Single-pixel imaging for a high-speed rotating object with varying rotation speed

We report a single-pixel imaging method that can capture high-quality images of a high-speed rotating object with varying rotation speed. Recently, single-pixel imaging methods for high-speed rotating objects were proposed, but the methods commonly require the object should rotate at a constant speed, which limits their practical use. Here we report an improved method that adopts synchronized rotation angle detection to ease the requirement of constant rotation speed of the target object. With the synchronized rotation angle detection, the single-pixel measurements at the same rotation angle can be extracted in the data post-processing, so that the target object and the structured patterns remain relatively motionless. We successfully demonstrate the reported method in imaging a central-process-unit cooling fan whose average rotation speed is 14,402 revolutions per minute (rpm) with a varying speed from 14,357.50 to 14,436.96 rpm. The method provides continuous and high-resolution imaging of a high-speed rotating object with a practical and robust solution. It might find various potential applications such as health monitoring of high-speed rotating machines in operation.