Serial robot kinematics parameter calibration method based on vision

Abstract

The invention provides a serial robot kinematics parameter calibration method based on vision. The optical axis of a camera serves as virtual straight line constraint, and a kinematics error model based on straight line constraint is built; a fixed point is selected from a calibration plate fixed to the tail end of a robot to serve as a feature point, motion of a mechanical arm is controlled through a visual control method based on images, and the feature point is made to arrive at the optical axis; according to joint angular data of the robot, the forward kinematics is used for calculating the nominal position of the feature point and the alignment error matrix; and the kinematics parameter error is estimated through the iterative least squares algorithm, and the actual kinematics parameter is calculated according to the nominal kinematics parameter. According to the serial robot kinematics parameter calibration method based on vision, the optical axis of the camera serves as virtualconstraint, calibration can be completed through only the joint angular data of the robot, the cost is low, operation is easy, expensive high-precision measuring equipment is not needed, and the method has the universality for serial robot calibration and can be widely applied to industrial, space and underwater environments to improve the absolute positioning precision of the mechanical arm.

Description

technical field [0001] The invention relates to a vision-based calibrating method for kinematics parameters of serial robots, belonging to the field of robot calibrating. Background technique [0002] As robots are more and more used in tasks such as assembly, surgery, and collaboration, there are increasingly higher requirements for the positioning accuracy of the robot's end. At present, the position and attitude errors of the robot end cannot be directly measured, and are usually calculated indirectly by using kinematic models and joint angle data. Due to the influence of manufacturing tolerances, wear, transmission errors, installation position, environmental changes and other factors, there are deviations between the actual kinematic parameters in the robot model and their nominal values. If the nominal kinematic parameters are used to calculate the end pose of the robot, it will lead to The absolute localization accuracy of the end pose is reduced. In order to improv...

AI Technical Summary

Problems solved by technology

[0003] Usually, high-precision measuring equipment is used in the robot calibration algorithm to measure the actual pose of the robot end, but such measuring instruments are very expensive and the calibration process is very complicated, which requires high technical requirements for installation, debugging and measurement process

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