Robot NURBS track interpolation method

Abstract

The invention discloses a robot NURBS track interpolation method. The method comprises the following steps: 1) obtaining three-dimensional coordinates and a rotation vector of a data point by using arobot; 2) fitting the data points by utilizing a cubic B spline curve to generate a track c (u); 3) sampling the parameter c (u) to obtain an arc length parameter corresponding to discrete point calculation; 4) generating a u-s model by utilizing quintic polynomial fitting; 5) performing T-shaped speed planning on the tool path to obtain an arc length parameter of an interpolation point; 6) obtaining discrete points corresponding to the B spline track according to the u-s model; and 7) performing quaternion spherical interpolation between two adjacent rotation vectors in sequence by utilizingthe arc length parameter to obtain a rotation vector corresponding to the B spline curve discrete point. The G2 continuous speed and acceleration of the cubic B-spline track are continuous; the u ands mapping relationship is established to improve the real-time interpolation calculation efficiency; and the T-shaped speed planning response is quick, simple and controlled.

Description

technical field [0001] The invention relates to the technical fields of computer-aided manufacturing and robot processing, and more specifically, relates to a robot NURBS trajectory interpolation method. Background technique [0002] The machining accuracy of the robot is closely related to the acceleration and deceleration motion control and interpolation algorithm. At present, the trajectory of robot processing is usually expressed by small line segments. The trajectory represented by small line segments has a large number of shortcomings, such as frequent acceleration and deceleration of the system, which reduces the processing accuracy and surface quality of parts. Aiming at the defects of robot trajectory represented by small line segment, NURBS curve is applied in robot trajectory fitting. [0003] Traditional robot systems only have linear interpolation and circular interpolation functions, and do not support direct interpolation of NURBS curves. NURBS interpolation...

AI Technical Summary

Problems solved by technology

NURBS interpolation uses the NURBS curve as the trajectory to interpolate it. Since the parameters of the NURBS curve have no obvious geometric meaning, and there is no analytical expression for the calculation of the arc length, the calculation amount is large and the speed is difficult to control during NURBS interpolation.

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