A Large Measuring Range Profilometer for Three-Dimensional Surface Topography Measurement

2007 ◽  
Vol 364-366 ◽  
pp. 750-755 ◽  
Author(s):  
Xu Dong Yang ◽  
Jia Chun Li ◽  
Tie Bang Xie
Keyword(s):  
Surface Topography ◽  
Three Dimensional ◽  
Displacement Sensor ◽  
Resistance Force ◽  
Sampling Point ◽  
Measuring Range ◽  
3D Surface Topography ◽  
Control Circuits ◽  
Industrial Control Computer ◽  
Zero Offset

A novel profilometer for three-dimensional (3D) surface topography measurement is presented. The profilometer has large measuring range, high precision and small measuring touch force. It is composed of a two-dimensional (2D) displacement sensor, a 3D platform based on vertical scanning, measuring and control circuits and an industrial control computer. When a workpiece is measured, the vertical undulation of the profile at a sampling point leads to a zero offset of the 2D displacement sensor. According to the zero offset, a piezoelectric actuator and a servo motor drive the vertical scanning platform to move vertically to ensure that the lever returns to its balance position. So the non-linear error caused by the rotation of the lever is very small even if the measuring range is large. When the stylus barges up against a steep wall, the horizontal resistance force results in another zero offset of the 2D displacement sensor. If the zero offset exceeds a quota, the vertical scanning platform descends to make the stylus climb the steep wall successfully. According to the theoretical and experimental analysis, the profilometer can measure roughness, profile of sphere, step, groove and other 3D surfaces with curvature precisely.

Leakage Monitoring in Static Sealing Interface Based on Three Dimensional Surface Topography Indicator

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Yiping Shao ◽  
Yaxiang Yin ◽  
Shichang Du ◽  
Tangbin Xia ◽  
Lifeng Xi
Keyword(s):  
Surface Topography ◽  
Three Dimensional ◽  
Machining Process ◽  
Void Volume ◽  
Engineering Practice ◽  
High Definition ◽  
Monitoring Method ◽  
3D Surface ◽  
3D Surface Topography ◽  
Leakage Monitoring

Leakage directly affects the functional behavior of a product in engineering practice, and surface topography is one of the main factors in static seal to prevent leakage. This paper aims at monitoring the leakage in static sealing interface, using three-dimensional (3D) surface topography as an indicator. The 3D surface is measured by a high definition metrology (HDM) instrument that can generate millions of data points representing the entire surface. The monitoring approach proposes a series of novel surface leakage parameters including virtual gasket, contact area percentage (CAP), void volume (VV), and relative void volume (SWvoid) as indicators. An individual control chart is adopted to monitor the leakage surface of the successive machining process. Meantime, based on the Persson contact mechanics and percolation theory, the threshold of leakage parameter is found using finite element modeling (FEM). Experimental results indicate that the proposed monitoring method is valid to precontrol the machining process and prevent leakage occurring.

Effect of Three-Dimensional Surface Topography on Gas Flow in Rough Micronozzles

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Han Yan ◽  
Wen-Ming Zhang ◽  
Zhi-Ke Peng ◽  
Guang Meng
Keyword(s):  
Surface Topography ◽  
Gas Flow ◽  
Rectangular Cross Section ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Navier Stokes ◽  
Slip Model ◽  
First Order ◽  
3D Surface Topography ◽  
Good Agreement

The gas flow characteristics in rectangular cross section converging–diverging micronozzles incorporating the effect of three-dimensional (3D) rough surface topography are investigated. The fractal geometry is utilized to describe the multiscale self-affine roughness. A first-order slip model suitable for rough walls is adopted to characterize the slip velocities. The flow field in micronozzles is analyzed by solving 3D Navier–Stokes (N–S) equation. The results show that the dependence of mass flow rate on the pressure difference has a good agreement with the reported results. The presence of surface topography obviously perturbs the gas flow near the wall. Moreover, as the surface roughness height increases, this perturbation induces the supersonic “multiwaves” phenomenon in the divergent region, in which the Mach number fluctuates. In addition, the effect of 3D surface topography on performance is also investigated.

Measuring Surface Topography with Scanning Electron Microscopy. I. EZEImage: A Program to Obtain 3D Surface Data

2005 ◽  
Vol 12 (2) ◽  
pp. 170-177 ◽  
Author(s):  
Ezequiel Ponz ◽  
Juan Luis Ladaga ◽  
Rita Dominga Bonetto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Topography ◽  
Three Dimensional ◽  
Sem Image ◽  
3D Surface ◽  
Surface Data ◽  
3D Surface Topography ◽  
Two Parameters ◽  
Scanning Electron

Scanning electron microscopy (SEM) is widely used in the science of materials and different parameters were developed to characterize the surface roughness. In a previous work, we studied the surface topography with fractal dimension at low scale and two parameters at high scale by using the variogram, that is, variance vs. step log–log graph, of a SEM image. Those studies were carried out with the FERImage program, previously developed by us. To verify the previously accepted hypothesis by working with only an image, it is indispensable to have reliable three-dimensional (3D) surface data. In this work, a new program (EZEImage) to characterize 3D surface topography in SEM has been developed. It uses fast cross correlation and dynamic programming to obtain reliable dense height maps in a few seconds which can be displayed as an image where each gray level represents a height value. This image can be used for the FERImage program or any other software to obtain surface topography characteristics. EZEImage also generates anaglyph images as well as characterizes 3D surface topography by means of a parameter set to describe amplitude properties and three functional indices for characterizing bearing and fluid properties.

scholarly journals Combining 3D Structured Light Imaging and Spine X-ray Data Improves Visualization of the Spinous Lines in the Scoliotic Spine

2020 ◽  
Vol 11 (1) ◽  
pp. 301
Author(s):  
Sławomir Paśko ◽  
Wojciech Glinkowski
Keyword(s):  
Radiation Exposure ◽  
Surface Topography ◽  
Structured Light ◽  
Spinous Process ◽  
Three Dimensional ◽  
Diagnostic System ◽  
Measurement Tool ◽  
Adequate Treatment ◽  
X Ray ◽  
Spinous Processes

Scoliosis is a three-dimensional trunk and spinal deformity. Patient evaluation is essential for the decision-making process and determines the selection of specific and adequate treatment. The diagnosis requires a radiological evaluation that exposes patients to radiation. This exposure reaches hazardous levels when numerous, repetitive radiographic studies are required for diagnostics, monitoring, and treatment. Technological improvements in radiographic devices have significantly reduced radiation exposure, but the risk for patients remains. Optical three-dimensional surface topography (3D ST) measurement systems that use surface topography (ST) to screen, diagnose, and monitor scoliosis are safer alternatives to radiography. The study aimed to show that the combination of plain X-ray and 3D ST scans allows for an approximate presentation of the vertebral column spinous processes line in space to determine the shape of the spine’s deformity in scoliosis patients. Twelve patients diagnosed with scoliosis, aged 13.1 ± 4.5 years (range: 9 to 20 years) (mean: Cobb angle 17.8°, SD: ±9.5°) were enrolled in the study. Patients were diagnosed using full-spine X-ray and whole torso 3D ST. The novel three-dimensional assessment of the spinous process lines by merging 3D ST and X-ray data in patients with scoliosis was implemented. The method’s expected uncertainty is less than 5 mm, which is better than the norm for a standard measurement tool. The presented accuracy level is considered adequate; the proposed solution is accurate enough to monitor the changes in the shape of scoliosis’s spinous processes line. The proposed method allows for a relatively precise calculation of the spinous process lines based on a three-dimensional point cloud obtained with a four-directional, three-dimensional structured light diagnostic system and a single X-ray image. The method may help reduce patients’ total radiation exposure and avoid one X-ray in the sagittal projection if biplanar radiograms are required for reconstructing the three-dimensional line of the spinous processes line.

Simulation of Plasto-Elastohydrodynamic Lubrication in Line Contacts of Infinite and Finite Length

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Tao He ◽  
Jiaxu Wang ◽  
Zhanjiang Wang ◽  
Dong Zhu
Keyword(s):  
Surface Roughness ◽  
Finite Length ◽  
3D Model ◽  
Three Dimensional ◽  
Elastohydrodynamic Lubrication ◽  
Axial Direction ◽  
Contact Length ◽  
Line Contact ◽  
Line Contacts ◽  
3D Surface Topography

Line contact is common in many machine components, such as various gears, roller and needle bearings, and cams and followers. Traditionally, line contact is modeled as a two-dimensional (2D) problem when the surfaces are assumed to be smooth or treated stochastically. In reality, however, surface roughness is usually three-dimensional (3D) in nature, so that a 3D model is needed when analyzing contact and lubrication deterministically. Moreover, contact length is often finite, and realistic geometry may possibly include a crowning in the axial direction and round corners or chamfers at two ends. In the present study, plasto-elastohydrodynamic lubrication (PEHL) simulations for line contacts of both infinite and finite length have been conducted, taking into account the effects of surface roughness and possible plastic deformation, with a 3D model that is needed when taking into account the realistic contact geometry and the 3D surface topography. With this newly developed PEHL model, numerical cases are analyzed in order to reveal the PEHL characteristics in different types of line contact.

Study on Feed Offset in Elliptical Vibration Cutting

2014 ◽  
Vol 490-491 ◽  
pp. 600-606
Author(s):  
Jie Qiong Lin ◽  
Jin Guo Han ◽  
Dan Jing ◽  
Xian Jing
Keyword(s):  
Surface Topography ◽  
Surface Quality ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Curved Surface ◽  
Elliptical Vibration Cutting ◽  
Vibration Cutting ◽  
Elliptical Vibration ◽  
Tool Edge

Elliptical vibration cutting (EVC) process and three dimensional cutting surfaces are analyzed in this paper to understand the formation of surface topography. The model of EVC surface topography is established based on curved surface remove function under the assumption that the tool edge is sharp enough. And simulation analysis of surface topography is conducted with different feed offset ratios. Results indicate that RMS change with feed offset ratios λ. The range of RMS is larger when feed offset ratio ranges from both 0 to 0.4 and 0.6 to 1, while the range is smaller when feed offset ratio changes from 0.4 to 0.6. Whats more, RMS reaches the minimum when feed offset ratio is 0.5. The present research provides some references for reducing the height of vibration ripples and improving EVC surface quality.

Three-dimensional surface topography segmentation through clustering

Wear ◽  
2007 ◽  
Vol 262 (3-4) ◽  
pp. 395-410 ◽  
Author(s):  
N. Senin ◽  
M. Ziliotti ◽  
R. Groppetti
Keyword(s):  
Surface Topography ◽  
Three Dimensional ◽  
Dimensional Surface
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