The Experts below are selected from a list of 4380 Experts worldwide ranked by ideXlab platform
Jungoh Choi - One of the best experts on this subject based on the ideXlab platform.
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fabrication and reliable implementation of an ionic polymer metal composite ipmc biaxial bending actuator
Smart Materials and Structures, 2011Co-Authors: Jungoh ChoiAbstract:Ionic polymer?metal composites (IPMCs) are one of the most popular types of electro-active polymer actuator, due to their low electric driving potential, large deformation range, and light weight. IPMCs have been used as actuators or sensors in many areas of biomedical and robotic engineering. In this research, IPMCs were studied as a biaxial bending actuator capable of smart and flexible motion. We designed and fabricated this bending actuator and implemented it to have a reliable Actuating motion using a systematic approach. The resulting device was bar shaped with a square cross section and had four insulated electrodes on its surface. By applying different voltages to these four electrodes, a biaxial bending motion can be induced. To construct this actuator, several fabrication processes were considered. We modified the Nafion stacking method, and established a complete sequence of actuator fabrication processes. Using these processes, we were able to fabricate an IPMC biaxial bending actuator with both high Actuating Force and high flexibility. Several experiments were conducted to investigate and verify the performance of the actuator. The IPMC actuator system was modeled from experimentally measured data, and using this actuator model, a closed-loop proportional integral (PI) controller was designed. Reference position tracking performances of open-loop and closed-loop systems were compared. Finally, circular motion tracking performances of the actuator tip were tested under different rotation frequencies and radii of a reference trajectory circle.
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Fabrication and reliable implementation of an ionic polymer–metal composite (IPMC) biaxial bending actuator
Smart Materials and Structures, 2011Co-Authors: Jungoh ChoiAbstract:Ionic polymer?metal composites (IPMCs) are one of the most popular types of electro-active polymer actuator, due to their low electric driving potential, large deformation range, and light weight. IPMCs have been used as actuators or sensors in many areas of biomedical and robotic engineering. In this research, IPMCs were studied as a biaxial bending actuator capable of smart and flexible motion. We designed and fabricated this bending actuator and implemented it to have a reliable Actuating motion using a systematic approach. The resulting device was bar shaped with a square cross section and had four insulated electrodes on its surface. By applying different voltages to these four electrodes, a biaxial bending motion can be induced. To construct this actuator, several fabrication processes were considered. We modified the Nafion stacking method, and established a complete sequence of actuator fabrication processes. Using these processes, we were able to fabricate an IPMC biaxial bending actuator with both high Actuating Force and high flexibility. Several experiments were conducted to investigate and verify the performance of the actuator. The IPMC actuator system was modeled from experimentally measured data, and using this actuator model, a closed-loop proportional integral (PI) controller was designed. Reference position tracking performances of open-loop and closed-loop systems were compared. Finally, circular motion tracking performances of the actuator tip were tested under different rotation frequencies and radii of a reference trajectory circle.
Zishun Liu - One of the best experts on this subject based on the ideXlab platform.
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Modeling and active vibration control of lattice grid beam with piezoelectric fiber composite using fractional order PD μ algorithm
Composite Structures, 2018Co-Authors: Cihang Xie, Ying Wu, Zishun LiuAbstract:Abstract One of challenging issues in structural dynamics is to accurately and rapidly control the vibration levels. It is even important to minimize the occurrence of structural failure in lightweight design. As smart sensors or actuators, the new piezoelectric fiber composite are able to coat onto large area in flexible smart structures, and also has large Actuating Force. But little is known about the performance of the piezoelectric fiber composite on active vibration control of lattice sandwich structure. In this paper, a novel fractional order PDμ control of lattice grid beam with piezoelectric fiber composite face sheets is proposed. Firstly, the dynamic model and the vibration responses of the smart sandwich structure are obtained on the basis of the third order shear deformation theory. The ply pattern of piezoelectric fiber composite and structural damping are taken into account for more accurately predict the dynamic behavior. Then, a new active control method by using the fractional order PDμ algorithm is presented, and simulations of vibration control of the lattice grid beam subjected to various dynamic loadings are conducted, such as initial disturbance, harmonic excitation, step excitation and explosive impact excitation. Consequently, it is proved that the fractional order PDμ control can reduce the vibration amplitude of lattice grid beam more significantly and more rapidly, by comparing its numerical results with those of the integer order PD algorithm and uncontrolled results.
A. Jamali - One of the best experts on this subject based on the ideXlab platform.
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A multi-objective differential evolution approach based on ε-elimination uniform-diversity for mechanism design
Structural and Multidisciplinary Optimization, 2015Co-Authors: I. Gholaminezhad, A. JamaliAbstract:In this paper, a new multi-objective uniform-diversity differential evolution (MUDE) algorithm is proposed and used for Pareto optimum design of mechanisms. The proposed algorithm uses a diversity preserving mechanism called the ε-elimination algorithm to improve the population diversity among the obtained Pareto front. The proposed algorithm is firstly tested on some constrained and unconstrained benchmarks proposed for the special session and competition on multi-objective optimizers held under IEEE CEC 2009. The inverted generational distance (IGD) measure is used to assess the performance of the algorithm. Secondly, the proposed algorithm has been used for multi-objective optimization of two different combinatorial case studies. The first case contains a two-degree of freedom leg mechanism with springs. Three conflicting objective functions that have been considered for Pareto optimization are namely, leg size, vertical Actuating Force, and the peak crank torque. The second case is a two-finger robot gripper mechanism with two conflicting objectives which are the difference between the maximum and minimum gripping Force and the transmission ratio of actuated and experienced gripper Forces. Comparisons of obtained Pareto fronts using the method of this work with those obtained in other references show significant improvements.
L.h. Yam - One of the best experts on this subject based on the ideXlab platform.
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Mechanical interaction issues in piezoelectric composite structures
Composite Structures, 2003Co-Authors: Y.j. Yan, L.h. YamAbstract:In this paper, the bending moment induced by piezoelectric patch actuators embedded in a plate is taken as the objective function to study the optimal thickness and optimal embedded depth of piezoelectric patch actuators. The purpose of optimization is to make the piezoelectric Actuating Force as large as possible in active vibration control of piezoelectric laminated structures with embedded piezoelectric patch actuators.
Cihang Xie - One of the best experts on this subject based on the ideXlab platform.
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Modeling and active vibration control of lattice grid beam with piezoelectric fiber composite using fractional order PD μ algorithm
Composite Structures, 2018Co-Authors: Cihang Xie, Ying Wu, Zishun LiuAbstract:Abstract One of challenging issues in structural dynamics is to accurately and rapidly control the vibration levels. It is even important to minimize the occurrence of structural failure in lightweight design. As smart sensors or actuators, the new piezoelectric fiber composite are able to coat onto large area in flexible smart structures, and also has large Actuating Force. But little is known about the performance of the piezoelectric fiber composite on active vibration control of lattice sandwich structure. In this paper, a novel fractional order PDμ control of lattice grid beam with piezoelectric fiber composite face sheets is proposed. Firstly, the dynamic model and the vibration responses of the smart sandwich structure are obtained on the basis of the third order shear deformation theory. The ply pattern of piezoelectric fiber composite and structural damping are taken into account for more accurately predict the dynamic behavior. Then, a new active control method by using the fractional order PDμ algorithm is presented, and simulations of vibration control of the lattice grid beam subjected to various dynamic loadings are conducted, such as initial disturbance, harmonic excitation, step excitation and explosive impact excitation. Consequently, it is proved that the fractional order PDμ control can reduce the vibration amplitude of lattice grid beam more significantly and more rapidly, by comparing its numerical results with those of the integer order PD algorithm and uncontrolled results.