Theory and application of a combined self-tuning adaptive control and cross-coupling control in a retrofit milling machine

In this paper, the control plant is a ball screw actuated milling machine table which has been retrofit with DC servo motor control. The retrofit milling machine has nonlinear time-varying behaviors because of the effect of irregular Coulomb friction of the sliding surface and obvious backlash. Thus, it is difficult for a conventional digital controller to provide a high contouring accuracy as well as adequate disturbance rejection and parameter variation robustness. To improve contouring performance of the retrofitted milling machine, a self-tuning adaptive control strategy, combined with cross-coupled control of axial motion is proposed. The proposed control scheme has been verified as being internally stable. Experimental results show that this control method achieves satisfactory contouring accuracy, transient response, tracking and robustness under the influence of backlash on each axis and irregular Coulomb friction. This performance verifies the applicability of this economic approach to automation of traditional milling machines.

[1]  Pau-Lo Hsu,et al.  An optimal and adaptive design of the feedforward motion controller , 1999 .

[2]  Yusuf Altintas,et al.  Sliding Mode Controller Design for High Speed Feed Drives , 2000 .

[3]  Masayoshi Tomizuka,et al.  Robust motion controller design for high-accuracy positioning systems , 1996, IEEE Trans. Ind. Electron..

[4]  Shiuh-Jer Huang,et al.  The adaptive control for retrofit traditional milling machine , 1993 .

[5]  Didier Dumur,et al.  Generalized Predictive Cascade Control (GPCC) for Machine Tools Drives , 1990 .

[6]  Masayoshi Tomizuka,et al.  Robust adaptive and repetitive digital tracking control and application to a hydraulic servo for noncircular machining , 1994 .

[7]  Chang-Huan Liu,et al.  Cross-Coupled Adaptive Feedrate Control for Multiaxis Machine Tools , 1991 .

[8]  Masayoshi Tomizuka,et al.  High-performance robust motion control of machine tools: an adaptive robust control approach and comparative experiments , 1997 .

[9]  Yusuf Altintas,et al.  High speed CNC system design. Part III: high speed tracking and contouring control of feed drives , 2001 .

[10]  Shyh-Leh Chen,et al.  Contouring control of biaxial systems based on polar coordinates , 2002 .

[11]  Manfred Weck,et al.  Sharp Corner Tracking Using the IKF Control Strategy , 1990 .

[12]  Yoram Koren,et al.  Cross-Coupled Biaxial Computer Control for Manufacturing Systems , 1980 .

[13]  K. Srinivasan,et al.  Optimal Contouring Control of Multi-Axial Feed Drive Servomechanisms , 1989 .

[14]  Graham C. Goodwin,et al.  Adaptive filtering prediction and control , 1984 .

[15]  Yoram Koren,et al.  Variable-Gain Cross-Coupling Controller for Contouring , 1991 .

[16]  Masayoshi Tomizuka,et al.  Adaptive Zero Phase Error Tracking Algorithm for Digital Control , 1987 .

[17]  Pau-Lo Hsu,et al.  Theory and Applications of the Robust Cross-Coupled Control Design , 1999 .

[18]  K. Srinivasan,et al.  Cross-Coupled Control of Biaxial Feed Drive Servomechanisms , 1990 .

[19]  W. Messner,et al.  Cancellation of Discrete Time Unstable Zeros by Feedforward Control , 1994 .

[20]  Chuang Hua-Yi,et al.  A model-referenced adaptive control strategy for improving contour accuracy of multi-axis machine tools , 1990 .

[21]  Masayoshi Tomizuka,et al.  Zero Phase Error Tracking Algorithm for Digital Control , 1987 .