Design of a Piezoelectric Speaker Driver Based on Fuzzy Theory and Taguchi Method

This paper investigates a new flat-panel type ceramic piezoelectric speaker. The proposed speaker offers a simple configuration compared to a conventional magnetic speaker. Piezoelectric materials can convert electrical energy into mechanical energy through a direct piezoelectric effect. The frequency and voltage signal captured by the output of the speaker driver are sampled. Those signals are sent to a fuzzy controller to regulate the value of a digital potentiometer. The output voltage gain of the piezoelectric speaker driver can be determined by the digital potentiometer value. Finally, this regulated voltage is sent to the piezoelectric speaker to improve low frequency response. The fuzzy controller membership function parameters are tuned using the Taguchi method to achieve the optimal design for low fundamental frequency and high acoustic output. The resulting design is then implemented and evaluated by experimentation.