Research

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16 pages, 18082 KiB

Open AccessArticle

Research on Maximum Power Control of Direct-Drive Wave Power Generation Device Based on BP Neural Network PID Method

by Xinyu Fan and Hao Meng

Actuators 2024, 13(5), 159; https://doi.org/10.3390/act13050159 - 24 Apr 2024

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Ocean wave energy is a new type of clean energy. To improve the power generation and wave energy conversion efficiency of the direct-drive wave power generation system, by addressing the issue of large output errors and poor system stability commonly associated with the [...] Read more.

Ocean wave energy is a new type of clean energy. To improve the power generation and wave energy conversion efficiency of the direct-drive wave power generation system, by addressing the issue of large output errors and poor system stability commonly associated with the currently used PID (proportional, integral, and derivative) control methods, this paper proposes a maximum power control method based on BP (back propagation) neural network PID control. Combined with Kalman filtering, this method not only achieves maximum power tracking but also reduces output ripple and tracking error, thereby enhancing the system’s control quality. This study uses a permanent magnet linear generator as the power generation device, establishes a system dynamics model, and predicts the main frequency of irregular waves through the Fast Fourier Transform method. It designs a desired current tracking curve that meets the maximum power strategy. On this basis, a comparative analysis of the control accuracy and stability of three control methods is conducted. The simulation results show that the BP neural network PID control method improves power generation and exhibits better accuracy and stability. Full article

(This article belongs to the Special Issue Actuators in 2024)

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42 pages, 3511 KiB

Open AccessArticle

An Ice Protection System Based on Phased Piezoelectric Transducers

by Salvatore Ameduri, Antonio Concilio, Angela Brindisi and Bernardino Galasso

Actuators 2024, 13(5), 158; https://doi.org/10.3390/act13050158 - 24 Apr 2024

Viewed by 177

Abstract

This study focuses on a system constituted of two piezoelectric transducers installed on a slat representative element, with ice protection purposes. The waves generated by these actuators can cause, in fact, shear actions between the slat panel and the ice accretion, with the [...] Read more.

This study focuses on a system constituted of two piezoelectric transducers installed on a slat representative element, with ice protection purposes. The waves generated by these actuators can cause, in fact, shear actions between the slat panel and the ice accretion, with the final effect of breaking and detaching it. A property of the system is, however, the possibility of regulating the phase between the excitation signals of the two transducers. This capability can be exploited to produce local advantageous wave interference with a consequent amplification of the shear actions. Benefits can be obtained in terms of: (1) reduction of needed power; (2) recovery of signal intensity losses due to distance, geometric, and mechanic discontinuities; (3) recovery of non-optimal functionality due to off-design conditions. The work starts with an overview of the impact of the ice on the aeronautic and other sectors. Then, attention is paid to the systems currently used to protect aircraft, with a specific focus on ultrasounds generated by piezoelectric transducers. The concept proposed in this work is then presented, illustrating the main components and the working modality. On this basis and considering the specific nature of the physical phenomenon, the modeling approach was defined and implemented. At first, the impact of some critical parameters, such as the temperature and the thickness of the ice, was investigated. Then, the impact of the phase delay parameter was considered, estimating the increase of magnitude potentially reachable by means of optimal tuning. Finally, a preliminary experimental campaign was organized and a comparison with the numerical predictions was performed. Full article

(This article belongs to the Special Issue Actuators in 2024)

19 pages, 7110 KiB

Open AccessArticle

Deployable Structures Based on Non-Flat-Foldable and Non-Developable Origami with Constant Curvature

by Bo Qin, Shiwei Liu, Jianzhi Wang and Shengnan Lyu

Actuators 2024, 13(4), 156; https://doi.org/10.3390/act13040156 - 19 Apr 2024

Viewed by 268

Abstract

Deployable structures based on origami are widely used in the application of actuators. In this paper, we present a novel family of origami-based deployable structures with constant curvature. Two categories of non-flat-foldable and non-developable degree-4 vertices (NFND degree-4 vertices) are introduced. Pyramid structures [...] Read more.

Deployable structures based on origami are widely used in the application of actuators. In this paper, we present a novel family of origami-based deployable structures with constant curvature. Two categories of non-flat-foldable and non-developable degree-4 vertices (NFND degree-4 vertices) are introduced. Pyramid structures are constructed based on the NFND degree-4 vertices. Doubly symmetric and singly symmetric spherical origami tubular cells (SOTCs) are established based on pyramid structures. To construct deployable origami modules using SOTCs, linking units are introduced. The mobility of the SOTCs and origami modules is analyzed using constraint screws. To realize the construction and simulation of deployable structures, kinematic and geometric analyses of the doubly symmetric and singly symmetric SOTCs are performed. Finally, we introduce four cases for deployable structures in spherical actuators based on the combination of multiple origami modules. These case studies demonstrate the potential of these deployable origami structures in the design of spherical actuators. Full article

(This article belongs to the Special Issue Actuators in 2024)

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16 pages, 9180 KiB

Open AccessArticle

Non-Electrically Driven Acoustic Actuator

by Takeru Niwano and Mitsuharu Matsumoto

Actuators 2024, 13(4), 148; https://doi.org/10.3390/act13040148 - 16 Apr 2024

Viewed by 479

Abstract

Nuclear power plants have high radiation levels and humans cannot work directly on them. Therefore, it is necessary to establish effective repair work methods. One promising approach is the use of disaster relief robots. However, strong radiation affects circuits and electronic devices. Because [...] Read more.

Nuclear power plants have high radiation levels and humans cannot work directly on them. Therefore, it is necessary to establish effective repair work methods. One promising approach is the use of disaster relief robots. However, strong radiation affects circuits and electronic devices. Because typical robots contain electrical circuits and are controlled by radio waves, they are difficult to use in highly radioactive environments. In this study, we propose a non-electrically driven acoustic actuator that does not use electronic circuits and is driven by sound waves. To realize this goal, we have investigated a sound wave drive using a cylindrical container. Full article

(This article belongs to the Special Issue Actuators in 2024)

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15 pages, 6137 KiB

Open AccessArticle

Comparison of Magnetostrictive-Actuated Semi-Active Control Methods Based on Synchronized Switching

by An Li, Yuusuke Kobayashi, Yushin Hara, Keisuke Otsuka and Kanjuro Makihara

Actuators 2024, 13(4), 143; https://doi.org/10.3390/act13040143 - 12 Apr 2024

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Abstract

Three distinct synchronized switching circuits based on a magnetostrictive actuator are compared in this paper to examine their control mechanisms and circuit characteristics. These circuits include a semi-active shunt circuit, a semi-active current inversion and amplification circuit, and a semi-active automatic current inversion [...] Read more.

Three distinct synchronized switching circuits based on a magnetostrictive actuator are compared in this paper to examine their control mechanisms and circuit characteristics. These circuits include a semi-active shunt circuit, a semi-active current inversion and amplification circuit, and a semi-active automatic current inversion and amplification circuit. Each circuit type employs an additional electronic switch. The synchronized switching method enables the rational control of the circuit current generated by the magnetostrictive actuator to fulfill any desired control strategy. Simulation and experimental results on a 10-bay truss structure reveal that the three circuits can effectively adjust the polarity of the induced current as needed. The three circuits are then compared to thoroughly analyze their unique characteristics and explain their respective advantages and dis-advantages. Using the comparison results, various options available for control circuit design are demonstrated. Full article

(This article belongs to the Special Issue Actuators in 2024)

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15 pages, 4347 KiB

Open AccessArticle

A Novel DC Electroosmotic Micromixer Based on Helical Vortices

by Sri Manikandan Saravanakumar, Mohsen Jamshidi Seresht, Ricardo Izquierdo and Paul-Vahe Cicek

Actuators 2024, 13(4), 139; https://doi.org/10.3390/act13040139 - 09 Apr 2024

Viewed by 421

Abstract

This work introduces a novel direct current electroosmosis (DCEO) micromixer designed for rapid and efficient fluid mixing. This micromixer demonstrates excellent capability, achieving approximately 98.5% mixing efficiency within a one-second timespan and 99.8% efficiency within two seconds, all within a simple channel of [...] Read more.

This work introduces a novel direct current electroosmosis (DCEO) micromixer designed for rapid and efficient fluid mixing. This micromixer demonstrates excellent capability, achieving approximately 98.5% mixing efficiency within a one-second timespan and 99.8% efficiency within two seconds, all within a simple channel of only 1000 µm in length. A distinctive feature of this micromixer is its ability to generate robust and stable helical vortices by applying a controlled DC electric field. Unlike complex, intricate microfluidic designs, this work proposes a simple yet effective approach to fluid mixing, making it a versatile tool suitable for various applications. In addition, through simple modifications to the driving signal configuration and channel geometry, the mixing efficiency can be further enhanced to 99.3% in one second. Full article

(This article belongs to the Special Issue Actuators in 2024)

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14 pages, 977 KiB

Open AccessArticle

Adaptive Quick Sliding Mode Reaching Law and Disturbance Observer for Robust PMSM Control Systems

by Hyeongki Ahn, Sangkyeum Kim, Jihoon Park, Yoonuh Chung, Mingyuan Hu and Kwanho You

Actuators 2024, 13(4), 136; https://doi.org/10.3390/act13040136 - 08 Apr 2024

Viewed by 411

Abstract

The permanent magnet synchronous motor (PMSM) has been of interest to eco-friendly industries on account of its advantages such as high performance, efficiency, and precision control. However, perturbations due to PMSM parameter uncertainty, load torque, and external disturbance interfere with the construction of [...] Read more.

The permanent magnet synchronous motor (PMSM) has been of interest to eco-friendly industries on account of its advantages such as high performance, efficiency, and precision control. However, perturbations due to PMSM parameter uncertainty, load torque, and external disturbance interfere with the construction of PMSM precision control systems. Therefore, a robust control system is needed to avoid unnecessary system movement caused by perturbations. In this paper, sliding mode control (SMC) is adopted to implement a robust control system for the PMSM. In order to reduce the reaching time from the initial system state to the sliding surface and the chattering phenomenon that can cause the system to malfunction, the adaptive quick sliding mode reaching law based on an exponential function and power equation is proposed. Although the SMC is robust to disturbance and parameter uncertainty, unexpected disturbances can destabilize the system. To estimate the unmatched disturbance in a short time, the second-order fast terminal sliding mode observer (SFTSMO) is proposed. The results show that the motor control system based on the proposed method has a fast convergence speed to an objective value, position tracking performance, and robustness. Full article

(This article belongs to the Special Issue Actuators in 2024)

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23 pages, 1782 KiB

Open AccessArticle

Predefined Time and Accuracy Adaptive Fault-Tolerant Control for Nonlinear Systems with Multiple Faults

by Yakun Su, Yaling Jiang, Miao Tong and Huanqing Wang

Actuators 2024, 13(4), 131; https://doi.org/10.3390/act13040131 - 05 Apr 2024

Viewed by 452

Abstract

This work mainly studies the issue of predefined time and accuracy adaptive fault-tolerant control for strict-feedback nonlinear systems with multiple faults. The faults in the controlled system include actuator faults and external system faults. The unknown functions for nonlinear systems are approximated by [...] Read more.

This work mainly studies the issue of predefined time and accuracy adaptive fault-tolerant control for strict-feedback nonlinear systems with multiple faults. The faults in the controlled system include actuator faults and external system faults. The unknown functions for nonlinear systems are approximated by fuzzy logic systems (FLSs). And then, according to the backstepping technique and the predefined time stability theory, an adaptive fuzzy control algorithm is presented, which can make sure that all closed-loop system signals remain predefined time bound and the tracking error converges to a predefined accuracy within the predefined time. Ultimately, the effectiveness of the presented control algorithm is proved through two simulation examples. Full article

(This article belongs to the Special Issue Actuators in 2024)

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31 pages, 51418 KiB

Open AccessArticle

Reaction Force-Based Position Sensing for Magnetic Levitation Platform with Exceptionally Large Hovering Distance

by Reto Bonetti, Lars Beglinger, Spasoje Mirić, Dominik Bortis and Johann W. Kolar

Actuators 2024, 13(3), 114; https://doi.org/10.3390/act13030114 - 16 Mar 2024

Viewed by 892

Abstract

This work introduces a novel sensing concept based on reaction forces for determining the position of the levitating magnet (mover) for magnetic levitation platforms (MLPs). Besides being effective in conventional magnetic bearings, the applied approach enables operation in systems where the mover is [...] Read more.

This work introduces a novel sensing concept based on reaction forces for determining the position of the levitating magnet (mover) for magnetic levitation platforms (MLPs). Besides being effective in conventional magnetic bearings, the applied approach enables operation in systems where the mover is completely isolated from the actuating electromagnets (EMs) of the stator (e.g., located inside a sealed process chamber) while levitating at an extreme levitation height. To achieve active position control of the levitating mover by properly controlling the stator’s EM currents, it is necessary to employ a dynamic model of the complete MLP, including the reaction force sensor, and implement an observer that extracts the position from the force-dependent signals, given that the position is not directly tied to the measured forces. Furthermore, two possible controller implementations are discussed in detail: a basic PID controller and a more sophisticated state-space controller that can be chosen depending on the characteristics of the MLP and the accuracy of the employed sensing method. To show the effectiveness of the proposed position-sensing and control concept, a hardware demonstrator employing a 207 mm outer-diameter (characteristic dimension, CD) stator with permanent magnets, a set of electromagnets, and a commercial multi-axis force sensor is built, where a 0.36 kg mover is stably levitated at an extreme air gap of 104 mm. Full article

(This article belongs to the Special Issue Actuators in 2024)

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Review

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36 pages, 2377 KiB

Open AccessReview

Dielectric Elastomer-Based Actuators: A Modeling and Control Review for Non-Experts

by Hector Medina, Carson Farmer and Isaac Liu

Actuators 2024, 13(4), 151; https://doi.org/10.3390/act13040151 - 17 Apr 2024

Viewed by 456

Abstract

Soft robotics are attractive to researchers and developers due to their potential for biomimicry applications across a myriad of fields, including biomedicine (e.g., surgery), the film industry (e.g., animatronics), ecology (e.g., physical ‘animats’), human–robot interactions (e.g., social robots), and others. In contrast to [...] Read more.

Soft robotics are attractive to researchers and developers due to their potential for biomimicry applications across a myriad of fields, including biomedicine (e.g., surgery), the film industry (e.g., animatronics), ecology (e.g., physical ‘animats’), human–robot interactions (e.g., social robots), and others. In contrast to their rigid counterparts, soft robotics offer obvious actuation benefits, including their many degrees of freedom in motion and their potential to mimic living organisms. Many material systems have been proposed and used for soft robotic applications, involving soft actuators, sensors, and generators. This review focuses on dielectric elastomer (DE)-based actuators, which are more general electro-active polymer (EAP) smart materials. EAP-based soft robots are very attractive for various reasons: (a) energy can be efficiently (and readily) stored in electrical form; (b) both power and information can be transferred rapidly via electrical phenomena; (c) computations using electronic means are readily available. Due to their potential and benefits, DE-based actuators are attractive to researchers and developers from multiple fields. This review aims to (1) provide non-experts with an “easy-to-follow” survey of the most important aspects and challenges to consider when implementing DE-based soft actuators, and (2) emphasize current solutions and challenges related to the materials, controls, and portability of DE-based soft-actuator systems. First, we start with some fundamental functions, applications, and configurations; then, we review the material models and their selection. After, we outline material limitations and challenges along with some thermo-mechano-chemical treatments to overcome some of those limitations. Finally, we outline some of the control schemes, including modern techniques, and suggest using rewritable hardware for faster and more adaptive controls. Full article

(This article belongs to the Special Issue Actuators in 2024)

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