# EfficiencyX: Study of Energy Efficiency between Two Robotic Arms
## 3 Results and Discussion
### Energy Efficiency  
For the study of energy efficiency between the original Dorna 1 aluminum robotic arm and the object of study (the carbon fiber robotic arm optimized at CIDESI), an IoT device was developed (see Figure 8b) to detect the consumption energy of both robotic arms. The device has an ESP32 chip and was programmed in C language for data collection. The device was connected to the driver of the robotic arm to detect energy consumption during the operation of this arm. This driver was used to control both arms and be able to measure efficiency in the same frame of reference. Figure 6: (a) Robotic arm with its elements. (b) Robotic arm with carbon fiber parts. Figure 7: Weighing of Dorna 1 Robotic Arms. (a) Aluminum robotic arm. (b) Carbon fiber robotic arm. For the analysis of energy consumption, it was proposed to evaluate the performance of the aluminum (Al) robot arm against the carbon fiber (CF) robot arm under the same movement scheme starting from its \"Home\" position during a period of 15 min with three different speeds: 1000 deg/min, 3000 deg/min, and 9000 deg/min. The speed values from a previous table were used as a basis (see Table 4). The values obtained for energy consumption in Watts (W), as well as the differences obtained in each test, are shown below (see Table 8). Based on Equation (1) and the data of test 1 from Table 4 and Table 8, respectively, we proceeded to calculate the useful mechanical energy as a result of comparing the Al and CF robotic arms:  
* Useful energy consumed by the CF robotic arm (\(E_{u}\)): 45.10 W
* Total energy consumed by the Al robotic arm (\(E_{t}\)): 45.67 W  
\[\eta=\frac{45.10}{45.67}\times 100\%=98.75\% \tag{2}\]  
where:  
* energy efficiency is \(\eta=98.75\%\),
* and energy gain is \(100\%-98.75\%=1.25\%\). The first experiment was performed at a joint speed of 1000 deg/min, obtaining an average energy consumption of 45.67 W and 45.10 W for the Al and CF arm, respectively, obtaining an energy gain of 1.25% for the CF arm. Figure 9 shows the comparison of consumption throughout the test. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Name** & **Test 1 (W)** & **Test 2 (W)** & **Test 3 (W)** \\ \hline Aluminum (\(Al\)) & 45.67 & 46.74 & 48.03 \\ Carbon fiber (\(CF\)) & 45.10 & 45.03 & 46.78 \\ Difference (\(Al-CF\)) & 0.57 & 1.71 & 1.25 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Comparison table of values of energy consumption obtained using the IoT device. Figure 8: Optimized robotic arm energy-efficiency measurement system. (**a**) Optimized robotic arm. (**b**) Energy IoT. Similarly, based on Equation (1) and the data of test 2 from Table 4 and Table 8, respectively, we proceeded to calculate the useful mechanical energy as a result of comparing the Al and CF robotic arms:  
* Useful energy consumed by the CF robotic arm (\(E_{u}\)): 45.03 W
* Total energy consumed by the Al robotic arm (\(E_{t}\)): 46.74 W  
\[\eta=\frac{45.03}{46.74}\times 100\%=96.34\% \tag{3}\]  
where:  
* energy efficiency is \(\eta=96.34\%\),
* and energy gain is \(100\%-96.34\%=3.66\%\). The second experiment was carried out at a joint speed of 3000 deg/min, obtaining an average energy consumption of 46.74 W and 45.03 W for the Al and CF arm, respectively, obtaining an energy gain of 3.66% for the CF arm. Figure 10 shows the comparison of consumption throughout the test. Figure 9: Energy consumption of the Al vs CF robot arm at a combined speed of 1000 deg/min. Finally, based on Equation (1) and the data of test 3 from Table 4 and Table 8, respectively, we proceed to calculate the useful mechanical energy as a result of comparing the Al and CF robotic arms:  
* Useful energy consumed by the CF robotic arm (\(E_{u}\)): 46.78 W
* Total energy consumed by the Al robotic arm (\(E_{t}\)): 48.03 W \[\eta=\frac{46.78}{48.03}\times 100\%=97.39\%\] (4) where: \[\text{energy efficiency is }\eta=97.39\%,\] and energy gain is \(100\%-97.39\%=2.61\%\).