Kinematics calibration method and system for flexible robot

Abstract

The invention discloses a kinematics calibration method and system for a flexible robot. The method comprises: obtaining the nominal position and posture of a linkage joint segment under zero linkageangle error according to the nominal joint angle of the linkage joint segment; driving the linkage joint segment to reach the nominal rope length of the linkage joint segment by using a parameter decoupling driving structure, obtaining the actual position and posture of the linkage joint segment, finally, obtaining the linkage angle error of the linkage joint segment according to the nominal position and posture of the linkage joint segment and the actual position and posture of the linkage joint segment; and obtaining the linkage angle error of the robot according to the linkage angle errorsof multiple linkage joint segments. The technical problem that the kinematics error parameters of the existing wire drive flexible robot are numerous, strong coupling between the parameters due to theseries-parallel structure, and the parameter calibration precision is low are overcome, and the calibration precision of the robot is improved.

Description

technical field [0001] The invention relates to the field of robots, in particular to a kinematics calibration method and system for a flexible robot. Background technique [0002] At present, the existing flexible robot with 2m degree of freedom is composed of m joint segments connected in series, and each joint segment is driven by more than 3 ropes, with motor position sensors and rope tension sensors. refer to figure 1 , figure 1 is a schematic diagram of a joint segment of an existing flexible robot; figure 1 In , the driving connection of a linkage joint segment is illustrated. The joint segment is driven by three driving cables, and the sub-joints of the joint segment form a series-parallel structure through the driving rope and the linkage cable. Compared with traditional manipulators, soft robots have a slender torso and redundant degrees of freedom. They show strong flexibility in complex and multi-obstacle environments. Therefore, they are widely used in the ma...

AI Technical Summary

Problems solved by technology

These errors are accumulated and amplified by multiple joints, which eventually lead to large errors at the end

[0004] (2) The limited space at the joints and the special rope driving method lead to the fact that the sensors are mainly concentrated at the root of the robot, and cannot directly feed back the angle of the joints, and there is an error in the joint angles

[0005] (3) The driving rope has a certain degree of elasticity. After repeated use, the driving rope of the flexible robot will become longer, which in turn will affect the angle of the joint, resulting in an error at the end

However, since the rope-driven flexible robot belongs to the series-parallel robot, its kinematic parameters are numerous and the parameters show a strong coupling effect on each other, resulting in the inconsistency between the kinematic parameter error of each kinematics and the position and attitude error of the end. Linear relationship, traditional model-based calibration methods are difficult to apply directly

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