Papers by Keyword: Cross Coupled Control

Abstract: The contour precision has been an important CNC machine accuracy index along with the increase of high precision complex parts NC machining. The error of perpendicularity and the mismatch error of position loop gains among linked axes are regarded as the prime reasons to bring about CNC machine contour error. After analyzing the influence of the error of orthogonal axes perpendicularity to CNC machine contour precision, a compensation approach is set up that the following error is corrected in each sampling period, by introducing a perpendicularity deflection parameter. After analyzing the influence of the mismatch error of position loop gains to contour precision, a cross-coupled control approach based on interpolation dots is developed to enhance the matching degree among all of the linked axes. Finally, the developed compensation approaches are testified on a CNC experiment table. The experimentation results reveal that the developed compensation approaches are effective to enhance contour precision.

Abstract: The paper focuses on cylinders synchronized control in continuum press for particleboard hot-pressing. An equal-status cross-coupled synchronized controller based on disturbance and synchronizing compensators has been designed and employed to an electro-hydraulic servo system driven by bi-cylinder. The simulations demonstrate that the controller eliminates synchronizing error faster and control two motion-units to move synchronously in a cross-coupled system than the controller with no compensator. And the robust of system has been enhanced.

Abstract: On the basis of analysis of linear contour errors model, a new strategy of independent contour error control was presented for high precision contour machining. The proposed control scheme, in which the equations of the well-known cross-coupling controller were implemented, is shown to be able to diminish the linear contour error without using any cross-feeding signals between the driving axes. The simulation results show that the proposed control scheme is effective and that better effect of the contour tracking can be obtained. As a result, the contour machining precision is improved greatly.

Abstract: The spatial contour error which exists in multi-axis machine tools is believed relative with the track-lag error existing in the single axis, the set value of feed-rate and the curvature of the contour. A spatial error model is taken for presenting a vector method to calculate the contour error in three-axis machine tool and an adaptive cross coupled controller which is based on neural network is presented. The simulation results of cross coupled control in three-axis, indicate that the contour precision can be improved effectively which exists in the machine tool, and the errors influenced by the change of curvature and the set value of feed-rate can be obviously reduced.