Characteristics Of Actuator Research Articles

Design and Characteristics of Shape Memory Alloy Bidirectional Torsional Actuator

To overcome the problems of the low power/weight ratio of traditional servo motors, complex transmission systems, and large space occupied by hydraulic drive systems, this paper designs a bidirectional torsional actuator using the shape memory effect of Ti-Ni shape memory alloy (SMA) wire, which aims to realize the folding and unfolding of the wings of flying cars. The model of the designed actuator was established and the theoretical calculation was analyzed, based on which the experimental verification was carried out. It is found that when the heating current is 1.6 A, the mechanism can take into account the economy under the premise of meeting a certain folding speed. When the pre-stretching amount of SMA wire is 3%, the residual strain corresponding to the wire is small, about 0.577%, and it can provide driving torque and torsion angle to meet the design requirements of the actuator. This verifies the feasibility of the actuator and obtains the driving characteristics of the actuator. Finally, the shortcomings and improvement measures of the actuator are analyzed briefly.

Design and Evaluation of Smart Textile Actuator with Chain Structure.

Textiles composed of fibers can have their mechanical properties adjusted by changing the arrangement of the fibers, such as strength and flexibility. Particularly, in the case of smart textiles incorporating active materials, various deformations could be created based on fiber patterns that determine the directivity of active materials. In this study, we design a smart fiber-based textile actuator with a chain structure and evaluate its actuation characteristics. Smart fiber composed of shape memory alloy (SMA) generates deformation when the electric current is applied, causing the phase transformation of SMA. We fabricated the smart chain column and evaluated its actuating mechanism based on the size of the chain and the number of rows. In addition, a crochet textile actuator was designed using interlooping smart chains and developed into a soft gripper that can grab objects. With experimental verifications, this study provides an investigation of the relationship between the chain actuator's deformation, actuating force, actuator temperature, and strain. The results of this study are expected to be relevant to textile applications, wearable devices, and other technical fields that require coordination with the human body. Additionally, it is expected that it can be utilized to configure a system capable of flexible operation by combining rigid elements such as batteries and sensors with textiles.

Effect of Structure on Driving Characteristics of the Tactile Pin Actuator for Reaction Force Variable Tactile Displays

Effect of Structure on Driving Characteristics of the Tactile Pin Actuator for Reaction Force Variable Tactile Displays

Nonlinear Inflatable Actuators for Distributed Control in Soft Robots.

As soft robotic systems grow in complexity and functionality, the size and stiffness of the needed control hardware severely limits their application potential. Alternatively, functionality can be embodied within actuator characteristics, drastically reducing the amount of peripherals. Functions such as memory, computation, and energy storage then result from the intrinsic mechanical behavior of precisely designed structures. Here, actuators are introduced with tunable characteristics to generate complex actuation sequences from a single input. Intricate sequences are made possible by harnessing hysteron characteristics encoded in the buckling of a cone-shaped shell incorporated in the actuator design. A large variety of such characteristics are generated by varying the actuator geometry. This dependency is mapped and used for creating a tool to determine the actuator geometry that yields a desired characteristic. Using this tool, a system with six actuators is created that plays the final movement of Beethoven's Ninth Symphony with a single pressure supply.

A chemotactic microrobot with integrated iridescent surface for optical-tracking

Recent advancements in materials, nanofabrication, actuation, and sensing have facilitated the development of untethered microrobots. However, realizing sub-millimeter-integrated microrobots with actuation, perception, and wireless communication capabilities remains elusive. In this study, we present the successful fabrication of chemotactic microrobots at the micron scale, featuring integrated iridescent structural color surfaces that can be utilized for robot motion control through optical tracking. Using a pH-responsive biopolymer as the carrier, we have created microrobots that employ bilayer joints, mimicking the actuation characteristics observed in arthropods. Additionally, biomimetic microstructures with structural color functionality have been incorporated onto the surface of the robots, serving as an optical-communication skin. The robots are actuated through reversible expansion triggered at the phase transition threshold of the biopolymer, while their geometric states and posture information are acquired by converting the volume strain into color variations. This research can potentially establish a critical pathway for developing state-feedback-controlled microrobots for future biomedical applications.

Design and dynamic analysis of a novel compound bending hollow piezoelectric beam miniature rotary actuator

In this paper, a miniature hollow piezoelectric beam rotary actuator is proposed and designed based on the compound bending vibration modes. The structure body is designed as an elastic hollow square beam with symmetrical piezoelectric patches attached at both ends, which directly eliminates the step of the frequency tuning. A conical rotor is driven by the hollow piezoelectric beam through the elliptical motions of the points on its inner surface. Based on the Timoshenko beam theory and Lagrange equation, the numerical continuum model is established to analyze the working mechanism. A prototype of the miniature rotary actuator with a size of 50 × 6 × 6 mm (2 mm through-hole) is manufactured and its performance under various excitation parameters is characterized in rotor speed experiments. The experimental results show that the maximum speed of the conical rotor is 913 rpm at the excitation voltage of 400 V. With a maximum load of 70.31 mN, the spherical rotor can achieve a speed of 450 rpm. The numerical results are in great agreement with the experimental results, so the output characteristics of the rotary actuator can be estimated. The simulation and test results demonstrate that the proposed rotary actuator has outstanding output performance and controllability. In addition, the simple structure design is easy to realize the frequency tuning and miniaturization.

High-integrated micro permanent magnet linear actuator positioning system

A tunnel magnetic resistance (TMR) sensor is a magnetic detection sensor with low power consumption and high sensitivity. The TMR sensor has promising applications in the position detection of micro permanent magnet linear actuators since the surrounding magnetic field of the micro actuator in this paper will be changed by its movement. Firstly, according to the air-gap magnetic field distribution characteristics of the micro permanent magnet linear actuator and the detection principle of the TMR sensor, the integrated installation parameters of TMR sensors were determined. Then, with the help of TMR technology, the backpropagation neural network (BPNN) algorithm and improved BPNN using particle swarm optimization (PSO) algorithm were used to study the position identification strategy of the slider, and the algorithm strategy with the minimum error was selected. Finally, the experimental results show that the slider position identification strategy based on the PSO-BPNN algorithm can achieve position tracking error within 0.1 mm under the given step position tracking and sinusoidal position tracking, and the movements can be repeated well.

Nanosecond plasma actuation by a bending actuator mounted on a sharp edge in quiescent air

An experimental investigation of the actuation characteristics of a repetitive nanosecond pulsed dielectric barrier discharge from bending plasma actuators mounted on a sharp edge is conducted. Four bending actuators with different bending angles are tested and compared with a planar actuator in quiescent air using schlieren imaging and electrical measurements. The results show that when fed by the same pulse, the plasma morphology, current waveform, and energy consumption of the bending and planar actuators are very similar. However, the thermal perturbations and induced flows differ significantly. In this experiment, at a low load voltage (V = 10–14 kV), when the plasma discharge is in the diffuse mode, the bending actuator can induce a stronger vortex and near-wall jet than the planar actuator, and as the bending angle decreases, the strength of the induced jet increases rapidly. At a higher load voltage (V = 18–20 kV), when the discharge is in the constricted mode, the plasma filaments produce hot plumes with both the bending and planar actuators, but the hot plumes from the bending actuator are injected into the air with a larger incidence. During the streamer-to-filament transition (V = 16 kV), induced flows from small-bending-angle (30° and 60°) actuators are characterized by a thickened near-wall jet, while those from the planar actuator are characterized by hot plumes.

Increasing the Force Exertion of a Soft Actuator Using Externally Attachable Inter-Chamber Plates

The application of soft actuators has become increasingly common in wearable devices. In this study, we investigated the force characteristics of soft actuators made entirely of elastic material, when equipped with solid external chamber plates of varying thickness that can be attached from the outside. This study examines the effect of these plates on the force characteristics of a fully silicone-based fifteen-chamber soft actuator without any non-stretchable internal components. The parameters of the actuator were determined with consideration of wearable applications, such as rehabilitation devices and exoskeletons. The observed differences in the behavior of the actuator at various pressure levels and plate thicknesses were measured. Furthermore, the effect of the externally inserted plates between the chambers on the passive bending of the actuator was examined. The obtained results were evaluated and compared to determine how external chamber plates of given thicknesses affect the operational performance of a soft actuator.

Parameter Identification of Model for Piezoelectric Actuators.

Piezoelectric actuators are widely used in high-precision positioning systems. The nonlinear characteristics of piezoelectric actuators, such as multi-valued mapping and frequency-dependent hysteresis, severely limit the advancement of the positioning system's accuracy. Therefore, a particle swarm genetic hybrid parameter identification method is proposed by combining the directivity of the particle swarm optimization algorithm and the genetic random characteristics of the genetic algorithm. Thus, the global search and optimization abilities of the parameter identification approach are improved, and the problems, including the genetic algorithm's poor local search capability and the particle swarm optimization algorithm's ease of falling into local optimal solutions, are resolved. The nonlinear hysteretic model of piezoelectric actuators is established based on the hybrid parameter identification algorithm proposed in this paper. The output of the model of the piezoelectric actuator is in accordance with the real output obtained from the experiments, and the root mean square error is only 0.029423 μm. The experimental and simulation results show that the model of piezoelectric actuators established by the proposed identification method can describe the multi-valued mapping and frequency-dependent nonlinear hysteresis characteristics of piezoelectric actuators.

Temperature dependence modeling and experimental evaluation of a multidimensional discrete magnetostrictive actuator

Active combustion control has shown a bright prospect for suppressing aero-engine combustion oscillations but also puts forward higher requirements for the actuator on the high bandwidth, large stroke, and high weight-power ratio. A multidimensional discrete magnetostrictive actuator proposed in our previous work can meet these requirements simultaneously. However, the temperature of the working environment around the aero-engine is high, so it is essential to further investigate the temperature-dependent characteristics of the actuator. In this paper, a multi-physics coupled temperature-dependent analytical model is developed, and the influence mechanism of temperature on the actuator is analyzed from the perspective of physics with a wide field of view from the material level to the actuator system level. Experiments based on a fabricated prototype were conducted and the results indicate that both the stroke, hysteresis, and closed-loop tracking performance of the actuator decrease with the increase in temperature, but the temperature has little effect on the frequency response; the proposed analytical model can accurately describe the temperature-dependent output characteristics of the multidimensional discrete magnetostrictive actuator, the root mean square error of which is less than 3% within 200 Hz.

Photothermal and Humidity Stimulus-Responsive Self-Sensing Soft Actuators for Smart Packaging

Soft actuators with both actuation and self-sensing characteristics can better adapt to the environment and more effectively realize intelligent human–machine interactions, which is highly desired for the upcoming era of soft robotics. Herein, a multi-stimulus response actuator (MSRA) is constructed based on the asymmetric expansion principle, and the sensing function is simply and quickly integrated into the soft actuator by screen printing technology. Taking advantage of the good photothermal conversion performance of the dopamine-modified graphene oxide (DGO) layer and the difference in the expansion coefficient between the DGO layer and the poly(vinylidene fluoride)/polydimethylsiloxane layer, the soft actuators exhibit different actuation behaviors under photothermal and humidity stimuli, respectively. Meanwhile, the introduction of a printed carbon black/highly elastic transparent adhesive cement sensing layer gives MSRA a self-sensing function which can provide feedback on its actuation process in real time. In addition, various complex deformations can be achieved by the macroscopic assembly of several actuators. Finally, we show that this soft actuator can be used as a smart packaging material to realize smart packaging. We believe that actuators with sensing feedback are significant in soft robots and smart packaging.

Preface

Nowadays, global energy industry is facing much more challenges ever. On the one hand, speeding up the transition to clean, renewable energy is one of the best ways to curb the dangerous carbon pollution that causes environment issue. On the other hand, smart grid and micro grid technology in the power systems are widely expected to improve sustainable energy efficiency. The International Conference on Energy and Electrical Power Systems is a leading academic conference, aiming at building a platform for communication and academic exchange in related fields.This volume contains the papers presented at the 2022 International Conference on Energy and Electrical Power Systems (ICEEPS 2022), held on November 25th-27th, 2022 in Guangzhou, China (virtual event). Everyone interested in this field were welcomed to join the online conference and to give comments and raise questions to the speeches and presentations.The online conference was composed of keynote speeches, oral presentations, and academic investigation, attracting about 150 individuals from all over the world. We have invited four sophisticated professors to perform keynote speeches. Among them, Prof. Kai Wang from Qingdao University, China is one of our keynote speakers and delivered a dramatic speech on the title Research on Life Prediction of Supercapacitor based on Improved Long-Term and Short-Term Memory Neural Network. Next, Prof. Huajun Dong from Dalian Jiaotong University, China performed a speech on Researches on Characteristics of Vacuum Switching Arc and Actuator. And then, Assoc. Prof. Yongzhi Ma from Qingdao University, China made a report on Research on Innovative Design of Split-Type All-Air Air Conditioning in Middle Apartment of Tall Buildings. Last but not the least, Prof. Abdul Hasib Chowdhury from Bangladesh University of Engineering and Technology, China shared with us his study A Talk on Stability and Resiliency of the Bangladesh Power System. All the keynote speakers made brilliant speeches combing their own research domains and experiences, and shared unique experience and insights, creating a great platform for academic communication.ICEEPS 2022 received a great many submissions in the areas of power electronics and advanced control. Each submission was reviewed by at least two expert reviewers and the committee picked out some excellent papers that are included in the proceedings, including but not limited to the following topics: Advanced Power Semiconductors, Control Science and Control Engineering, Electromagnetic Compatibility, Power Electronics and Power Drives, Power System Stability, etc.On behalf of the Conference Organizing Committee, we would like to extend our sincere acknowledgement to all the keynote speakers, peer reviewers, and all the participants. In particular, our heartfelt thanks and appreciation go to the Editors and Managers, Journal of Physics: Conference Series for their help and kind cooperation during the preparation of the proceedings. Hopefully, all participants and other interested readers can benefit significantly from the proceedings and find it rewarding.The Committee of ICEEPS 2022List of Committee member is available in this pdf.

A bio‐gel electric actuator prepared from tannic acid and carboxymethyl cellulose by green cross‐linking process with good output performance

AbstractIn this article, a chitosan‐based bio‐gel electric actuator with tannic acid and carboxymethyl cellulose (CMC)as cross‐linked materials was fabricated. By evaluating the output force and electrochemical characteristics of the electric actuator under different doping amounts of tannic acid and CMC, it was found that the sample with appropriate amount of cross‐linking can improve its output force, service life, specific capacitance. Infrared spectroscopy, scanning electron microscopy(SEM), and ion channel test showed that tannic acid and CMC were uniformly distributed in the chitosan matrix. The proper crosslinking was beneficial to transform the internal dense and uniform structure into a loose and porous structure, promote the migration of ions, improve the electrochemical performance of the electric actuator, and thereby improve its output performance. This study provided a facile and eco‐friendly method to construct chitosan‐based electromotive membrane with enhanced output properties.

Reliability of tunable lenses: feedback sensors and the influence of temperature, orientation, and vibrations.

We compare different aspects of the robustness to environmental conditions of two different types of piezo-actuated fluid-membrane lenses: a silicone membrane lens, where the piezo actuator indirectly deforms the flexible membrane through fluid displacement, and a glass membrane lens, where the piezo actuator directly deforms the stiff membrane. While both lenses operated reliably over the temperature range of 0°-75°C, there was a significant effect on their actuation characteristics, which can be well described through a simple model. The silicone lens in particular showed a variation in focal power of up to 0.1m-1 ∘C-1. We demonstrated that integrated pressure and temperature sensors can provide feedback for focal power, however, limited by the response time of the elastomers in the lenses, with polyurethane in the support structures of the glass membrane lens being more critical than the silicone. Studying the mechanical effects, the silicone membrane lens showed a gravity-induced coma and tilt, and a reduced imaging quality with the Strehl ratio decreasing from 0.89 to 0.31 at a vibration frequency of 100Hz and an acceleration of 3g. The glass membrane lens was unaffected by gravity, and the Strehl ratio decreased from 0.92 to 0.73 at a vibration of 100Hz, 3g. Overall, the stiffer glass membrane lens is more robust against environmental influences.

The Development of Piezoelectric Inchworm Actuator Clamped With Magnetorheological Elastomer and Its Potential Application in Brain–Computer Interface Implantation

The piezoelectric inchworm actuator with high-positioning accuracy and large output force is a potential device to implant microelectrode in the invasive brain–computer interface (BCI). However, the traditional piezoelectric inchworm actuator adopts multichannel electrical control signals from external equipment and rigid-to-rigid friction contact to drive, resulting in complex control and uneven friction. To solve the above problems, in this article, magnetorheological elastomer (MRE) is first proposed as the clamping material of the piezoelectric inchworm actuator. An MRE–capillary–cover sandwich structure is adopted to achieve rigid-to-elastomeric clamping. The driving and clamping actions of the actuator are controlled by two cam mechanisms mounted on the same shaft, and a battery can feed the actuator. A kinetic model is established to analyze and predict the actuator motion. Several crucial clamping parameters are explored, and the performance experiments are conducted to evaluate actuator characteristics. A verification experiment is carried out to prove the feasibility of the microelectrode implantation in the pig brain (0.6% agarose gel). The actuator can reach the maximum velocity of 1250.4 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m/s and the maximum output force of 420 mN; in the forward/backward motion, the minimum step is 0.5837/0.5912 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m, and the repeatability is 0.0465/0.0469 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m; thus, the actuator has great application potential in BCI.

Design and experiment of a large displacement linear piezoelectric actuator

To increase the output displacement of the linear piezoelectric actuator, a linear piezoelectric actuator with large displacement and three operation modes is proposed. The operating principle of the piezoelectric actuator is presented. The magnification factor of the displacement amplification mechanism is deduced and verified by finite element analysis. To improve the output precision of the actuator, a feedforward PID control model is established. Based on the experimental test platform, the output characteristics of the piezoelectric actuator are tested. Results show the maximum output displacement of the piezoelectric actuator is 558.3 μm under a driving voltage of 150 V with two piezoelectric stacks. When the driving frequencies are less than 3 Hz, the control accuracy of feedforward PID is higher than that of PID, and the error between the measured displacement and the ideal value is less than 10% after applying the control to the piezoelectric actuator.

Virtual flight test of pitch and roll attitude control based on circulation control of tailless flying wing aircraft without rudders

Circulation Control (CC) realizes rudderless flight control by driving compressed air jet to generate a virtual rudder surface, which significantly improves low detectability. The layout plan of combined control rudder surface is proposed based on the tailless flying wing aircraft. The closed-loop jet actuator system and stepless rudder surface switching control strategy are used to quantitatively study the control characteristics of circulation actuator for pitch and roll attitude through 3-DOF virtual flight test in a wind tunnel with a powered model at wind speed of 40 m/s. The results show that the combined use of circulation actuators can achieve bidirectional continuous and stable control of the aircraft’s pitch and roll attitude, with the maximum pitch rate of 12.3 (°)/s and the maximum roll rate of 21.5 (°)/s; the response time of attitude angular rate varying with the jet pressure ratio is less than 0.02 s, which can satisfy the control response requirements of aircraft motion stability for the control system; the jet rudder surface has a strong moment control ability, and the pitch moment of the jet elevator with a pressure ratio of 1.28 is the same as that of the mechanical elevator with 28° rudder deflection, which can expand the flight control boundary.

Modeling of Rapid Response Characteristics of Piezoelectric Actuators for Ultra-Precision Machining

Piezoelectric actuators are characterized by high positioning accuracy, high stiffness and a fast response and are widely used in ultra-precision machining technologies such as fast tool servo technology and ultrasonic machining. The rapid response characteristics of piezoelectric actuators often determine the overall quality of machining. However, there has been little research on the fast response characteristics of piezoelectric actuators, and this knowledge gap will lead to low precision and poor quality of the final machining. The fast response characteristics of a piezoelectric actuator were studied in this work. Firstly, the piezoelectric actuator was divided into a no-load state and a load state according to the working state. A fast response analysis and output characteristic analysis were carried out, the corresponding dynamic model was established, and then the model was simulated. Finally, an experimental system was established to verify the dynamic model of the piezoelectric actuator's fast response by conducting an experiment in which the piezoelectric actuator bounces a steel ball. The experimental results verify the correctness of the model and show that the greater the cross-sectional area and height of the piezoelectric actuator, the higher the bouncing height of the ball, and the better the dynamic performance of the piezoelectric actuator. It is believed that this study has guiding significance for the application of the dynamic characteristics of piezoelectric actuators in the machining field.

Analysis of ideal models of real nonlocal acoustic and elastic metamaterials

Nonlocal coupling in acoustic and elastic systems has received growing attention for its potential to expand the capabilities of active metamaterials. Previously, we have shown experimentally how nonlocality imposed through action at a distance, where signals from disturbances at one location are used to drive actuators at separate locations, gives rise to unique scattering characteristics, namely highly nonreciprocal transmission. We showed how the mathematical models for these experimental systems were excellent predictors for real system behavior, and as such, represented powerful experimental design tools. However, these models were elaborate, incorporating the characteristics of real sensors and actuators, electronic controllers, and material properties and geometries, consequently obscuring the underlying nonlocal physics responsible for their unique behavior. Here, we present simplified models of these real systems that feature closed form expressions for system scattering characteristics, allowing for the identification of relevant dimensionless quantities and revealing how the interactions of those quantities affect both system performance and stability. We compare and contrast ideal models for both acoustic and elastodynamic nonlocal systems, highlighting how each ideal model is qualitatively representative of its real counterpart, thus providing a pathway to a deeper understanding and further exploration of nonlocality in wave-bearing systems.