Form and Texture Control of Free-Form Surface Polishing

2006 ◽  
Vol 304-305 ◽  
pp. 113-117 ◽  
Author(s):  
Shi Ming Ji ◽  
Xian Zhang ◽  
Li Zhang ◽  
Qiao Ling Yuan ◽  
Y.H. Wan ◽  
...  
Keyword(s):  
Surface Texture ◽  
Polar Coordinates ◽  
Free Form ◽  
Polished Surface ◽  
Work Piece ◽  
Rotational Axis ◽  
Spatial Frequencies ◽  
New Type ◽  
Free Form Surface ◽  
Polishing Tool

In this paper, a new type of flexible sub-size polishing tool, and an advanced polishing technique for free-form surface based on the new type of tool will be researched. The configuration of the flexible polishing tool and the method of controlling the multi-DOF precessions of the flexible polishing tool will be introduced. The rectilineal movement along X,Y, Z axis and flirts on two polar coordinates rotational axis of the polishing tool are used to control the form precision and the surface texture of polished surface. This polishing technique is enable to change continuously the polishing pressure and contact area and makes the flexible polishing tool well suited both to control the texture of work-piece surface and to control the form of work-piece surface. The influence functions the flexible polishing tool is near-Gaussian, symmetrical, and lacks the high spatial frequencies and center-zero of removal. The example of multi-DOF precessions polishing for optic spherical and aspherical will be introduced. The results show that the form, the size and the movement mode of the polishing tool will have important effect to polishing quality and multi-DOF precessions polishing can obtain better surface texture quality, form precision and higher polishing efficiency than traditional pole-down polishing for free-form surface.

Study on the Fuzzy-PID Policy for Force Control in Free-Form Surfaces Polishing by Robots

2011 ◽  
Vol 101-102 ◽  
pp. 422-426
Author(s):  
Xiao Ling Su ◽  
Jian Ming Zhan
Keyword(s):  
Force Control ◽  
Normal Direction ◽  
Curved Surface ◽  
Free Form ◽  
Work Piece ◽  
Fuzzy Pid ◽  
Polishing Force ◽  
The Right ◽  
Free Form Surfaces ◽  
Polishing Tool

When a robot is used to polish or finish a curved surface, both feed movement and contact force have to be controlled at the same time so that the polishing tool would machine its work-piece at the right position in right posture with required force. In this paper, a passive wrist system is developed to adapt the shape of the machining curved surface by changing its posture along with the surface. And under the Fuzzy-PID policy, polishing force is controlled at a stable value in the normal direction of the named machining point while the polishing tool moving along the curved surface by multi-point machining. It means that the passive wrist system and the model of the surroundings could be used in force controlling when robots polish free-form surfaces with multi-point machining by a grinding ring.

Characteristics of Free Form Finishing Applying V-CAM System

2007 ◽  
Vol 329 ◽  
pp. 273-278
Author(s):  
Wei Min Lin ◽  
Hitoshi Ohmori ◽  
T. Suzuki ◽  
Yoshihiro Uehara ◽  
Y. Watanabe ◽  
...  
Keyword(s):  
Research And Development ◽  
Fabrication Process ◽  
Free Form ◽  
Polished Surface ◽  
Precision Control ◽  
Form Accuracy ◽  
Cad System ◽  
Free Form Surface ◽  
The Relationship ◽  
Fundamental Experiment

A new CAD system, which is called Volume-CAD (VCAD) have been developed. We carried out research and development of VCAD fabrication process based on VCAD/CAM precision control. In this study, a developed V-CAM had been used for a polishing fundamental experiment of a free form surface. The relationship between NC resolution and form accuracy of polished surface are discussed.

Development of Polishing Tool Capable of Self-Adaptive to Processing Site Using Steel Balls and Magnetic Force

2016 ◽  
Vol 1136 ◽  
pp. 466-471
Author(s):  
Lei Ma ◽  
Tatsuya Furuki ◽  
Takashi Kure ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Magnetic Force ◽  
Free Form ◽  
Machining Center ◽  
Abrasive Finishing ◽  
Processing Site ◽  
Free Form Surface ◽  
Steel Balls ◽  
Free Form Surfaces ◽  
Polishing Tool ◽  
Self Adaptive

There has been the requirement in recent times for environmentally friendly methods for finishing free-form surfaces such as those of molding dies [1]. This has led to interest in the development of a new polishing technology that utilizes less abrasive slurry and magnetic abrasive finishing. However, it is well known that the traditional magnetic polishing method is unstable and produces insufficient surface smoothness. In the present paper, we discuss the causes of the instability of conventional magnetic polishing. We also propose a self-adaptive polishing tool comprising a brush with steel balls and a coating of thin slurry and present the results of its use to polish various incline surfaces on a three-axis machining center. The proposed self-adaptive polishing tool was found to be effective for polishing a free-form surface using less abrasive slurry.

scholarly journals Reflection curves—new computation and rendering techniques

2004 ◽  
Vol 2004 (21) ◽  
pp. 1121-1132 ◽  
Author(s):  
Dan-Eugen Ulmet
Keyword(s):  
Industrial Applications ◽  
Free Form ◽  
3D Cad ◽  
Cad Cam ◽  
New Type ◽  
Matlab Implementation ◽  
Free Form Surface ◽  
Curves On Surfaces ◽  
Cam Systems ◽  
Rendering Techniques

Reflection curves on surfaces are important tools for free-form surface interrogation. They are essential for industrial 3D CAD/CAM systems and for rendering purposes. In this note, new approaches regarding the computation and rendering of reflection curves on surfaces are introduced. These approaches are designed to take the advantage of the graphics libraries of recent releases of commercial systems such as the OpenInventor toolkit (developed by Silicon Graphics) or Matlab (developed by The Math Works). A new relation between reflection curves and contour curves is derived; this theoretical result is used for a straightforward Matlab implementation of reflection curves. A new type of reflection curves is also generated using the OpenInventor texture and environment mapping implementations. This allows the computation, rendering, and animation of reflection curves at interactive rates, which makes it particularly useful for industrial applications.

Research on Contact Force Control in Process of Aspheric Surface Polish

2012 ◽  
Vol 621 ◽  
pp. 216-222
Author(s):  
Jie Qiong Lin ◽  
Tong Huan Ran ◽  
Li Feng
Keyword(s):  
Contact Force ◽  
Force Control ◽  
Position Control ◽  
Control Method ◽  
Free Form ◽  
Force Output ◽  
Compliant Control ◽  
Free Form Surface ◽  
Polishing Tool ◽  
Contact Force Control

Contact force control is one of the key technologies of polishing aspheric optical parts, and keeping a stable polishing contact force on the basis of accurate position control is an important condition to obtain high quality aspheric. The paper bases on ideal surface, decouples the contact force that between polishing tool and workpiece in each direction of the drive shaft in process of polish. Then get output force of all sports shaft. Finally, realize the polishing contact force control that take the position as a control goals, and take constant force output as a constraints. Simulation results show that the control method can achieve constant contact force output in the processing of polishing free-form surface, which provide a new idea to research the compliant control of polishing free-form surface.

Registration of 3-D Shape with Free-Form Surface Using Imageware and Genetic Algorithm

2012 ◽  
Vol 472-475 ◽  
pp. 317-322 ◽  
Author(s):  
Xiao Yi Wang ◽  
Jing Chen ◽  
Jiang Zhu ◽  
Yoshio Saito ◽  
Tomohisa Tanaka
Keyword(s):  
Genetic Algorithm ◽  
Point Cloud ◽  
Point Clouds ◽  
Free Form ◽  
Work Piece ◽  
Cad Model ◽  
Manufacturing Accuracy ◽  
Free Form Surface ◽  
Point Data ◽  
Fine Registration

Registration of 3-D shape is significant in quantizing the error between the part and its CAD model and evaluating the part's manufacturing accuracy. In the past, various improved methods of the iterative closest point (ICP) had been proposed in registration. However, without fine initial pose of point clouds, the ICP algorithm often could not converge to the best (or near best) solution. According to the characteristics of 3-D shape with free-form surface, a new method for registration of 3-D shape with free-form surface is given, by which there are not rigid requests in initial pose of point data and the 3-D shape model could be in arbitrary positions and orientations in space. To improve the efficiency and accuracy of solving, this method is divided into general registration and fine registration. General registration is to fit rapidly and roughly the measured point cloud to designing point cloud from CAD model by Imageware. Fine registration is to further accurately fit the two group points using genetic algorithm (GA). Case study is finally given for a work piece with free-form surface to show the effectiveness of the above method.

scholarly journals Surface Texturing of Fan-blade Body by Random-orbital Polishing With in-line Aqueous Mist

2021 ◽  
Author(s):  
Edgar Jeevan Danaraj ◽  
Swee Hock Yeo
Keyword(s):  
Surface Roughness ◽  
Surface Topography ◽  
Leading Edge ◽  
Free Form ◽  
Polished Surface ◽  
Polishing Process ◽  
Scallop Height ◽  
Cold Air ◽  
Fan Blade ◽  
Polishing Tool

Abstract Airfoil structures such as fan blades have free form geometry which require a high level of precision in order to create a uniform finish for ideal gas path flow. Challenges in machining of such parts have led to rework in order to remove defects and conform to dimensional requirements at the same time. Mechanical polishing is the most common method to remove surface irregularities on fan blades such as scallop height, while maintaining the required dimensions. After the polishing process, the part will undergo shot peening, vibratory finishing and later, painting and coating at the final stages. It is therefore essential for the fan blade surface to pre-treated with rough, uniform textures in order to promote good surface-to-surface adhesion at the end of the manufacturing cycle. Generally, the polishing process is assisted by an external cooling medium applied on the part surface at intervals. This method of removing heat is not effective, as the polished surface may experience scratches or distortion, especially around thin-walled sections of the leading edge in fan blade. The existing polishing method uses a single-axis rotary tool can produce average surface roughness, Ra, of 1.2 µm that satisfies the requirement. However, this form of aggressive polishing has a high material removal rate, resulting in excessive reduction in material thickness which leads to the rejection of costly fan blade.This study a new localized polishing method and examines its effect on the surface topography of an airfoil component made of aluminum alloy. The area of interest is focused on the leading edge of a fan blade at which polishing is carried out using a random-orbital polishing tool with modified features to incorporate internal cooling capability. Experimental trials are conducted to study the effects of surface finish with fixed grain abrasive disks under four conditions. A cold gun is connected in-line to guide cold air inside the internal passages of the tool and out onto the surface of the part directly. A secondary cooling source by water nozzle spray is integrated in the tool to mix with the cold air jet and form an aerosol mist during tool activation. Surface topography of the samples are determined by arithmetic mean deviation, maximum height and root mean square of the profile. Surface roughness was performed using an optical profilometer. The localized polishing method achieved a desirable surface roughness, Ra of 0.8 µm, while removing all traces of scallop height and maintaining the leading-edge thickness within tolerance. The study showed that the new method produced a topography that is uniformly textured. This method can improve the manufacturing cycle time.

Soft-Consolidation Abrasives Pneumatic Wheel Technology Oriented to Finishing of High-Hardness Free-Form Surface

2012 ◽  
Vol 523-524 ◽  
pp. 149-154 ◽  
Author(s):  
Shi Ming Ji ◽  
Xi Zeng ◽  
Ming Sheng Jing
Keyword(s):  
Large Scale ◽  
High Hardness ◽  
Rubber Matrix ◽  
Free Form ◽  
Grinding Wheel ◽  
Work Piece ◽  
Mechanics Model ◽  
Pneumatic Wheel ◽  
Self Adaptation ◽  
Free Form Surface

In order to improve the efficiency of high-hardness laser strengthening mold polishing, especially to the free-form surface, a new precision finishing method based on soft-consolidation abrasives pneumatic wheel is brought forward. The pneumatic wheel is constituded by flexible rubber maxtrix, combined with the robbet control. The abrasives group is bond to the rubber matrix by the polymer binder. In the way, compared with those free abrasives used in other polishing method, the soft-consolidation abrasives can get more stable surpport from nearby polymer to form effective cutting. On the other hand, it is unlike the abrasive of rigid grinding wheel because the flexibility of pneumatic wheel can have self-adaptation according to the changes in local curvature and achieve large scale copying contact between tools and work piece. Combined with the lay elastic system theory and Preston equation and coefficients, the mechanics model of polishing is given. The results of experiment shows the Ra of workpiece can be reached to 0.09um and the efficiency of process can be improved three times more than free abrasive machining. It will show its wild prospects in the process of polishing.

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