Tool Path Correction on a Numerically Controlled Machine-Tool by Characterisation of Scattering in Relation to Type of Machining

Author(s):  
G. Dessein ◽  
J. M. Redonnet ◽  
P. Lagarrigue ◽  
W. Rubio
Author(s):  
Hongwei Liu ◽  
Rui Yang ◽  
Pingjiang Wang ◽  
Jihong Chen ◽  
Hua Xiang

The objective of this research is to develop a novel correction mechanism to reduce the fluctuation range of tools in numerical control (NC) machining. Error compensation is an effective method to improve the machining accuracy of a machine tool. If the difference between two adjacent compensation data is too large, the fluctuation range of the tool will increase, which will seriously affect the surface quality of the machined parts in mechanical machining. The methodology used in compensation data processing is a simplex method of linear programming. This method reduces the fluctuation range of the tool and optimizes the tool path. The important aspect of software error compensation is to modify the initial compensation data by using an iterative method, and then the corrected tool path data are converted into actual compensated NC codes by using a postprocessor, which is implemented on the compensation module to ensure a smooth running path of the tool. The generated, calibrated, and amended NC codes were immediately fed to the machine tool controller. This technique was verified by using repeated measurements. The results of the experiments demonstrate efficient compensation and significant improvement in the machining accuracy of the NC machine tool.


Author(s):  
Jui-Jen Chou ◽  
D. C. H. Yang

Abstract In the integration of CAD and CAM, it is necessary to relate machine tool kinematics and control in a CAM process to the geometrical data in a CAD model. The data stored in a CAD model is usually static in nature and represented by unitless parameters. Yet, in machine tool motion and control, the data should be transformed into a time dependent domain. In this paper, a general theory on the conversion from desired paths to motion trajectory is analytically derived. The geometrical properties of a desired path, including position, tangent, and curvature are related to the kinematics of coordinated motion including feedrate, acceleration, and jerk. As a result, the motion commands used as control references to track arbitrary space curves for five-axis computer-controlled machines can be generated in a rather straight-forward as well as systematic way.


Author(s):  
James A. Stori ◽  
Paul K. Wright

Abstract Within the Integrated Design And Manufacturing Environment (IMADE), operation planning provides a mapping from geometric design primitives to machining operation sequences for manufacturing processes. Operation planning includes tool selection, machining parameter selection, and tool path generation. An object oriented approach to program structure is adopted, whereby features, operations and tools, inherit behaviors and attributes from the appropriate class-hierarchies for the part, the manufacturing operations, and tooling classes. A detailed example is presented illustrating the operation planning search algorithm. Scripts are generated by the individual machining operations for execution on a machine tool. Tooling information is maintained in an object-oriented database through the FAR libraries for Common LISP. Examples of particular process plans show that the inherent trade-offs between specified precision and machining time can be investigated. An Open Architecture Machine Tool (MOSAIC-PM) has been used to machine the parts created by the feature based design and planning system. The novel contributions of this paper relate to the demonstration of “seamless” links between, a) design, b) planning, and c) actual fabrication by milling.


2014 ◽  
Vol 622-623 ◽  
pp. 382-389 ◽  
Author(s):  
Antonio Fiorentino ◽  
G.C. Feriti ◽  
Elisabetta Ceretti ◽  
C . Giardini ◽  
C.M.G. Bort ◽  
...  

The problem of obtaining sound parts by Incremental Sheet Forming is still a relevant issue, despite the numerous efforts spent in improving the toolpath planning of the deforming punch in order to compensate for the dimensional and geometrical part errors related to springback and punch movement. Usually, the toolpath generation strategy takes into account the variation of the toolpath itself for obtaining the desired final part with reduced geometrical errors. In the present paper, a correction algorithm is used to iteratively correct the part geometry on the basis of the measured parts and on the calculation of the error defined as the difference between the actual and the nominal part geometries. In practice, the part geometry is used to generate a first trial toolpath, and the form error distribution of the resulting part is used for modifying the nominal part geometry and, then, generating a new, improved toolpath. This procedure gets iterated until the error distribution becomes less than a specified value, corresponding to the desired part tolerance. The correction algorithm was implemented in software and used with the results of FEM simulations. In particular, with few iterations it was possible to reduce the geometrical error to less than 0.4 mm in the Incremental Sheet Forming process of an Al asymmetric part, with a resulting accuracy good enough for both prototyping and production processes.


2013 ◽  
Vol 26 (5) ◽  
pp. 799-816 ◽  
Author(s):  
Cong Geng ◽  
Dong Yu ◽  
Liaomo Zheng ◽  
Han Zhang ◽  
Feng Wang

2011 ◽  
Vol 697-698 ◽  
pp. 309-313 ◽  
Author(s):  
Chen Hua She ◽  
Yueh Hsun Tsai

Designs of free-form surface products are becoming increasingly complex. In traditional three-axis machine tool machining, errors that are caused by repetitive positioning and the costs of fixture jig design and manufacturing are critical. Since multi-axis machining provides two more rotational degrees of freedom than a three-axis machine tool, the former can solve these problems, and has therefore become the trend of precision cutting. As multi-axis machined parts often have holes and grooves on the tilted plane, this work proposes a method for machining tilted working plane features and for NC generation on a five-axis machine. The developed module can provide common geometric features, allowing the user to alter the machining feature and sequence on the tilted plane quickly using the parent-child relationship in a tree diagram, and plan the tool path. The postprocessor module developed in this paper can transform the tool path into an NC program required for machining. Finally, solid cutting simulation software is utilized to confirm the feasibility and correctness of the tool path and NC data of the tilted plane machining feature.


2013 ◽  
Vol 554-557 ◽  
pp. 1282-1289 ◽  
Author(s):  
Jérémy Belchior ◽  
Dominique Guines ◽  
Lionel Leotoing ◽  
Eric Ragneau

In this work, an off-line compensation procedure, based on an elastic modelling of the machine structure coupled with a Finite Element Analysis (FEA) of the process is applied to Robotized Single Point Incremental Forming (RSPIF). Assuming an ideal stiff robot, the FEA evaluates the Tool Center Point (TCP) forces during the forming stage. These forces are then defined as an input data of the elastic robot model to predict and correct the tool path deviations. In order to make efficient the tool path correction, the weight of three numerical and material parameters of the FEA on the predicted forces is investigated. Finally, the efficiency of the proposed method is validated by the comparison between numerical and experimental geometries obtained with or without correction of the tool path.


2010 ◽  
Vol 156-157 ◽  
pp. 1238-1242
Author(s):  
Kui Zhou ◽  
Si Tu Yu ◽  
Shi De Xiao

According to the motion characteristics of 4-axis CNC machine tool, this paper studies a new way for manufacturing the mushroom turbine blade boot .It must rotate the turbine blade to ensure the tool axis consistent with the normal of the interpolating point on the arc of the blade boot, and move the tool to keep the cutting point in contact with the interpolating point. Meanwhile, this paper researches an algorithm to calculate the tool path in the MCS, According to this algorithm, a program with R variable parameter for manufacturing the mushroom turbine blade boot is provided.


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