An Evolution Strategy for Improving the Design of Phased Array Transducers

Continuum Probe Designertrade by Acoustic Ideas Inc. is a tool that can help design an optimized phased array ultrasonic transducer for a given inspection task. One component of Continuum Probe Designertrade can calculate the cost of a probe for a given geometry, and the fmincon function in the MATLABreg optimization toolbox has been used to find the optimal probe geometry. However, the search space of probe geometries is very noisy, and the inconsistent performance of fmincon in this noisy search space has interfered with the deployment of Continuum Probe Designertrade as a commercial product. An evolution strategy has been developed that includes "smart" start points and coordinated parallel runs. Compared to fmincon, the developed evolution strategy finds solutions that require an average of 61.4% fewer elements. Since control instrumentation can only handle a limited number of independent channels, the evolution strategy designs are also more than five times more likely to be implementable. These improvements that have been achieved by the evolution strategy will play an important role in the commercial deployment of Continuum Probe Designertrade.