Image-free real-time 3-D tracking of a fast-moving object using dual-pixel detection

Real-time 3-D tracking of a fast-moving object has found important applications in industry, traffic control, sports, biomedicine, defense, etc. However, it is difficult to adopt typical image-based object tracking systems in a fast-moving object tracking in real time and for a long duration, because reliable and robust image processing and analysis algorithms are often computationally exhausted, and limited storage and bandwidth can hardly fulfill the great demand of high-speed photography. Here we report an image-free 3-D tracking approach. The approach uses only two single-pixel detectors and a high-speed spatial light modulator for data acquisition. By illuminating the target moving object with six single-period Fourier basis patterns, the approach is able to analytically calculate the position of the object with the corresponding single-pixel measurements. The approach is low-cost, and data- and computation-efficient. We experimentally demonstrate that the proposed approach can detect and track a fast-moving object at a frame rate of 1666 frames per second by using a 10,000 Hz digital micromirror device. Benefiting from the wide working spectrum of single-pixel detectors, the reported approach might be applicable for hidden fast-moving object tracking.