基于稳定裕度的机床轮廓控制器增益设计方法

The contour controllers were usually designed as a P controller, and the gain value was the key parameter to determine the control effectiveness. In order to design the gain values of contour controllers quantitatively, a gain design method of contour controllers was proposed based on stability margin herein. Firstly, the discrete transfer functions of each axis of the machine tool were identified by applying the least squares method. Secondly, the stability domain of the gain was calculated based on the Jury criterion and transfer functions. Finally, the objective function was constructed, and the gain values satisfying the stability margin requirements were obtained in the stability domain. A contour controller was designed on a three-axis machine tool, and a trajectory tracking experiment was carried out to verify the effectiveness of the proposed method. The experimental results show that the contour controller designed based on stability margin may reduce the maximum trajectory error of the spiral trajectory by 39.06% and the maximum trajectory error of the fan-shaped trajectory by 34.33%, under the conditions of ensuring the motion stability of the machine tools.