High precision real-time contour error estimation method

A contour error, high-precision technology, applied in the direction of instruments, digital control, control/regulation systems, etc., can solve the problem of low estimation accuracy

CN106125674AActive Publication Date: 2016-11-16DALIAN UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-11-16

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Abstract

The invention relates to a high precision real-time contour error estimation method, belongs to the precise high efficiency numerical control processing technology field and particularly relates to the high precision real-time contour error estimation method on the basis of an initial value regeneration Newton iterative method in a numerical control parameter curve interpolation processing process. The method comprises steps that firstly, before each step of iterative calculation, according to present interpolation point parameters and actual cutter location points, an iteration parameter initial value on a parameter curve for Newton iterative calculation perpendicular foot points is calculated on the basis of a first order Taylor series expansion method; secondly, a Newton iterative method is utilized, a single step iteration parameter final value is calculated according to the iteration initial value; thirdly, for avoiding greatly increasing the algorithm calculation time, iteration is ended through double constraints of an iteration termination condition and a largest iteration frequency condition, a perpendicular foot point parameter estimate is acquired, and a contour error vector estimate is further calculated. Through the method, iteration divergence can be effectively avoided, contour error estimation precision is improved, and the method has great signification for guaranteeing contour control precision during parameter curve interpolation processing.
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Description

technical field

[0001] The invention belongs to the technical field of precision and high-efficiency numerical control machining, and in particular relates to a high-precision real-time contour error estimation method based on an initial value regeneration Newton iteration method in the process of numerical control parameter curve interpolation. Background technique

[0002] With the rapid development of major engineering fields such as aerospace, energy and power, the requirements for the machining accuracy of CNC machine tools for processing complex curved surface parts are constantly increasing. Due to the existence of factors such as servo hysteresis, nonlinear links, external disturbances, and dynamic characteristic mismatches in the CNC system, deviations between the actual machining trajectory and the ideal contour often occur, affecting machining accuracy. Therefore, it is the key to ensure the machining accuracy of CNC machine tools to consider the multi-axis coupli...

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Embodiment Construction

[0033] The specific implementation manner of the present invention will be described in detail in conjunction with the technical scheme and the accompanying drawings.

[0034] Due to servo lag and external disturbances in the CNC system, it will cause a large machining trajectory contour error. In the process of direct interpolation of the parameter curve, the ideal machining contour is a free curve, which is difficult to calculate the contour error in real time and with high precision, which limits the contour control. Effect. Accordingly, a real-time high-precision contour error estimation method based on initial value regenerative Newton iteration is invented, with figure 1 Flow chart of the estimation method.

[0035] attached figure 2 The geometric model diagram of the "inverted eight" shaped tool path is attached figure 2 The shown "inverted eight" shaped non-uniform rational B-spline tool path profile is an example, and the specific implementation process of the pr...