Kinematic Chain Design Method of CNC Machine Tool Considering Nonlinear Error and Generalized Mode

Abstract

The invention discloses a numerical control machine tool kinematic chain design method considering a nonlinear error and a generalized modal. The method includes the steps of constructing a kinematicchain design and calculation model, with solving goals of minimizing a cumulative nonlinear error and minimizing the reciprocal of the generalized modal; generating a kinematic chain configuration population, for each kinematic chain configuration, calibrating a workpiece coordinate system, and subjecting cutter location data to the rotation transformation and the straight line transformation without travel constraints to obtain N groups of machine tool attitudes; determining whether the kinematic chain configuration matches the machine tool motion needed to realize the workpiece forming, andif not, carrying out the kinematic chain reconfiguration; calculating the generalized modal using a neural network model and calculating the cumulative nonlinear error using a differential method; andsolving the kinematic chain design and calculation model to obtain a Pareto solution set, and obtaining an optimal kinematic chain configuration by a TOPSIS method. The method of the invention overcomes the defects that a traditional kinematic chain design method relies on experience, only considers the forming characteristics of parts and has poor applicability, improves the kinematics and dynamics characteristics of a machine tool, and improves the machining accuracy of the machine tool.

Description

technical field [0001] The invention relates to the field of numerically controlled machine tools, in particular to a design method for a kinematic chain of a numerically controlled machine tool considering nonlinear errors and generalized modes. Background technique [0002] The overall scheme design of CNC machine tool guides the follow-up design work and plays a decisive role in the performance of the machine tool. The kinematic chain design is the primary work of the whole machine scheme design, while the traditional analogy and empirical design methods are bound by experience. At present, the personalization and customization of products have become a general trend in the design and manufacture of mechanical equipment. The kinematic chain of CNC machine tools obtained by analogy and empirical methods cannot meet the needs of personalized and customized processing, especially for processing such as aerospace engine impellers. Parts with complex freeform surfaces. [00...

AI Technical Summary

Problems solved by technology

When completing the same processing task, the inherent defects of some kinematic chains will cause large processing errors, low motion efficiency, large work space, singular points, and interference.

These defects can be reduced by relevant optimization algorithms in subsequent designs, but cannot be completely eliminated

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