## 3 Results and Discussion  
### Control System  
In Figure 5a, the temperature fuzzy control simulation in the micro-greenhouse is shown, where a 30 \({}^{\circ}\)C reference was established starting from a temperature of 24 \({}^{\circ}\)C. The desired value was reached in 20 s and it remains stable with a difference of 0.4 \({}^{\circ}\)C compared to the reference. In Figure 5b, the humidity NN control simulation can be observed. A 75%  
Figure 4: Control system general diagram. reference was established from 35%. A steady-state difference of 0.05% was obtained. With the temperature and humidity values, it is possible to obtain the VPD control values, as shown in Figure 5c. The VPD result in the simulation was 1.03 kPa. Figure 6a shows the PID control simulation result for soil moisture. An 85% reference was established, starting with 0% soil moisture. The desired value was reached in 40 s and presented a steady-state difference of 0.1%. In the VPD and soil moisture control implementation, the standard error (SE) and mean absolute error (MAE) for each one was determined and compared with simulation, as shown in Table 4. The same references were established in the simulation as in the implementation for contrast. In Figure 6b, the PID control behavior for soil moisture is  
Figure 5: Simulation (**a–c**) and implementation (**d–f**) graphs of temperature FL control, humidity NN control and VPD control. Figure 6: Simulation (**a**) and implementation (**b**) of soil moisture PID control. shown, where it is observed that an overshoot occurs when the reference is reached, but later it achieves the stable state. In Figure 5d,e, the temperature FL control and humidity NN control implementation are shown; temperature takes approximately 70 s to rise from 24 \({}^{\circ}\)C to 30 \({}^{\circ}\)C and the humidity reaches the reference in 105 s. The VPD behavior control can be observed in Figure 5f. The VPD has an MAE of 0.93 \(\pm\) 0.09 kPa and an SE of 0.93 \(\pm\) 0.004 kPa. In comparison with the VPD obtained in the traditional technique, a variation in temperature and humidity caused the VPD to fluctuate in the range of 1.6-1.7 kPa. In contrast, the temperature and humidity are close to the reference value in the micro-greenhouse. Humidity takes approximately 35 s longer than the temperature to reach the reference; this is because the temperature must first be stabilized to bring the humidity to the desired value. However, when it falls below the desired value, it can be observed in Figure 5d,e that, when the heat exchanger is activated, it causes a momentary drop in the humidity value, which causes the VPD to rise. This happens because the outside air is drier than the air inside of the micro-greenhouse, and when the exchanger is activated, it enters through the fan. Likewise, in Figure 5e,f, it is observed that, when the humidity falls, it causes the VPD to rise at the same time. Despite this, in a few seconds, the control system can resume within an acceptable range the humidity value again, causing the VPD to remain within the acceptable values for sesame seed germination. The scientific community has researched VPD control in microclimates. For example, [20] proposed a fogging system in a screenhouse to increase humidity. They obtained VPD values between 2.9 and 3.3 kPa. In another study by [21] a micro-fog system in a greenhouse was proposed to raise humidity and thus reduce VPD in summer temperatures. They obtained, as a result, a minimum VPD value of 0.75 kPa. A study presented by [18] involved different experiments in chambers to raise the humidity using airflow to vary the VPD value. They obtained VPD values that ranged between 1.1 and 3.7 kPa. The authors of [19] also executed three experiments where humidity values were increased to evaluate the VPD in growth chambers. They obtained results that varied between 0.7 and 2 kPa by applying automated irrigation four times a day.