Control method for reducing contour error of multi-axis motion system

Abstract

The invention discloses a control method for reducing contour errors of a multi-axis motion system. The method comprises: on the basis of a traditional single-motor position, speed and current three-closed-loop cascade control structure, using the contour error and the tracking error of the multi-axis motion system as the control target of the multi-axis motion system; modeling a multi-axis motionsystem and a corresponding power converter through a prediction model; designing an overall position-current prediction controller by adopting a model prediction method; obtaining the control quantity at the current moment by the aid of the multi-axis motion system position loop, observing the disturbance condition of the multi-axis motion system position loop by the aid of the extended state observer, optimizing the control quantity according to the disturbance condition, thereby reducing contour errors of the multi-axis motion system, estimation is performed before elimination, and overallcontrol precision is improved. According to the control method for reducing the contour error of the multi-axis motion system, the control structure is simplified, the position synchronization effectbetween the multi-axis motion systems is good, and good contour tracking performance is obtained.

Description

technical field [0001] The invention relates to a contour error of a multi-axis motion system. In particular, it relates to a control method for reducing the contour error of a multi-axis motion system. Background technique [0002] In low-power occasions such as CNC machine tool contour processing and robots, permanent magnet synchronous motor AC servo systems have been widely used due to their high precision and fast response. In the cutting process, the quality of the synchronization performance between the axes directly determines the quality of the product, so the control goal is to maintain better synchronization performance between the multi-axis motion systems and reduce the contour error of the system. [0003] However, due to factors such as the mismatch of position loop parameters, the complexity of the nonlinear contour, and external interference, the motion of the drive shaft is uncoordinated, resulting in a large error in the contour of the system, which canno...

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Problems solved by technology

However, these methods do not take into account the dependence of the model predictive control algorithm on the system model, and the inaccurate system model will inevitably affect the accuracy of the system

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