Standard pose calibration method for six-degree-of-freedom parallel robot used for Stewart platform structure

Abstract

The invention discloses a standard pose calibration method for a six-degree-of-freedom parallel robot used for a Stewart platform structure. The method comprises the following steps: establishing a base coordinate system {O} and a motion platform coordinate system {P}; under the condition of six-degree-of-freedom parallel robot open chain organization, calibrating position coordinate vectors of Hooke hinge centers and spherical hinge centers of the parallel robot in the{O} and the {P} respectively; selecting three mark points on a motion platform and measuring local coordinates of the mark points in the motion platform coordinate system; installing an optocoupler limit switch at the push rod extending end of an electric cylinder of each supporting leg, and assembling the parallel robot to form a closed chain organization; controlling each supporting leg of the six-degree-of-freedom parallel robot to shorten slowly at a constant speed until each optocoupler limit switch is triggered and stimulates the six legs to stop moving successively, and thus the standard pose of the motion platform is generated; measuring the three mark points on the motion platform, ad calculating the standard pose of the parallel robot; and calculating the initial length of the supporting leg corresponding to the standard pose according to the standard pose. With the method, repeated positioning accuracy is high and reliability is high.

Description

technical field [0001] The invention belongs to the technical field of parallel robots, and in particular relates to a kinematic model-based six-degree-of-freedom parallel robot reference pose calibration method, which is used to guide and assist the kinematic modeling and precise control of the six-degree-of-freedom parallel robot. Background technique [0002] Six-degree-of-freedom parallel robots are widely used in systems such as motion simulation, pose adjustment, and NC machining. The reference pose of the parallel robot is the pose reference point to realize its motion accuracy. Only through the calibration of the reference pose, the motion of the parallel robot has physical meaning. In order to guide the kinematic modeling of the six-degree-of-freedom parallel robot and realize the precise motion control of the motion platform, it is very necessary to study the reference pose calibration method of the six-degree-of-freedom parallel robot. [0003] The reference pose...

AI Technical Summary

Problems solved by technology

[0009] The pose calibration methods for parallel robots proposed in the above literature all have the defects of high difficulty in implementation and low computational efficiency when determining the reference pose of a six-degree-of-freedom parallel robot.

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