Method for measuring rigidity of joint J2 and joint J3 of six-axis industrial robot

The invention relates to a method for measuring the rigidity of a joint J2 and a joint J3 of a six-axis industrial robot. The method comprises the following steps: calculating a tail end load capacity of a measured robot; adjusting the robot to a specified posture; shielding the measured joint of the robot, and meanwhile, keeping the robot in a servo power-on state; mounting a robot load to meet a torque required for testing the joint rigidity, and fixing a dial indicator on the robot; mounting a hexagon socket cap screw used for positioning on the robot, and meanwhile, abutting a measuring head of a dial indicator against the tail end of the hexagon socket cap screw; starting the robot, applying different moments to the measured joint, and recording the value of the dial indicator; and drawing a hysteretic curve according to the recorded value of the dial indicator and the moment applied to the measured joint so as to calculate the joint rigidity and hysteresis loss. The joint rigidity of the industrial robo