Monocular vision hand-eye calibration method for rehabilitation mechanical arm based on S-R-S structure

Abstract

The invention discloses a monocular vision hand-eye calibration method for a rehabilitation mechanical arm based on an S-R-S structure. Firstly, a kinematics model of the rehabilitation mechanical armis established; then an internal reference matrix of the camera is calibrated; coordinate representation of the tail end of the rehabilitation mechanical arm and each joint rotating shaft of the basein a camera coordinate system is obtained by utilizing an arc track analysis method; a conversion matrix between the tail end and the coordinate system of the base and the coordinate system of the camera is further obtained, a conversion relation between the tail end and the target is obtained through the conversion matrix between the target and the coordinate system of the camera, the conversionmatrix between the coordinate system of the base and the coordinate system of the camera is obtained in the same way, and hand-eye calibration is achieved; according to the calibrated conversion matrix between the target and the tail end, the calibrated conversion matrix between the base and the camera and the calibrated real-time conversion matrix between the target and the camera after the rehabilitation mechanical arm rotates, a conversion matrix between a tail end coordinate system and a base coordinate system can be obtained, and pose measurement is achieved. According to the invention,the system structure of monocular measurement is simplified, and hand-eye calibration and pose measurement can be carried out at the same time.

Description

technical field [0001] The invention belongs to the technical field of mobile robot positioning and monocular vision measurement, and in particular relates to a monocular vision hand-eye calibration method of a rehabilitation manipulator based on an S-R-S structure. Background technique [0002] Accurate measurement of the pose of the end of the manipulator is a key issue in robot localization technology. Vision sensors have attracted widespread attention because of their low price and ease of use. Positioning methods based on vision sensors have always been a research hotspot. Depending on the number of sensors, visual positioning methods can be divided into monocular vision positioning, binocular vision (stereo vision) positioning and multi-eye vision (omnidirectional vision) positioning. Monocular vision positioning only needs one camera to complete the positioning work. It is easy to use and widely applicable. It does not need to solve the calibration and matching of fe...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem that the calculation process of the hand-eye calibration method in the prior art is complicated, the present invention proposes a monocular vision hand-eye calibration method for a rehabilitation manipulator based on the S-R-S structure; this method does not need to solve complex nonlinear equations, and does not need to provide All 28 DH parameters, only need to provide d 1 and d 7 Parameters, the specific technical scheme is as follows:

Images