Method for calibrating structural parameters of robot using double-ball-bar

Abstract

The present invention belongs to the field of robot structural parameter calibration, and discloses a method for calibrating structural parameters of a robot using a double-ball-bar. The method comprises the following steps: (a) mounting a calibration rod and a tool cup, and fixing a calibration baseplate and three central seats; (b) calibrating a tool coordinate system and a user coordinate system, and measuring the lengths of the sides of a triangle BCD using the double-ball-bar; (c) presetting a point A in space to form a spatial tetrahedron with the BCD, and obtaining the coordinates of point A under the user coordinate system according to the lengths of the sides of the tetrahedron; (d) obtaining vector <base>O'6-CO6-Ai through conversion of coordinates of robot joints to base coordinates; (e) measuring the lengths of the lateral sides of the tetrahedron using the double-ball-bar, and obtaining vector <base>aAi*c according to conversion of user coordinates to base coordinates; and (f) obtaining the structural parameters of the robot according to the parallelogram principle. According to the present invention, the calibration of the structural parameters of a six-degree-of-freedom articulated robot using the double-ball-bar is achieved simply and quickly, and the calibration result has high accuracy.

Description

technical field [0001] The invention belongs to the field of robot structural parameter calibration, and more specifically relates to a method for calibrating robot structural parameters by using a ballbar. Background technique [0002] The most basic function of an industrial robot is to accurately position the end effector so that it can successfully complete the set operation. A six-DOF articulated robot is an open-chain structure composed of coupled motions of adjacent links. The completion of the pose (position and attitude) of the end effector requires independent and precise control of the parameter values ​​of each joint. However, for a single robot body in a flexible manufacturing production line, there are inevitably many factors including manufacturing, maintenance, assembly errors, transmission errors, wear, and compliance. Influenced by these factors, the internally defined kinematics model in the controller cannot accurately describe the relationship between t...

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Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides a method of using a ballbar to calibrate the structural parameters of a robot. By using the ballbar and the principle of a parallelogram, it solves the problem of using a ballbar for a six-degree-of-freedom articulated industrial robot. Technical Problems of Rod Meter Calibration of Robot Structure Parameters

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