## 4 Conclusions  
The implementation of an infrared local positioning system has been described in this work. The transmitter system is based on four transmitter beacons, each one of them emitting a particular  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Points**} & \multirow{2}{*}{**Angle of Rotation (\(\beta\))**} & \multicolumn{3}{c}{**Absolute Error (cm)**} & \multicolumn{3}{c}{**Standard Deviation (cm)**} \\  & & **X** & **Y** & **Z** & **X** & **Y** & **Z** \\ \hline \multirow{6}{*}{Point P1} & 5\({}^{\circ}\) & 2.47 & 0.48 & 67.64 & 0.48 & 0.36 & 13.30 \\  & 15\({}^{\circ}\) & 1.63 & 0.28 & 81.60 & 0.61 & 0.49 & 13.09 \\  & 30\({}^{\circ}\) & 0.48 & 0.79 & 11.20 & 1.02 & 1.12 & 22.88 \\  & 45\({}^{\circ}\) & 4.07 & 1.70 & 8.03 & 1.88 & 0.76 & 21.92 \\  & Total (all angles) & 2.16 & 0.81 & 42.12 & 1.00 & 0.68 & 17.80 \\ \hline \multirow{6}{*}{Point P2} & 5\({}^{\circ}\) & 0.47 & 6.06 & 39.90 & 2.69 & 1.06 & 35.08 \\  & 15\({}^{\circ}\) & 2.97 & 6.09 & 57.17 & 2.84 & 1.23 & 43.31 \\  & 30\({}^{\circ}\) & 5.95 & 0.39 & 48.36 & 2.17 & 1.03 & 8.04 \\  & 45\({}^{\circ}\) & 2.77 & 3.15 & 175.50 & 0.97 & 0.76 & 3.53 \\  & Total (all angles) & 3.04 & 3.92 & 80.23 & 2.17 & 1.02 & 22.49 \\ \hline \multirow{6}{*}{Point P3} & 5\({}^{\circ}\) & 7.70 & 7.35 & 30.24 & 3.14 & 0.83 & 9.89 \\  & 15\({}^{\circ}\) & 0.09 & 4.77 & 156.50 & 1.36 & 0.85 & 3.15 \\  & 30\({}^{\circ}\) & 0.39 & 2.91 & 96.48 & 2.61 & 1.67 & 22.71 \\  & 45\({}^{\circ}\) & 0.00 & 4.73 & 63.01 & 3.03 & 1.43 & 29.71 \\  & Total (all angles) & 2.05 & 4.94 & 86.56 & 2.54 & 1.20 & 16.37 \\ \hline \multirow{6}{*}{Point P4} & 5\({}^{\circ}\) & 9.60 & 14.99 & 31.82 & 4.89 & 2.66 & 8.42 \\  & 15\({}^{\circ}\) & 4.71 & 10.93 & 20.48 & 4.42 & 1.89 & 11.88 \\  & 30\({}^{\circ}\) & 2.92 & 3.96 & 5.34 & 5.77 & 1.50 & 10.13 \\  & 45\({}^{\circ}\) & 6.39 & 0.86 & 1.18 & 5.07 & 1.53 & 15.65 \\  & Total (all angles) & 5.91 & 7.69 & 14.71 & 5.04 & 1.90 & 11.52 \\ \hline \multirow{6}{*}{Point P5} & 5\({}^{\circ}\) & 11.33 & 15.64 & 102.85 & 2.43 & 4.05 & 135.80 \\  & 15\({}^{\circ}\) & 11.27 & 6.01 & 57.14 & 1.33 & 3.26 & 32.99 \\ \cline{1-1}  & 30\({}^{\circ}\) & 12.05 & 5.26 & 47.34 & 1.19 & 2.17 & 35.10 \\ \cline{1-1}  & 45\({}^{\circ}\) & 11.43 & 8.33 & 67.39 & 1.10 & 1.19 & 15.22 \\ \cline{1-1}  & Total (all angles) & 11.52 & 8.81 & 68.68 & 1.51 & 2.67 & 54.78 \\ \hline \multirow{6}{*}{Point P6} & 5\({}^{\circ}\) & 6.43 & 1.13 & 1.25 & 2.96 & 3.68 & 170.52 \\  & 15\({}^{\circ}\) & 12.79 & 1.11 & 3.86 & 2.98 & 3.14 & 9.50 \\ \cline{1-1}  & 30\({}^{\circ}\) & 18.96 & 5.48 & 12.32 & 4.24 & 4.17 & 31.21 \\ \cline{1-1}  & 45\({}^{\circ}\) & 20.62 & 5.78 & 19.13 & 4.64 & 4.56 & 56.02 \\ \cline{1-1}  & Total (all angles) & 14.70 & 3.38 & 9.14 & 3.71 & 3.89 & 66.81 \\ \hline \multirow{6}{*}{Point P7} & 5\({}^{\circ}\) & 2.38 & 4.89 & 38.96 & 6.96 & 4.13 & 11.15 \\ \cline{1-1}  & 15\({}^{\circ}\) & 0.56 & 8.84 & 46.26 & 6.12 & 3.79 & 11.26 \\ \cline{1-1}  & 30\({}^{\circ}\) & 13.71 & 1.76 & 23.24 & 6.93 & 4.25 & 13.08 \\ \cline{1-1}  & 45\({}^{\circ}\) & 23.76 & 17.49 & 9.72 & 4.94 & 3.63 & 8.27 \\ \cline{1-1}  & Total (all angles) & 10.10 & 8.25 & 29.55 & 6.24 & 3.95 & 10.94 \\ \hline \multirow{6}{*}{P1 to P7} & Total (all angles) & 7.07 & 5.40 & 47.28 & 3.17 & 2.19 & 28.67 \\ \cline{1-1} \cline{2-1} \cline{2 LS code; on a reception module, which consists of a QADA photoreceptor, a filtering system and an acquisition system; and on a synchronism system built with a particular IR beacon and a photodetector. Synchronism detectors are located in the receiving module and in each of the transmitting beacons, thus allowing a simultaneous reception and transmission. The processing stage at the receiver module performs the correlations of the acquired signal with the different codes used in each transmitter. From the correlation peaks, the global sum of energy received in the QADA, as well as the differences in energy between the left-right side and the bottom-top one, are obtained.