Kinematics parameter calibration method and system of multi-axis motion platform

A kinematics parameter calibration method of a multi-axis motion platform, comprising the following steps of:

• calibrating intrinsic parameters of a camera;
• establishing a theoretical kinematics model of the multi-axis motion platform, establishing a kinematics error model of the multi-axis motion platform according to the theoretical kinematics model, and determining an error parameter;
• based on photos of a calibration board taken by the camera at different spatial positions, solving for a first homogeneous coordinate pose matrix of a calibration board coordinate system in a camera coordinate system using a PnP (Perspective-n-Point) algorithm and recording a first motor motion amount corresponding to the multi-axis motion platform at each spatial position;
• substituting the first motor motion amount into the theoretical kinematics model to obtain a platform pose matrix;
• based on a one-to-one relationship between the first homogeneous coordinate pose matrix and the platform pose matrix, and using a hand-eye calibration method corresponding to a type of hand-eye position relationship, calculating a hand-eye pose relation matrix and a pose matrix of the calibration board coordinate system in an end coordinate system of the multi-axis motion platform;
• wherein the types of the hand-eye position relation include an eye outside hand and an eye on hand;
• controlling the multi-axis motion platform to move to different poses, capturing images of the calibration board through the camera;
• based on the images of the calibration board, solving for a second homogeneous coordinate pose matrix of the calibration board coordinate system in the camera coordinate system using the PnP algorithm;
• obtaining a corner point coordinate matrix formed by at least three coplanar calibration board corner points in the calibration board coordinate system;
• and based on the hand-eye pose relationship matrix, the corner point coordinate matrix, and the second homogeneous coordinate pose matrix, determining coordinate measurement values of the calibration board corner points in a platform base coordinate system;
• based on second motor motion amounts in different poses, the theoretical kinematic model, the pose matrix and the corner point coordinate matrix of the calibration board in the end coordinate system of the multi-axis motion platform, determining coordinates theoretical values of an end position matrix of the multi-axis motion platform;
• and based on multiple sets of coordinate measurement values and coordinates theoretical values, determining a residual error matrix, and identifying error parameters to obtain a calibration result of the kinematic parameters of the multi-axis motion platform.