Fuzzy pattern recognition for PIV image analysis

Fuzzy logic analysis has been proven to be a simple and robust method for process control. In this paper the principle of fuzzy logic is applied to analyse the motion of the particles in a PIV (particle image velocimetry) image. The analysis is based on pattern recognition, and the patterns are composed of several adjacent particles. The principle of the decision making is based on the basic principles of fluid mechanics. As the particles move, the patterns change their shape and position in the second exposure, tracing the consequent matches of the corresponding patterns between two exposures the flow in a whole field will be obtained. A particle image-tracking algorithm based on this method is proposed and developed for the PIV image analysis. The pattern analysis executes in software on a PC without the use of specialised fuzzy logic processors. The objects of analysis were in both numerical simulated PIV images and an experimental PIV image. The results were encouraging.