Design and Development of Robotic System for Visual Inspection of Boiler Tube Inner Surface

In general, inspection routine at power plant industry can be significantly improved by implementing integrated inspection system of which offer various advantages in term of ease of use, reliability, safety, cost and efficiency. Our research center have developed few inspection robots namely MK-01 and LS-01 to inspect boiler header inner surface condition. The robots is specifically designed for inspection of inner surface of boiler header. However, the robots are not suitable for boiler tube inspection due to the size constraint. Later, much smaller robots with magnetic wheels namely ND-01 and ND-02 are developed for boiler tube inspection. In this paper, the design and development of integrated modular borescope guide with acquisition and localization system is presented. The modular borescope guides are able to transverse in 28 mm tube with straight, wavy or bended tube arrangement. The guides use spring as passive support and wall press element to overcome buckling effect. The user can manipulate the robot movement and visually inspect the inner tube surface via developed GUI. The embedded localisation system enable the user to pinpoint the exact location of defects inside the boiler tubes. Inspection aspects include checking for cracks, inspecting the coating layer on the inner surface, welded joints, inlet and outlet tubes etc. The testing result on comparing actual distance and distance measured by the encoder shows ± 0.9% accuracy, of which considered reasonable for the application.