A linear piezoelectric actuator with the parasitic motion of equilateral triangle flexure mechanism

This paper presents an approach of utilizing parasitic motion compensation for designing high-precision flexure mechanism. This approach is expected to improve the accuracy of flexure mechanism without changing its degree of freedom (DOF) characteristic. Different from the method which mainly concentrates on how to compensate the parasitic translation error of a parallelogram-type flexure mechanism existing in most of the literatures, the proposed approach can compensate the parasitic motion produced by rotation in company with translation. Besides, the parasitic motion of a flexure mechanism is formulated and evaluated by utilizing its compliance. To specify it, the compliance of a general flexure mechanism is calculated firstly. Then the parasitic motions introduced by both rotation and translation are analyzed by utilizing the resultant compliance. Subsequently, a compliance-based compensation approach is addressed as the most important part of this paper. The design principles and procedure are further proposed in detail to help with improving the accuracy of the flexure mechanism. Finally, a case study of a 2R1T flexure mechanism is provided to illustrate this approach, and FEA simulation is implemented to demonstrate its validity. The result shows that it is a robust design method for the design of high-precision flexure mechanism.

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Robust Design of Flexure Based Nano Precision Compliant Mechanisms With Application to Nano Imprint Lithography

Volume 4: 20th International Conference on Design Theory and Methodology; Second International Conference on Micro- and Nanosystems ◽

10.1115/detc2008-50114 ◽

2008 ◽

Cited By ~ 1

Author(s):

Chinmaya B. Patil ◽

S. V. Sreenivasan ◽

Raul G. Longoria

Keyword(s):

Analytical Model ◽

Robust Design ◽

Compliant Mechanisms ◽

Design Approach ◽

Iteration Step ◽

Geometric Errors ◽

Imprint Lithography ◽

Flexure Mechanism ◽

Parasitic Motion ◽

Nano Imprint

Flexure-based compliant mechanisms are the preferred motion guiding systems for small range, nano-precision positioning applications because of excellent characteristics like friction-free continuous motion. These mechanisms are commonly used in nano fabrication equipment and ultra precision instruments. However, machining imperfections induced geometric errors in the mechanisms are known to cause undesirable parasitic motion and significant loss of precision. A systematic design approach to minimize the sensitivity of the flexure mechanisms to geometric errors induced by machining tolerances is presented here. Central to the design approach is the screw systems based analytical model to study the spatial motion characteristics of flexure mechanisms. Using this model, the parasitic motion is classified into those errors which can be corrected by calibration (extrinsic) and those which are coupled with the mechanism motion and cannot be corrected by apriori calibration (intrinsic). Metric to quantify the intrinsic parasitic motion results naturally from the screw systems analysis, and is used to represent the precision capability of the flexure mechanism. The analytical model enables the selection of geometric parameters of flexure joints of the mechanism via an optimization scheme with the aim of minimizing the parasitic motion metric. The statistical nature of the machining tolerances is accounted for by sampling the random variables at every iteration step of the optimization, leading to a stochastic formulation. The robust design approach is illustrated using a one DOF rotational flexure mechanism that is used in nano-imprint lithography equipment. Numerical results of the optimization indicate up to 40% improvement in the precision capability of the mechanism without any change in the manufacturing tolerance limits. Further, it is shown via eigenscrew analysis of mechanism compliance that the robustness resulting from the optimal flexure joint design can be attributed to the improved compliance distribution.

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Analysis and comparison of flexible mechanisms for parasitic motion principle piezoelectric actuator

Smart Materials and Structures ◽

10.1088/1361-665x/ac0399 ◽

2021 ◽

Author(s):

Jiru Wang ◽

Hu Huang ◽

Zhaoxin Wang ◽

Tianwei Liang ◽

Hongwei Zhao

Keyword(s):

Piezoelectric Actuator ◽

Parasitic Motion ◽

Flexible Mechanisms

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A new motion mode of a parasitic motion principle (PMP) piezoelectric actuator by preloading the flexible hinge mechanism

Sensors and Actuators A Physical ◽

10.1016/j.sna.2019.06.025 ◽

2019 ◽

Vol 295 ◽

pp. 396-404 ◽

Cited By ~ 1

Author(s):

Zhixin Yang ◽

Xiaoqin Zhou ◽

Hu Huang ◽

Jingshi Dong ◽

Hongwei Zhao

Keyword(s):

Piezoelectric Actuator ◽

Flexible Hinge ◽

Parasitic Motion ◽

Motion Mode

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Active suppression of the backward motion in a parasitic motion principle (PMP) piezoelectric actuator

Smart Materials and Structures ◽

10.1088/1361-665x/ab4e07 ◽

2019 ◽

Vol 28 (12) ◽

pp. 125006 ◽

Cited By ~ 3

Author(s):

Haoyin Fan ◽

Jinyan Tang ◽

Tao Li ◽

Xiaofeng Yang ◽

Jiahui Liu ◽

...

Keyword(s):

Piezoelectric Actuator ◽

Active Suppression ◽

Parasitic Motion

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Analytical and Experimental Characterization of Parasitic Motion in Flexure-Based Selectively Compliant Precision Mechanisms

Volume 2: 32nd Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2008-50111 ◽

2008 ◽

Cited By ~ 3

Author(s):

Chinmaya B. Patil ◽

S. V. Sreenivasan ◽

Raul G. Longoria

Keyword(s):

Degrees Of Freedom ◽

Compliant Mechanisms ◽

Ideal Behavior ◽

Modeling And Analysis ◽

Flexure Mechanism ◽

Parasitic Motion ◽

Pure Rotation ◽

The One ◽

Spatial Kinematics

Flexure-based selectively compliant mechanisms with less than six degrees of freedom are capable of meeting the demanding requirements of ultra precision positioning and scanning systems. However, machining imperfections induce undesirable motion and limit the mechanisms precision capability. A spatial kinematics based kinetostatic model is presented here that not only enables determination of inherently spatial parasitic motion due to machining imperfections, but also offers critical geometric insight into the motion characteristics of flexure mechanisms. The analytical development reveals that the geometric errors induced by machining imperfections perturb the special screw systems of motion of ideal flexure mechanisms to their corresponding general screw systems. This insight leads to clearly defined metrics that can capture the non-ideal behavior using screw system theory and is applicable to all selectively compliant mechanisms. This result is illustrated using one and two DOF mechanisms as examples. In the case of rotational DOF flexure mechanisms, the pitch of twist of motion captures the difference between the special and general screw systems and represents the intrinsic parasitic motion. The machining imperfections are regarded as Gaussian random variables with known variance, and the model is used to determine the variance of the pitch of twist via Monte Carlo simulation, leading to determination of the precision capability of the flexure mechanisms. The modeling and analysis is illustrated using one and two DOF rotation flexure mechanisms. Finally, the details of a test setup built to determine the parasitic motion of the one DOF rotational mechanism are presented. Experimental results indicate that the one DOF flexure mechanism is indeed executing screw motion rather than pure rotation.

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