## 3 Results and Discussion
The comparison of the power consumption from the vehicle's battery for SDt = SDC = 350 mm is presented in Figure 22. Similarly to SDt = SDc = 250 mm, when using the camera, the transit time was noticeably shorter. The instantaneous power values drawn from the battery showed a larger range of variation and higher frequency in the configuration with reflective optocouplers. Figure 23 presents a comparison of the power profiles for the analyzed values of SDt and SDc. Comparing the power curves in Figure 23a, it can be observed that the power registration for the distance SDt = 250 mm ended earlier, indicating a shorter transit time (by approximately 9.4 s) compared to SDt = 350 mm. This was caused by significantly higher frequencies of power oscillations. The power oscillations in the control system with reflective optocouplers are reflected in the vehicle's oscillations during maneuvers. As mentioned, this could be due to the relatively long response time of the system to the input signal. This issue is much less pronounced in the camera-based control system, which can be explained by the presence of a processor in the Pixy camera that determines the direction of the guiding line, thereby significantly offloading the microcontroller on the Arduino Uno board. Comparing the curves in Figure 23b, it is noticeable that the transit was completed in a shorter time (about 3.3 s) with SDc = 350 mm. With the increased transit time, there is also a noticeable increase in the vehicle's energy consumption, as illustrated in Figure 24. When using reflective optocouplers, the placement of the optocouplers has a significant impact on average energy consumption. A larger value of SDt (350 mm) resulted in higher energy consumption and a longer transit time. This could be attributed to the control method, which, in this case, was associated with a significantly higher frequency of the system's response to line detection defining the  
Figure 21: The electrical power profile of the left wheel motor driving the vehicle: (**a**) SDt = 350 mm, (**b**) SDc = 350 mm. Figure 22: The comparison of the electrical power profiles drawn from the vehicle’s battery: (**a**) SDt = 350 mm, (**b**) SDc = 350 mm. The energy consumption values obtained using reflective optocouplers for a distance of SDt = 250 mm in consecutive tests were 0.430 Wh, 0.425 Wh, and 0.432 Wh, while for a distance of SDt = 350 mm, these values were higher, at 0.523 Wh, 0.533 Wh, and 0.515 Wh. The average energy consumption using reflective optocouplers at SDt = 350 mm was approximately 22% higher. For the camera system, the greater distance of SDc = 350 mm was more favorable in terms of energy consumption. In the individual tests, the energy consumption for this distance was 0.317 Wh, 0.319 Wh, and 0.317 Wh. For the distance of SDc = 250 mm, the energy consumption values in the individual tests were 0.331 Wh, 0.329 Wh, and 0.329 Wh. The difference in average energy consumption using the camera for the analyzed SDc distances was approximately 4%. The results summarized in Table 3 confirm the benefits of using a camera for the vehicle navigation system. The average energy consumption was approximately 26% lower when using the camera compared to the value obtained with reflective optocouplers. The shortest average transit time was 64.2 s (using the camera), while the longest was 87.5 s. This was also related to the higher average vehicle speeds when using the camera, which were 0.24 m/s for SDc = 250 mm and 0.25 m/s for SDc = 350 mm. In the case of using reflective optocouplers, the average speeds were 0.21 m/s for SDt = 250 mm and 0.18 m/s for SDt = 350 mm.