A universal velocity limit curve generator considering abnormal tool path geometry for CNC machine tools

The method used for measurement and calibration of machine tool errors should be general and efficient. With this method, the machine tool status can be completely identified and its accuracy can be enhanced by software error compensation. The point compensation method can be used as a means for modifying the nominal tool path and on-machine inspection where the machine tool is used as a coordinate measuring machine. The validity of the error calibration method proposed in this' paper was shown using a vertical 3-axis CNC machine with a laser interferometer and a ball bar technique.

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Global tool-path smoothing for CNC machine tools with uninterrupted acceleration

International Journal of Machine Tools and Manufacture ◽

10.1016/j.ijmachtools.2017.03.002 ◽

2017 ◽

Vol 121 ◽

pp. 81-95 ◽

Cited By ~ 33

Author(s):

Shingo Tajima ◽

Burak Sencer

Keyword(s):

Machine Tools ◽

Tool Path ◽

Cnc Machine Tools ◽

Cnc Machine ◽

Path Smoothing

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A Real-Time C3 Continuous Local Corner Smoothing and Interpolation Algorithm for CNC Machine Tools

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4042606 ◽

2019 ◽

Vol 141 (4) ◽

Cited By ~ 12

Author(s):

Qin Hu ◽

Youping Chen ◽

Xiaoliang Jin ◽

Jixiang Yang

Keyword(s):

Real Time ◽

Machine Tools ◽

Tool Path ◽

Control Period ◽

Cnc Machining ◽

Numerical Control ◽

Cnc Machine Tools ◽

Interpolation Algorithm ◽

Cnc Machine ◽

Highly Nonlinear

Linear tool path segments of computer numerical control (CNC) machine tools need to be smoothed and interpolated in order to guarantee continuous and steady machining. However, because of the highly nonlinear relation between arc lengths and spline parameters, it is difficult to develop algorithms to simultaneously achieve real-time corner smoothing and interpolation with high-order continuity, although it is important to guarantee both high calculation efficiency and good dynamic performance of high-speed CNC machining. This paper develops a computationally efficient real-time corner smoothing and interpolation algorithm with C3 continuous feature. The corners at the junction of linear segments are smoothed by inserting Pythagorean-hodograph (PH) splines under the constraints of user-defined tolerance limits. Analytical solutions of the arc length and curvature of the smoothed tool path are obtained by evaluating a polynomial function of the spline parameter. The smoothed tool path is interpolated in real time with continuous and peak-constrained jerk. Simulations and experimental results show that the proposed tool path smoothing and interpolation algorithm can be executed in real time with 0.5 ms control period. Acceleration and jerk continuity of each axis are achieved along the tool path. Comparisons with existing corner smoothing algorithms show that the proposed method has lower jerk than existing C2 algorithms and the real-time interpolation algorithms based on the Taylor series expansion.

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