage power supplies were developed, each independently controlled. These power supplies can be modulated through the control loop, enabling closed-loop adjustment of thrust levels and allowing assessment of how electrode placement influences stability. Two electrode configurations were tested: edge-based placement, where thrust is produced along the triangle’s sides, and vertex-based placement, where thrust is generated near the corners. Experimental results demonstrated that, while both configurations provide similar lifting capability, the vertex-based configuration significantly improves stabilization and orientation control. The improvement stems from reduced actuator coupling and a larger effective moment arm relative to the platform’s center of mass, enabling more efficient torque generation. Full article
(This article belongs to the Section Control Systems)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-76
Previous Issue
Next Issue
Back to TopTop