When it comes to using drones for land surveying, mapping or 3D reconstructions, flight precision plays an important role. Each drone has its level of accuracy of flying predefined routes.
We decided to test most of UgCS supported drones, to illustrate the diverse precision of autopilots. To do that, all drones will fly a short photogrammetry mission planned with UgCS (Figure 1). It is a simple yet typical photogrammetry route with added overshoot, to compare different turn types and to see more accurately how precise the drone is flying according to survey lines.
The flight path will be recorded and demonstrated in Google Earth. The flight conditions are similar to all drones: wind speed around 2-3m/s.
DJI Phantom 4
One of most modern ready-to-fly drones, which has become quite popular also for photogrammetry even amongst professionals. The DJI Phantom 4 flew the mission twice comparing flight precision with different turn types: first flight with Stop and Turn, second - Adaptive Bank. See the flight comparison in the video:
The performance of the Yuneec H520 flying the UgCS Test-photogrammetry rout has no deviations and Yunueec H520 manage to fly exactly according to survey lines, even when cornering, the drone managed to keep itself on the path. Also the altitude of the drone matches perfectly the preplanned route's path.
The M600 has slight deviation while cornering, which can be explained with the larger mass of the drone, comparing to other drones. The altitute of the M600 flying the photogrammetry route matches perfectly the preplanned flight path.
DJI Inspire 1
Like all DJI drones, also Inspire 1 flew the test route with 2 different turn types: first flight with Stop and Turn, second - Adaptive Bank. See the flight comparison in the video:
DJI Naza-M V2
The Naza-M V2 is a popular autopilot from DJI used by hobbyists and professionals alike. In our case it was mounted on a DJI F450 frame. It flew the exact same photgrammetry route as DJI Phantom 4 with three different turn types: Stop and Turn, Bank turn and Adaptive Bank turn.
As expected, with DJI Naza-M V2 being an older autopilot, it did not fly as precisely as the Phantom 4. Out of the three turn types the Adaptive Bank gave the best results as far as keeping to survey lines.
MikroKopter Quad XL
MikroKopter is a well-established German company making drone systems for quite some time. MikroKopter drones are quite popular in Germany, many other European countries as well as internationally.
Here is the video of MikroKopter Quad XL flying the same photogrammetry route created in UgCS which we used for other drones:
A2 is mounted on a DJI S900 platform. Each of three flights was performed with different turn type – stop and turn, bank turn and adaptive bank turn. Here are the results:
3DR Iris with PX4 firmware
The flight trajectory is very smooth and consistent with no unexpected deviations from survey lines. The drone went off the planned route only when turning - but, because there is overshoot added to the survey lines, it wouldn’t affect the overall photogrammetry mission.
3DR Iris Pixhawk with ArduCopter
Pixhawk with ArduCopter 3.4.6 firmware is tested in the tenth episode in our series of videos comparing precision of various autopilots. The flight is very smooth and precise! See the flight details in the video:
DJI Phantom 3
The DJI Phantom 3 flew the mission twice comparing flight precision with different turn types: first flight with Stop and Turn, second - Adaptive Bank. The flight path of Phantom 3 corresponds with test-route almost exactly, slightly diverging only when cornering. See the flight comparison in the video:
Lockheed Martin Indago
The flight trajectory of Lockheed Martin Indago is very smooth and precise - perfect result. For our test flight automatic settings of Indago were not changed, therefore Indago reached routes planned height gradually - this has to be taken in account when planning photogrammetry missions with Indago: before starting the flight in automatic mode, manually desired height should be reached. See the flight details in the video:
Microdrone MD4-200 starts flying the route higher than the set altitude - this is due to the fact that the Auto-mode was enabled after the drone was already in the air causing the gap in altitude. See the flight details in the video: