High-precision displacement sensor based on resonant cavities through an electronic interface based on Arduino

A novel stand-alone, high-precision, compact and cost-effective positioning sensor based on resonant cavities is described. It consists of two parts: the transducer based on radio frequency resonant cavities; and an electronic system that uses a voltage-controlled oscillator (VCO), a mixer as phase detector, and an Arduino interface to find the voltage through which the VCO operates the transducer. The resonant frequency of the device is directly related to a voltage null in the mixer output signal, in such a way that its measurement allows to deduce the correct driving signal value. This value represents the complete system displacement. Experimental tests have proven the effectiveness of the presented system in proposed displacement measurement tests performed in the range of micrometers. (C) 2019 Elsevier B.V. All rights reserved.