Investigation of Glass Polishing Motion Based on Micro-Oscillating Pressing Force with a Compact Robot and Fine Diamond Stone

2014 ◽  
Vol 1017 ◽  
pp. 129-134
Author(s):  
Wei Wu ◽  
Yu Dong Liu ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Glass Plate ◽  
Voice Coil Motor ◽  
Robot Arm ◽  
Chatter Vibration ◽  
Pressing Force ◽  
Fine Diamond ◽  
Low Stiffness ◽  
Abrasive Stone ◽  
Fixed Abrasive ◽  
Glass Polishing

To reduce the environmental impact of abrasive polishing, we have investigated using a compact robot and fixed-abrasive polishing. We look at a five-joint closed-link compact robot with a fine diamond stone on its main axis to polish a glass plate. In this method, we measured the chatter vibration in glass polishing motion due to the low stiffness of the robot arm. Therefore, we estimated a dynamic characteristic of the robot arm by a hammering test and measured the friction coefficient between the glass plate and the abrasive stone. From these results, we attempted a novel polishing method to prevent its self-vibration using micro-oscillating pressing force with a voice coil motor. As a result, the proposed method of polishing a glass plate with a compact robot and a fine diamond stone was found to be effective.

Investigation of Abrasive Super Finishing under Various Paths with a 5-Axis Closed-Link Compact Robot and Fine Diamond Stone

2016 ◽  
Vol 1136 ◽  
pp. 472-477
Author(s):  
Tao Liu ◽  
Takashi Kure ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Yu Dong Liu
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Glass Plate ◽  
Robot Arm ◽  
Stick Slip ◽  
Fine Diamond ◽  
Polishing Force ◽  
Abrasive Stone ◽  
Fixed Abrasive ◽  
Polishing Pressure

To reduce the environmental impact of abrasive polishing, we investigated fixed-abrasive polishing using a compact robot. We used a five-joint closed-link compact robot with a fine diamond stone on the main axis to polish a glass plate and measured the polishing pressure and polishing force. We analyzed the stick-slip vibration of a glass polishing motion due to the low stiffness of the robot arm and estimated the influence of relative speed changes on the friction coefficient between the glass plate and the abrasive stone. We also used various paths to polish the workpiece to examine the characteristics of the polishing equipment. Based on the results, we proposed a method that can estimate a workpiece's surface roughness based on the friction coefficient. Using the compact robot and a fine diamond stone, the workpiece's surface roughness decreased and polishing processes on the glass plate were more stable.

Influence of Polishing and Pressing Force on the Material Removal Rate in Fixed Abrasive Polishing with Compact Robot

2012 ◽  
Vol 565 ◽  
pp. 243-248 ◽  
Author(s):  
Masaki Niwa ◽  
Sachiko Ogawa ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Yoshiaki Onchi
Keyword(s):  
Friction Coefficient ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Glass Plate ◽  
Pressing Force ◽  
Constant Area ◽  
Polishing Force ◽  
Fixed Abrasive ◽  
Polishing Pressure

To help reduce the environmental impact of abrasive polishing, we have investigated the use of a compact robot and fixed-abrasive polishing. We used a five-joint closed-link compact robot with a fine diamond stone on its main axis to polish the glass plate and measured the polishing pressure(=pressing force/stone constant area), the polishing force, and the material removal rate. From these results, we investigated the relationship between the polishing pressure and the polishing force and between the polishing pressure and the material removal rate. We found that there is an interesting relationship between the polishing pressure and polishing force, which is not simply proportional but exponential, that the friction coefficient(=polishing force/pressing force) increases as the polishing pressure increases, and that by focusing on the friction coefficient, we can estimate the material removal rate.

The vibratory alignment of the parts in robotic assembly

2017 ◽  
Vol 44 (6) ◽  
pp. 720-729 ◽  
Author(s):  
Bronius Baksys ◽  
Jolanta Baskutiene ◽  
Saulius Baskutis
Keyword(s):  
Design Methodology ◽  
Robotic Assembly ◽  
Mathematical Approach ◽  
Robot Arm ◽  
Content Type ◽  
Pressing Force ◽  
Passive Compliance ◽  
Alignment Process ◽  
Assembly Operations ◽  
Practical Implications

Purpose This paper aims to consider the experimental and theoretical investigation of the vibratory alignment of the peg-hole, when the peg is fixed in the remote centre compliance (RCC) device, and the vibrations are provided either to the hole or to the peg. Design/methodology/approach The experimental analysis of the circular and rectangular peg-hole vibratory alignment using the attached to the robot arm RCC device, under vibratory excitation of the hole, has been performed. The parameters of the vibratory excitation and the part-to-part pressing force influence on the alignment process have been analysed. The mathematical approach of the vibratory alignment using the passive compliance device with the vibrations provided to the peg has been proposed, and the simulation has been carried out. Findings The research has approved the applicability of the RCC device for both of the vibratory alignments of the non-chamfered peg-hole parts either circular or rectangular ones. The compensation of the axial misalignments has been resulted by the directional displacement of the peg supported compliantly. To perform the successful alignment of the parts, it has been necessary to adjust the frequency and the amplitude of the vibrations, the pressing force, the lateral, as well as the angular stiffness of the device. Research limitations/implications The experiments on the vibratory alignment of the rectangular peg-hole parts have been carried out considering only the translational misalignment moved into one direction. The non-impact regime of the vibratory alignment has been analysed. Practical implications The obtained results can be applied in designing the reliable and efficient devices of the vibratory assembly for the alignment of the non-chamfered peg-hole parts, as well as for chamfered ones, if the axial misalignment exceeds the width of the chamfer. The vibratory technique and passive compliance provide possibility to accomplish the assembly operations using the non-expensive low accuracy robots. Originality/value The new method and the mathematical approach of the vibratory assembly using the RCC device can ensure the reliable alignment of the non-chamfered parts, chamfered circular and the rectangular ones, in case the axial misalignment exceeds the assembly clearance, and prevent jamming and wedging.

A new transmissive-type tilting actuator for a smooth projected television image

2010 ◽  
Vol 224 (6) ◽  
pp. 1327-1333 ◽  
Author(s):  
H Im ◽  
W Kim ◽  
J Chung
Keyword(s):  
Glass Plate ◽  
Voice Coil Motor ◽  
Basic Structure ◽  
Modal Test ◽  
Design Requirements ◽  
Television Image

In this article, a new transmissive-type tilting actuator is presented for smooth projected television images. In order to implement the transmissive-type tilting actuator, a basic structure of the tilting actuator is proposed, which is composed of a voice coil motor, a transmissive glass plate, and frames. After designing and analysing the actuator electromagnetically and mechanically, a prototype of the actuator is built. With the manufactured prototype, the performances and design requirements of the actuator are experimentally verified by the modal test and response measurements.

Design of Anisotropic Boring Tools With L/D = 10 for Chatter Free Cutting

2017 ◽  
Author(s):  
Wataru Takahashi ◽  
Norikazu Suzuki ◽  
Eiji Shamoto
Keyword(s):  
Past Research ◽  
Depth Of Cut ◽  
Chatter Stability ◽  
Chatter Vibration ◽  
Element Analysis ◽  
Boring Bar ◽  
The Past ◽  
Cylinder Length ◽  
Low Stiffness ◽  
Stable Zone

This paper presents design of a novel boring bar with a ratio of cylinder length to diameter (L/D) of 10 to suppress chatter vibration regardless of low stiffness. It is essentially difficult to decrease the compliance of the long slender structures. However, nominal compliance of the displacement along the depth of cut direction against the resultant cutting force may be regulated by giving the designated anisotropy upon the boring bar dynamics. The past research has clarified the feasibility through turning experiments by using the developed boring bar with L/D of 4. In the present study, much slenderer ones with L/D of 10 are designed, which are significantly flexible but attractive to manufacturers. Finite element analysis (FEA) is utilized to estimate dynamics of the anisotropic boring bar. Through analytical investigations, two kinds of boring bars were designed, where the compliance ratio of 1.53 or 1.88 was accomplished. Influence of several conditions on the chatter stability was investigated. Analytical investigations revealed that the chatter stability is significantly improved at a designated depth of cut by utilizing the proposed designs regardless of feed rate. In particular, the compliance ratio of 1.55 showed wider stable zone to attain chatter free boring, while chatter avoidance is impossible by use of the conventional isotropic boring bar under the same conditions.

An Innovative Machining Strategy for Efficient Peripheral Finishing of Hard Materials with Highly-Varied-Helix End Mill

2015 ◽  
Vol 9 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Atsushi Ito ◽  
◽  
Eiji Shamoto ◽  
Keyword(s):  
Helix Angle ◽  
Hardened Steel ◽  
Chatter Vibration ◽  
End Mill ◽  
Rough Machining ◽  
Regenerative Chatter ◽  
Hard Materials ◽  
End Mills ◽  
Low Stiffness ◽  
Low Radial Immersion

Grinding is usually applied to the peripheral finishing of hardened steel since the high specific cutting force and low stiffness of slender end mills often causes chatter vibration. On the other hand, varied-helix end mills have suppressed regenerative chatter vibration successfully in the rough machining of flexible workpieces. In this research, varied-helix end mills are applied to the extremely low radial immersion finishing of hardened steel, and the validity of this application is discussed and verified experimentally in terms of suppression of regenerative chatter vibration. A special varied-helix end mill with an extremely large helix angle difference is developed for this new application, and its performance is compared to that of an ordinarily-varied-helix end mill for the low-radial-immersion peripheral finishing of hard materials.

Control of Low-Cost Customizable Robot Arm Actuated by Elastic Tendons

2016 ◽  
Vol 28 (4) ◽  
pp. 509-522 ◽  
Author(s):  
Junki Togashi ◽  
◽  
Kazuhisa Mitobe ◽  
Genci Capi ◽  
Keyword(s):  
Force Control ◽  
Control Method ◽  
Low Cost ◽  
String Tension ◽  
Machining Accuracy ◽  
Robot Arm ◽  
Compliant Joints ◽  
Low Stiffness ◽  
Static Conditions ◽  
The Cost

[abstFig src='/00280004/09.jpg' width='300' text='Elastic tendon driven robot arm' ] This paper presents a low-cost, lightweight robot arm with very low stiffness actuated by elastic tendons. To simplify the string tension control, a new winding device was developed. Small pulleys were incorporated into the winding drum to reduce friction between the tendon and the drum. A marionette-style two-link robot arm with compliant joints was prototyped. Because the arm and winding devices were separate from each other, the cost and weight of the robot were reduced. The links are made with lightweight wood connected by simple shaft joints. The robot design can be easily modified by the user because the mechanical parts do not require high machining accuracy. This robot is intended for implementation in tasks that do not require high positioning accuracy using a simple force control under environmental constraints. Because of its low stiffness, simple and sensor-less force control can be easily implemented based on the relationship between forces under static conditions. The proposed simple control method was evaluated experimentally by conducting position, static force, and hybrid position/force control tasks and was shown to perform well. The results also demonstrate that employing additional sensors, such as a camera, improves the accuracy of the controller.

scholarly journals Analysis of High Force Voice Coil Motors for Magnetic Levitation

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 133
Author(s):  
Jae-Yeol Kim ◽  
Dahoon Ahn
Keyword(s):  
Magnetic Levitation ◽  
Voice Coil Motor ◽  
Simulation Models ◽  
Volumetric Change ◽  
Element Simulation ◽  
Different Types ◽  
Positioning Device ◽  
Low Stiffness ◽  
The Voice ◽  
Fast Dynamic

A voice coil motor is a simple and linear electromagnetic actuator. Since it has a non-contact force and very low stiffness, it is widely used for precision positioning devices including magnetic levitation systems. During magnetic levitation, high force of a voice coil motor is required to compensate for the weight of the device and ensure a fast dynamic response. In this paper, two types of voice coil motors were analyzed by their volumetric change. The change of the generated force according to the volumetric change was inspected by finite element simulation models. The enhancement of force was dependent on which type of the voice coil motor is used, which component is enlarged, and which direction is the voice coil motor expands in. Based on the analysis results, two voice coil motors were optimally designed for a magnetic levitation positioning device. As a result of the design, it was confirmed that different types of voice coil motor generate different forces even if they have the same volume. For the two types of voice coil motors, the force differed by up to 40%.

Effects of compression during formation on the microstructure of composite hydroxylapatite/plaster implants for bone reconstruction

1988 ◽  
Vol 46 ◽  
pp. 750-751
Author(s):  
J. Hanker ◽  
K. Cowden ◽  
R. Noecker ◽  
P. Yates ◽  
N. Georgiade ◽  
...  
Keyword(s):  
Cosmetic Surgery ◽  
Glass Plate ◽  
Surgical Reconstruction ◽  
Equal Weight ◽  
Sintered Ceramic ◽  
Setting Times ◽  
Excess Water ◽  
Mixture Prior ◽  
Mechanical Strengths ◽  
Calcium Sulfate Hemihydrate

Composites of plaster of Paris (PP) and hydroxylapatite (HA) particles are being applied for the surgical reconstruction of craniofacial bone defects and for cosmetic surgery. Two types of HA particles are being employed, the dense sintered ceramic (DHA) and the porous, coralline hydroxylapatite (PHA) particles. Excess water is expressed out of the moistened HA/PP mixture prior to implantation and setting by pressing it in a non-tapered syringe against a glass plate. This results in implants with faster setting times and greater mechanical strengths. It was therefore of interest to compare samples of the compressed versus noncompressed mixtures to see whether or not any changes in their microstructure after setting could be related to these different properties.USG Medical Grade Calcium Sulfate Hemihydrate (which has the lowest mortar consistency of any known plaster) was mixed with an equal weight of Interpore 200 particles (a commercial form of PHA). After moistening with a minimum amount of water, disc-shaped noncompressed samples were made by filling small holes (0.339 in. diameter x 0.053 in. deep) in polypropylene molds with a microspatula.

Crack divergence phenomena in tempered glass

2020 ◽  
Vol 13 (3) ◽  
pp. 115-129
Author(s):  
Shin’ichi Aratani
Keyword(s):  
Optimal Design ◽  
High Speed ◽  
Glass Plate ◽  
Acute Angle ◽  
Divergence Angle ◽  
High Speed Photography ◽  
Tempered Glass ◽  
Thick Glass

High speed photography using the Cranz-Schardin camera was performed to study the crack divergence and divergence angle in thermally tempered glass. A tempered 3.5 mm thick glass plate was used as a specimen. It was shown that two types of bifurcation and branching existed as the crack divergence. The divergence angle was smaller than the value calculated from the principle of optimal design and showed an acute angle.

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