*4.1. Design of the Testing Environments*

As previously mentioned, the scope of this work is focused on the development of a robust control algorithm for the autonomous takeoff, tracking, and landing of a UAV on a moving landing platform for life-long operation. Therefore, the experiments were designed so as to facilitate the detection task. Nevertheless, it should be noted that the control algorithm can operate together with any kind of detection method.

The initial approach was based on placing a visual marker on top of the landing platform, as shown in Figure 1. However, this approach was discarded after testing that from a height of 4 m the downward-looking camera of the real AR Drone 2.0 was unable to detect the marker robustly. Therefore, the visual marker was replaced by a red-colored, square-like landing platform like that shown in Figures 3 and 5 for the real and simulated environments, respectively. Such a landing platform can be easily detected by using standard computer vision techniques based on color and shape detection, as already described in Section 3.2. To further simplify this task, both simulated and real tests were performed on flat and feature-less terrains.

**Figure 5.** Simulated environment and robotic platforms.
