Method and system to quickly determine a weight
A method for determining the weight of an entity/item to be weighed on a weighing device ( 1 ), the weighing device comprising at least a weight sensor and a control unit ( 4 ), the method comprising the following steps: /a/ collecting weight raw samples (WSi) of the total weight sensed at the weight sensor(s), at a sampling frequency (F 0 ), and converting each of the weight raw samples (WSi) into digitalized weight raw samples (DSi), /b/ entering sequentially each of the digitalized weight raw samples (DSi) into a Butterworth filter, the latter issuing filtered weight samples (FSi), /c/ defining a rolling window (RW) containing a parametrized number NS of latest filtered weight samples (FSi), /d1/ determining, in the rolling window, the minimum (MIN) and maximum (MAX) values of filtered weight samples, /d2/ comparing the value of MAX−MIN with regard to a parametrized Threshold (T), /e/ if MAX−MIN is greater than Threshold (T), repeat steps /a/ to /d2/, and as soon as MAX−MIN is less than Threshold (T), output a final weight value (DV), obtained from one or more of the most recent filtered weight samples.
1. A weighing device, formed as a bathroom scale or a baby scale, comprising at least a weight sensor and a control unit, the control unit being configured to:
/a/ collect weight raw samples (WSi) of the total weight sensed at the load cells, at a sampling frequency (F 0 ), and converting each of the weight raw samples (WSi) into digitalized weight raw samples (DSi),
/b/ enter sequentially each of the digitalized weight raw samples (DSi) into a Butterworth filter, the latter issuing filtered weight samples (FSi),
/c/ define a rolling window (RW) containing the last NS filtered weight samples (FSi), NS being a parametrized number,
/d1/ determine, in the rolling window, the minimum (MIN) and maximum (MAX) values of filtered weight samples,
/d2/ compare the value of MAX-MIN with regard to a parametrized Threshold (T),
/e/ and as soon as MAX-MIN is less than Threshold (T), output a final weight value (DV), obtained from one or more of the most recent filtered weight samples.
2. The device of claim 1 , further comprising the at least weight sensor is formed as a plurality of load cells and further comprising a display.
3. The device of claim 1 , further comprising an impedance sensor.
4. A system comprising a device as defined in claim 1 , and further comprising a smartphone ( 9 ) configured to display data and weight histograms.
5. A method for determining the weight of an entity/item to be weighed on a weighing device ( 1 ), the weighing device comprising at least a weight sensor and a control unit ( 4 ),
the method comprising the following steps:
/a/ collecting weight raw samples (WSi) of the total weight sensed at the weight sensor(s), at a sampling frequency (F 0 ), and converting each of the weight raw samples (WSi) into digitalized weight raw samples (DSi),
/b/ entering sequentially each of the digitalized weight raw samples (DSi) into a Butterworth filter, the latter issuing filtered weight samples (FSi),
/c/ defining a rolling window (RW) containing a parametrized number NS of latest filtered weight samples (FSi),
/d1/ determining, in the rolling window, the minimum (MIN) and maximum (MAX) values of filtered weight samples,
/d2/ comparing the value of MAX−MIN with regard to a parametrized Threshold (T),
/e/ if MAX−MIN is greater than Threshold (T), repeat steps /a/ to /d2/, and as soon as MAX−MIN is less than Threshold (T), output a final weight value (DV), obtained from one or more of the most recent filtered weight samples.
6. The method of claim 5 , wherein the entity/item is a human individual standing or lying on the weighing device, and wherein at step /e/ the final weight value (DV) is displayed on a display.
7. The method of claim 6 , wherein the Butterworth filter is a second order Butterworth filter.
8. The method of claim 6 , wherein the sampling frequency (F 0 ) is comprised between 20 Hz and 500 Hz.
9. The method of claim 6 , wherein the number NS is less than 100.
10. The method of claim 6 , wherein the parametrized Threshold (T) is predefined and comprised between 100 g and 200 g.
11. The method of claim 6 , wherein the parametrized Threshold (T) is set according to the weight range.
12. The method of claim 5 , wherein the outputted final weight value (DV) is equal to the average of the NS most recent filtered weight sample.
13. The method of claim 5 , wherein all the steps are performed subsequently at the sampling frequency (F 0 ).