## 3 Results and Discussion  
In order to determine the performance of the designed system, an experimental setup is created, in which current, voltage and illuminance measurements can be performed in the system (Figure 8). Here, the digital luxmeter is used to externally measure the illuminance level for the robotic platform. In addition, the power consumed by the LED strip lamp is determined by obtaining current and voltage measurements with a True RMS digital multimeter. In the experimental study, in order to obtain the colors properly, the illumination is performed with white light, and a low-reflection white background is used on the platform floor. Within the scope of the study, the system is covered with a black fabric cover in order to eliminate the effects of external environment, such as reflection and glare. In the experimental study, first, the switching performance of the driver circuit used to adjust the platform illuminance level is examined. For this purpose, the power change in the LED strip lamp driven by the MOSFET-based circuit depending on frequency and duty cycle change in the PWM signal is investigated. In the experimental setup, the power changes applied to the LED strip lamp depending on the duty cycle value for the PWM frequencies 100 Hz, 1 KHz, 5 KHz and 10 KHz are obtained (Figure 9). In the lighting system, in order to minimize flicker, the LED strip lamp is driven using the hardware PWM output on the Raspberry Pi GPIO18 output. In a PWM application, the flicker effect on LED lighting decreases as the frequency increases and cannot be perceived visually, as it exceeds 100 Hz. In this respect, the PWM frequency of the driver circuit in the designed system is determined as 1 KHz because it is closest to the ideal. In order to perform the switching properly depending on the duty cycle at higher frequencies in the system, it is necessary to drive a double MOSFET separately for the pulse, on and off. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Reference Color** & \
\begin{tabular}{c} **Lower Limit** \\ **(H, S, V)** \\ \end{tabular} &
\begin{tabular}{c} **Upper Limit** \\ **(H, S, V)** \\ \end{tabular} \\ \hline R—Red & (160, 100, 100) & (179, 255, 255) \\ G—Green & (38, 100, 100) & (75, 255, 255) \\ B—Blue & (75, 100, 100) & (130, 255, 255) \\ Y—Yellow & (22, 100, 100) & (38, 255, 255) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Color ranges of the HSV color space model for RGBY reference colors in the designed system. Figure 8: Experimental measurement setup. In the second stage of the experimental study, the changes in platform illuminance level depending on electrical lighting power are investigated for different environmental initial illuminance level (E\({}_{\text{i}}\)) values. For this purpose, the E\({}_{\text{i}}\) on the platform is adjusted separately as 0 lx, 50 lx, 100 lx, 150 lx and 200 lx by utilizing the daylight condition and using a black cover. For each E\({}_{\text{i}}\) value, the electrical lighting power of the LED driver circuit is adjusted to the required value by changing the duty cycle of the 1 KHz PWM signal. The platform illuminance values obtained in this way are measured with a digital luxmeter (Figure 10). In the lighting system, when E\({}_{\text{i}}\) = 0 lx at the beginning, the P\({}_{\text{LED}}\) value is adjusted to between 0 and 780 mW with the help of the PWM signal, and it is observed that the obtained E increases approximately linearly between 0 and 163 lx. In the third stage of the experimental study, the minimum platform illuminance levels required for color-based image processing for object detection processes are investigated according to different colors.