Error-controllable four-axis industrial robot B-spline transition type smooth trajectory generating method

Abstract

The invention discloses an error-controllable four-axis industrial robot B-spline transition type smooth trajectory generating method which comprises the following steps of step1, pretreatment of a fourth-axis industrial robot trajectory: the trajectory is divided into a trajectory segment requiring smoothness and a trajectory segment without requiring the smoothness, and pretreatment is performedon a four-axis attitude to ensure an inferior arc trajectory between two trajectory points; and step 2, smoothing of a four-axis trajectory B-spline: the trajectory segment, requiring the smoothness,generated in the step 1 is traversed, and a geometric iteration method is adopted to generate a B-spline transition type smooth trajectory according to a trajectory point error threshold value, a position point chord height error threshold value and the continuity requirement for each trajectory segment. The B-spline transition type smooth trajectory is composed of a linear trajectory and a B-spline trajectory, and the whole trajectory has the G1 or G2 continuity with synchronization of a position and a posture, and a position chord height error between the trajectory point error and each trajectory point is satisfied; and in addition, trajectory smoothing of complex application of a four-axis industrial robot can be realized by adopting a spline trajectory, so that the operation efficiency and the quality of the four-axis industrial robot are improved.

Description

technical field [0001] The invention belongs to the field of trajectory optimization of industrial robots, and in particular relates to a method for generating a B-spline transitional smooth trajectory of a four-axis industrial robot with controllable errors. Background technique [0002] Four-axis industrial robots, also known as planar joint (SCARA) robots, have three rotation axes and one translation axis, and are widely used in operations such as handling, assembly and gluing. [0003] Most of the motion commands of four-axis industrial robots are consistent with those of six-axis industrial robots, including linear commands, arc commands and axis joint motion commands. At the same time, each command can specify accurate to point or smooth transition. Accurate-to-point commands can meet the trajectory accuracy requirements, but the speed must be reduced to zero when reaching the trajectory point, resulting in a reduction in work efficiency; smooth transition can be made...

AI Technical Summary

Problems solved by technology

[0006] In the trajectory (position and posture, referred to as pose) expression of the existing four-axis industrial robot, it does not have the ability to simultaneously satisfy high continuity (position and posture synchronous continuity) and high precision (satisfy the error of the trajectory point and the position chord height between the trajectory points) error) smooth trajectory expression

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