The dynamic digital radiography system design and data calibration method for monitoring the running aero-engine

To improve the aerodynamic performance and efficiency, monitoring the exact geometry and position information of the internal structure with the aero-engine under various operational statuses is a very important and meaningful job task. First, a dynamic digital radiography system is designed for the data acquisition in this paper. However the exposure time of each frame is limited by the rapid rotating speed of the aero-engine, which eventually leads to a high noise level and the loss of low-contrast structures in the acquired image. Therefore the average of multi-frame images, with the aero-engine under a stable operation state, is needed and a synchronization device is used to control the accelerator x-ray source in the system. Second, the body vibration of the running aero-engine often results in the blurs of the averaging image. The marker based data calibration and correction method is presented. Three steel balls are used as the markers to estimate the vibration parameters and data calibrations. The dynamic digital radiography model is built with such parameters to recover a clear image from the images of multi-frames. Finally, experiments are carried out to demonstrate the effectiveness and feasibility of the proposed system design and corresponding data calibration methods.