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In order to solve the singular fault modes of redundant position sensors in electric actuators, a fault diagnosis method based on Hall sensor analytical model is proposed on the basis of traditional redundancy comparison algorithm. Through the complete self-monitoring design of Hall sensor and the analytical model design, non-similar redundancy signals of sensors are formed. At the same time, a hypothesis testing method based on sliding data window is adopted, and by adjusting the width of the sliding window to meet the indicators of false alarm rate and missed alarm rate, a fault diagnosis algorithm for position sensors is formed as a whole. Finally, an algorithm validation was conducted for the 2∶2 singular fault mode of the position sensor. The results showed that the fault diagnosis algorithm based on the Hall sensor model can effectively solve the problems caused by 2∶2 singular faults, greatly improve the availability of sensor signals, and ensure the control accuracy and fault tolerance of the servo closed-loop.

An electric actuator, which integrates power electronics technology, computer technology, sensor technology, and motor technology, is a new on-site terminal control device. Especially with the application of intelligent frequency conversion technology, the same device can have different operating speeds and breaking torques within a certain range. This feature is particularly suitable for different working conditions such as valve opening, closing, and operation. In this way, the product specifications and models are significantly reduced, which is conducive to production and user selection. At present, the prototype's test has been completed, and all performance indicators have met the requirements of industry standards. Some technical indicators have even been improved compared with the same type of products of internationally renowned brands. Therefore,its small batch production is being prepared. [ABSTRACT FROM AUTHOR]

With the global attention given to energy issues, the electrification of aviation and the development of more electric aircraft (MEA) have become important trends in the modern aviation industry. The electric actuator plays multiple roles in aircraft such as flight control, making it a crucial technology for MEA. Given the limited space available inside an aircraft, the power density of electric actuators has become a critical design factor. However, the pursuit of high power density results in the need for larger rated power and higher switching frequency, which can lead to severe electromagnetic interference (EMI) issues. This, in turn, poses significant challenges to the overall reliability of the electric actuator. This paper provides a comprehensive review of EMI in high power density motor drive systems for electric actuator systems. Firstly, the state of the art of electric actuator systems are surveyed, pointing out the contradictory relationship between high power density and EMI. Subsequently, various EMI modeling approaches of motor control systems are reviewed. Additionally, the main EMI suppression methods are summarized. Active EMI mitigation methods are emphasized in this paper due to their advantages of higher power density compared with passive EMI filters. Finally, the paper concludes by summarizing the EMI research in motor drive systems and offering the prospects of electric actuators. [ABSTRACT FROM AUTHOR]

This paper presents the experimental validation of a Fault-Tolerant Control (FTC) system for Permanent Magnet Synchronous Motor (PMSM) drives, specifically focusing on current sensors. The FTC system is designed to detect and diagnose both single and multiple faults in the current sensors and to reconfigure the control loop to ensure uninterrupted operation in the presence of such faults. Several crucial aspects are addressed in the proposed approach, including fault detection, isolation of faulty sensors, and reconfiguration of the control system through accurate current estimation. To achieve this, a novel adaptation of the Luenberger observer is proposed and employed for estimating the stator currents. The effectiveness of the fault-tolerant control strategy is demonstrated through experimental tests conducted on a 7.2 kW PMSM utilizing a field-oriented vectorial strategy implemented in a dSpace 1104 platform. [ABSTRACT FROM AUTHOR]

Recent advances in manufacturing methods have accelerated the exploration of new materials and advantageous shapes that could not be produced by traditional methods. In this context, additive manufacturing is gaining strength among manufacturing methods for its versatility and freedom in the geometries that can be produced. Taking advantage of these possibilities, this research presents a case study involving an electric aerospace actuator manufactured using additive manufacturing. The main objectives of this research work are to assess the feasibility of additively manufacturing electric actuators and to evaluate potential gains in terms of weight, volume, power consumption and cost over conventional manufacturing technologies. To do so and in order to optimise the actuator design, a thorough material study is conducted in which three different magnetic materials are gas-atomised (silicon iron, permendur and supermalloy) and test samples of the most promising materials (silicon iron and permendur) are processed by laser powder bed fusion. The final actuator design is additively manufactured in permendur for the stator and rotor iron parts and in 316L stainless steel for the housing. The electric actuator prototype is tested, showing compliance with design requirements in terms of torque production, power consumption and heating. Finally, a design intended to be manufactured via traditional methods (i.e., punching and stacking for the stator laminations and machining for the housing) is presented and compared to the additively manufactured design. The comparison shows that additive manufacturing is a viable alternative to traditional manufacturing for the application presented, as it highly reduces the weight of the actuator and facilitates the assembly, while the cost difference between the two designs is minimal. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In 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. [ABSTRACT FROM AUTHOR]

Unmanned systems such as legged robots require fast-motion responses for operation in complex environments. These systems therefore require explosive actuators that can provide high peak speed or high peak torque at specific moments during dynamic motion. Although hydraulic actuators can provide a large force, they are relatively inefficient, large, and heavy. Industrial electric actuators are incapable of providing instant high power. In addition, the constant reduction ratio of the reducer makes it difficult to eliminate the tradeoff between high speed and high torque in a given system. This study proposes an explosive electric actuator and an associated control method for legged robots. First, a high-power-density variable transmission is designed to enable continuous adjustment of the output speed to torque ratio. A heat-dissipating structure based on a composite phase-change material (PCM) is used. An integral torque control method is used to achieve periodic and controllable explosive power output. Jumping experiments are conducted with typical legged robots to verify the effectiveness of the proposed actuator and control method. Single-legged, quadruped, and humanoid robots jumped to heights of 1.5, 0.8, and 0.5 m, respectively. These are the highest values reported to date for legged robots powered by electric actuators.

With the global attention given to energy issues, the electrification of aviation and the development of more electric aircraft (MEA) have become important trends in the modern aviation industry. The electric actuator plays multiple roles in aircraft such as flight control, making it a crucial technology for MEA. Given the limited space available inside an aircraft, the power density of electric actuators has become a critical design factor. However, the pursuit of high power density results in the need for larger rated power and higher switching frequency, which can lead to severe electromagnetic interference (EMI) issues. This, in turn, poses significant challenges to the overall reliability of the electric actuator. This paper provides a comprehensive review of EMI in high power density motor drive systems for electric actuator systems. Firstly, the state of the art of electric actuator systems are surveyed, pointing out the contradictory relationship between high power density and EMI. Subsequently, various EMI modeling approaches of motor control systems are reviewed. Additionally, the main EMI suppression methods are summarized. Active EMI mitigation methods are emphasized in this paper due to their advantages of higher power density compared with passive EMI filters. Finally, the paper concludes by summarizing the EMI research in motor drive systems and offering the prospects of electric actuators.

Recent advances in manufacturing methods have accelerated the exploration of new materials and advantageous shapes that could not be produced by traditional methods. In this context, additive manufacturing is gaining strength among manufacturing methods for its versatility and freedom in the geometries that can be produced. Taking advantage of these possibilities, this research presents a case study involving an electric aerospace actuator manufactured using additive manufacturing. The main objectives of this research work are to assess the feasibility of additively manufacturing electric actuators and to evaluate potential gains in terms of weight, volume, power consumption and cost over conventional manufacturing technologies. To do so and in order to optimise the actuator design, a thorough material study is conducted in which three different magnetic materials are gas-atomised (silicon iron, permendur and supermalloy) and test samples of the most promising materials (silicon iron and permendur) are processed by laser powder bed fusion. The final actuator design is additively manufactured in permendur for the stator and rotor iron parts and in 316L stainless steel for the housing. The electric actuator prototype is tested, showing compliance with design requirements in terms of torque production, power consumption and heating. Finally, a design intended to be manufactured via traditional methods (i.e., punching and stacking for the stator laminations and machining for the housing) is presented and compared to the additively manufactured design. The comparison shows that additive manufacturing is a viable alternative to traditional manufacturing for the application presented, as it highly reduces the weight of the actuator and facilitates the assembly, while the cost difference between the two designs is minimal.

This paper presents the experimental validation of a Fault-Tolerant Control (FTC) system for Permanent Magnet Synchronous Motor (PMSM) drives, specifically focusing on current sensors. The FTC system is designed to detect and diagnose both single and multiple faults in the current sensors and to reconfigure the control loop to ensure uninterrupted operation in the presence of such faults. Several crucial aspects are addressed in the proposed approach, including fault detection, isolation of faulty sensors, and reconfiguration of the control system through accurate current estimation. To achieve this, a novel adaptation of the Luenberger observer is proposed and employed for estimating the stator currents. The effectiveness of the fault-tolerant control strategy is demonstrated through experimental tests conducted on a 7.2 kW PMSM utilizing a field-oriented vectorial strategy implemented in a dSpace 1104 platform.

[Introduction] In order to reduce the influence of the positioning accuracy of the electric actuator by the change of its internal parameters, and to reduce the maintenance frequency of the electric actuator. [Method] After the model of the electric actuator was improved, the influence factors of the steady-state error were obtained through simulation experiments. The compensation loop was further added to reduce the steady-state error. The parameters of the compensation loop were obtained by utilizing the BP neural network algorithm. [Result] The simulation result shows that the steady-state error of the electric actuator is related to the width of the dead zone of the controller, the backlash width of the reducer and the sign of the input signal. After adding the compensation circuit, the absolute value of the steady-state error can be guaranteed to fluctuate within 0.1% when the controller dead zone width and reducer backlash width change. [Conclusion] It solves the contradiction between the positioning accuracy and stability of electric actuator, and the problem of positioning accuracy being reduced due to the wear of reducer.

A common heavy vehicle, such as a bus, has a drum brake system as its safety feature. This braking system utilizes air pressure inside pneumatic cylinders as an actuator for moving the braking cam in order to create friction between the brake shoe with the drum. Air pressure is produced by a compressor with the help of the internal combustion engine (ICE) rotational part. However, in the case of electric vehicles (EV), there is no rotational moving part on the engine when the vehicle stops. Furthermore, EVs use electric power as their fuel obtained from the battery. Thus, this study focuses on developing an alternative actuator for EV braking to substitute the air actuator system by the direct electric powered actuator system. By utilizing a magnetic system via a solenoid for moving the lever of the cam, the tests confirm that the implementation of the alternative actuator functionally works. The objective of this research is to obtain the proper control system in order to gradually generate the magnetic field. Additionally, the signal from the operator is then processed by an intelligent method—so-called fuzzy control—to produce a signal for the magnetic braking system comparable to the behavior of the pneumatic actuator. The results show that the intensity of braking can be alternated depending on the braking signal variation using 10 µs sampling period input pulse width modulation (PWMs) with 10 ms periods of execution time. Furthermore, this method improves the time response that compensates the delay due to piping-hoses in the pneumatic system.

In order to meet the needs of industrial automation places with narrow installation space， a compact electric actuator is developed by taking NGWN （II） type （3Z） planetary gear mechanism as the main transmission mechanism and combining the fixed axis gear train and worm gear drive. In order to shorten the design cycle and reduce the workload of manual calculation，a multi-objective optimization mathematical model of planetary gear mechanism is established and solved with the volume and efficiency as design objectives， and the design parameters of electric actuator are obtained. On this basis， the three-dimensional model of the electric actuator is established， and finally the manufacturing of the electric actuator is completed. The results show that， for the NGWN （II） type （3Z） planetary gear mechanism with small modulus， when the average value of the reference center distance of all gear pairs or that of two of the gear pairs is taken as the common actual center distance， the calculated profile shift coefficient of each involute gear is more reasonable， and the design result is more in line with the actual requirements.

The paper analyzes the constructive parameters of all parts of the shut-off valves with a flat seating system designed for operation on the steam pipe with values of temperature and pressure overheated steam 535 °C and 135 bar. All parts of the shut-off valve are given guidelines on the maintenance, packing and repair of possible damage, including the necessary machines, tools, equipment and materials. Based on a good knowledge of the design characteristics of the shut-off valve with flat seating, operating fluid parameters and the torque calculation necessary for rotating the spindle, the dimensioning and selection of an electric actuator for valve operation has been performed. The basic data on the drive, the motor and the control unit of the selected electric actuator are given, as well as the connection forms for the connection of the flange of the electric actuator and the shut-off valve.

To study the electric actuator, a model is established with backlash nonlinearity and equivalent rigidity considered. Applying the describing function, the limit cycle of the actuator system is analyzed, and the characteristics of the limit cycle's frequency and amplitude are also analyzed. A method adding negative feedback moment to the load is proposed. The feedback moment can suppress the limit cycle of the actuator by changing the motion state of the load. The effect of the feedback moment to the servo system is analyzed and the principle of the feedback coefficient is given. The simulation results show the effectiveness of the describing function in predicting the limit cycle in the nonlinear system, and the proposed method does not affect the servo performance of the system and the negative feedback moment is valid in suppressing the limit cycle of the electric actuator with the backlash nonlinearity. [ABSTRACT FROM AUTHOR]

A common heavy vehicle, such as a bus, has a drum brake system as its safety feature. This braking system utilizes air pressure inside pneumatic cylinders as an actuator for moving the braking cam in order to create friction between the brake shoe with the drum. Air pressure is produced by a compressor with the help of the internal combustion engine (ICE) rotational part. However, in the case of electric vehicles (EV), there is no rotational moving part on the engine when the vehicle stops. Furthermore, EVs use electric power as their fuel obtained from the battery. Thus, this study focuses on developing an alternative actuator for EV braking to substitute the air actuator system by the direct electric powered actuator system. By utilizing a magnetic system via a solenoid for moving the lever of the cam, the tests confirm that the implementation of the alternative actuator functionally works. The objective of this research is to obtain the proper control system in order to gradually generate the magnetic field. Additionally, the signal from the operator is then processed by an intelligent method—so-called fuzzy control—to produce a signal for the magnetic braking system comparable to the behavior of the pneumatic actuator. The results show that the intensity of braking can be alternated depending on the braking signal variation using 10 μs sampling period input pulse width modulation (PWMs) with 10 ms periods of execution time. Furthermore, this method improves the time response that compensates the delay due to piping-hoses in the pneumatic system. [ABSTRACT FROM AUTHOR]

One of the important problems of the designing of maneuverable unmanned aerial vehicles (UAV) is to ensure aeroelastic stability with automatic control system (ACS). One of the possible types of aeroelastic instability of UAV with ACS is loss of stability in the system "surface control – actuator". A nonlinear model for the study of the stability of the system "surface control – actuator" is designed for solving problems of joint design of airframe and ACS with the requirements of aeroelasticity. The electric actuator is currently the most widely used on highly maneuverable UAV. The wide bandwidth and the availability of frequency characteristic lifts are typical for the modern electric actuator. This exacerbates the problem of providing aeroelastic stability of the UAV with ACS, including the problem of ensuring the stability of the system "surface control – actuator". In proposed model the surface control, performing bending-torsion oscillations in aerodynamic flow, in fact, is the loading for the actuator. Experimental frequency characteristics of the isolated actuator, obtained for different levels of the control signal, are used for the mathematical description of the actuator, then, as dynamic hinge moment, which is determined by aeroelastic vibrations of the surface control in the air flow, is calculated. Investigation of the stability of the system "surface control – actuator" is carried out by frequency method using frequency characteristics of the open-loop system. The undeniable advantage of the proposed model is the simplicity of obtaining the transfer functions of the isolated actuator. The experiment by its definition is a standard method of determining frequency characteristics of the actuator in contrast to time-consuming experiments for determining the dynamic stiffness of the actuator (with the surface control) or the transfer function of the actuator using electromechanical simulation of aeroelastic loading of the surface control, that also used in research stability problems of the system "surface control – actuator".

This study aims to develop and evaluate an automated manual transmission (AMT) for agricultural tractors with high efficiency and high convenience by using electric actuators. An AMT system to control manual-type shuttle gearboxes and transmissions for tractors is developed by adding a shuttle shifting actuator, a clutch actuator, and a control system to a conventional manual transmission (MT). The clutch actuator is designed using an electric motor and a reduction gear. The AMT control system is developed and experimental tests are conducted to evaluate the performance of the AMT. The results of the performance of the actuator position control demonstrate that the shuttle shifting actuator and clutch actuator are controlled appropriately, achieving a maximum overshoot of less than 5% and 0%, a settling time of less than 0.500 s and 1.50 s, and a steady-state error of less than 1% and 1%, respectively. The performance of the automatic forward and reverse control demonstrates a shift control time of less than 2.50 s and target revolutions per minute (RPM) reaching time of less than 3.00 s. Thus, AMT systems for tractors can be easily developed by applying shuttle shifting actuators, clutch actuators, and a control system to conventional manual transmissions. [ABSTRACT FROM AUTHOR]

Fluid control is one of the essential automation application area in industry. In order to fluid control effectively and precisely, valves which are crucial components, need a controlled rotating motion which leads to implement electric motors, electronic controller and gear systems altogether. In this study, an electric motor actuated valve system is designed and prototyped. The design phases are including switch mode power supply (SMPS) design, motor controller circuit design, mechanical implementation and controller design. The designed valve system is manufactured and tested using multi-disciplinary fashion. The application problems are solved by using the proper control techniques and strategies. The precise position control of butterfly disc is also achieved. According to the related industrial standard and application requirements, the experimental results show the effectiveness of the design approach. [ABSTRACT FROM AUTHOR]

This study aims to develop and evaluate an automated manual transmission (AMT) for agricultural tractors with high efficiency and high convenience by using electric actuators. An AMT system to control manual-type shuttle gearboxes and transmissions for tractors is developed by adding a shuttle shifting actuator, a clutch actuator, and a control system to a conventional manual transmission (MT). The clutch actuator is designed using an electric motor and a reduction gear. The AMT control system is developed and experimental tests are conducted to evaluate the performance of the AMT. The results of the performance of the actuator position control demonstrate that the shuttle shifting actuator and clutch actuator are controlled appropriately, achieving a maximum overshoot of less than 5% and 0%, a settling time of less than 0.500 s and 1.50 s, and a steady-state error of less than 1% and 1%, respectively. The performance of the automatic forward and reverse control demonstrates a shift control time of less than 2.50 s and target revolutions per minute (RPM) reaching time of less than 3.00 s. Thus, AMT systems for tractors can be easily developed by applying shuttle shifting actuators, clutch actuators, and a control system to conventional manual transmissions.

As a new kind of smart materials for fabricating ionic electric actuator, Chitosan Gel Polymer (CGP) known as bionic artificial muscle, has broad application prospects and high academic value with advantages of simple structure, good biocompatibility and large deflection under low driving voltage (≤5 V). In this paper, effects and enhancement mechanism of the heat treating optimization technology on response speed performance of the CGP actuator were mainly investigated. Furthermore, its preparation process including material selection, membrane fabrication and the assembly along with fabrication principle were deeply researched. The CGP actuator consisted of two parts; electric actuating membrane which is sandwiched between non-metallic electrode membranes. On one hand, high viscosity chitosan inside the actuating membrane served as framework which gives access to anions and cations within the electrode membranes. On the other hand, Multi-walled Carbon Nanotube (MCNT) was adopted to modify chitosan in the electrode membrane for obtaining good conductivity and stable chemical character. Moreover, response speed of the CGP actuator that underwent repeated heat treating for a short time, would be continuously improved with the increase of heat treating times. But as the heat treating time prolonged, electromechanical properties of the CGP actuator began to degrade. In addition, since conduction velocity of microscopic ions inside the CGP actuator was presented as macroscopic current magnitude, the experimental results revealed that the changing trend of response speed was almost in accord with the current trend of the CGP actuator. Both of these are fitted in a quadratic function relationship. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The remarkable ability of humans to perform jump maneuvers greatly contributes to the improvements of the obstacle negotiation ability of humans. The paper proposes a jumping control scheme for a bipedal robot to perform a high jump. The half-body of the robot is modeled as three planar links and the motion during the launching phase is taken into account. A geometrically simple motion was first conducted through which the gear reduction ratio that matches the maximum motor output for high jumping was selected. Then, the following strategies to further exploit the motor output performance was examined: (1) to set the maximum torque of each joint as the baseline that is explicitly modeled as a piecewise linear function dependent on the joint angular velocity; (2) to exert it with a correction of the joint angular accelerations in order to satisfy some balancing criteria during the motion. The criteria include the location of ZMP (zero moment point) and the torque limit. Using the technique described above, the jumping pattern is pre-calculated to maximize the jump height. Finally, the effectiveness of the proposed method is evaluated through simulations. In the simulation, the bipedal robot model achieved a 0.477-m high jump. [ABSTRACT FROM AUTHOR]

An all-electric, cart-mounted, single-stage scissor lift with a capacity of 185 kg has been designed and fabricated with ASTM A36 steel. The lift's platform measures 508 mm by 813 mm and elevates the load 811 mm from the floor. The lift is optimized in terms of mobility, stability, rigidity, safety, and versatility. An 8897-N screw-drive, electric actuator is mounted horizontally at the lift's base. Operation is by 12VDC battery with an optional 120VAC plug-in power supply. Both two- and three-dimensional finite element analyses were employed to evaluate structural material choices and thicknesses based on a safety factor of two. This effort was conducted as part of a university-level capstone manufacturing engineering technology student project. [ABSTRACT FROM AUTHOR]

Recently, there has been a growing interest in reducing the number or replacing the hydraulic/pneumatic actuators utilised on aircraft with electric actuators coupled to mechanical gears, which would improve the reliability and performance. This is involved in the concept of more electric aircraft. The electrification of actuators would affect the primary and secondary flight controls, as well as the movement of flight surfaces, retraction of the landing gear, and steering of the nose landing gear, which is also considered in this study. This study considers the design of a multiphase permanent‐magnet (PM) motor to be utilised for the electric steering of a commercial aircraft nose landing gear. This multiphase motor would make it possible to achieve a highly reliable actuator and, coupled with a harmonic drive, avoid the use of a multi‐motor configuration. Moreover, a multiphase motor would increase the power density and efficiency of the actuator, through improving the torque ripple. The performance variation due to temperature swings is considered, and a design procedure for the PM motor is described using the worse operation case for the electric actuator. The adequate performance of the designed motor and actuator is demonstrated by means of a finite element analysis. [ABSTRACT FROM AUTHOR]

The remarkable ability of humans to perform jump maneuvers greatly contributes to the improvements of the obstacle negotiation ability of humans. The paper proposes a jumping control scheme for a bipedal robot to perform a high jump. The half-body of the robot is modeled as three planar links and the motion during the launching phase is taken into account. A geometrically simple motion was first conducted through which the gear reduction ratio that matches the maximum motor output for high jumping was selected. Then, the following strategies to further exploit the motor output performance was examined: (1) to set the maximum torque of each joint as the baseline that is explicitly modeled as a piecewise linear function dependent on the joint angular velocity; (2) to exert it with a correction of the joint angular accelerations in order to satisfy some balancing criteria during the motion. The criteria include the location of ZMP (zero moment point) and the torque limit. Using the technique described above, the jumping pattern is pre-calculated to maximize the jump height. Finally, the effectiveness of the proposed method is evaluated through simulations. In the simulation, the bipedal robot model achieved a 0.477-m high jump.

We have been developing power assist suits as labor-reducing equipments for non-handicapped elderly, weak young and female workers. This paper describes the verification tests of validity of an electrically actuated power assist suit for practical use. This power assist suit supports the motion of antigravity direction using electric motors and arranges passive joints appropriately in order not to disturb wearer's motions. We realized the support of walking and lifting a heavy object. It is necessary to detect wearer's intention and predict following motion because the power assist suit is required to move simultaneously with the wearer. We estimate the motion intentions using hip joint angles, foot switches and glove switches, without using bioelectrical signals such as surface electromyogram signals, which usually have inferior S/N ratio. The experimental results of energy expenditure and oxygen consumption rate show the effectiveness of proposed mechanism and control method of power assist suit.

The aim of this paper is to present an original architecture for a linear electric actuator; a multi-air gap actuator for aeronautical applications. This linear actuator is designed to replace pneumatic or hydraulic devices functioning as a cylinder. One particularity of this actuator is the friction of movable parts on fixed parts, allowing the use of active parts with very small dimensions, thereby increasing performance. We present the definition of this concept, its operating principle, the study performed, and experimental results from a prototype. Experimental results confirm the high performance of this structure (1000 N/kg and 5000 N/dm3). [ABSTRACT FROM PUBLISHER]

Theoretical and experimental methods of investigating the performance of an electric actuator of maneuverable unmanned aerial vehicle (UAV) is considered in order to solve the aeroelasticity tasks. Models of the stability analysis for the rudder-actuator system as well as the examples of numerical and experimental studies of this system performance are given. [ABSTRACT FROM AUTHOR]

SUMMARY Working in extreme environments (e.g., at disaster sites) is dangerous for humans. Hence, it is important to use teleoperated robots in such extreme environments. Because heavy lifting work is involved, hydraulic actuators with high output are more commonly used than electric actuators. Therefore, it is necessary to operate remotely controlled robots driven by hydraulic actuators. Bilateral control is remote control with a sense of force. Because most bilateral control systems have been studied mainly using electric actuators, bilateral control using hydraulic actuators is still a challenge. In this study, we propose placing a bilateral controller between an electric actuator on the master side and a hydraulic actuator on the slave side using position and velocity. The controller exhibits the dynamics of bilateral control systems using position and velocity. In addition, the control performance of conventional methods and that of the proposed method are compared and experimentally verified. [ABSTRACT FROM AUTHOR]

As part of the More Electric Initiative, there is a significant interest in designing energy-optimized More Electric Aircraft, where electric power meets all non-propulsive power requirements. To achieve this goal, the aircraft subsystems must be analyzed much earlier than in the traditional design process. This means that the designer must be able to compare competing subsystem solutions with only limited knowledge regarding aircraft geometry and other design characteristics. The methodology presented in this work allows such tradeoffs to be performed and is driven by subsystem requirements definition, component modeling and simulation, identification of critical or constraining flight conditions, and evaluation of competing architectures at the vehicle and mission level. The methodology is applied to the flight control actuation system, where electric control surface actuators are likely to replace conventional centralized hydraulics in future More Electric Aircraft. While the potential benefits of electric actuation are generally accepted, there is considerable debate regarding the most suitable electric actuator – electrohydrostatic or electromechanical. These two actuator types form the basis of the competing solutions analyzed in this work, which focuses on a small narrowbody aircraft such as the Boeing 737-800. The competing architectures are compared at both the vehicle and mission levels, using as metrics subsystem weight and mission fuel burn, respectively. As shown in this work, the use of this methodology aids the decision-making process by allowing the designer to rapidly evaluate the significance of any performance advantage between the competing solutions. [ABSTRACT FROM AUTHOR]

In this paper, control system is designed to reduce roll angle which consequently leads into increasing vehicle roll threshold during high lateral accelerations. Accordingly, the two same rotation-electric actuators are mounted on front and rear suspension system anti-roll bars. This control system turns by applying an opposite couple that is acted upon the chassis, as time varying, reduce the lateral acceleration as it possible and improves lateral stability and roll threshold during extreme maneuvers. In order to find out the effects of the performance of this active system on vehicle stability, firstly based on ?? nonlinear eight degrees of freedom model of the lateral dynamics of the vehicle and by taking Steering angle as an input, the kinematic parameters and finally roll threshold that is defined lateral load transfer, is estimated. Then, the optimized second order control theory with three degrees of freedom of the vehicle model is used to design the controller. Finally, with the aid of comprehensive model of the vehicle, the lateral dynamics of the vehicle as well as the effects of the controller during path of standard Fish hook maneuver are investigated. [ABSTRACT FROM AUTHOR]

Abstract: The method based on data fusion fault diagnosis is put forward and the two-step fusion diagnosis model of neural network and D-S evidence theory is given against the complexity and multiplicity when the fault of control system happens; the fault detection laboratory platform is erected based on the data fusion through the analysis of the electric actuator''s principle and typical faults, and on this basis, the fault of the electric actuator is diagnosed by the experiment and computer simulation. This method overcomes the uncertainty of the neural network fault diagnosis and improves the accuracy of system diagnosis, and the experiment result verified the method''s validity. [Copyright &y& Elsevier]

A novel electric servo based on piezoelectric actuator is designed and is comprised by two separate piezoelectric angel servos. The displacement produced by piezoelectric actuator is amplified by lever mechanism and transferred into angel output. The mathematic model of piezoelectric servo is deduced, and we discuss the factors which affect the servo's performance based on this model and confirm the conclusion by experiments. The research results indicate that the novel piezoelectric servo has several advantages, such as compact structure, small capacity, high mass-power ratio, fast response and low price. The piezoelectric servo is appropriate used for small spinning guided munitions. [ABSTRACT FROM AUTHOR]

Pneumatic components are rather rugged and suitable for harsh environments and therefore are an attractive alternative for mobile robots. Many robotics control algorithms require that the robot actuators be force or torque generators, so the robot controller can impose proper torque levels onto the robot joints as required by the control algorithm. While creating a torque generator using electric actuators is relatively straightforward using current feedback, there are challenges in transforming pneumatic actuators into pure force generators. This paper develops a control algorithm to convert pneumatic actuators into force generators. Because delivered work from a pneumatic actuator is product of the actuator force and the piston's displacement, the actuator force can be effectively controlled through precise measurement of the piston's displacement and robust control of the actuator's work. This paper first develops an exact model of a pneumatic system consisting of a double-acting cylinder and a servo-valve, with the goal of providing an insight into the design and control requirements for pneumatically actuated systems. Using the model, two subjects are presented in detail: 1) derivation of a control algorithm that converts a pneumatic actuator into a force generator for robotics control applications and 2) derivation of equations that can be used to design or size the power source for mobile robotic systems, where continuous source of power is unavailable. [ABSTRACT FROM PUBLISHER]

The implementation of the control system for a variable speed electric actuator composed of an induction motor with scalar control technique is presented. Details are given on the laboratory experiment involving the actuator control system and its modes of operation. Also, the configured hardware, the operation control software and the results obtained on performance from laboratory tests are described. Thus, a high performance actuator employing a V/f controlled induction motor with a digital inverter has been developed and tested. [Copyright &y& Elsevier]