Calibration method for relative positions of three-dimensional sensor and mechanical arm

Abstract

The invention discloses calibration methods for relative positions of a three-dimensional sensor and a mechanical arm. A method comprises the steps of S1, moving the mechanical arm, thereby enabling aflange plate at a tail end of the mechanical arm to face the three-dimensional sensor, recording point cloud information obtained by the three-dimensional sensor at this time, extracting at least onefeature point of the flange plate through utilization of a three-dimensional vision algorithm, and obtaining a three-dimensional coordinate value of the feature point relative to a three-dimensionalsensor coordinate system; S2, for the extracted feature point, obtaining the three-dimensional coordinate value of the feature point relative to a mechanical arm base coordinate system; S3, repeatingthe S1 and S2, extracting a plurality of non-coplanar feature points, obtaining a plurality of groups of three-dimensional coordinate values of each feature point relative to the three-dimensional sensor coordinate system and the mechanical arm base coordinate system, and computing the optimum hand and eye conversion matrix. According to the methods, through adoption of geometrical features of theflange plate at the tail end of an existing mechanical arm, the problem of selecting calibration points is solved, a mark point does not need to be installed in calibration, a calibration process isremarkably simplified, and calibration cost is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of a hand-eye calibration method for a robotic arm, in particular to a calibration method for the relative positions of a three-dimensional sensor and a robotic arm. Background technique [0002] With the development of Industry 4.0, more and more industrial application scenarios use high-precision robotic arms to replace manual work, such as multi-joint robotic arms and rectangular coordinate system robotic arms. Usually, the robotic arm needs to cooperate with different end effectors to complete specific tasks. The robotic arm referred to in this article does not include the end effector. In recent years, the rapid development and application of high-precision three-dimensional sensors have also made the application of robotic arms no longer limited to a single structured industrial scene and simple repetitive operations. The high-precision point cloud information collected by the 3D sensor contains the s...

AI Technical Summary

Problems solved by technology

Therefore, the end of the robotic arm as a whole cannot be directly used as a landmark for hand-eye calibration

Moreover, the existing hand-eye calibration method cannot provide real-time feedback on the calibration accuracy and automatically adjust the calibration process

The number of feature points that need to be obtained for hand-eye calibration usually needs to be solved by engineering experience, human intervention and a large number of points. The hand-eye calibration process is time-consuming and labor-intensive, especially affecting the efficiency of large-scale robot applications.

Images