An Improved Radar Echo Signal Processing Algorithm for Industrial Liquid Level Measurement

In this article, based on the study of Linear Frequency Modulated Continuous Wave (LFMCW) radar, a ranging algorithm for high-precision liquid level measurement in the industry is proposed. A new algorithm is developed based on the MacLeod algorithm. The frequency offset
$\delta _{0}$
is estimated, and then (
$\delta _{0}-q$
,
$\delta _{0}+q)$
is used as the iterative estimation initial iteration interval to determine the frequency offset
$\delta _{0}$
more precisely. The improved algorithm is the Golden–MacLeod algorithm, referred to as the GM algorithm. Simulation results show that the GM can effectively reduce the estimation error and maintain the high-frequency estimation accuracy at a signal-to-noise ratio (SNR) of up to −10 dB, which is better than the MacLeod algorithm. In addition, the estimation accuracy, stability, and noise immunity are better than other algorithms in the variation interval of SNR greater than −5 dB. The liquid level measurement experiment is tested by Texas Instruments (TI’s) IWR 6843ISK and DCA1000EVM. The measurement results also show that the measurement accuracy of the GM can meet the requirements of industrial applications. This also proves the reliability of the GM in practical applications.