A method of rtcp parameter calibration of five-axis machine tool based on r-test

Abstract

A five -axis machine tool RTCP parameter calibration method based on R‑Test first defines the error item that affects the RTCP parameter. The machine tool coordinate system is used as a reference.The A -axis control point is compared to the two displacement errors of the bed in the direction of the Y -axis and the direction of the Z axis. Define the two displacement errors of the fifth axis C -axis control point in the X -axis direction and the Y -axis direction.The R‑Test measuring instrument, which measures and calculates the error component of the A -axis control point in the direction of the Y axis and the direction of the Z axis; then based on the R‑Test measuring instrument, the C -axis control point is relative to the A shaft in the A shaft inThe error component of the X -axis direction and the Y -axis direction is measured and calculated; the RTCP parameter calculation is finally performed to obtain the coordinates of the A and C axis control points, and the RTCP parameter error is obtained according to the RTCP definition;, Accurate and simple advantage.

Description

technical field [0001] The invention belongs to the technical field of five-axis numerical control machine tools, in particular to an R-test-based RTCP parameter calibration method for a five-axis machine tool. technical background [0002] Five-axis CNC machine tools are used for the processing of complex surface parts such as aerospace structural parts, engine impellers and ship propellers, and are key equipment supporting aerospace, marine, automotive and energy engineering fields. Reducing the error of the five-axis machine tool and ensuring the machining error of the parts has always been the appeal of the five-axis CNC machine tool processing field. [0003] The RTCP function of the five-axis machine tool is to automatically compensate the linear axis coordinate change caused by the rotation of the rotary axis. The RTCP parameter is the vector from the control point of the fourth axis to the control point of the fifth axis of the five-axis machine tool. The RTCP parame...

AI Technical Summary

Problems solved by technology

[0003] The RTCP function of the five-axis machine tool is to automatically compensate the coordinate change of the linear axis caused by the rotation of the rotary axis. The RTCP parameter is the vector from the fourth-axis control point to the fifth-axis control point of the five-axis machine tool. The RTCP parameter directly acts on the interpolation command generation process. Affect the calculation accuracy of the linear axis interpolation command, resulting in part contour error

This method mainly has the following shortcomings: 1) It is difficult to predict the degree of tightness of the ball head against the block each time, which will affect the measurement results; 2) The coordinate value of the numerical control system is used for calculation, and the calculation accuracy is affected by the spatial accuracy of the linear axis of the numerical control system ;3) The amount of measurement data is small, and the measurement results are difficult to represent the average level of the entire journey, and the method is inefficient and the process is cumbersome; 4) The measurement method and measurement process are not universal

This method has the following problems: 1) Only the AK1 motion trajectory is used to calculate and compensate the structural parameters of the A-axis, while the RTCP parameters have components in three directions, the measurement results are incomplete, and the complete RTCP parameters cannot be compensated; 2) the acquisition The tool nose point error sequence is a comprehensive error item, which not only includes the structural error of the rotary axis of the machine tool, but the accuracy of the measurement results needs to be further improved

[0006] In summary, the existing technology has disadvantages such as cumbersome operation, low degree of automation, low efficiency, lack of versatility, and need to further improve accuracy. At present, there is an urgent need for a five-axis machine tool RTCP with good versatility, high efficiency, accuracy and simplicity. Parameter Calibration Method

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