Multi-Period Turning Interpolation Algorithm for High-Speed Machining of Continuous Line Segments With Limited Acceleration, Jerk and Chord Error

2012 ◽  
Author(s):  
Lixian Zhang ◽  
Xiao-shan Gao ◽  
Hongbo Li
Keyword(s):  
Real Time ◽  
High Speed ◽  
Control Method ◽  
Dynamic Performance ◽  
Interpolation Algorithm ◽  
Cnc Machine ◽  
Look Ahead ◽  
Geometric Precision ◽  
S Curve ◽  
Accumulated Error

In this paper, a multi-period turning interpolation algorithm, with real-time look-ahead scheme based on S-curve control method, is presented. In this interpolation algorithm, the geometric precision and the dynamic performance are both satisfied. The machining efficiency is improved by multi-period turning transition, and the precision is also improved by S-curve control method. The computational efficiency of this algorithm meets the need of real-time machining. In addition, there is no accumulated error. At last, this algorithm is verified the validation by the experiments on 3-axis CNC machine.

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%.

An Interpolation Algorithm Based on S-Curve Feedrate Profile and Look-Ahead Function

2013 ◽  
Vol 300-301 ◽  
pp. 1389-1396 ◽  
Author(s):  
Ke Zheng Sun ◽  
Xue Feng Zhou ◽  
Gong Zhang ◽  
Xian Shuai Chen
Keyword(s):  
Machine Tools ◽  
High Speed ◽  
High Speed Machining ◽  
Interpolation Algorithm ◽  
Processing Efficiency ◽  
Look Ahead ◽  
Interpolation Accuracy ◽  
Acceleration And Deceleration ◽  
S Curve ◽  
Time Division

In this paper, a novel interpolation algorithm for high speed machining is presented, which integrates S-curve acceleration/deceleration method in look-ahead function. A time division based speed planning method is used to implement discrete S-curve acceleration/deceleration method. The implementation of the proposed algorithm is given out. The proposed algorithm improves the processing efficiency and avoids the shock of machine tools caused by frequent acceleration and deceleration. The experiment shows that the proposed algorithm satisfies the requirements of interpolation accuracy and machining efficiency in high speed machining.

A Network Implementation of Real-Time Dynamic Simulation With Interactive Animated Graphics

1988 ◽  
Author(s):  
M. W. Dubetz ◽  
J. G. Kuhl ◽  
E. J. Haug
Keyword(s):  
Real Time ◽  
Dynamic Simulation ◽  
High Speed ◽  
Dynamic Performance ◽  
Data Communication ◽  
Computing System ◽  
Data Sets ◽  
Parallel Processor ◽  
Network Computing ◽  
Time Dynamic

Abstract This paper presents a network based implementation of real-time dynamic simulation methods. An interactive animated graphics environment is presented that permits the engineer to view high quality animated graphics rendering of dynamic performance, to interact with the simulation, and to study the effects of design variations, while the simulation is being carried out. An industry standard network computing system is employed to interface the parallel processor that carries out the dynamic simulation and a high speed graphics processor that creates and displays animated graphics. Multi-windowing and graphics processing methods that are employed to provide visualization and operator control of the simulation are presented. A vehicle dynamics application is used to illustrate the methods developed and to analyze communication bandwidth requirements for implementation with a compute server that is remote from the graphics workstation. It is shown that, while massive data sets are generated on the parallel processor during realtime dynamic simulation and extensive graphics data are generated on the workstation during rendering and display, data communication requirements between the compute server and the workstation are well within the capability of existing networks.

Development of Real-Time Look-Ahead Methodology Based on Quintic PH Curve with G2 Continuity for High-Speed Machining

2013 ◽  
Vol 464 ◽  
pp. 258-264 ◽  
Author(s):  
Jing Shi ◽  
Qing Zhen Bi ◽  
Yu Han Wang ◽  
Gang Liu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Tool Path ◽  
Approximation Error ◽  
Machining Process ◽  
Transition Curve ◽  
Look Ahead ◽  
Cad Cam ◽  
Feedrate Fluctuation ◽  
Ph Curve

Curving tool paths composed of straight lines, which are often represented as G01 blocks, are still the most widespread format form in the machining process chain of CAD/CAM/CNC. At the junctions between consecutive segments, the tangency and curvature discontinuities may lead to feedrate fluctuation and acceleration oscillation, which would deteriorate the machining efficiency and quality. In this paper, a real-time look-ahead interpolation methodology is proposed, which adopts a curvature-continuous PH curve as a transition to blend corner at the junction of adjacent lines in the tool path. The blending algorithm can guarantee the approximation error exactly, and the control points of the curve can be calculated analytically. On the other hand, the arc length and the curvature of the transition curve, which are important items in speed planning, also have analytical expressions. All the advantages are the guarantee of calculation efficiency during the interpolation. Except for a curvature-continuous tool path, our look-ahead algorithm adopts a speed planning window strategy to achieve a balance between the calculation capabilities and the real-time interpolation requirements. In this window, the corner transition algorithm and speed planning are implemented simultaneously and dynamically during the interpolation. By defining the width of this window, which is actually the number of linear segments contained in this window, can adjust the time consuming of speed planning. Simulation and experiments on our own developed CNC platform are conducted. The results demonstrate the feasibility and efficiency of the proposed algorithms.

Development of a Smart Computer Numerical Control System

2013 ◽  
Author(s):  
Zhiqian Sang ◽  
Xun Xu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Machining Process ◽  
Cnc Machine ◽  
Field Bus ◽  
Nc System ◽  
Tool Paths ◽  
Cnc Controller

Traditional Computer Numerical Control (CNC) machines use ISO6983 (G/M code) for part programming. G/M code has a number of drawbacks and one of them is lack of interoperability. The Standard for the Exchange of Product for NC (STEP-NC) as a potential replacement for G/M code aims to provide a unified and interoperable data model for CNC. In a modern CNC machine tool, more and more motors, actuators and sensors are implemented and connected to the NC system, which leads to large quantity of data being transmitted. The real-time Ethernet field-bus is faster and more deterministic and can fulfill the requirement of data transmission in the high-speed and high-precision machining scenarios. It can provide more determinism on communication, openness, interoperability and reliability than a traditional field-bus. With a traditional CNC system using G/M code, when the machining is interrupted by incidents, restarting the machining process is time-consuming and highly experience-dependent. The proposed CNC controller can generate just-in-time tool paths for feature-based machining from a STEP-NC file. When machining stoppage occurs, the system can recover from stoppage incidents with minimum human intervention. This is done by generating new tool paths for the remaining machining process with or without the availability of the original cutting tool. The system uses a real-time Ethernet field-bus as the connection between the controller and the motors.

Research on Interpolation Control of 6-DOF Water Cutting Robot

2010 ◽  
Vol 455 ◽  
pp. 257-263
Author(s):  
Ming Hong Xie ◽  
W. Wang
Keyword(s):  
Real Time ◽  
Control Method ◽  
Robot Kinematics ◽  
Interpolation Algorithm ◽  
Kinematics Model ◽  
Precise Control ◽  
Robot Trajectory ◽  
Cutting Surface ◽  
The Matrix ◽  
Water Cutting

In order to get the exact water cutting of the complexity shape, the 6-DOF robot kinematics model is put forward. The gesture of every point can be calculated in real-time through NC interpolation algorithm of the expected discrete points on the track. On the basis of the matrix of position and gesture, a precise control method of 6-DOF water cutting robot trajectory and attitude of the end is proposed which comes from the improved NC-based code and could get any angle cutting surface, which is easy to program off-line. Finally, the simulation verity of NC interpolation control is made by VC and MATLAB tools.

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