Real-Time Particle Image Velocimetry for Feedback Loops Using FPGA Implementation

Digital Particle Image Velocimetry (PIV) is well established as a fluid dynamics measurement tool, being capable of non-intrusively and concurrently measuring a distributed velocity filed. Yet the intensive computational requirements of PIV limit its usage almost exclusively to off-line processing, analysis and modelling. This paper proposes hardware implementation of the cross-correlation algorithm as a means to make real-time PIV available for closed-loop control. This paper introduces a real-time PIV system which exploits the low-level parallelism of the cross-correlation computation by implementing it with reconfigurable hardware. The system processes 15 complete image pairs per second, which is more than 70 times speedup over a sequential software implementation. Moreover, our hardware structure can be easily expanded to a more parallel design for faster processing given sufficient hardware resources. This design can be reused with only minor modifications for different image sizes and interrogation areas.