Application of an FFT-based algorithm to signal processing of LVDT position sensors

摘要

This paper presents a new method for signal processing of linear variable differential transformer (LVDT) position sensors. Based on a spectral estimation of the differential secondary signal, the method has been implemented using a floating-point digital signal processor (DSP) and a 14-bit analog interface circuit (AIC) to generate the primary signal and to process the primary and the secondary signals. Compared with the classic solution based on synchronous demodulation the resulting accuracy is improved. Heavy filtering is not required, except for the anti-aliasing function. The algorithm decreases the measuring time and offers diagnostic capability.