scholarly journals Design, Analysis and Experiment of a Bridge-Type Piezoelectric Actuator for Infrared Image Stabilization

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1197
Author(s):  
Mengxin Sun ◽  
Yong Feng ◽  
Yin Wang ◽  
Weiqing Huang ◽  
Songfei Su
Keyword(s):  
Piezoelectric Actuator ◽  
Control Strategy ◽  
Structural Parameters ◽  
Infrared Image ◽  
Feedback Signal ◽  
Maximum Output ◽  
Stabilization System ◽  
Image Stabilization ◽  
Bridge Type ◽  
Amplification Mechanism

Piezoelectric actuators are widely used in the optical field due to their high precision, compact structure, flexible design, and fast response. This paper presents a novel piezoelectric actuator with a bridge-type mechanism, which can be used to stabilize the images of an infrared imaging system. The bridge amplification mechanism is used to amplify the actuation displacement, and its structural parameters are optimized by the response surface method. The control strategy of the image stabilization system is formulated, and the overall structure of the infrared image stabilization system is designed according to the principle of image stabilization and the control strategy. The prototype was fabricated and verified by a series of experiments. In the test, the laminated piezoelectric ceramics are used as the driving element, and its maximum output displacement was about 17 μm under a voltage of 100 V. Firstly, the performance of the piezoelectric amplification mechanism was tested, and the maximum displacement of the piezoelectric micro-motion mechanism was 115 μm. The displacement amplification ratio of the mechanism was 5.7. Then, the step distance and response time of the micro-displacement mechanism were measured by inputting the stepping signal. When the input voltage increased to 3 V, 5 V, and 7 V, the stepping displacements of the mechanism were 2.4 μm, 4.1 μm, and 5.8 μm. Finally, the image stabilization effect of the designed mechanism was verified by imaging timing control and feedback signal processing.

scholarly journals Design, Modeling, and Testing of a Novel XY Piezo-Actuated Compliant Micro-Positioning Stage

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 581 ◽  
Author(s):  
Quan Zhang ◽  
Jianguo Zhao ◽  
Xin Shen ◽  
Qing Xiao ◽  
Jun Huang ◽  
...  
Keyword(s):  
Modal Analysis ◽  
Cross Coupling ◽  
Maximum Error ◽  
Analytical Models ◽  
Amplification Ratio ◽  
Proposed Model ◽  
Positioning Stage ◽  
Bridge Type ◽  
Amplification Mechanism ◽  
Coupling Error

A novel decoupled XY compliant micro-positioning stage, based on a bridge-type amplification mechanism and parallelogram mechanisms, is designed in this paper. Analytical models of the bridge-type amplification mechanism and parallelogram mechanisms are developed by Castigliano’s second theorem and a Beam constrained model. The amplification ratio, input stiffness, and output stiffness of the stage are further derived, based on the proposed model. In order to verify the theoretical analysis, the finite element method (FEM) is used for simulation and modal analysis, and the simulation results indicate that the errors of the amplification ratio, input stiffness, and output stiffness of the stage between the proposed model and the FEM results are 2.34%, 3.87%, and 2.66%, respectively. Modal analysis results show that the fundamental natural frequency is 44 Hz, and the maximum error between the theoretical model and the FEM is less than 4%, which further validates the proposed modeling method. Finally, the prototype is fabricated to test the amplification ratio, cross-coupling error, and workspace. The experimental results demonstrate that the stage has a relatively large workspace, of 346.1 μm × 357.2 μm, with corresponding amplification ratios of 5.39 in the X-axis and 5.51 in the Y-axis, while the cross-coupling error is less than 1.5%.

scholarly journals Pressure Control of Insulation Space for Liquefied Natural Gas Carrier with Nonlinear Feedback Technique

2018 ◽  
Vol 6 (4) ◽  
pp. 133
Author(s):  
Jinghua Cao ◽  
Xianku Zhang ◽  
Xiang Zou
Keyword(s):  
Natural Gas ◽  
Control Strategy ◽  
Control Strategies ◽  
Nonlinear Function ◽  
Pressure Control ◽  
Feedback Signal ◽  
Control Input ◽  
Nonlinear Feedback ◽  
Pressure Control System ◽  
Liquid Natural Gas

This paper introduces a novel control strategy into the insulation space for liquid natural gas carriers. The control strategy proposed can improve the effects of control for differential pressure and reduce the energy consumption of nitrogen. The method combines a nonlinear feedback technique with a closed-loop gain shaping algorithm (CGSA). It is designed for the pressure control system which is vital for liquid natural gas carriers (LNGCs) in marine transportation. The control error is modulated using nonlinear function. The deviation signal is replaced with a nonlinear feedback signal. Comparison experiments are conducted under different conditions to prove the effectiveness of this strategy. This paper compares three control strategies: a control strategy with nonlinear feedback based on CGSA, a control strategy without nonlinear feedback based on CGSA, and a two-degree-of-freedom (DOF) control strategy. The simulation results show that this control strategy with nonlinear feedback performs better than the other two. The average reduction of control input is about 38.8%. The effect of pressure control is satisfactory.

scholarly journals A Novel Control Strategy for Grid-Connected Inverter Based on Iterative Calculation of Structural Parameters

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3306 ◽  
Author(s):  
Zhenao Sun ◽  
Dazhi Wang ◽  
Tianqing Yuan ◽  
Zairan Liu ◽  
Jiahui Yu
Keyword(s):  
Control Strategy ◽  
Structural Parameters ◽  
Dynamic Performance ◽  
Open Loop ◽  
Output Current ◽  
Open Loop System ◽  
Iterative Calculation ◽  
Static Performance ◽  
Grid Connected Inverter ◽  
Pv Grid

A novel control strategy that is based on iterative calculation of structural parameters is proposed for grid-connected inverter in this paper. The proposed strategy has a good dynamic performance, which makes it particularly suitable for the application of PV grid-connected generation. First, a second-order discretization mathematical model of grid-connected inverter control is established in the dq frame. The corresponding relation between the control signal and the output current is deduced in formulas. Then, the values of structural parameters in the formulas can be obtained through iterative calculation, which can further reduce the amount of calculation. After several iteration cycles, the structural parameters are approximately equal to their actual values and the inverter can be controlled as an open-loop system with its dynamic performance optimized. At last, simulation and experiments are performed. The results show that the static performance of the proposed strategy is as good as that of the classical ones, but its dynamic performance is improved significantly.

Task-Based Knee Rehabilitation With Assist-as-Needed Control Strategy and Recovery Tracking System

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Yimesker Yihun ◽  
Visharath Adhikari ◽  
Amirhossein Majidirad ◽  
Jaydip Desai
Keyword(s):  
Motion Capture ◽  
Control Strategy ◽  
Structural Parameters ◽  
Tracking System ◽  
Three Dimensional ◽  
Parallel Mechanisms ◽  
Emg Signal ◽  
Knee Rehabilitation ◽  
Synthesis Procedure ◽  
Serial Chains

Abstract This research aims to design and implement a novel task-based knee rehabilitation strategy through kinematic synthesis, assist-as-needed control strategy, and recovery tracking system. Experimental kinematic data collected through motion capture system are utilized as an input to the mechanism synthesis procedure. Parallel mechanisms with single degree-of-freedom are considered to generate the complex three-dimensional (3D) motions of the lower leg. An exact workspace synthesis approach is utilized, in which the implicit description of the workspace is made to be a function of the structural parameters of the serial chains of the parallel mechanism, making it easy to relate those parameters to the desired trajectory from the motion capture. The synthesis procedure resulted an exoskeleton which can guide the complex motion of the human knee without the need of mimicking the joint by the exoskeleton counterpart. This can potentially reduce the improper alignment problems arising due to the constantly varying axis of rotation of human joint, which is often very difficult to predict. An assist-as-needed control and recovery tracking strategy is outlined based on an electromyography (EMG) signals and force sensing resistors (FSRs) mounted on the user and exoskeleton, respectively. The EMG signal is captured from the user leg and FSRs are applied at the attachment area of the exoskeleton and the leg, this helps to get the amount of force applied by the exoskeleton to the leg as well as for the recovery tracking. The assist-as-needed controller eliminates the need of constant supervision, and hence saves time and reduces cost of the rehabilitation process. Similarly, the real-time progress tracking system will motivate and actively engage users

scholarly journals Research on three-stage amplified compliant mechanism-based piezo-driven microgripper

2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091147 ◽  
Author(s):  
Xiaodong Chen ◽  
Zilong Deng ◽  
Siya Hu ◽  
Xingjun Gao ◽  
Jinhai Gao
Keyword(s):  
Amplification Factor ◽  
Compliant Mechanism ◽  
Structural Parameters ◽  
Maximum Output ◽  
Driving Voltage ◽  
Element Analysis ◽  
Compact Structure ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Input Variables

The microgripper based on the principle of lever amplification is easy to realize; however, the theoretical amplification factor is limited by the space size and the structure is not compact enough. The microgripper based on the triangular amplification principle has a compact structure and high amplification factor, but it is not conducive to miniaturization design. Considering compactness, parallel clamping, high magnification, and miniaturization design, a three-stage amplifier consisting of a semi-rhombic amplifier and lever amplifiers is designed. To begin with, the theoretical amplification ratio and the relationship between input variables and output variables are calculated by energy method. Furthermore, the finite element analysis software is used to optimize the structural parameters and analyze the performance of the model. Lastly, the experimental verification is carried out. At 150 V of driving voltage, the maximum output displacement was 530mm, and the actual magnification was 24 times. Microparts can be gripped in parallel and stably, which confirms the validity of the design.

A FAILURE CONTROL METHOD FOR SMART COMPOSITE MORPHING AIRFOIL BY PIEZOELECTRIC ACTUATOR

2011 ◽  
Vol 35 (3) ◽  
pp. 369-381
Author(s):  
Shahin Zareie ◽  
Abolghassem Zabihollah
Keyword(s):  
Piezoelectric Actuator ◽  
Control Strategy ◽  
Applied Load ◽  
Control Mechanism ◽  
Control Method ◽  
Nonlinear Finite Element ◽  
Smart Composite ◽  
Interlaminar Stresses ◽  
Morphing Structure ◽  
Displacement Theory

In this paper, a nonlinear Finite Element (FE) approach based on the layerwise displacement theory is utilized to obtain the interlaminar stresses due to buckling phenomena in unsymmetric laminated smart composite morphing structure. An On/Off control strategy is designed to control the snap-through phenomena. Due to cycling nature of applied load on morphing, these structures are vulnerable to failure due to fatigue. A failure control mechanism utilizing a piezoelectric actuator is developed to control the failure.

Sign in / Sign up

Export Citation Format

Share Document