Displacement Amplification Analysis for Parallel Four-Bar Mechanism

2012 ◽  
Vol 160 ◽  
pp. 229-233
Author(s):  
Xue Feng Yang ◽  
Wei Li ◽  
Yu Fei Liu

The displacement amplification and hysteresis of parallel four-bar mechanism using piezo actuator were researched in this paper. The displacement amplification was analyzed by employing the material bending theory firstly. Theoretical and FEM analysis proved that the amplification ratio of parallel four-bar mechanism is only related to the position of driving point and the guiding arm displacement is directly proportional to the input with the certain structure. Then the Preisach model was employed to model the hysteresis of guiding arm and using the model to perform the research on the output displacement of the mechanism. Experiments proved that the analysis is correct and showed that this model can effectively improve the accurate of the guiding arm output displacement and can realize output arbitrary series displacement using the Preisach interpolation surface.

2012 ◽  
Vol 155-156 ◽  
pp. 201-205
Author(s):  
Xue Feng Yang ◽  
Wei Li ◽  
Yu Qiao Wang

This paper researched the displacement amplification and hysteresis of parallel four-bar amplification mechanism using piezo actuator. Firstly, the displacement amplification was analyzed by employing the material bending theory. Theory and finite element model (FEM) proved that the amplification ratio of parallel four-bar mechanism is only related to the position of driving point and the guiding beam displacement is linear with the driving point input when it is fixed. Then the Preisach model was employed to model the hysteresis of guiding beam and performed to control the output displacement of the mechanism. Experiments proved that the model can effectively improve the output displacement accurate of the guiding beam and can realize random sequence output displacement using the Preisach interpolation surface.


2021 ◽  
Author(s):  
Amiraslan Eskandari

Piezoelectric (PZT) actuators are micro motion generators capable of producing a high displacement resolution and low strain with high force outputs. However, due to their relatively short motion ranges, the functions of PZT actuators become limited or infeasible for many of the above mentioned applications. One technique to overcome the mentioned shortcoming is to integrate a PZT actuator with a mechanical displacement amplifier. Such an amplification mechanism can be based on a compliant mechanical displacement amplifier (CMDA). A CMDA has many advantages such as no friction losses, no need for lubrication, no tolerance, and et al. over conventional rotating pinjoint mechanisms. Hence, the primary goal of a CMDA is to achieve a large output displacement in desired direction(s) for a given input displacement generated by a PZT actuator, and to keep a high positioning resolution at the same time. This thesis describes a complete study on the design, development and optimization of two proposed CMDA’s, one for the use in prostate Magnetic Resonance Elastography (MRE) application, and the other for the use as a planar motion generator mechanism for the application in high precision manipulation systems. The design of the both proposed mechanisms are based on the symmetric five-bar topology which facilitates a high amplification ratio (AR) with maintaining a relatively high natural frequency (NF). The first proposed CMDA was designed and optimized to amplify the generated motion of a PZT actuator in only one direction with keeping the NF as high as possible. On the other hand, the design and optimization of the second proposed CMDA was done to convert the linear motions of the integrated PZT actuators into a XY planar motion with high accuracy and resolution. In this study the comprehensive FEM analysis and simulations of both proposed CMDA designs are provided.


2021 ◽  
Author(s):  
Amiraslan Eskandari

Piezoelectric (PZT) actuators are micro motion generators capable of producing a high displacement resolution and low strain with high force outputs. However, due to their relatively short motion ranges, the functions of PZT actuators become limited or infeasible for many of the above mentioned applications. One technique to overcome the mentioned shortcoming is to integrate a PZT actuator with a mechanical displacement amplifier. Such an amplification mechanism can be based on a compliant mechanical displacement amplifier (CMDA). A CMDA has many advantages such as no friction losses, no need for lubrication, no tolerance, and et al. over conventional rotating pinjoint mechanisms. Hence, the primary goal of a CMDA is to achieve a large output displacement in desired direction(s) for a given input displacement generated by a PZT actuator, and to keep a high positioning resolution at the same time. This thesis describes a complete study on the design, development and optimization of two proposed CMDA’s, one for the use in prostate Magnetic Resonance Elastography (MRE) application, and the other for the use as a planar motion generator mechanism for the application in high precision manipulation systems. The design of the both proposed mechanisms are based on the symmetric five-bar topology which facilitates a high amplification ratio (AR) with maintaining a relatively high natural frequency (NF). The first proposed CMDA was designed and optimized to amplify the generated motion of a PZT actuator in only one direction with keeping the NF as high as possible. On the other hand, the design and optimization of the second proposed CMDA was done to convert the linear motions of the integrated PZT actuators into a XY planar motion with high accuracy and resolution. In this study the comprehensive FEM analysis and simulations of both proposed CMDA designs are provided.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 795
Author(s):  
Xiaochao Tian ◽  
Yuze Sun ◽  
Zhiyao Li ◽  
Hu Wang ◽  
Zhicong Wang ◽  
...  

This paper describes the design of a piezoelectric-driven hydraulically amplified Braille-flexible bump device that enables the flexible formation of Braille characters. A piezoelectric vibrator is used to excite fluid resonance in a cavity, and displacement is realized by compressing the fluid, allowing Braille character dots to be formed. First, the structural design and working principle of the device, as well as the method used to drive the fluid, are explained. Expressions for the output displacement and amplification ratio of the flexible film and piezoelectric vibrator are then obtained through kinetic analysis of the system unit. Subsequently, the structural parameters that affect the output displacement and the liquid amplification are described. Finally, experimental tests of the system are explained. The results indicate that the output displacement of the contact formed by the flexible film reaches 0.214 mm, satisfying the requirements of the touch sensitivity standard for the blind, when the fluid cavity diameter measures 31 mm and the resonance frequency is 375.4 Hz. The corresponding water discharge is 8.8 mL. This study proves that constructing a Braille bump device in this way is both feasible and effective.


2020 ◽  
pp. 1-7
Author(s):  
Wenjing Wang ◽  
Qiuyue Du ◽  
Wenjing Chen ◽  
Bin Tian ◽  
Wenjing Wang

In this study, we take the effect of the anterior movement of the optic into account and propose a novel haptic based on lever-type and bridge-type flexible amplification mechanisms. Based on the consideration of the offset of the rotation center of the flexible hinge, we have deduced the formula for calculating the amplification ratio of the proposed four-stage amplifier. The geometric parameters and the material property parameters, in terms of the clinical measurement data of the human eye, are assumed to restrain the structural features and motion trajectories for the amplifier. As the ciliary muscle achieves the contraction limit, the output displacement and amplification ratio reach the highest and lowest values, separately, and gradually approach a stable range. The amplification ratio of formula calculation and FEA (Finite Element Analysis) are around 18.86 and 17.79, respectively, with the input displacement ranging from 0.115mm to 0.127mm. The error of the amplification ratio between theoretical method and FEA is less than 5%. The presented haptic acting as a four-stage displacement amplifier, enables an improved lens power of 3.80 diopters to obtain much more focus shift to achieve a better near visual performance for patients.


1999 ◽  
Author(s):  
Dongwoo Song ◽  
C. James Li

Abstract This paper describes a micro-positioning system based on piezo actuators and a spring mechanism, and a hybrid hysteresis model integrating a neural network and Preisach model to identify the inverse dynamics of the micro-positioning system. To improve the workpiece form accuracy in diamond turning, feedforward control using the hybrid inverse model and feedback PID control were applied individually and in combination. The performance of these controllers are compared in actual cutting tests.


2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091147 ◽  
Author(s):  
Xiaodong Chen ◽  
Zilong Deng ◽  
Siya Hu ◽  
Xingjun Gao ◽  
Jinhai Gao

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.


Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 25
Author(s):  
Xiaodong Chen ◽  
Zilong Deng ◽  
Siya Hu ◽  
Jinhai Gao ◽  
Xingjun Gao

The existing symmetrical microgrippers have larger output displacements compared with the asymmetrical counterparts. However, the two jaws of a symmetrical microgripper are less unlikely to offer the same forces on the two sides of a grasped micro-object due to the manufacture and assembly errors. Therefore, this paper proposes a new asymmetric microgripper to obtain stable output force of the gripper. Compared with symmetrical microgrippers, asymmetrical microgrippers usually have smaller output displacements. In order to increase the output displacement, a compliant mechanism with four stage amplification is employed to design the asymmetric microgripper. Consequently, the proposed asymmetrical microgripper possesses the advantages of both the stable output force of the gripper and large displacement amplification. To begin with, the mechanical model of the microgripper is established in this paper. The relationship between the driving force and the output displacement of the microgripper is then derived, followed by the static characteristics’ analysis of the microgripper. Furthermore, finite element analysis (FEA) of the microgripper is also performed, and the mechanical structure of the microgripper is optimized based on the FEA simulations. Lastly, experimental tests are carried out, with a 5.28% difference from the FEA results and an 8.8% difference from the theoretical results. The results from theoretical calculation, FEA simulations, and experimental tests verify that the displacement amplification ratio and the maximum gripping displacement of the microgripper are up to 31.6 and 632 μm, respectively.


2016 ◽  
Vol 852 ◽  
pp. 1234-1242
Author(s):  
Zheng Long Zhao ◽  
Zhong Bo He ◽  
Dong Wei Li ◽  
Guang Ming Xue ◽  
Zhao Shu Yang

A new bone conduction pronunciation vibrator with a bow-type structure is proposed based on the excellent characteristics of the giant magnetostrictive material (GMM); The theoretical derivation of displacement amplification ratio is carried on based on the elastic mechanics theory; And the theoretical result is simulated in magnetic-structure coupling field through ANSYS; Eventually the actual output displacement is measured using some equipment such as the laser displacement sensor. And the reliability of the theoretical derivation is vertified by the simulation and the test. All the work done in the paper provides reference and basis for the structure parameters design and optimization of the pronunciation vibrator.


Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 312 ◽  
Author(s):  
Guoping Liu ◽  
Zhongbo He ◽  
Guo Bai ◽  
Jiawei Zheng ◽  
Jingtao Zhou ◽  
...  

Giant magnetostrictive actuators (GMA) are widely used in the field of servo valves, but the displacement of GMA is limited, which renders meeting the requirements of large flow direct-drive electro-hydraulic servo valves (DDV) difficult. In order to solve these problems, this study proposes a double-row bow-type micro-displacement amplifier (DBMA), used to increase output displacement of GMA to meet the requirements. This study, by static analysis, analyzes the force of a flexure hinge based on theoretical mechanics and material mechanics, derives the stiffness matrix of the flexure hinge by the influence coefficient method, establishes the pseudo-rigid model, and derives the amplification ratio of a DBMA. Also, by kinetic analysis, using Castigliano’s second theorem, a formula of equivalent stiffness and natural frequency of DBMA were derived and the influences of different parameters on them were analyzed, respectively. After that, we analyzed the amplifier using finite element method (FEM) simulation software and verified the model by manufacturing a prototype and building a test system. Theoretical calculations and experimental results showed that the amplification ratio of the DBMA fluctuated between 15.43 and 16.25. The natural frequency was about 305 Hz to 314 Hz and the response bandwidth was up to 300 Hz. The error among the theoretical, simulated, and experimental values was within 8%, supporting the accuracy of the model.


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