Method for Avoiding Singular Points in Five-Axis Machining Tool Trajectory

Abstract

The invention discloses a method for avoiding singular points of a five-axis machining tool feeding track, which aims at solving the technical problem of low machining accuracy in the existing method for avoiding the singular points of the five-axis machining tool feeding track. The method adopts the technical scheme with the following steps of using a quaternion to express a conversion relationship between the tool axis direction and the reference direction, and projecting the quaternion onto a P plane, wherein a singular cone in the P plane corresponds to a singular circle with center of circle at the origin point; using a B spline to interpolate a projecting point in a two-dimensional plane; establishing a constraint optimization problem again, wherein a target function is a sum of squares of increments of control top points, the constraint is the distance between the point of the B spline to the origin point in the P plane to be greater than the radius of the singular circle, and an initial value of the control top point is the control top point of the B spline obtained by interpolation; linearly expressing the constraint of the constraint optimization problem by the increment of the control top point of the B spline, and using a quadratic programming theory to solve an optimal solution of the optimizing problem. The method has the advantage that the common constraint optimization problem is converted into the quadratic programming problem, so that the processing accuracy is guaranteed.

Description

technical field [0001] The invention belongs to the field of numerical control machining, and in particular relates to a method for avoiding the singular point of the five-axis machining tool path. Background technique [0002] Document 1 "A.Affouard, E.Duc, C.Lartigue, J.M.Langeron, P.Bourdet, Avoiding 5-axis singularities using tool path deformation, International Journal of Machine Tools and Manufacture 44 (2004) 415-425." discloses a A singular point avoidance method for five-axis CNC machine tools suitable for dual B-spline paths, which proposes to use the concept of "singular cone" to replace the concept of singular point, and at the same time avoid the direction of the tool axis from entering the "singular cone" by modifying the control vertices of B-spline ". However, this tool path deformation cannot guarantee the minimum machining error caused by the tool path deformation. [0003] Document 2 "J.X.Yang, Y.Altintas, Generalized kinematics of five-axis serialmachin...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the shortcomings of the existing five-axis machining tool path singular point avoidance method with low machining accuracy, the present invention provides a five-axis machining tool path singular point avoidance method

Therefore, the present invention can ensure that the deformation of the path obtained after avoiding the singular point is the smallest, and the processing error caused by the path deformation is the smallest, which solves the problem of large processing accuracy loss caused by the existing singular point avoiding method

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