Design of inspection robot for spherical tank

• 1、School of Mechanical Engineering, Southeast University, Nanjing, 211189

Abstract：Large spherical tanks are widely used in the industry as large-capacity pressure vessels, and weld inspection is critical to the safety of their operations. Traditional manual testing has high cost, low efficiency and high degree of danger. It is of great significance to design an automated weld flaw detection system. In this paper, a wheeled wall-climbing robot capable of crawling on the outer wall of the spherical tank is designed. The Mecanum wheel trolley is used as a mobile platform for ultrasonic testing with ultrasonic testing equipment. Firstly, the key structure of the robot is introduced, and the independent suspension structure and spherical adjustment mechanism are designed. The reliability of magnetic adsorption was analyzed by static calculation, and the rationality of the structure was verified. According to the ultrasonic equipment flaw detection process, a probe fixture capable of fitting a spherical surface is designed. In the motion control of the robot, the motion model of the robot on the spherical surface is established, and the kinematic inverse solution of the robot is obtained by combining the plane motion decomposition of the Mecanum wheel to control the movement of the wall-climbing robot. Finally, the motion effect of the wall-climbing robot on the curved surface is analyzed by experiments, and the rationality and application value of the wall-detecting robot flaw detection scheme are verified.

Keywords： Climbing robot Weld inspection of spherical tank Mecanum wheel Ultrasonic inspection