Online Roundness Error Compensation for 2X/Y-type Linear Feed Axes Using Intelligent Learning Method

摘要

In order to propose a method to improve circular contour interpolation accuracy for 2X/Y gantry linear feed axes, the research of the literature focuses on circular accuracy measurement, evaluation and its error compensation of the axes. Firstly, the causes of circular contour error in interpolation process and its compensation complexity were analyzed for 2X/Y gantry feed axis driven by linear motors. Then a learning algorithm based compensation method was presented to increase the contour accuracy for this type of gantry axis. The dynamic precision measurement function of laser interferometer was utilized in acquisition of real-time interpolation error data. Recognition learning patterns for the algorithm were obtained through calculation of the data with least square roundness calculation method. A model based on least square support vector regression technique (LS-SVR) was established to recognize the error generation rules. With the support vectors after learning process, real-time error compensation values were acquired through the model regression calculation. In the end, the compensation output control strategy and corresponding realization system were also proposed to show the applicability of the method. To demonstrate the procedure of the proposed approach, an experiment was conducted on the self-construction 2X/Y axis feeding platform. The result shows that the combination technique can compensate the interpolation error and increase the roundness accuracy 68.7%.