Analysis of geometric error of tool path in high speed cutting -Error of tool path in linear interpolation caused by accelerations

1997 ◽  
pp. 295-302 ◽  
Author(s):  
X. R. Yan ◽  
K. Shirase ◽  
M. Hirao ◽  
T. Yasui
2021 ◽  
Vol 15 (5) ◽  
pp. 621-630
Author(s):  
Shingo Tajima ◽  
◽  
Satoshi Iwamoto ◽  
Hayato Yoshioka

The demands for machining by industrial robots have been increasing owing to their low installation cost and high flexibility. A novel trajectory generation algorithm for high-speed and high-accuracy machining by industrial robots is proposed in this paper. Linear interpolation in the workspace and smooth trajectory generation at the corners are important in industrial machining robots. Because industrial robots are composed of rotational joints, the joint space has a nonlinear relationship with the workspace. Therefore, linear interpolation in the joint space, which has been widely used in conventional machine tools, does not guarantee linear interpolation in the actual machining workspace. This results in the degradation of the machining surface. The proposed trajectory generation algorithm based on the decoupled approach can achieve linear interpolation in the workspace by separating the position commands into Cartesian coordinates and the orientation commands into spherical coordinates. In addition, a novel corner smoothing method that generates a smooth and continuous trajectory from discrete commands is proposed in this paper. The proposed kinematic local corner smoothing generates a smooth trajectory by using a 3-segmented constant jerk profile at the corners in the joint space. The sharp corners can thereby be replaced by smooth curves. The resulting cornering error is controlled by varying the cornering duration. The simulation results demonstrate the effectiveness of the proposed kinematic smoothing algorithm in achieving linear tool motion in straight sections and in generating smooth trajectories at corner sections within the user-defined tolerance.


2010 ◽  
Vol 426-427 ◽  
pp. 572-576
Author(s):  
Can Zhao ◽  
Y.Y. Guo ◽  
Guang Bin Bu

There are two key problems in the manufacture process of impeller with HSM(High Speed Machining). One is the collision between tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. The control algorithm of collision-free cutter-axis was described and applied in this paper. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. And the qualified impeller was produced. It indicated that the tool vector control method was feasible.


2016 ◽  
Vol 836-837 ◽  
pp. 501-508
Author(s):  
Laureen Grandguillaume ◽  
Sylvain Lavernhe ◽  
Christophe Tournier

This paper deals with singular configurations of a 5-axis machine tool in high speed milling which may lead to the appearance of large incoherent movements of rotary axes near singularity points. These movements generate slowdowns of the actual feedrate during the execution of the tool path, which affect quality and productivity. Thus, this paper proposes a method to detect these behaviors during machining simulation and correct the tool path. Unlike the literature methods, this correction consists in modifying the tool axis orientation by going through the singularity point while respecting maximum velocity, acceleration and jerk of the rotary axis. For that purpose, the initial articular positions of the rotary axis near the singularity point are fitted with B-spline curves, modified and finally discretized for linear interpolation. Experimental investigations on a test part are carried out to show the efficiency of the method.


2011 ◽  
Vol 141 ◽  
pp. 449-454
Author(s):  
Jing Chuan Dong ◽  
Qing Jian Liu ◽  
Tai Yong Wang

High speed CNC machining relies on the smooth interpolation of tool path in order to prevent impact and vibration. We present a new interpolation scheme for CNC controller based on 6-point subdivision. The subdivision interpolation improves the smoothness of the original trajectory, while maintaining the accuracy. The algorithm is simple and effective, and therefore it is suitable for real-time execution in CNC controllers. Simulation results show that the proposed method performs better than linear interpolation, since the tracking error and contour error is reduced.


2011 ◽  
Vol 467-469 ◽  
pp. 252-256
Author(s):  
Zhen Yu Zhao ◽  
Dong Ying Liang ◽  
Yong Shan Xiao ◽  
Bai Liu

At present, high speed machining (HSM) features in high efficiency, high precision, high flexibility and high quality. HSM technology involves many factors, including cutting mechanisms, machining performance, tool path and other aspects. The key techniques on HSM such as linear interpolation, circular interpolation, cubic B-spline curve interpolation, non-uniform rational B-spline (NURBS) curve interpolation and their respective characteristics are paid more attention and expatiated.


Author(s):  
Angela A. Sodemann ◽  
J. Rhett Mayor

This study will present an experimental evaluation of the variable-feedrate intelligent segmentation (VFIS) method described by Mayor and Sodemann (2008, “Intelligent Tool-Path Segmentation for Improved Stability and Reduced Machining Time in Micromilling,” ASME J. Manuf. Sci. Eng., 130(3), p. 031121). The apparatus for the tests will be identified and the approach to the testing procedure will be laid out, including the means of evaluation of the method. A detailed explanation is then given for the choice of process parameters. This is followed by the introduction of the β parameter as an additional factor in the VFIS implementation. Results are presented from cutting tests. The first set of test results presented is from a complete set of evaluation tests performed on sine wave geometries. The second set is an evaluation of the fan and airfoil shapes used previously in the numerical simulations of the VFIS method. It is found that the VFIS method is able to successfully constrain geometric error to within specified bounds in most cases. The cutting time for the VFIS method shows as much as 53% reduction relative to the nonuniform rational B-spline-based trajectory generation method.


2013 ◽  
Vol 581 ◽  
pp. 478-484 ◽  
Author(s):  
Sergey N. Grigoriev ◽  
Andrey A. Kutin ◽  
Mikhail Turkin

This paper presents a method to simultaneously increase the accuracy and decrease the calculation time for complex tool path programming in multi-axis machining centers. Examples of complex parts requiring such complex tool paths include various kinds of turbine blades, pump-forcing augers, teeth surfaces, etc. It explains the creation of topological structures on the basis of analytical spline curves with floating range definitions. The method for tool path calculation accommodates the specific requirements for multi-axis milling. The algorithms developed are the foundation for the CAD/CAM software that allows for NC programming and machining on 5-axis centers employing any design model. Industrial tests reveal a 70-80% reduction of NC programming time of parts with complex surfaces, reduced machining time of approximately 40-50% using basic high-speed cutting methods and custom-made tools. The advanced methods of NC programming result in substantially increasing machining accuracy.


2012 ◽  
Vol 723 ◽  
pp. 337-342
Author(s):  
Li Juan Liu ◽  
Wen Ge Wu ◽  
Ming Lv

High speed machining (HSM) is one of the main trends of cutting machinery and is an important development direction of advanced manufacturing technology. In our country, the relevant research of HSM database starts later, especially of the cutting of hardworking material, the actual machining and experiment on the machining technology and the machining parameters of HSM are few, the reasonable machining parameters selection scheme and the appropriate cutter choice method are lack. The paper established HSM database system of the hardworking material based on web to improve cutting efficiency. According to the different feed and cutting tool by the Web form, it gets the rational cutting parameters. And the system determines the tool-path planning by the manufacture HSM of hardworking material processing animation to simulate the high-speed milling. The results of inquiry as a Web page and let you get parameters of optimization, increases efficiency of factories.


2015 ◽  
Vol 1 (1) ◽  
pp. 5-16
Author(s):  
John Ohoiwutun

Utilization of conventional energy sources such as coal, fuel oil, natural gas and others on the one hand has a low operating cost, but on the other side of the barriers is the greater source of diminishing returns and, more importantly, the emergence of environmental pollution problems dangerous to human life. This study aims to formulate the kinematics and dynamics to determine the movement of Solar Power Mower. In this study, using solar power as an energy source to charge the battery which then runs the robot. Design and research was conducted in the Department of Mechanical Workshop Faculty of Engineering, University of Hasanuddin of Gowa. Control system used is a manual system using radio wave transmitter and receiver which in turn drive the robot in the direction intended. Experimental results showed that treatment with three variations of the speed of 6.63 m / s, 8.84 m / s and 15.89 m / sec then obtained the best results occur in grass cutting 15.89 sec and high-speed cutting grass 5 cm. Formulation of kinematics and dynamics for lawn mowers, there are 2 control input variables, x and y ̇ ̇ 3 to control the output variables x, y and θ so that there is one variable redudant. Keywords: mobile robots, lawn mower, solar power


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