FPGA implementation of adaptive Kalman filter for industrial ultrasonic applications

Abstract

This paper achieves an FPGA system, which is specifically designed for the industrial ultrasonic application. The FPGA system contains a feedback sensing circuit module and an adaptive Kalman filter (AKF) module. Industrial ultrasonic application system can be described as a time-varying nonlinear system, which directly relates to the temperature and the pressure of objects at certain timing. The frequency controller of the FPGA circuit generates the optimal working frequency based on continuously sensing the value of feedback voltage, current and the phase difference among both. This work aims to design an FPGA filter circuit to phases detecting as well as the value of its current and voltage feedback. This paper also implements an AKF to feedbacks to prevent feedback signal noise and jitters, which are causing by electromagnetic interference of the ultrasonic circuit. In the experimental results of this work, the feedback results by AKF successfully lead the implementation of MPPT (maximal power point track, MPPT) algorithm to achieve very clean and stable feedback results on the industrial ultrasonic system.