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Compact geared servo drives are a common part of modern industrial automation; thus, their proper modelling is a necessary part for the application and control design. The presented paper focuses on the mathematical model of the cycloidal gearbox, which is used in the compact actuator with a permanent magnet synchronous motor. A measurement procedure to obtain the necessary gearbox parameters is presented along with its mathematical model. A new approach was used to model the stiction and nonlinear gearbox friction behaviour in all four quadrants. A simulation of the actuator with the modelled gearbox is described and its results are compared with the real system measurement. Obtained results show a high match between simulation and experimental results and confirm the correctness of the simulation model. [ABSTRACT FROM AUTHOR]

This paper presents the results of experimental and numerical investigations on synthetic jet actuators with various arrangements. First, an actuator with one membrane in the cavity is a standard, reference arrangement; and second, one novel modified arrangement has two membranes in the cavity. Authors use constant temperature-anemometry measurements to identify the characteristic frequencies in which the output jet velocity reaches a maximal value, namely, the resonant frequency of the actuator (Helmholtz frequency) and of the membrane (structural resonance). A numerical model of a synthetic jet actuator has been validated using experimental data for the case with one membrane in a cavity. The simulation results confirm the existence of a toroidal vortex at the actuator exit for the frequencies determined in the experiment. Numerical results of a modified actuator with two membranes in the cavity give promising results in the context of separation control by synthetic jet devices, i.e., increase of output velocity and vorticity from the same occupied space is obtained. Numerical simulations show that in the modified actuator with two membranes in the cavity, the jet output velocity and vorticity of a created toroidal vortex at the actuator outlet can be increased by 80%, compared to the case with one membrane. The new geometry of a synthetic jet actuator with perpendicular membranes is to be implemented into the wind tunnel measurements to prove the use of a modified synthetic jet actuator as a device applicable for active flow control. [ABSTRACT FROM AUTHOR]

Rehabilitation robots have become one of the main technical instruments that Treat disorder patients in the biomedical engineering field. The robotic glove for the rehabilitation is basically made of specialized materials which can be designed to help the post-stroke patients. In this paper, a review of the different types of robotic glove for Rehabilitation have been discussed and summarized. This study reviews a different mechanical system of robotic gloves in previous years. The selected studies have been classified into four types according to the Mechanical Design: The first type is a tendon-driven robotic glove. The second type of robotic glove works with a soft actuator as a pneumatic which is operated by air pressure that passes through a plastic pipe, pressure valves, and air compressor. The third type is the exoskeleton robotic gloves this type consists of a wearable mechanical design that can used a finger-based sensor to measure grip strength or is used in interactive video applications. And the fourth type is the robotic glove with a liner actuator this type consists of a tape placed on the fingers and connected to linear actuators to open and close the fingers during the rehabilitation process. [ABSTRACT FROM AUTHOR]

To achieve the control of a small-sized robotmanipulator, we focus on an actuator using a shape memory alloy (SMA). By providing an adjusted voltage, an SMA wire can itself generate heat, contract, and control its length. However, a strong hysteresis is generally known to be present in a given heat and deformation volume. Most of the control methods developed thus far have applied detailed modeling and model-based control. However, there are many cases in which it is difficult to determine the parameter settings required for modeling. By contrast, iterative learning control is a method that does not require detailed information on the dynamics and realizes the desired motion through iterative trials. Despite pioneering studies on the iterative learning control of SMA, convergence has yet to be proven in detail. This paper therefore describes a stability analysis of an iterative learning control to mathematically prove convergence at the desired length. This paper also details an experimental verification of the effect of convergence depending on the variation in gain. [ABSTRACT FROM AUTHOR]

Due to the rapid development of intelligent technology and the pursuit of green environmental protection, responsive materials with single response and actuation can no longer meet the requirements of modern technology for intelligence, diversification, and environmental friendliness. Therefore, intelligent responsive materials have received much attention. In recent years, with the development of new materials and technologies, cellulose materials have become increasingly used as responsive materials due to their advantages of sustainability and renewability. This review summarizes the relevant research on cellulose-based intelligent responsive materials in recent years. According to the stimuli responses, they are divided into temperature-, light-, electrical-, magnetic-, and humidity-responsive types. The response mechanism, application status, and development trend of cellulose-based intelligent responsive materials are summarized. Finally, the future perspectives on the preparation and applications of cellulose-based intelligent responsive materials are presented for future research directions. [ABSTRACT FROM AUTHOR]

In this paper, an adaptive sliding mode controller (ASMC) is proposed for an electromechanical clutch position control system to apply in the automated manual transmission. Transmission systems undergo changes in parameters with respect to the wide range of driving condition, such as changing in friction coefficient of clutch disc and stiffness of diaphragm spring, hence, an adaptive robust control method is required to guarantee system stability and overcome the uncertainties and disturbances. As the majority of transmission dynamics variables cannot be measured in a cost-efficient way, a non-linear estimator based on unscented Kalman filter (UKF) is designed to estimate the state valuables of the system. Also, a non-linear dynamic model of the electromechanical actuator is presented for the automated clutch system. The model is validated with experimental test results. Numerical simulation of a reference input for clutch bearing displacement is performed in computer simulation to evaluate the performance of controller and estimator. The results demonstrate the high effectiveness of the proposed controller against the conventional sliding mode controller to track precisely the desired trajectories. [ABSTRACT FROM AUTHOR]

This paper deals with the electrohydrodynamic airflow control realized by the kinetic energy provided by an electrical discharge created at the surface of a dielectric material. We will present the results of the airflow control above an NACA0015 profile, this application is ensured by the action of the ionic wind generated by an applied dc corona discharge. The actuation consists in creating a nonthermal plasma sheet at the NACA0015 suction side. Plasma is created between two electrodes flush-mounted on the surface of the airfoil and excited with a dc power supply. To highlight the effect of plasma actuator on the free airflow, we will present streamlines fields with plasma actuator ON and OFF. We will show that the plasma sheet can modify the size of the mean recirculation region and that it changes the flow topology. In addition, the observed velocity profiles above the NACA0015 highlight the reduction of the boundary layer thickness under the effect of the corona electrical discharge. [ABSTRACT FROM PUBLISHER]

The paper presents the motivations for the application of actively controlled elements in the running gear of a rail vehicle and the challenges that need to be addressed before deploying vehicles with actively controlled elements in real operation. Furthermore, the paper presents the design of an active element concept and its control for steering the axles of an urban rail vehicle to improve the vehicle’s passage through small radius curves. The design takes into account the fundamental issues of cost and safety of the application of active elements, which are addressed in the presented control design by using data from autonomous driving subsystems such as the environmental database or the anti-collision system.

The objective of this review paper is to discuss the various channel access methodologies applied in various sensor and actuation based wireless networks. In most of Wireless Sensor Networks (WSNs) researchers have focused on priority centered approaches for channel accessibility. This paper also explains the procedure for Medium Access Control (MAC) in Cyber Physical Systems (CPSs) which is a combination of Wireless Sensor Actuator Networks (WSANs) and WSNs. Finally, we discuss the successive collision avoidance technique using the IEEE 802.11 MAC protocol, and also brief on how the Internet of Thing (IoT) approach connects and transfers information among smart devices linked in a wireless network. [ABSTRACT FROM AUTHOR]

Linear first/second order fin direct current (DC) actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX) performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviour. [ABSTRACT FROM AUTHOR]

An electromagnetic proportional solenoid is used as a force control device to generate thrust force acting on a valve element in a hydraulic pressure control valve. However, a conventional proportional solenoid has the problem of hysteresis appearing in its current–thrust force characteristics, which is induced by friction and magnetic hysteresis. In order to reduce hysteresis, this paper proposes the three-phase ac solenoid that reproduces a pseudo-magnetic bearing. Its prototype reduces hysteresis and achieves the same performance as the conventional proportional solenoid. The magnetic pole shape and the current input condition considering the magnetic flux density saturation are presented based on electromagnetic field analysis. [ABSTRACT FROM AUTHOR]

In this paper we introduce the concept, modelling and analysis of triangular and sinusoidal springs intended for large in-plane translational displacements for MEMS-guiding applications. The proposed spring systems combine the advantages of minimal space requirement, low stiffness in the axial direction and high mechanical resistance in off-axis directions. An analytical model for the description of the force-displacement characteristic of triangular springs is derived considering typical mechanical constraints. Based on the model, geometrical parameters of the springs influencing linearity and selectivity with respect to the in- and off-axis stiffness are analyzed. The validity of the models is demonstrated by finite element analysis and experimental verification realized by silicon-on-insulator demonstrators. [2020-0360] [ABSTRACT FROM AUTHOR]

A rotational/linear two degrees-of-freedom switched reluctance motor (2DOF-SRM) has been developed for the purpose of independent control of rotational and linear actuations on one actuator. In the previous study, noncontact-type angular and linear position sensing system that used photoelectric sensors was developed. It was successfully applied to the independent rotational speed and linear displacement control of the 2DOF-SRM. In this paper, both the torque and thrust control are developed as the new function of the 2DOF-SRM. This control is achieved by the electric current control for each phase windings. In this system, actual torque and thrust are independently estimated by a simplified matrix expression from the information of the phase winding current. The performance test results for torque and thrust estimation are presented. [ABSTRACT FROM PUBLISHER]

The conversion of electrical to mechanical power on a sub-centimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper, we present a type of a capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These microhydraulic actuators use a high surface-to-volume ratio to deliver high power at a relatively low voltage with an energy conversion efficiency of over 65%. The capillary pressure generated grows linearly with shrinking capillary diameter, as does the frequency of actuation. We present the pressure, frequency, and power scaling properties of these actuators and demonstrate that power density scales up as the inverse capillary diameter squared, leading to high-efficiency actuators with a strength density exceeding biological muscle. Two potential applications for microhydraulics are also demonstrated: soft-microrobotics and energy harvesting. [2015-0214] [ABSTRACT FROM PUBLISHER]

This paper proposes a novel ten-phase fault-tolerant permanent-magnet synchronous motor (FTPMSM) with two stators and two rotors on the same shaft. Furthermore, a concentrated, single-layer, and alternate-teeth-wound winding is adopted to enhance the fault isolation capacity of the motor. In addition, we propose a new approach to the speed control of the developed motor, which takes the electromagnetic torque ripple in the fault switch process into account. The control can guarantee the uniform boundedness and uniform ultimate boundedness of the system regardless of the load disturbance and the parameter variation, particularly for the fault switch process after a fault occurrence before the fault-tolerant control can take effect. Moreover, an optimal torque control is adopted to further improve the fault-tolerant performance, which enables a ripple-free torque operation under open-circuit and short-circuit fault conditions. Simulation and experimental results show that the FTPMSM system with the proposed control strategy has excellent fault-tolerant performance and good robustness. This paper provides an innovative approach by employing a robust control for a speed loop to guarantee the fault-tolerant performance of the proposed motor system under normal and fault conditions, even in the fault switch process. [ABSTRACT FROM PUBLISHER]

Paper deal with experimental identification of the electro-mechanical linear actuator properties. Force-velocity dependence and positional accuracy has been identified. Results show the difference between the data declared via producer and experimental obtained data. [ABSTRACT FROM AUTHOR]

This review paper discusses the development trends of agricultural autonomous all-terrain vehicles (AATVs) from four cornerstones, such as (1) control strategy and algorithms, (2) sensors, (3) data communication tools and systems, and (4) controllers and actuators, based on 221 papers published in peer-reviewed journals for 1960–2023. The paper highlights a comparative analysis of commonly employed control methods and algorithms by highlighting their advantages and disadvantages. It gives comparative analyses of sensors, data communication tools, actuators, and hardware-embedded controllers. In recent years, many novel developments in AATVs have been made due to advancements in wireless and remote communication, high-speed data processors, sensors, computer vision, and broader applications of AI tools. Technical advancements in fully autonomous control of AATVs remain limited, requiring research into accurate estimation of terrain mechanics, identifying uncertainties, and making fast and accurate decisions, as well as utilizing wireless communication and edge cloud computing. Furthermore, most of the developments are at the research level and have many practical limitations due to terrain and weather conditions.

The first part of the paper presents the topological structure of the horse skeleton, highlighting the tubular architecture of long bones that is mechanically conditioned by the stresses to which the bone is subjected during walking. The mechanical structure of the bone acts as reinforced concrete, consisting of the fibrillated fundamental matter, molecularly embedded by lime salts. The muscle structure of the same-side horse limbs (anterior and posterior) is pointed out. The muscles are the actuators that allow the movement and coordination of the movement of each horse leg. In the second part of the paper two models of constructive schemes of the anterior and posterior limbs have been considered. The kinematic schemes of the two articulated planar models have been achieved. The topological structure of each kinematic scheme has been analyzed by highlighting the consisting kinematic elements, the specific kinematic joints, and by confirming the degree of mobility using an original formula. [ABSTRACT FROM AUTHOR]

The rotary type electromagnetic actuator is often used in the electromagnetic mechanical components design, such as high-sensibility switch, signal electromagnetic relay, and so on. This type of actuator is required to have high conversion speed and action frequency, high signal reliability, and low power consumption per volume. In this paper, a new type of rotary electromagnetic actuator with permanent magnet (PM) is designed. Based on the polarity characteristics of PM, a couple of coils are designed in diagonal direction. A flux guide path is designed to optimize the magnetic circuit. PM is applied as the armature, and the electromagnetic system and the contact system are designed individually, which can achieve a high level maximum space utilization. In order to study the characteristic of PM, the PM is divided into several subsections. The migration analysis of the working point based on analytic model is carried on for the selection of PM, and the precise static characteristics of the actuator are analyzed by the finite-element model. The prototype actuator is assembled and tested, and the advantages of fast conversion speed and high reliability is verified by the test. [ABSTRACT FROM AUTHOR]

The abundance of resources in the deep sea continues to inspire mankind’s desire for exploration. However, the extreme environments pose a huge challenge for designing deep-sea mechanical devices that are primarily driven by hydraulic and electric motor technology. Researchers are beginning to explore more flexible and innovative drive methods suitable for the deep-sea environment. This paper presents a simple joint mechanism based on a paraffin phase change thermal expansion drive. Its unique design combines a flexible cell with an open structure that allows it to adapt to different pressures at different water depths. Paraffin is enclosed in multiple sets of smaller paraffin cells, which act as thermal expansion material for generating hydraulic pressure. The software comsol was used to perform a finite element analysis of the phase change process in paraffin. By fabricating the mechanical structure, the displacement generated by the thermal expansion is amplified and converted, thus enabling a bi-directional rotational displacement output from the joint while reducing the complexity of the structure. The joints in this paper provide a reliable reference for the design of small deep-sea robot drive systems.

Soft actuators that execute diverse motions have recently been proposed to improve the usability of soft robots. Nature-inspired actuators, in particular, are emerging as a means of accomplishing efficient motions based on the flexibility of natural creatures. In this research, we present an actuator capable of executing multi-degree-of-freedom motions that mimics the movement of an elephant's trunk. Shape memory alloys (SMAs) that actively react to external stimuli were integrated into actuators constructed of soft polymers to imitate the flexible body and muscles of an elephant's trunk. The amount of electrical current provided to each SMA was adjusted for each channel to achieve the curving motion of the elephant's trunk, and the deformation characteristics were observed by varying the quantity of current supplied to each SMA. It was feasible to stably lift and lower a cup filled with water by using the operation of wrapping and lifting objects, as well as effectively performing the lifting task of surrounding household items of varying weights and forms. The designed actuator is a soft gripper that incorporates a flexible polymer and an SMA to imitate the flexible and efficient gripping action of an elephant trunk, and its fundamental technology is expected to be used as a safety-enhancing gripper that requires environmental adaptation. [ABSTRACT FROM AUTHOR]

The use of lightweight materials such as carbon fibre reinforced plastics (CFRP) is increasing due to the demand for rising resource and energy efficiency, especially in the aerospace and automotive industries. Because of the high delamination tendency of these materials and their abrasive impact on the tool, the challenges in machining CFRP lie primarily in the drilling process and thus in the design of the drilling tool. In this paper, an innovative design of a drilling tool for machining CFRP with force-controlled radial feed movement of the cutting edges is presented. The aim of this tool is to create a tool axial force free process that uses a force-controlled radial feed motion, which matches the chip cross-section to the wear condition of the cutting edge. The tool concept is explained based on the functionality of the actuating process. Tests were evaluated with regard to process forces and drilling quality to show that the tool is capable of producing delamination-free bores in a tool axial force free process. [ABSTRACT FROM AUTHOR]

In order to improve the quality of the laser and shorten the optical path of the fast steering mirror (FSM) laser compensation system, this paper proposes a four-degrees-of-freedom (4-DOF) voice coil motor (VCM) with the function of reducing laser geometrical fluctuations. The feature of this paper is the combination of a DC brushed spindle motor and the proposed 4-DOF VCM. A diffuser is installed on the shaft of the DC brushed motor for suppressing the laser speckle. The proposed 4-DOF VCM is combined with a laboratory-designed mirror set, controlling the laser direction to compensate for laser fluctuations. The proposed actuator was designed and verified by using the commercial CAD software SolidWorks and finite element analysis (FEA) software ANSYS. A mathematical model was built to simulate the dynamic response of the proposed 4-DOF VCM in MATLAB Simulink. [ABSTRACT FROM AUTHOR]

A means to cause continuous vibratory deflection of a flexurally stressed beam of ferromagnetic, non-zero magnetostriction material, by a longitudinally conducted time varying current is described. The deflection of a horizontal cantilever beam, caused by a weight attached at its free end, is due to a difference in strains between those regions under tensile stress and those under compressive stress, in which these strains have both mechanical and magnetoelastic components. The circumferential uniformity of the field from the current acts to reduce the magnetoelastic strain inequality, hence also a small portion of the beam’s deflection. Alternating between current on and current off thus acts to raise and lower the weight. Cycling the applied current at a frequency that matches the prime mode frequency will produce vibratory deflection. Round wire beams, 20–85 mm long, ~1 mm diameter, of three different materials, with attached weights ranging from 60 to 600 mN were made to vibrate at their specific natural frequency (8–80 Hz) with peak strokes up to >10 mm by currents alternating between 0 and up to 9 A. [ABSTRACT FROM AUTHOR]

The initial internal temperature of a hard disk drive (HDD) differs according to the operating environment, and the various heat sources from the surrounding environment raise the internal temperature of the HDD after operation starts. Such temperature change ranges from 0 °C to 60 °C in the usual operating environment. This affects the characteristics of a pivot bearing that supports the HDD actuator. This paper predicts how the characteristics of pivot bearings change in relation to temperature and how the dynamic characteristics of actuators change according to the change of bearing characteristics. These changes are also verified through experiments. [ABSTRACT FROM AUTHOR]

Ionic polymer metal composites (IPMCs) are special smart materials that are biocompatible and can be used in biomedical and industrial applications. Using previous samples of a system output in a model (autoregressive models) is not feasible in dominant applications of IPMCs especially in biomedical applications. In this paper, we present a generalized Volterra-based model to achieve a nonautoregressive, nonparametric, and nonlinear identification of IPMC. The significant superiority of this approach is its capability to nonautoregressive identification of both linear and nonlinear behaviors of IPMC actuators even in large deformation situations. [ABSTRACT FROM AUTHOR]

This paper presents a digital control technique to achieve valley switching in a bidirectional flyback converter used to drive a dielectric electroactive polymer-based capacitive incremental actuator. This paper also provides the design of a low input voltage (24 V) and variable high output voltage (0–2.5 kV) bidirectional dc–dc flyback converter for driving a capacitive incremental actuator. The incremental actuator consists of three electrically isolated mechanically connected capacitive actuators. It requires three high-voltage (HV) (2–2.5 kV) bidirectional dc–dc converters to accomplish the incremental motion by charging and discharging the capacitive actuators. The bidirectional flyback converter employs a digital controller to improve the efficiency and charge/discharge speed using the valley switching technique during both charge and discharge processes, without the need to sense signals on the output HV side. Experimental results verifying the bidirectional operation of a HV flyback converter are presented using a 3-kV polypropylene-film capacitor as the load. The energy-loss distributions of the converter are presented when 4- and 4.5-kV HV mosfets are used on HV side. The flyback prototype with a 4 kV mosfet demonstrated 89% charge energy efficiency to charge the capacitive load from 0 V to 2.5 kV, and 84% discharge energy efficiency to discharge it from 2.5 kV to 0 V. [ABSTRACT FROM AUTHOR]

Transformer parasitics such as leakage inductance and self-capacitance are rarely calculated in advance during the design phase, because of the complexity and huge analytical error margins caused by practical winding implementation issues. Thus, choosing one transformer architecture over another for a given design is usually based on experience or a trial and error approach. This paper presents analytical expressions for calculating leakage inductance, self-capacitance, and ac resistance in transformer winding architectures (TWAs), ranging from the common noninterleaved primary/secondary winding architecture, to an interleaved, sectionalized, and bank winded architecture. The calculated results are evaluated experimentally, and through finite-element simulations, for an RM8 transformer with a turns ratio of 10. The four TWAs such as, noninterleaved and nonsectioned, noninterleaved and sectioned, interleaved and nonsectioned, and interleaved and sectioned, for an EF25 transformer with a turns ratio of 20, are investigated and practically implemented. The best TWA for an RM8 transformer in a high-voltage bidirectional flyback converter, used to drive an electro active polymer based incremental actuator, is identified based on the losses caused by the transformer parasitics. For an EF25 transformer, the best TWA is chosen according to whether electromagnetic interference due to the transformer interwinding capacitance, is a major problem or not. [ABSTRACT FROM AUTHOR]

Featured Application: The direct-vibration actuator is used in mobile devices that have bezel-less display panels. The actuator replaces the conventional dynamic receiver. With the development of technology, multimedia devices such as smartphones, tablets, and wearable devices have become necessities in our lives, and many new products are introduced every year. Companies are expanding smartphone displays and are developing bezel-less display panel designs. The enlarged display limits the space available for a speaker, and a new actuator must therefore be developed. Indirect-vibration actuators were developed for full-wide display designs. Using the same sound-generation principle as that of the indirect-vibration actuator, the mechanism and design of the direct-vibrating actuator is proposed in this paper. Using 3D finite element method (FEM), the force factor is obtained and used for design optimization. A sample is produced, and an experiment is conducted for sound pressure level (SPL) comparison. The experiment results show that the newly designed direct-vibration actuator can replace the dynamic receiver in mobile devices and enable the application of the bezel-less display design. [ABSTRACT FROM AUTHOR]

This paper presents the design and fabrication of a wearable tactile communication interface with vibrotactile feedback for assistive communication. The interface is based on finger Braille, which is a simple and efficient tactile communication method used by deafblind people. It consists of a flexible piezoresistive sensor and a vibrotactile actuator integrated together and positioned at the index, middle and ring fingers of both hands to represent the six dots of Braille. The sensors were made using flexible piezoresistive material whereas the actuator utilizes electromagnetic principle by means of a flexible coil and a tiny NdFeB permanent magnet. Both were integrated to realize a Bluetooth-enabled tactile communication glove which enables deafblind people to communicate using Braille codes. The evaluation with 20 end-users (10 deafblind and 10 sighted and hearing person) of the tactile interface under standardized conditions demonstrated that users can feel and distinguish the vibration at frequencies ranging from 10Hz to 200Hz which is within the perceivable frequency range for the FA-II receptors. The results show that it took non-experts in Braille within 25s and 55s to send and receive words like “BEST” and “JOURNAL”, with an accuracy of ~75% and 68% respectively. [ABSTRACT FROM AUTHOR]

The actuator is the key to the stepless capacity control system of a reciprocating compressor. The coupling effect between the actuator and the reciprocating compressor was not considered in the traditional design, and the large design margin led to low system reliability, high cost and low safety. In this paper, a reciprocating compressor and actuator were taken as research objects. The backflow clearance of the suction valve was simulated by CFD (computational fluid dynamics), The relationship between backflow clearance and resultant gas force of the valve plate was discussed. By building a mathematical model of actuators considering backflow clearance and impact rebound, the relationship between the parameters of actuators was studied. Based on the mathematical model and CFD analysis, the hydraulic force and spring stiffness were taken as the design variables, the impact velocity of ejection or withdrawal and the backflow clearance were taken as objective functions, and the actuator parameters were optimized with NSGA-II (Non-dominated Sorting Genetic Algorithm – II). The optimization results show that when the backflow clearance is 0.0065 mm, the hydraulic force is 94.25 N, and the spring stiffness is 11,575.84 N/m, the objective functions are optimized, the parameters are significantly improved, and a good effect is achieved on the experimental table of a 2D reciprocating compressor. [ABSTRACT FROM AUTHOR]

This paper presents a review of the current applications of Micro-Electro-Mechanical Systems (MEMS) in the robotics and industrial applications. MEMS are widely used as actuators or sensors in numerous respects of our daily life as well as automation lines and industrial applications. Intersection of founding new polymers and composites such as silicon and micro manufacturing technologies performing micro-machining and micro-assembly brings about remarkable growth of application and efficacy of MEMS devices. MEMS indicated huge improvement in size reduction, higher reliability, multi-functionality, customized design, and power usage. Demonstration of various devices and technologies utilized in robotics and industrial applications are illustrated in this article along with the use and the role of silicon in the development of the sensors. Some future trends and its perspectives are also discussed. [ABSTRACT FROM AUTHOR]

The magnetic field-induced stress and strain of magnetic shape memory alloy (MSMA) are fundamental to describe its magnetomechanical behavior. In order to investigate the operating characteristics of MSMA-based actuator, this paper presents a 3-D quasi-static modeling approach of magnetomechanical behavior of MSMA with the improved constitutive equation by introducing the activation field strength. The relationships between three critical parameters of the activation field strength, the maximum of strain, as well as the saturation field strength, and the pre-compressing force are obtained by fitting the data collected from the experiment. Two kinds of test specimen in different geometric dimensions are studied by the numerical modeling method. Considering that the key material parameters vary dramatically depending on the size and composition, verifications through experiments show that this numerical modeling and simulation can accurately describe the force and deformation characteristics of MSMA. The modeling analysis and simulation results are significant to design of the actuator based on MSMA to predict the actuator performance under the given working conditions. [ABSTRACT FROM AUTHOR]

The design of the smartphone LCD is gradually shifting to a full-wide screen. This requires a new type of actuator rather than a conventional dynamic receiver. For this purpose, a new actuator is used as a dynamic receiver. This paper introduces and analyzes new types of actuators and compares their force factors. For an analysis tool, a prototype of actuator is analyzed and verified with its experimental results. By using this verified tool, new types of actuators are designed and analyzed. Furthermore, a comparison is done to find out which one is the best for vibration performance. [ABSTRACT FROM AUTHOR]

Many temperature indicators or sensors show color changes for materials used in food and medical fields. However, they are not helpful for a color-blind person or children who lack judgment. In this paper, we introduce simply fabricated and more useful low-temperature indicator (~30 °C) for devices that actuates using paraffin-infiltrated multi-walled carbon nanotube (MWCNT) coiled yarn. The density difference of MWCNT yarn provides large strain (~330 %) when heat causes the melted polymer to move. Furthermore, the MWCNT yarn decreases the melting point of paraffin. These properties allow control of the actuating temperature. In addition, mechanical strength was enhanced by MWCNT than previously reported temperature-responsive actuators based on shape memory polymers. This simply fabricated temperature indicator can be applied in latching devices for medical and biological fields. [ABSTRACT FROM AUTHOR]

In this paper, we consider the improvement of the stator structure of the self-propelled rotary actuator, whose rotational axis is parallel to the exciting magnetic field. The stator of the actuator is constructed from the grain-oriented electrical steel sheet. The relation between the rolling direction of the steel sheet and the direction of the exciting magnetic field is important for the starting torque and rotational stability of the actuator’s rotor. Therefore, we analyze the rotor in consideration of the rolling direction using the finite-element method that introduced the complex E&S model, which is able to express the 2-D vector magnetic properties. As a result, we estimate the suitable setting direction of the rolling direction in the steel sheet of the actuator’s stator by this analysis. [ABSTRACT FROM AUTHOR]

The attitude determination and control subsystem is tasked with identifying the location and the orientation of the satellite at all times during the mission. Momentum exchange actuators such as reaction wheels are mounted on the satellites to transfer some of their torque, turning them through its centre of mass along each of three axes. In this paper, the design process of a momentum exchange actuator is presented, which has been designed and manufactured in Space Research Laboratory. This device named as RW2000 is the engineering model of reaction wheel for the satellite control simulator. In this approach in designing, design parameters related to the manoeuvrability of the system are considered as the inputs of the design process. After presenting the overall concept of the design process along with constrains, the general analysis of the actuator’s performance is investigated and the related equations are derived. Using the derived equations, the design process is developed. Finally, the engineering model of reaction wheel is designed using the proposed algorithm. The results of the performance test of the manufactured actuator accredit the accuracy and the correctness of the proposed design algorithm. [ABSTRACT FROM PUBLISHER]

To meet the requirements of amphibious exploration, ocean exploration, and military reconnaissance tasks, a pneumatic amphibious soft bionic robot was developed by taking advantage of the structural characteristics, motion forms, and propulsion mechanisms of the sea lion fore-flippers, inchworms, Carangidae tails, and dolphin tails. Using silicone rubber as the main material of the robot, combined with the driving mechanism of the pneumatic soft bionic actuator, and based on the theory of mechanism design, a systematic structural design of the pneumatic amphibious soft bionic robot was carried out from the aspects of flippers, tail, head–neck, and trunk. Then, a numerical simulation algorithm was used to analyze the main executing mechanisms and their coordinated motion performance of the soft bionic robot and to verify the rationality and feasibility of the robot structure design and motion forms. With the use of rapid prototyping technology to complete the construction of the robot prototype body, based on the motion amplitude, frequency, and phase of the bionic prototype, the main execution mechanisms of the robot were controlled through a pneumatic system to carry out experimental testing. The results show that the performance of the robot is consistent with the original design and numerical simulation predictions, and it can achieve certain maneuverability, flexibility, and environmental adaptability. The significance of this work is the development of a pneumatic soft bionic robot suitable for amphibious environments, which provides a new idea for the bionic design and application of pneumatic soft robots. [ABSTRACT FROM AUTHOR]

This article first reviews the position control of piezoelectric actuators, particularly charge-based sensorless control systems, which often include a charge estimator as a key component. The rest of the paper is about charge estimators for piezoelectric actuators. Two of the most recent/effective types of these estimators utilise either a sensing capacitor (type I in this paper) or a sensing resistor (type II); the latter (and the newer) type is broadly known as a digital charge estimator. Some experimental results in the literature show that, with the same loss in excitation voltage, a considerably higher amount of charge can be estimated with a type II estimator in comparison with a type I estimator; therefore, the superiority of type II estimators was acknowledged. In order to re-assess this conclusion, this paper equitably compares type I and II estimators through analytical modelling and experimentation. The results indicate that type II estimators have only a slight advantage in estimating higher amounts of charge, if both type I and II estimators are designed appropriately. At the same time, type II estimators have disadvantages; e.g., the resistance of type II estimators has to be tuned to suit different excitation frequencies. This research concludes that capacitor-based (type I) charge estimators for piezoelectric actuators, with pertinent design and implementation, can be still the prime solution for many charge estimation problems despite claims in the literature in the last decade.

The paper presents the design of a damper based on a multilayer magnetorheological elastomer that has high load capacity, up to 500 N. The damper is able to operate in all vibration control modes, depending on its control signal. The damper cooling system is presented. Vibration tests were carried out and the damper amplitude-frequency characteristics were obtained. The transition process of damper displacement with a control step signal was analyzed.

Animals can incorporate large numbers of actuators because of the characteristics of muscles; whereas, robots cannot, as typical motors tend to be large, heavy, and inefficient. However, shape-memory alloys (SMA), materials that contract during heating because of change in their crystal structure, provide another option. SMA, though, is unidirectional and therefore requires an additional force to reset (extend) the actuator, which is typically provided by springs or antagonistic actuation. These strategies, however, tend to limit the actuator's work output and functionality as their force–displacement relationships typically produce increasing resistive force with limited variability. In contrast, magnetic springs—composed of permanent magnets, where the interaction force between magnets mimics a spring force—have much more variable force–displacement relationships and scale well with SMA. However, as of yet, no method for designing magnetic springs for SMA-actuators has been demonstrated. Therefore, in this paper, we present a new methodology to tailor magnetic springs to the characteristics of these actuators, with experimental results both for the device and robot-integrated SMA-actuators. We found magnetic building blocks, based on sets of permanent magnets, which are well-suited to SMAs and have the potential to incorporate features such as holding force, state transitioning, friction minimization, auto-alignment, and self-mounting. We show magnetic springs that vary by more than 3 N in 750  $\mu$ m and two SMA-actuated devices that allow the MultiMo-Bat to reach heights of up to 4.5 m without, and 3.6 m with, integrated gliding airfoils. Our results demonstrate the potential of this methodology to add previously impossible functionality to smart material actuators. We anticipate this methodology will inspire broader consideration of the use of magnetic springs in miniature robots and further study of the potential of tailored magnetic springs throughout mechanical systems. [ABSTRACT FROM AUTHOR]

The joint W3C (World Wide Web Consortium) and OGC (Open Geospatial Consortium) Spatial Data on the Web (SDW) Working Group developed a set of ontologies to describe sensors, actuators, samplers as well as their observations, actuation, and sampling activities. The ontologies have been published both as a W3C recommendation and as an OGC implementation standard. The set includes a lightweight core module called SOSA (Sensor, Observation, Sampler, and Actuator) available at: http://www.w3.org/ns/sosa/ , and a more expressive extension module called SSN (Semantic Sensor Network) available at: http://www.w3.org/ns/ssn/. Together they describe systems of sensors and actuators, observations, the used procedures, the subjects and their properties being observed or acted upon, samples and the process of sampling, and so forth. The set of ontologies adopts a modular architecture with SOSA as a self-contained core that is extended by SSN and other modules to add expressivity and breadth. The SOSA/SSN ontologies are able to support a wide range of applications and use cases, including satellite imagery, large-scale scientific monitoring, industrial and household infrastructures, social sensing, citizen science, observation-driven ontology engineering, and the Internet of Things. In this paper we give an overview of the ontologies and discuss the rationale behind key design decisions, reporting on the differences between the new SSN ontology presented here and its predecessor [Web Semantics: Science, Services and Agents on the World Wide Web17 (2012), 25–32] developed by the W3C Semantic Sensor Network Incubator group (the SSN-XG). We present usage examples and describe alignment modules that foster interoperability with other ontologies. [ABSTRACT FROM AUTHOR]

In this paper, we propose a model for ionic polymer metal composite (IPMC) actuators that its superiority over the other models is its capability to make a confident prediction about the bending displacement of all points along the IPMC strip in large bending displacements, without using previous data of the output and also with consideration of the effects of the ambient conditions on its performance. To achieve this aim, we used a nonautoregressive model named as Laguerre-multilayer perceptron network. Moreover, the effect of ambient temperature and humidity changes in the range of biomedical applications of IPMC was investigated using variance analysis of experimental data and also these ambient conditions were applied to the proposed model as operating points. This model was described in detail and validated by experimental results. [ABSTRACT FROM AUTHOR]

This paper presents the dynamic analytical solution of a piezoelectric stack utilized in an actuator and a generator based on the linear piezo-elasticity theory. The solutions for two different kinds of piezoelectric stacks under external load were obtained using the displacement method. The effects of load frequency and load amplitude on the dynamic characteristics of the stacks were discussed. The analytical solutions were validated using the available experimental results in special cases. The proposed model is able not only to predict the output properties of the devices, but also to reflect the inner electrical and mechanical components, which is helpful for designing piezoelectric actuators and generators in a comprehensive manner. [ABSTRACT FROM AUTHOR]

Safety and reliability of electrical actuators are essential for success of all electric and more electric aircrafts (MEA). Torque limiters improve the reliability of electromechanical actuators (EMA) by restricting the amount of force experienced by the actuator drive train components. If transmitted torque in the shaft exceeds a limit, it gives way in a controlled manner. This protects the actuator from potential failure and jamming. In this paper, different types of existing torque limiters are investigated for their suitability in aerospace EMA application and further integration within the electric motor. They classified based on the torque transmission mechanism and each type is described in detail. Operating principle and basic characteristics are reported. Comparative evaluation of commercially available devices is presented. It is found that those based on friction based and permanent magnet are most suitable due to their good torque density, reliability and high speed capability. Further, based on the characteristics, integration of torque limiter within the actuator motor is investigated in this paper. An example actuator motor is considered for integration. Different integration options suitable for the different types of torque limiting devices are described. Reduction in overall volume is shown for the integration options. Such integration can lead to improved reliability as well as higher power density resulting in next-generation actuator electrical drives for MEA. [ABSTRACT FROM AUTHOR]

In the process industry, the actuator has complex operating processes. Its steady working conditions are easy to change. Moreover, it is in a dynamic process for long periods of time. These phenomena reduce the accuracy and timeliness of many condition monitoring (CM) methods. In this paper, a fault detection mechanism considering the complex operating processes of the actuator is proposed. One of its main feature is that it can detect faults under steady state regardless of variable load changes. The other is that it has ability to detect faults during dynamic processes refusing the interference of nonlinearity and dynamic characteristics. Firstly, an actuator data model library based on historical data is established offline. Secondly, in the online situation, after the R indicator divides the testing data into steady state or dynamic, it is input into the model library to obtain a standard training set. Finally, the steady-state/dynamic fault detection module will determine whether a fault has occurred based on the testing data and the training set. Moreover, open-loop experiments based on the DAMADICS (Development and Application of Methods for Actuator Diagnosis in Industrial Control Systems) platform and closed-loop experiments based on the water tank system are designed. These experiments show that, compared with other methods, the proposed fault detection framework has better monitoring performance during complex operating processes of actuators. • A novel actuator fault detection method is proposed. • It can deal with various complex operating processes containing steady and dynamic state. • It contains two novel extended non-negative matrix factorization algorithms. • The presented mechanism is verified by simulations and experiments. [ABSTRACT FROM AUTHOR]