Table 4 Calculation of variables from the sensor axis records.
From: Modern livestock farming under tropical conditions using sensors in grazing systems
Variable | Equation |
|---|---|
SMAa | \(\left|{X}_{i}\right|+\left|{Y}_{i}\right|+\left|{Z}_{i}\right|\) |
SVMb | \(\sqrt{{X}_{i}^{2}+{Y}_{i}^{2}+{Z}_{i}^{2}}\) |
Movement variation | \(\left|{X}_{i+1}-{X}_{i}\right|+\left|{Y}_{i+1}-{Y}_{i}\right|+\left|{Z}_{i+1}-{Z}_{i}\right|\) |
Energy | \({\left({X}_{i}^{2}+{Y}_{i}^{2}+{Z}_{i}^{2}\right)}^{2}\) |
Entropy | \({\left(1+\left({X}_{i}+{Y}_{i}+{Z}_{i}\right)\right)}^{2}\times ln \left(1+{\left({X}_{i}+{Y}_{i}+{Z}_{i}\right)}^{2}\right)\) |
Pitch (degrees) | \(tan^{ - 1} \left( {{{ - X_{i} } \mathord{\left/ {\vphantom {{ - X_{i} } {\left( {\sqrt {Y_{i}^{2} + Z_{i}^{2} } } \right)}}} \right. \kern-\nulldelimiterspace} {\left( {\sqrt {Y_{i}^{2} + Z_{i}^{2} } } \right)}}} \right) \times 180{/}\pi\) |
Roll (degrees) | \(atan2(Y_{i} ,Z_{i} ) \times 180{/}\pi\) |
Inclination (degrees) | \(tan^{ - 1} \left( {{{\left( {\sqrt {X_{i}^{2} + Y_{i}^{2} } } \right)} \mathord{\left/ {\vphantom {{\left( {\sqrt {X_{i}^{2} + Y_{i}^{2} } } \right)} {Z_{i} }}} \right. \kern-\nulldelimiterspace} {Z_{i} }}} \right) \times 180{/}\pi\) |
