Apparatus and method for measuring RPM of fan by using IR-UWB radar
AssigneeIucf-Hyu (Industry-University Cooperation Foundation Hanyang University)
InventorsSung Ho Cho, Dae Hyeon Yim, Seong Kwon Yoon
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Abstract
An apparatus and method are provided for non-contact measurement of fan RPM using an IR-UWB radar. A reflected radar signal is processed to obtain variance values for each position, from which a first position closest to the radar and a second position furthest from the radar are determined. Fast Fourier transform (FFT) calculations are performed on the reflected signals corresponding to the first and second positions, and the second FFT signal is subtracted from the first FFT signal to determine the RPM of the fan. This approach enables accurate RPM measurement without reliance on lighting conditions or additional markers, providing high reliability across different fan and radar arrangements.
Claims3
A method for dynamically adjusting radar signal processing to accurately measure revolutions per minute (RPM) of a fan in a multipath environment using an impulse radio ultra-wideband (IR-UWB) radar, the method being performed by a computing device including a processor and a memory, the method comprising:
- transmitting ultra-wideband radar signals by the IR-UWB radar to the fan,
- receiving reflected signals of the IR-UWB radar resulting from reflection of the transmitted ultra-wideband radar signals from the fan,
- processing the reflected signals by the processor
- to acquire a variance of the reflected signals at each of a plurality of positions, the variance representing a change in amplitudes of the reflected signals classified at each position which corresponds to an arrival time duration of each reflected signal;
- determining candidate positions having a variance equal to or greater than a position-specific predetermined boundary value that is adaptively updated based on local noise power around each specific position among the variance of the reflected signals;
- selecting, from among the candidate positions, the closest position to the IR-UWB radar as a first position and a furthest position from the IR-UWB radar as a second position;
- performing a first fast Fourier transform (FFT) calculation on the reflected signals of the IR-UWB radar corresponding to the first position to acquire a first FFT signal, and performing a second FFT calculation on the reflected signals of the IR-UWB radar corresponding to the second position to acquire a second FFT signal;
- reducing environmental effects in the first FFT signal by subtracting the second FFT signal from the first FFT signal to obtain a filtered subtracted signal;
- and
- determining the RPM of the fan by using the subtracted signal.
An apparatus for dynamically adjusting radar signal processing to accurately measure revolutions per minute (RPM) of a fan in a multipath environment using an impulse radio ultra-wideband (IR-UWB) radar, the apparatus comprising:
- a processor;
- and
- a memory electrically coupled to the processor,
- wherein the processor is configured to:
- receive reflected signals of the IR-UWB radar to acquire a variance of the reflected signals at each of a plurality of positions, the variance representing a change in amplitudes of the reflected signals classified at each position which corresponds to an arrival time duration of each reflected signal;
- determine candidate positions having a variance equal to or greater than a position-specific predetermined boundary value that is adaptively updated based on local noise power around each specific position among the variance of the reflected signals;
- select, from among the candidate positions, the closest position to the IR-UWB radar as a first position, and a furthest position from the IR-UWB radar as a second position;
- perform a first fast Fourier transform (FFT) calculation on the reflected signals of the IR-UWB radar corresponding to the first position to acquire a first FFT signal, and perform a second FFT calculation on the reflected signals of the IR-UWB radar corresponding to the second position to acquire a second FFT signal;
- reduce environmental effects by subtracting the second FFT signal from the first FFT signal to obtain a filtered subtracted signal;
- and determine the RPM of the fan by using the subtracted signal.
Dependencies are inferred from the claim text.