Automated Robotic Deburring of Parts Using Compliance Control

1991 ◽  
Vol 113 (1) ◽  
pp. 60-66 ◽  
Author(s):  
M. G. Her ◽  
H. Kazerooni
Keyword(s):  
Cutting Forces ◽  
Control Method ◽  
Metal Removal ◽  
Roller Bearing ◽  
Force Sensor ◽  
Normal Direction ◽  
Contact Forces ◽  
Normal Vector ◽  
Two Dimensional ◽  
Removal Process

This work presents a method for robotic deburring of two-dimensional planar parts with unknown geometry. Robotic deburring requires “compliancy” and “stiffness” in the robot in the directions tangent and normal to the part, respectively. Compliancy in the tangential direction allows robotic accommodation of tangential cutting forces, while stiffness in the normal direction impedes a robotic response to normal cutting forces. But, to track the part contour, the robot requires compliancy in the normal direction. These conflicting requirements are addressed in this article as two problems: control of the metal removal process and tracking of the part contour. In general, these two problems are coupled; however, here they are separated into a hardware problem and a control problem. A tracking mechanism has been designed and built which incorporates a roller bearing mounted on a force sensor at the robot endpoint. This force sensor is located directly below the cutter and measures the contact forces which are the input to the tracking controller. These contact forces are used not only to calculate the normal vector to the part surface, but also to generate compliancy in the robot. However, the deburring algorithm uses another set of forces (cutting forces generated by the cutter) to produce a stable metal removal process. This deburring control method guarantees compliancy and stiffness in the robot in response to the tangential and normal cutting forces, respectively. Experimental results are given to show the effectiveness of this method for deburring of two-dimensional parts with unknown geometry.

Analysis of Machining Disturbance and Development of a Support System for the Finishing Process

2009 ◽  
Author(s):  
Daiki Sakito ◽  
Yasushi Yasuda ◽  
Tsuginobu Osada ◽  
Ken’ichi Yano
Keyword(s):  
Contact Force ◽  
Support System ◽  
Control Method ◽  
Force Sensor ◽  
Tangential Direction ◽  
Friction Torque ◽  
Normal Direction ◽  
Haptic Device ◽  
Sensor Output ◽  
Finishing Process

In this paper we address the development of a finish machining support system that can operate without machining mistakes for the limited production of diversified products. The machining is supported by a haptic device. One challenge is that it is necessary to separate the force sensor output that exists in the operation force from the machining influence force. We propose a control method to remove the influence of the rotation tool disturbance force from the operation force by using adaptive modeling, which estimates the force of rotation tool friction torque in the tangential direction of the machining side from the contact force in the normal direction of the machining side. The effectiveness of this research is shown by a machining experiment.

scholarly journals Simulation Verification of the Contact Parameter Influence on the Forces’ Course of Cereal Grain Impact against a Stiff Surface

2021 ◽  
Vol 11 (2) ◽  
pp. 466
Author(s):  
Włodzimierz Kęska ◽  
Jacek Marcinkiewicz ◽  
Łukasz Gierz ◽  
Żaneta Staszak ◽  
Jarosław Selech ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Decisive Role ◽  
Force Sensor ◽  
Contact Forces ◽  
Correct Selection ◽  
Contact Parameter ◽  
Cereal Grain ◽  
Wide Range ◽  
The Impact ◽  
Selection Of

The continuous development of computer technology has made it applicable in many scientific fields, including research into a wide range of processes in agricultural machines. It allows the simulation of very complex physical phenomena, including grain motion. A recently discovered discrete element method (DEM) is used for this purpose. It involves direct integration of equations of grain system motion under the action of various forces, the most important of which are contact forces. The method’s accuracy depends mainly on precisely developed mathematical models of contacts. The creation of such models requires empirical validation, an experiment that investigates the course of contact forces at the moment of the impact of the grains. To achieve this, specialised test stations equipped with force and speed sensors were developed. The correct selection of testing equipment and interpretation of results play a decisive role in this type of research. This paper focuses on the evaluation of the force sensor dynamic properties’ influence on the measurement accuracy of the course of the plant grain impact forces against a stiff surface. The issue was examined using the computer simulation method. A proprietary computer software with the main calculation module and data input procedures, which presents results in a graphic form, was used for calculations. From the simulation, graphs of the contact force and force signal from the sensor were obtained. This helped to clearly indicate the essence of the correct selection of parameters used in the tests of sensors, which should be characterised by high resonance frequency.

Kontaktkräfte beim ungeführten Vibrationsgleitschleifen*/Contact forces in unguided vibratory finishing

2015 ◽  
Vol 105 (06) ◽  
pp. 377-383
Author(s):  
F. Klocke ◽  
R. Brocker ◽  
F. Vits ◽  
P. Mattfeld
Keyword(s):  
Measurement System ◽  
Electrical Power ◽  
Force Sensor ◽  
Contact Forces ◽  
Work Piece ◽  
Data Logging ◽  
Vibratory Finishing ◽  
Revolution Speed ◽  
Measurement Results ◽  
Finishing Processes

Beim Vibrationsgleitschleifen wird der Werkstoffabtrag maßgeblich durch die vorherrschenden Kontaktkräfte zwischen dem Werkstück und den Schleifkörpern bestimmt. Dieser Fachartikel stellt ein Messsystem vor, mit dem die messtechnische Erfassung der Kontaktkräfte beim ungeführten Vibrationsgleitschleifen möglich ist. Ein Alleinstellungsmerkmal ist dabei die vollständig kabellose Ausführung des Messsystems. Somit wurden die Messergebnisse nicht durch Kabel beeinflusst, die üblicherweise für die Energieversorgung und Datenübertragung notwendig sind. Mithilfe dieses Messsystems wurde der Einfluss folgender Prozesseingangsgrößen systematisch untersucht: Schleifkörpergröße, Unwuchtmotordrehzahl, Versatzwinkel der Unwuchtgewichte sowie die Masse des unteren und oberen Unwuchtgewichts auf die Kontaktkräfte.   In vibratory finishing the material removal is influenced by the contact forces between work piece and media. In this paper a measurement system is presented which is able to measure contact forces between work piece and media in unguided vibratory finishing. The unique feature of the measurement system is its completely wireless construction so that the measurement results are not influenced by wires of the force sensor system including the electrical power supply and the data logging. By means of this measurement system, contact forces can be measured in unguided vibratory finishing processes for the first time. Furthermore, the influence of media size and adjustment of the unbalance motor like revolution speed, phase angle and mass distribution between the upper and the lower eccentric weight on the contact forces was investigated.

scholarly journals Two-dimensional photonic crystals increasing vertical light emission from Si nanocrystal-rich thin layers

2018 ◽  
Vol 9 ◽  
pp. 2287-2296
Author(s):  
Lukáš Ondič ◽  
Marian Varga ◽  
Ivan Pelant ◽  
Alexander Kromka ◽  
Karel Hruška ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Light Emission ◽  
Periodic Structures ◽  
Normal Direction ◽  
Thin Layers ◽  
Two Dimensional ◽  
Lattice Constants ◽  
Leaky Modes ◽  
Si Nanocrystals ◽  
Si Nanocrystal

We have fabricated two-dimensional photonic crystals (PhCs) on the surface of Si nanocrystal-rich SiO2 layers with the goal to maximize the photoluminescence extraction efficiency in the normal direction. The fabricated periodic structures consist of columns ordered into square and hexagonal pattern with lattice constants computed such that the red photoluminescence of Si nanocrystals (SiNCs) could couple to leaky modes of the PhCs and could be efficiently extracted to surrounding air. Samples having different lattice constants and heights of columns were investigated in order to find the configuration with the best performance. Spectral overlap of the leaky modes with the luminescence spectrum of SiNCs was verified experimentally by measuring photonic band diagrams of the leaky modes employing angle-resolved spectroscopy and also theoretically by computing the reflectance spectra. The extraction enhancement within different spatial angles was evaluated by means of micro-photoluminescence spectroscopy. More than 18-fold extraction enhancement was achieved for light propagating in the normal direction and up to 22% increase in overall intensity was obtained at the spatial collection angle of 14°.

Contribution of Strain and Elasto-Optical Effect to Resonant Mode in the Two-Dimensional Photonic Crystals Force Sensor

2011 ◽  
Vol 216 ◽  
pp. 148-152 ◽  
Author(s):  
Yan Li ◽  
Hai Wei Fu ◽  
Xiao Li Li ◽  
Min Shao
Keyword(s):  
Finite Difference Time Domain ◽  
Resonant Cavity ◽  
Force Sensor ◽  
Resonant Mode ◽  
Resonant Wavelength ◽  
Two Dimensional ◽  
Optical Effect ◽  
Sensor Model ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

The resonant wavelength of the two-dimensional photonic crystal force sensor model changing with normal stress along y direction is calculated by finite-difference time-domain method. The result shows that the variation of the size and shape of the resonant cavity has a main contribution to the variation of the resonant wavelength. The elasto-optical effect of GaAs medium can not obviously change the wavelength of the resonant cavity below score of megapascal.

scholarly journals Modeling and Dynamic Analysis of Spherical Roller Bearing with Localized Defects: Analytical Formulation to Calculate Defect Depth and Stiffness

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Behnam Ghalamchi ◽  
Jussi Sopanen ◽  
Aki Mikkola
Keyword(s):  
Dynamic Model ◽  
Contact Stiffness ◽  
Roller Bearing ◽  
Measurement Data ◽  
Contact Forces ◽  
Hertzian Contact ◽  
Radial Clearance ◽  
Outer Race ◽  
Rolling Elements ◽  
Localized Defects

Since spherical roller bearings can carry high load in both axial and radial direction, they are increasingly used in industrial machineries and it is becoming important to understand the dynamic behavior of SRBs, especially when they are affected by internal imperfections. This paper introduces a dynamic model for an SRB that includes an inner and outer race surface defect. The proposed model shows the behavior of the bearing as a function of defect location and size. The new dynamic model describes the contact forces between bearing rolling elements and race surfaces as nonlinear Hertzian contact deformations, taking radial clearance into account. Two defect cases were simulated: an elliptical surface on the inner and outer races. In elliptical surface concavity, it is assumed that roller-to-race-surface contact is continuous as each roller passes over the defect. Contact stiffness in the defect area varies as a function of the defect contact geometry. Compared to measurement data, the results obtained using the simulation are highly accurate.

Design and Modeling of a Novel Two Dimensional Nano-Scaled Force Sensor Based on Silicon Photonic Crystal

2014 ◽  
Vol 58 (40) ◽  
pp. 65-73
Author(s):  
T. Li ◽  
L. Li ◽  
W. Song ◽  
G. Zhang ◽  
Y. Li
Keyword(s):  
Photonic Crystal ◽  
Force Sensor ◽  
Two Dimensional ◽  
Silicon Photonic

Investigation of Fan Blades Vibration due to Blade/Casing Rubbing Interactions Using In-Plane Two-Dimensional Model

2018 ◽  
Author(s):  
Jiaguangyi Xiao ◽  
Yong Chen ◽  
Hua Ouyang ◽  
Anjenq Wang
Keyword(s):  
Travelling Waves ◽  
Golden Section ◽  
Contact Forces ◽  
Two Dimensional ◽  
Rotating Speed ◽  
Bladed Disk ◽  
Speed Range ◽  
Blade Vibrations ◽  
Blade Tip ◽  
External Forces

Interactions between casings and bladed-disks of modern turbofan engines may occur through various mechanisms: casing distortions, rotor vibrations and casing vibrations to name a few. These interactions might lead to nonlinear blade vibrations, which could then induce severe damages to both structures. The impacts of casing vibrations on the vibration behaviors of engine blades are studied in this paper. A two-dimensional in-plane model is established in this paper. Fan blade, disk and casing are modeled using beam element. Craig-Bampton model reduction is applied to simplify the model. Penalty method mixed with golden section method is created and used for contact treatments. The interaction is initiated by the external forces acting on the casing. The casing is excited to two-, three- and four-nodal diameter vibration patterns, respectively. In order to capture the core of the problem, contact forces applied to the casing, and casing damping are neglected. Steady casing vibrations could thus be generated. Blade vibrations are calculated in a wide rotating speed range, maximum amplitudes are recorded and studied. The results show that the bladed-disk will have several vibration peaks in the calculated rotating speed range. To figure out the physical mechanisms of these peaks, Fourier spectrums as well as different bladed-disk materials are introduced. Almost all vibration peaks can be explained by three kinds of mechanisms found and summarized in this paper. Two of them are related to travelling waves and the third is related to harmonics. Speed and frequency margins that are related to blade-tip-rub induced vibrations are defined and analyzed. The findings and ideas shown in this paper can be used as a reference in engine preliminary structural design to avoid potential blade tip-rub induced damages.

Analysis of radial roller bearing rating life in complex loading conditions

2021 ◽  
pp. 1-27
Author(s):  
Vladimir Ivannikov ◽  
Mikhail Leontiev ◽  
Sergey Degtyarev ◽  
Valeriy Popov
Keyword(s):  
High Performance ◽  
Roller Bearing ◽  
Complex Loading ◽  
Contact Forces ◽  
Loading Conditions ◽  
Jet Engines ◽  
Inertia Effects ◽  
Internal Contact ◽  
Rolling Elements ◽  
Life Analysis

Abstract An approach for accurate life analysis of radial roller bearings in complex loading conditions is presented. It employs ISO~16281 and accounts not only for external radial loads applied to the inner ring, but also for (i) internal bearing clearance, (ii) flexibility of the bearing rings, (iii) rings out-of-roundness, (iv) inertia effects, (v) rolling elements profile and (vi) rings misalignment. In the last decades these factors have been becoming more and more important for modern high-performance jet engines, whose shafts are commonly hollow and the housing and the rings thicknesses may be of comparable magnitudes. To obtain the distribution of internal contact forces, an advanced static model of a bearing with deformable, potentially misaligned, rings is developed. The bending deformations of the rings are reproduced superimposing deformed shapes from each of the arising internal contact force applied individually. Bearing rollers are allowed to have non-cylindrical profile, its geometry is approximated by means of slices each having constant diameter. A robust numerical scheme for solving the resultant set of equations with the aid of the barrier functions method is constructed. To increase even further the accuracy of rating life analysis, distributions of the contact stresses between the roller and the ring surfaces, obtained by solving numerically the problem of non-Hertzian interaction, are added to computations. A numerical benchmark test is presented to demonstrate the applicability of the developed approach. It shows how the aforementioned factors influence the bearing contact forces and its rating life.

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