scholarly journals Design and optimization of compliant mechanical amplifiers

2021 ◽  
Author(s):  
Amiraslan Eskandari
Keyword(s):  
Fem Analysis ◽  
The Other ◽  
Planar Motion ◽  
Design Development ◽  
Pzt Actuator ◽  
Mechanical Displacement ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Design And Optimization ◽  
Complete Study

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.

scholarly journals Design and optimization of compliant mechanical amplifiers

2021 ◽  
Author(s):  
Amiraslan Eskandari
Keyword(s):  
Fem Analysis ◽  
The Other ◽  
Planar Motion ◽  
Design Development ◽  
Pzt Actuator ◽  
Mechanical Displacement ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Design And Optimization ◽  
Complete Study

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.

Analysis and Research of GMM Bone Conduction Pronunciation Vibrator Output Characteristics

2016 ◽  
Vol 852 ◽  
pp. 1234-1242
Author(s):  
Zheng Long Zhao ◽  
Zhong Bo He ◽  
Dong Wei Li ◽  
Guang Ming Xue ◽  
Zhao Shu Yang
Keyword(s):  
Bone Conduction ◽  
Displacement Sensor ◽  
Theoretical Derivation ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Design And Optimization ◽  
Giant Magnetostrictive Material ◽  
Output Characteristics ◽  
Work Done ◽  
Elastic Mechanics

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.

Displacement Amplification Analysis for Parallel Four-Bar Mechanism

2012 ◽  
Vol 160 ◽  
pp. 229-233
Author(s):  
Xue Feng Yang ◽  
Wei Li ◽  
Yu Fei Liu
Keyword(s):  
Fem Analysis ◽  
Piezo Actuator ◽  
Preisach Model ◽  
Output Displacement ◽  
Amplification Ratio

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.

scholarly journals Design and optimization of a XY compliant mechanical displacement amplifier

2013 ◽  
Vol 4 (2) ◽  
pp. 303-310 ◽  
Author(s):  
A. Eskandari ◽  
P. R. Ouyang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compliant Mechanism ◽  
Piezoelectric Actuators ◽  
Range Limits ◽  
Static And Dynamic Characteristics ◽  
Mechanical Displacement ◽  
Amplification Ratio ◽  
Design And Optimization ◽  
Motion Range

Abstract. Piezoelectric actuators are increasingly becoming popular for the use in various industrial, pharmaceutical, and engineering applications. However, their short motion range limits their wide applications. This shortcoming can be overcome by coupling the piezoelectric actuators with a mechanical displacement amplifier. In this paper, a new design for a XY planar motion compliant mechanical displacement amplifier (CMDA) based on the design of a symmetric five-bar compliant mechanical amplifier is introduced. Detailed analysis with Finite Element Method (FEM) of static and dynamic characteristics of the proposed XY CMDA design is also provided. Finally, the optimization process and results to increase the Amplification Ratio (AR) of the proposed XY compliant mechanism with minimal compromise in Natural Frequency (NF) is discussed.

scholarly journals Design and Experiment Using Flexible Bumps for Piezoelectric-Driven Hydraulically Amplified Braille Dot Display

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 795
Author(s):  
Xiaochao Tian ◽  
Yuze Sun ◽  
Zhiyao Li ◽  
Hu Wang ◽  
Zhicong Wang ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Water Discharge ◽  
Experimental Tests ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Fluid Resonance ◽  
Piezoelectric Vibrator ◽  
Flexible Film ◽  
Touch Sensitivity ◽  
Sensitivity Standard

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.

The effect of displacement of the esophagus by transoesophageal echocardiography probe in cryoablation of atiral fibrillation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Sun ◽  
X.M Yin ◽  
L.J Gao ◽  
X.J Xiao ◽  
X.H Yu ◽  
...  
Keyword(s):  
Lower Risk ◽  
Transoesophageal Echocardiography ◽  
The Other ◽  
Esophageal Injury ◽  
Funding Source ◽  
Success Rates ◽  
Procedure Time ◽  
Mechanical Displacement ◽  
Significant Difference

Abstract Background Esophageal injury caused by cryoballoon-based PVI is common. Cryoablation guided by transoesophageal echocardiography (TEE) for occlusion of the pulmonary vein (PV) is safe and effective. Objective To investigate the protective effect of mechanical displacement of the esophagus by TEE probe in cryoablation of atiral fibrillation. Methods Fifty patients with paroxysmal AF (PAF) were enrolled in the present study. 25 patients underwent cryoablation without TEE (non-TEE group) and the other 25 underwent with TEE (TEE group) for PV occlusion guidance and displacement of the esophagus. In the TEE group during the procedure, TEE was used to guide the movement of the balloon to achieve PV occlusion. And before freezing, the probe of the TEE was moved to displace the esophagus away from the PV being freezed in order to reduce the risk of cryoinjury. All patients underwent esophagogastroscopy within 2 days of the procedure. The patients were followed up in our center at regularly scheduled visits every 2 months. Results There was no significant difference between the TEE group and non-TEE group in regard to the procedure time. The fluoroscopy time in the TEE group was less compared to the non-TEE group (4.1±3.3 min vs. 16.6±6.9 min, P<0.05), and the amount of contrast agent in the TEE group was less than the non-TEE group (4.7±5.7ml vs. 17.9±3.4 ml, P<0.05). The incidence of esophageal injury was significantly lower in TEE group compared with non-TEE group (0 vs. 20%, P<0.05). At a mean of 14.0 months follow-up, success rates were similar between the TEE group and non-TEE group (80.0% vs. 84.0%, P=0.80). Conclusion Cryoablation of AF with TEE for protecting the esophagus from cryoinjury is safe and effective. Lower risk of esophageal injury can be achieved with the help of TEE probe movement for mechanical displacement of the esophagus during freezing. Funding Acknowledgement Type of funding source: None

Macro-Micro Dual-Drive Stages Based on Dual Switching Condition and Local Closed Loop

2015 ◽  
Author(s):  
Jiwen Fang ◽  
Zhili Long ◽  
Lufan Zhang
Keyword(s):  
Steady State ◽  
Theoretical Analysis ◽  
Closed Loop ◽  
Voice Coil Motor ◽  
Switching Control ◽  
Positioning Error ◽  
Vibration Displacement ◽  
Pzt Actuator ◽  
Output Displacement ◽  
State Error

This paper presents macro-micro dual-drive stages using the hybrid actuators composed of voice coil motor (VCM) and piezoelectric actuator (PZT actuator). The macro stage driven by voice coil motor can achieve large travel range and coarse positioning. The micro stage with an embedded flexure hinges mechanism, actuated by the PZT actuator, can realize short range but high precision positioning. To gain precise performance, the dynamic modes of macro stage and micro stage are equivalent to mass-damping-spring system in this research. According to theoretical analysis, the output displacement of micro stage is proportional to the extension of the PZT Actuator. The linear relationship will be used to the motion control of micro stage. To realize perfect performance, the variable gain PID controller is designed to control the macro stage. In order to prevent saturation and damage of PZT actuator, dual switching control, positioning error threshold and small vibration displacement, are applied to the switching control. Beyond the micro stage range, the micro stage must be kept in its equilibrium position while the VCM instead reaches a long travel. The PZT actuator controller is used to compensate for position error after switching control. When the error is less than a set thres hold value, the error signal is added into the micro control loop. So the macro-micro dual-drive stages are working together to reduce the positioning error. The relationship between PZT actuator of closed loop and input voltage is linear by theoretical analysis and experiment test. So the micro stage uses an open servo loop structure, but the PZT actuator is controlled with PI controller in local closed loop in order to eliminate the nonlinear of PZT. The experimental system used in this study is single-axis dual-driving stages. Turbo PMAC PCI-Lite is the core of the whole system and executes PLC programs with motion programs. Experiments show that the steady state error of dual-drive stage is nano level. The steady state error of dual-drive stage can be improved. So dual-drive stages can increase the positioning accuracy of the whole system and the performance is superior to the single VCM stage.

Planar Motion Control, Coordination and Dynamic Entrainment in Chaplygin Beanies

2018 ◽  
Author(s):  
Scott Kelly ◽  
Rodrigo Abrajan-Guerrero ◽  
Jaskaran Grover ◽  
Matthew Travers ◽  
Howie Choset
Keyword(s):  
Energy Transfer ◽  
Motion Control ◽  
Nonholonomic Constraint ◽  
The Other ◽  
Planar Motion ◽  
Single Input ◽  
Robotic Vehicle

The Chaplygin beanie is a single-input robotic vehicle for which partial planar motion control can be achieved by exploiting a simple nonholonomic constraint. A previous paper suggested a strategy for such motion control. In the present paper, this strategy is validated experimentally and extended to the context of multi-vehicle coordination. It is then shown that when the plane on which two such vehicles operate is translationally compliant, energy transfer between the two can enable a mechanism whereby one (operating under control) may entrain the other (operating passively), partly coordinating their motion. As an extension to this result, it is further demonstrated that a pair of passive vehicles operating on a translationally compliant platform can eventually attain the same heading when released from their deformed configurations.

scholarly journals Accommodative Haptics Study Based on Flexible Amplification Mechanism

2020 ◽  
pp. 1-7
Author(s):  
Wenjing Wang ◽  
Qiuyue Du ◽  
Wenjing Chen ◽  
Bin Tian ◽  
Wenjing Wang
Keyword(s):  
Measurement Data ◽  
Theoretical Method ◽  
Structural Features ◽  
Stable Range ◽  
Element Analysis ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Motion Trajectories ◽  
Bridge Type ◽  
Lens Power

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.

scholarly journals Design and manufacturing of an ultrasonic reactor for biodiesel obtaining by transesterification

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 75-83
Author(s):  
Juan Fernando Florez Marulanda ◽  
Daniel Rodrigo Ortega Alegria
Keyword(s):  
Castor Oil ◽  
Potassium Hydroxide ◽  
The Other ◽  
Design Development ◽  
External Temperature ◽  
Operational Characteristics ◽  
Design And Manufacturing ◽  
Production Value ◽  
Reaction Speed ◽  
Commercial Equipment

It presents the design, development, and implementation of the ultrasonic reactor in laboratory level for batch transesterification with temperature variation, with a mechanic and electronic modular development, its operational characteristics were obtained through commercial equipment revision. To evaluate its performance, a mixture was made using castor oil, methanol, and potassium hydroxide, to obtain biodiesel and glycerin; by taking the glycerin stoichiometric value obtained in the reaction as the reference production value, an efficiency of 97% was reached with only the ultrasound incidence; in the processes with external temperature incidence, it was observed that it influences the reaction speed, since the stabilization times are around 30% less than the other observed processes.

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