Lead-Free Piezoelectric Ultrasonic Transducer and Its Application in Car Reversing Aid System

摘要

Lead zirconate titanate (PZT) and related composites have dominated the application of high performance piezoelectric actuators and transducers owing to their superior dielectric, piezoelectric properties, and electromeohanical coupling coefficients. However, PZT contains more than 60 weight percent lead, which is toxic to environment. The paper is dedicated to develop a lead-free ultrasonic transducer used for car reversing aid system. We have developed a leadfree ultrasonic transducer with BaTiO3-based piezoelectric ceramic, and then an excellent signal processing circuit is designed to match the new transducer. The lead-free ultrasonic ranging system is tested and shows a good performance with a measuring range larger than 200 cm and an absolute error within 2 cm.