Visual Measurement of Levitation Gap in Maglev Ball System Based on Pixel Area

The levitation control system is a key part of maglev train. The measurement of levitation gap plays an important role in the suspension system. Traditional gap sensors have some disadvantages such as high power supply voltage, temperature influence and measurement distance limitation. In this paper, a method is designed on visual measurement of levitation gap. The maglev ball system is taken as the research object. We first obtain the original high-definition images of the ROI(region of interest) in the levitation gap. Then, the pixel area in the ROI of levitation gap is obtained by calculating the number of pixel points whose results are “1” in the binarization image. Finally, the pixel area is calibrated with the actual gap distance and the actual gap distance is calculated. This method calculates the actual gap according to the image pixel area in the ROI of levitation gap. It has high measuring accuracy and strong anti-interference ability, which could effectively remove the asymmetric interference in the ROI of levitation gap, locating and alarming the interfered fault position.