Variable-parameter stiffness identification and modeling method for industrial robot

A variable-parameter stiffness identification and modeling method for an industrial robot, comprising the following steps:

• Step 1:
• within an effective working range of a given type of industrial robot, dividing a whole operating space into a series of cubic grids according to a given maximum step length;
• Step 2:
• using theoretical coordinates of eight vertices of one cubic grid divided in Step 1 and a center point of a grid space for controlling the robot for positioning, selecting at least 3 robot accessible postures in each position of the eight vertices and the center point, measuring a magnitude and direction of a load attached by a six-dimensional force sensor mounted on a flange, and using a laser tracker to measure position and posture changes of a robot end before and after loading in all positions and postures;
• Step 3:
• by collecting end loads and deformations in different positions and postures, realizing identification of robot joint stiffness satisfying an operating task of the grid space;
• and
• Step 4:
• according to the identification method in the grid space in Step 3 above, realizing the identification of joint stiffness of the series of cubic grids in the whole operating space, and establishing a stiffness model of the whole operating space.