Research on CNC Key Technology for High Speed Milling

2011 ◽  
Vol 467-469 ◽  
pp. 252-256
Author(s):  
Zhen Yu Zhao ◽  
Dong Ying Liang ◽  
Yong Shan Xiao ◽  
Bai Liu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
High Efficiency ◽  
Linear Interpolation ◽  
Machining Performance ◽  
B Spline ◽  
Curve Interpolation ◽  
High Flexibility ◽  
Circular Interpolation ◽  
Cutting Mechanisms

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.

Interpolation Algorithm on Numerical Control Technology

2011 ◽  
Vol 467-469 ◽  
pp. 247-251
Author(s):  
Zhen Yu Zhao ◽  
Ming Jun Liu ◽  
Yong Shan Xiao ◽  
Bai Liu
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Linear Interpolation ◽  
Numerical Control ◽  
Machining Accuracy ◽  
B Spline ◽  
Curve Interpolation ◽  
Nurbs Interpolation ◽  
High Flexibility ◽  
Circular Interpolation

High speed machining (HSM) features in high efficiency, high precision, high flexibility and high quality. 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. Circle arcs are approximated by using intersecting polygons instead of general inscribed polygons. NURBS interpolation algorithms can reduce feedrate fluctuation and improve machining accuracy.

scholarly journals Kinematic Tool-Path Smoothing for 6-Axis Industrial Machining Robots

2021 ◽  
Vol 15 (5) ◽  
pp. 621-630
Author(s):  
Shingo Tajima ◽  
◽  
Satoshi Iwamoto ◽  
Hayato Yoshioka
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Trajectory Generation ◽  
Linear Interpolation ◽  
Joint Space ◽  
Industrial Robots ◽  
Generation Algorithm ◽  
High Flexibility ◽  
Tool Motion ◽  
Trajectory Generation Algorithm

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.

Five-Axis HSM Tool-Path Planning of Integral Impeller

2010 ◽  
Vol 426-427 ◽  
pp. 572-576
Author(s):  
Can Zhao ◽  
Y.Y. Guo ◽  
Guang Bin Bu
Keyword(s):  
High Speed ◽  
Control Algorithm ◽  
Tool Path ◽  
Control Method ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Normal Vector ◽  
Manufacture Process ◽  
Five Axis ◽  
Uniform Change

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.

scholarly journals Kinematical Smoothing of Rotary Axis near Singularity Point

2016 ◽  
Vol 836-837 ◽  
pp. 501-508
Author(s):  
Laureen Grandguillaume ◽  
Sylvain Lavernhe ◽  
Christophe Tournier
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Maximum Velocity ◽  
Linear Interpolation ◽  
Experimental Investigations ◽  
Axis Orientation ◽  
Rotary Axis ◽  
Spline Curves ◽  
Tool Axis ◽  
Singularity Point

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.

Research on Subdivision Interpolation for High Speed CNC Applications

2011 ◽  
Vol 141 ◽  
pp. 449-454
Author(s):  
Jing Chuan Dong ◽  
Qing Jian Liu ◽  
Tai Yong Wang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Tracking Error ◽  
Linear Interpolation ◽  
Cnc Machining ◽  
Contour Error ◽  
Interpolation Scheme ◽  
Simulation Results ◽  
Cnc Controller ◽  
Better Than

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.

Experimental Research on Surface Roughness in High Speed Milling of Complex Surface Mold Steel

2009 ◽  
Vol 626-627 ◽  
pp. 123-128 ◽  
Author(s):  
Cao Qing Yan ◽  
Jun Zhao ◽  
Yue En Li ◽  
Shi Guo Han
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Tool Path ◽  
High Efficiency ◽  
Complex Surface ◽  
Spindle Speed ◽  
Cnc Milling ◽  
Cutting Depth ◽  
High Speed Milling ◽  
Longitudinal Roughness

Complex surface mold has been widely used in various industries, and high efficiency and high quality can been achieved through high-speed CNC milling processing. Surface roughness including transverse and longitudinal roughness is an important criterion for mold quality. A high-speed milling experiment was performed in mold steel P20 using cemented carbide ball-end mill to investigate the surface roughness. The effects of process parameters on roughness including spindle speed, feed per tooth and radial cutting depth were examined, and an analysis on the mechanism for two kinds of roughness of different tool paths was finished. The experimental results show that the longitudinal roughness improve obviously while the spindle speed and the feed per tooth increase on the high-speed conditions, and the transverse roughness increase significantly when the radial cutting depth increases. And for a smaller roughness value, the tool path should be selected along the direction in which the curvature changes evidently.

An Improvement and Simulation of NURBS Curve Algorithm

2013 ◽  
Vol 655-657 ◽  
pp. 1191-1194 ◽  
Author(s):  
Guo Qing Qiu ◽  
Le Fei Tu ◽  
Tian Yue Jiang ◽  
Han Qing Feng
Keyword(s):  
Feed Rate ◽  
Adaptive Algorithm ◽  
High Speed ◽  
Nurbs Curve ◽  
Curve Interpolation ◽  
Variable Step ◽  
Speed Fluctuation ◽  
Acceleration And Deceleration ◽  
Simulation Results ◽  
Circular Interpolation

Although the chord height error might be ensured, the adaptive algorithm of the NURBS curve circular interpolation feed rate is still likely to result in the speed fluctuation which is not in accordance with given acceleration or deceleration rules. On the foundation of the analytic principle of the NURBS curve circular interpolation, a kind of interpolating algorithm based on the NURBS curve continuous small segments of S-shaped acceleration and deceleration is presented. And considering the chord height error, the variable step and feed rate can be effectively combined to make a better estimation. The simulation results on real examples show that the method not only simplifies the complicated calculation of curve interpolation process, simultaneously improves the speed of Motion Smoothing Implementation for NURBS curve interpolation, but also ensures the interpolation precision. The algorithm can be commonly applied in real manufacturing for high-speed and high-precision curve process.

Fractionally Spaced Frequency Equalization Method for Orthogonal Frequency Division Multiplexing (OFDM) Jointing with Modified Pilot Sequences

2012 ◽  
Vol 198-199 ◽  
pp. 1569-1572
Author(s):  
Ye Cai Guo ◽  
Qu Chen ◽  
Jun Guo ◽  
Xiao Li Miao
Keyword(s):  
Frequency Domain ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
High Efficiency ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Single Carrier ◽  
Frequency Domain Response

In order to obtain accurate and high-speed data transmission, the orthogonal frequency division multiplexing(OFDM) technology is introduced and it is a kind of a multi-carriers modulation technology with high efficiency in the use of frequency band and characteristics of strong anti-interference ability. The fractionally spaced OFDM frequency domain equalization algorithm based on modified pilot sequences is proposed. In this proposed algorithm, one-dimensional linear interpolation method is used to estimate the frequency domain response of all subcarriers by part of the subcarriers’ frequency domain response with reducing the number of transmitted pilot sequences, and received signals are oversampled to acquire more detailed channel information. The computer simulations in underwater acoustic channel show that the performance of proposed method outperforms the single-carrier system and traditional OFDM system.

Real-Time B-Spline Interpolator with Look-Ahead Scheme for High-Speed CNC Machine Tools

2010 ◽  
Vol 455 ◽  
pp. 599-605
Author(s):  
Yong Qiao Jin ◽  
Yu Han Wang ◽  
Jian Guo Yang
Keyword(s):  
Real Time ◽  
High Speed ◽  
Tool Path ◽  
Cnc Machine Tools ◽  
Interpolation Algorithm ◽  
Cnc Machine ◽  
Machining Time ◽  
B Spline ◽  
Optimal Speed ◽  
Look Ahead

NC tool paths of digital CAD models are currently generated as a set of discrete data points. The CNC interpolator must convert these points into continuous machine tool axis motions. In order to achieve high-speed and high-accuracy machining, the development of a real-time interpolation algorithm is really indispensable, which can deal with a large number of short blocks and still maintain smooth interpolation with an optimal speed. In this paper, a real-time local cubic B-spline interpolator with look-ahead scheme is proposed for consecutive micro-line blocks interpolation. First, the consecutive micro-line blocks that satisfy the bi-chord error constraints are fitted into a C1 continuous cubic B-spline curve. Second, machining dynamics and tool path contour constrains are taken into consideration. Third, local cubic B-spline interpolator with an optimal look-ahead scheme is proposed to generate the optimal speed profile. Simulation and experiment are performed in real-time environment to verify the effectiveness of the proposed method. Compared with the conventional interpolation algorithm, the proposed algorithm reduces the machining time by 70%.

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