Development of Magnetic Flux Leakage Robot for Large-Sized Tanks Bottom Floor

This study develops a wheeled robot with magnetic flux leakage testing device. This testing robot is designed to detect the corrosion-oriented defects on the bottom plates of large-sized tanks at petrochemical plants. A Hall-effect encoder is used to achieve the function of location detection. Besides, the magnetization device consists of NdFeB permanent magnets and silicon steel sheets, with the detection probe adopting Hall magnetic sensor. Experimental results show that the magnetic flux leakage testing device is highly reliable as it can accurately detect defects sized 2 mm and being 4 mm deep on the surface of a S20C steel plate being 10 mm thick. Besides, with a S20C steel plate being 5 mm thick, the device can detect defects sized 2 mm and being 2 mm deep on the front and reverse sides.