A Contour Error Estimation Method Based on h-Type Precision Motion Platform

Abstract

The invention belongs to the technical field of precision and high-efficiency numerical control machining, and can effectively improve the accuracy of contour error estimation for free curves with different curvature changes, thereby reducing contour errors generated during contour tracking motion. It includes the following steps: Step 1: Calculate any reference point R on the desired machining contour of the H-type precision motion platform 1 Curvature ρ and curvature radius r at (t); Step 2: Calculate any reference point R on the expected machining contour of the H-type precision motion platform 1 (t) place tangent line and X-axis angle α; Step 3: calculate the circle center coordinate (O of the inscribed circle according to geometric relationship x o y ); Step 4: Use the area of ​​the triangle to calculate the central angle β and its corresponding arc length l; Step 5: Calculate R with the arc length l 2 (t) to R 1 (t) the motion time Δt; Step 6: use the second-order Taylor series expansion to calculate R 2 (t) coordinates (R 2x R 2y ); Step 7: Calculate the estimated contour error E of any trajectory by using the area of ​​the triangle c .

Description

Technical field[0001]The present invention belongs to the field of precision and efficient numerical control processing, and it is related to a contour error estimation method based on an H-type precision motion platform.Background technique[0002]In modern CNC machine tools, the contour tracking movement of the multi-axis servo system is an important application and is widely used in various types of processing. Therefore, how to reduce the error in the process of contour tracking motion, which is currently used for the indicator of the contour tracking accuracy to track the error and contour error, where the tracking error is defined as the distance from the expected location point to the actual location point; The error is defined as the shortest distance from the actual location point to the entire desired track, so the contour error is an important basis for judging the processed profile deviation from the desired trajectory.[0003]The method of estimating the contour error, more...

AI Technical Summary

Problems solved by technology

When the distance from the actual position point to the approximate contour error occurrence point is used as the estimated value, if the desired contour is a free curve, the approximate trajectory will deviate from the actual command trajectory, resulting in inaccurate approximate contour error occurrence points and increasing the estimation error

However, the iterative comparison method takes a long time to calculate. If you want to obtain a more accurate contour error, the number of iterations and the time used may exceed the load of the contour tracking system. less suitable for contour-following motion control with compensation

Images