Regenerative Instability of Impact-cutting Material Removal in the Grinding Process Performed by a Flexible Robot Arm

The material removal depth in the pre-polishing stage of the precision optics is usually tens of microns to remove the subsurface damage and grinding marks left by the previous grinding process. This processing of the upstand edge takes a large part of the time at this stage. The purpose of this paper is to develop a method that can reduce the edge effect and largely shorten the processing time of the pre-polishing stage adopting the semirigid (SR) bonnet. The generation of the edge effect is presented based on the finite element analysis of the contact pressure at the edge zone firstly. Then, some experimentations on the edge effect are conducted, and the results proved that the SR bonnet tool can overhang the workpiece edge in the pre-polishing stage to reduce the width and height of the upstand edge to largely shorten the subsequent processing time of it. In addition, there exists a perfect overhang ratio, which generates the upstand edge with the smallest width and height, with no damage to the bonnet tool in the meantime. In addition, one combination of the pre-polishing parameters is concluded according to this method, which can be safely adopted in practical process.

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Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

Applied Sciences ◽

10.3390/app11094128 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4128

Author(s):

Peng-Zhan Liu ◽

Wen-Jun Zou ◽

Jin Peng ◽

Xu-Dong Song ◽

Fu-Ren Xiao

Keyword(s):

Residual Stress ◽

Surface Roughness ◽

Service Life ◽

Material Removal ◽

Removal Rate ◽

Grinding Force ◽

Grinding Wheel ◽

Grinding Process ◽

Grinding Temperature ◽

Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

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Grinding Acoustic Emission Classification in Terms of Mechanical Behaviours

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.329.15 ◽

2007 ◽

Vol 329 ◽

pp. 15-20 ◽

Cited By ~ 2

Author(s):

Xun Chen ◽

James Griffin

Keyword(s):

Neural Network ◽

Acoustic Emission ◽

Material Removal ◽

Grinding Process ◽

Short Time Fourier Transform ◽

Fundamental Investigation ◽

Mechanical Behaviours ◽

Wavelets Transform ◽

Short Time ◽

Ae Signals

The material removal in grinding involves rubbing, ploughing and cutting. For grinding process monitoring, it is important to identify the effects of these different phenomena experienced during grinding. A fundamental investigation has been made with single grit cutting tests. Acoustic Emission (AE) signals would give the information relating to the groove profile in terms of material removal and deformation. A combination of filters, Short-Time Fourier Transform (STFT), Wavelets Transform (WT), statistical windowing of the WT with the kurtosis, variance, skew, mean and time constant measurements provided the principle components for classifying the different grinding phenomena. Identification of different grinding phenomena was achieved from the principle components being trained and tested against a Neural Network (NN) representation.

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Integration of model-based and sensor-based control for a two-link flexible robot arm

10.1109/icsyse.1990.203188 ◽

2002 ◽

Cited By ~ 4

Author(s):

J.T. Feddema ◽

G.R. Eisler ◽

D.J. Segalman

Keyword(s):

Robot Arm ◽

Flexible Robot ◽

Model Based

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Optimal control of a flexible robot arm

Computers & Structures ◽

10.1016/0045-7949(88)90398-7 ◽

1988 ◽

Vol 29 (3) ◽

pp. 459-467 ◽

Cited By ~ 16

Author(s):

James D. Lee ◽

Ben-Li Wang

Keyword(s):

Optimal Control ◽

Robot Arm ◽

Flexible Robot

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A Material Removal Model for Nonconstant-contact Flexible Grinding

10.21203/rs.3.rs-741799/v1 ◽

2021 ◽

Author(s):

Huan Ye ◽

Zhitong Chen ◽

Zhuoqun Xie ◽

Shangbin Li ◽

Shuai Su

Keyword(s):

Material Removal ◽

Model Parameters ◽

Grinding Process ◽

Element Analysis ◽

The Finite Element Analysis ◽

Material Removal Model ◽

Contact Situation ◽

Equivalent Method ◽

Removal Model ◽

Novel Model

Abstract Contact calculation is of great importance in predicting the material removal (MR) of flexible grinding process (FGP). The contact is mostly considered approximately constant in the existing MR models, while the situations that contact varies a lot after FGP are ignored. Therefore, a novel model is proposed in this paper to take those situations into consideration. Firstly, the nonconstant-contact situation is introduced. Then an equivalent method is developed to convert the nonconstant-contact grinding process into the accumulation of several quasi-constant-contact grinding processes. Based on the equivalent method, a MR model is established, and the procedure to obtain the model parameters by the finite element analysis (FEA) is introduced. In the end, the equivalent method and the MR model are tested by a series experiments of different process parameters. Results show that the proposed MR model can predict the material removal effectively for the nonconstant-contact situations.

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Design, Kinematics and Prototype of a Flexible Robot Arm With Planar Springs

Volume 5A: 39th Mechanisms and Robotics Conference ◽

10.1115/detc2015-46503 ◽

2015 ◽

Cited By ~ 2

Author(s):

Peng Qi ◽

Hongbin Liu ◽

Lakmal Seneviratne ◽

Kaspar Althoefer

Keyword(s):

Preliminary Test ◽

Industrial Applications ◽

Robot Arm ◽

Kinematic Modeling ◽

Flexible Robot ◽

Element Analysis ◽

Robot Arms ◽

Environmental Interactions ◽

In Series ◽

Fea Simulation

Flexible robot arms have been developed for various medical and industrial applications because of their compliant structures enabling safe environmental interactions. This paper introduces a novel flexible robot arm comprising a number of elastically deformable planar spring elements arranged in series. The effects of flexure design variations on their layer compliance properties are investigated. Numerical studies of the different layer configurations are presented and finite Element Analysis (FEA) simulation is conducted. Based on the suspended platform’s motion of each planar spring, this paper then provides a new method for kinematic modeling of the proposed robot arm. The approach is based on the concept of simultaneous rotation and the use of Rodrigues’ rotation formula and is applicable to a wide class of continuum-style robot arms. At last, the flexible robot arms respectively integrated with two different types of compliance layers are prototyped. Preliminary test results are reported.

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