Dynamic Electromechanical Modeling of a Spring-Biased Dielectric Electroactive Polymer Actuator System

2014 ◽  
Author(s):  
Gianluca Rizzello ◽  
Micah Hodgins ◽  
David Naso ◽  
Alexander York ◽  
Stefan Seelecke
Keyword(s):  
Position Control ◽  
Compressive Force ◽  
Electromechanical Modeling ◽  
Out Of Plane ◽  
Polymer Actuator ◽  
Linear Spring ◽  
Actuator System ◽  
Plane Direction ◽  
Electromechanical Dynamics ◽  
Driving Circuit

This paper presents a dynamic electromechanical model for an actuator system based on a Dielectric Electro-Active Polymer (DEAP) membrane biased with a linear spring. The motion is generated by the deformation of the membrane caused by the electrostatic compressive force between two compliant electrodes applied on the surface of the polymer. A mass and a linear spring are used to pre-load the membrane, allowing stroke in the out-of-plane direction. The development of mathematical models which accurately describe the nonlinear system dynamics is a fundamental step in order to design model-based, high-precision position control algorithms. In particular, knowledge of the nonlinear electrical dynamics of the actuator driving circuit can be exploited during the control system design in order to achieve desirable features, such as self-sensing or control energy minimization. This work proposes an electromechanical physical model of the DEAP actuator system. By means of numerous experiments, it is shown that the model can be used to predict the current by measuring deformation and voltage (electrical dynamics), as well as predicting deformation and current by measuring the voltage (electromechanical dynamics).

Experimental Investigation of a Loaded Circular Dielectric Electro-Active Polymer Actuator Coupled to Negative-Rate Bias Spring Mechanism

2012 ◽  
Author(s):  
Micah Hodgins ◽  
Alex York ◽  
Stefan Seelecke
Keyword(s):  
Constant Force ◽  
Loading Rates ◽  
Stable Element ◽  
Stable Mechanism ◽  
Out Of Plane ◽  
Polymer Actuator ◽  
Linear Spring ◽  
Spring Mechanism ◽  
Plane Displacement ◽  
Force Equilibrium

A constant force input, a linear spring, and a bi-stable mechanism are separately tested as the biasing element of a circular/diaphragm DEAP. Each of the bias elements are systematically coupled to an unloaded 2 layer DEAP and are tested under various DEAP pre-deflections, bias element stiffness and electrical loading rates. The out-of-plane displacement output is measured as the voltage is cycled. The tests showed that the bi-stable element, with aid of a mechanical stop, gave the largest displacement output. This bi-stable element actuator is then tested against a hanging mass to examine the work capabilities against a constant force. However, the actuator failed to work even against a hanging mass of 20 grams. This change in behavior of the actuator is analyzed by considering the force equilibrium curves. Finally, suggestions are made for the design of future biasing methods in order to achieve higher actuator performance.

scholarly journals Backstepping Sliding-Mode Control of Piezoelectric Single-Piston Pump-Controlled Actuator

Actuators ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 154
Author(s):  
Bin Wang ◽  
Pengda Ren ◽  
Xinhao Huang
Keyword(s):  
Sliding Mode Control ◽  
Position Control ◽  
Control Method ◽  
Sliding Mode ◽  
Piezoelectric Pump ◽  
Mode Control ◽  
Control Precision ◽  
Backstepping Sliding Mode Control ◽  
Actuator System ◽  
The Mathematical Model

A piston piezoelectric (PZT) pump has many advantages for the use of light actuators. How to deal with the contradiction between the intermittent oil supplying and position control precision is essential when designing the controller. In order to accurately control the output of the actuator, a backstepping sliding-mode control method based on the Lyapunov function is introduced, and the controller is designed on the basis of establishing the mathematical model of the system. The simulation results show that, compared with fuzzy PID and ordinary sliding-mode control, backstepping sliding-mode control has a stronger anti-jamming ability and tracking performance, and improves the control accuracy and stability of the piezoelectric pump-controlled actuator system.

Mechanism of the Transition From In-Plane Buckling to Helical Buckling for a Stiff Nanowire on an Elastomeric Substrate

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Youlong Chen ◽  
Yong Zhu ◽  
Xi Chen ◽  
Yilun Liu
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Stretchable Electronics ◽  
Buckling Mode ◽  
Design And Optimization ◽  
Out Of Plane ◽  
Plane Direction ◽  
Plane Displacement ◽  
Helical Buckling ◽  
Selection Of

In this work, the compressive buckling of a nanowire partially bonded to an elastomeric substrate is studied via finite-element method (FEM) simulations and experiments. The buckling profile of the nanowire can be divided into three regimes, i.e., the in-plane buckling, the disordered buckling in the out-of-plane direction, and the helical buckling, depending on the constraint density between the nanowire and the substrate. The selection of the buckling mode depends on the ratio d/h, where d is the distance between adjacent constraint points and h is the helical buckling spacing of a perfectly bonded nanowire. For d/h > 0.5, buckling is in-plane with wavelength λ = 2d. For 0.27 < d/h < 0.5, buckling is disordered with irregular out-of-plane displacement. While, for d/h < 0.27, buckling is helical and the buckling spacing gradually approaches to the theoretical value of a perfectly bonded nanowire. Generally, the in-plane buckling induces smaller strain in the nanowire, but consumes the largest space. Whereas the helical mode induces moderate strain in the nanowire, but takes the smallest space. The study may shed useful insights on the design and optimization of high-performance stretchable electronics and three-dimensional complex nanostructures.

scholarly journals Comparison of Induced Deflection and Forces in Piles Adjacent to Tunnelling and Deep Excavation in 2D and 3D Problems

2018 ◽  
Vol 203 ◽  
pp. 04011
Author(s):  
Ong Yin Hoe ◽  
Hisham Mohamad
Keyword(s):  
Bending Moment ◽  
Pile Group ◽  
3D Models ◽  
Deep Excavation ◽  
Pile Groups ◽  
Out Of Plane ◽  
National University ◽  
Plane Direction ◽  
2D And 3D ◽  
2D Model

There is a trend in Malaysia and Singapore, engineers tend to model the effect of TBM tunneling or deep excavation to the adjacent piles in 2D model. In the 2D model, the pile is modelled using embedded row pile element which is a 1-D element. The user is allowed to input the pile spacing in out-of-plane direction. This gives an impression to engineers the embedded pile row element is able to model the pile which virtually is a 3D problem. It is reported by Sluis (2014) that the application of embedded pile row element is limited to 8D of pile length. It is also reported that the 2D model overestimates the axial load in pile and the shear force and bending moment at pile top and it is not realistic in comparison to 3D model. In this paper, the centrifuge results of single pile and 6-pile group - tunneling problem carried out in NUS (National University of Singapore) are back-analysed with Midas GTS 3D and a 2D program. In a separate case study, pile groups adjacent to a deep excavation is modelled by 3D and 2D program. This paper compares the deflection and forces in piles in 2D and 3D models.

Modeling and position control of a high performance twisted-coiled polymer actuator

2018 ◽  
Author(s):  
Tuan Luong ◽  
Kihyeon Kim ◽  
Sungwon Seo ◽  
Jae Hyeong Park ◽  
Youngeun Kim ◽  
...  
Keyword(s):  
High Performance ◽  
Position Control ◽  
Polymer Actuator

Magnetic quantum oscillations in doped antiferromagnets

2017 ◽  
Vol 31 (25) ◽  
pp. 1745015
Author(s):  
V. V. Kabanov
Keyword(s):  
Magnetic Field ◽  
Polar Angle ◽  
Two Dimensional ◽  
Plane Angle ◽  
Arbitrary Direction ◽  
Magnetization Direction ◽  
Quantum Oscillations ◽  
Out Of Plane ◽  
Plane Direction ◽  
Magnetic Quantum Oscillations

Energy spectrum of electrons (holes) doped into two-dimensional (2D) antiferromagnetic (AF) semiconductors is quantized in an external magnetic field of arbitrary direction. A peculiar dependence of de Haas–van Alphen (dHvA) magneto-oscillation amplitudes on the azimuthal in-plane angle from the magnetization direction and on the polar angle from the out-of-plane direction is found. The angular dependence of the amplitude is different if the measurements are performed in the field above and below of the spin-flop field.

scholarly journals Prediction of Crushing Response for Metal Hexagonal Honeycomb under Quasi-Static Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xinyu Geng ◽  
Yufei Liu ◽  
Wei Zheng ◽  
Yongbin Wang ◽  
Meng Li
Keyword(s):  
Mathematical Models ◽  
Static Loading ◽  
Theoretical Basis ◽  
Theoretical Models ◽  
Excellent Correlation ◽  
Static Compression ◽  
Out Of Plane ◽  
Plane Direction ◽  
Element Theory ◽  
Quasi Static Compression

To provide a theoretical basis for metal honeycombs used for buffering and crashworthy structures, this study investigated the out-of-plane crushing of metal hexagonal honeycombs with various cell specifications. The mathematical models of mean crushing stress and peak crushing stress for metal hexagonal honeycombs were predicted on the basis of simplified super element theory. The experimental study was carried out to check the accuracy of mathematical models and verify the effectiveness of the proposed approach. The presented theoretical models were compared with the results obtained from experiments on nine types of honeycombs under quasi-static compression loading in the out-of-plane direction. Excellent correlation has been observed between the theoretical and experimental results.

scholarly journals Novel Design and Position Control Strategy of a Soft Robot Arm

Robotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 72 ◽  
Author(s):  
Alaa Al-Ibadi ◽  
Samia Nefti-Meziani ◽  
Steve Davis ◽  
Theo Theodoridis
Keyword(s):  
Position Control ◽  
Control Strategies ◽  
Tensile Force ◽  
Compressive Force ◽  
Soft Robot ◽  
Robot Arm ◽  
Bending Actuator ◽  
Muscle Actuators ◽  
Novel Design ◽  
Bending Behaviour

This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their performances. The contraction and extension behaviour have been illustrated with single contractor actuators and single extensor actuators, respectively. The tensile force for the contractor actuator and the compressive force for the extensor PMA are thoroughly explained and compared. Furthermore, the bending behaviour has been explained for a single extensor PMA, multi extensor actuators and multi contractor actuators. A two-section continuum arm has been implemented from both types of actuators to achieve multiple operations. Then, a novel construction is proposed to achieve efficient bending behaviour of a single contraction PMA. This novel design of a bending-actuator has been used to modify the presented continuum arm. Two different position control strategies are presented, arising from the results of the modified soft robot arm experiment. A cascaded position control is applied to control the position of the end effector of the soft arm at no load by efficiently controlling the pressure of all the actuators in the continuum arm. A new algorithm is then proposed by distributing the x, y and z-axis to the actuators and applying an effective closed-loop position control to the proposed arm at different load conditions.

scholarly journals Development of a New Piezoelectric Actuator with Slits

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Yasutomo Uetsuji ◽  
Hiroyuki Kuramae ◽  
Kazuyoshi Tsuchiya ◽  
Hidetoshi Sakamoto
Keyword(s):  
Piezoelectric Actuator ◽  
Large Deflection ◽  
Superior Performance ◽  
Uniform Electric Field ◽  
Optimum Geometry ◽  
Out Of Plane ◽  
Fixed Condition ◽  
Plane Direction ◽  
Health Monitoring Systems ◽  
Bimorph Actuators

A piezoelectric actuator was developed for fluid pumps in health monitoring systems. We devised a piezoelectric actuator with some slits, which allows the stretching and contracting deformation in in-plane direction and creates large deflection in out-of-plane direction. The static behaviors under uniform electric field have been analyzed by finite element method. And then, the optimum geometry of slits was searched by response surface methodology for unimorph and bimorph actuators to output the largest deflection under various fixed conditions. The computational results indicated that a bimorph actuator with cross-shaped slit under outside-fixed condition has superior performance for fluid pumps. The proposed slit-inserted actuators have been manufactured as an experiment. As a result, it was verified that the developed actuator can amplify the deflection compared with conventional nonslit actuators.

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