In defiance of inclement weather conditions, we conducted tests last week addressing the challenge of precise altitude control in uneven terrain. The drone’s altitude above ground directly influences the working width and the dispersion of spray mist, penetrating foliage with precision, an aspect crucial in agricultural applications.

Fluktor pursues an innovative approach by incorporating detailed elevation data into the flight planning process. In this methodology, distance sensors serve solely for collision avoidance. When the „calculate above ground“ option is selected in mission planning, a flight path is computed with a relative distance to the ground profile. Elevation data is sourced through an internet service utilizing satellite data, with a resolution typically around 30 meters per pixel, sufficient for moderately undulating terrains with sparse vegetation. However, when accounting for bushes, trees, rocks, or steep inclines, especially during low-altitude flights, we recommend employing photogrammetric height profiling before mission planning and execution.

The procedure involves flying a photo drone at an altitude of approximately 70 to 120 meters, capturing images, and processing them reliably with tools like Pix4DCapture and Pix4DFields. The subsequent generation of a high-resolution orthomosaic and surface model yields profile data with a resolution typically in the centimeter range. This elevation profile can be exported from Pix4DFields and seamlessly integrated into the flight planning software. The resolution disparity is visible in the video at 0:42 minutes compared to 0:37 minutes, showcasing the precision of the photogrammetric assessment in detecting field vegetation height, trees, and bushes.

Our tests were conducted at relatively low speeds of 2.5 m/s and altitudes of 10 meters and 5 meters, with the mission planning algorithm calculating intermediate points at varying altitudes for the drone to traverse. Satisfied with the results of these tests in viticulture, the drone maintained the pre-planned altitude with impeccable precision. Further experimentation awaits us, adjusting ascent speed and the number of intermediate points to ensure a uniformly controlled flight. As we progress into spring, our focus will shift to spreading and spraying trials in the same terrain. We want to thank Weinbau Rapp near Halle for allowing us to conduct these tests.