Drone Drops After Hovering Fine for a Few Seconds (Log Analysis Help)

We are working on a senior design project to get a drone to navigate autonomously indoors. Using a 2D Lidar for SLAM and a 1D Lidar for height, we are able to get the drone to hover pretty well in Guided_NoGPS mode. However, after about 15-20 second of hovering, the drone yaws slightly and suddenly drops in height to the ground. The drone will then recover its height before dropping again. We have spent weeks trying to diagnose the problem, and this is might force us to switch projects if we can’t find a solution, Any help is appreciated! I have included three logs of flights where this issue has occurred. We are using APM3.5.3 with the Intel Aero RTF and Dronekit to control the drone. I have looked at the logs and not seen anything strange, but I am also very new to Ardupilot.

This is the log which shows the problem the best:
00654-2019-02-20_17-50-37.bin (276.6 KB)
00654-2019-02-20_17-50-37.log (535.9 KB)

These logs also have the same flight problem:
00655-2019-02-20_17-51-39.log (442.2 KB)
00655-2019-02-20_17-51-39.bin (230.7 KB)

00419-2019-01-29_18-10-09.bin (272.5 KB)
00419-2019-01-29_18-10-09.log (534.6 KB)

Too much information are missing from your log.

Your battery (current and voltage) is not monitored,

From first look, your drone is under powered,


Thanks for taking a look! I will try to get our battery monitoring up and check out the log. If the drone is underpowered, would it be able to hover fine for an initial 15 seconds? Would this mean we need a higher voltage battery or one with more of a discharge capacity (higher C)?

With the technical data of the drone (weight, motors, propellers, battery data) it will be easy to help you.


Sorry for the late reply. I finally got the battery monitoring going, but it only seems to monitor the voltage and not the current. I have attached the new log. The weight of the drone is 1492g with the 2D lidar on top and the max takeoff weight listed on the website is 1900g. The propellor lengths are 230mm and are made by Yuneec. It says the motors are based on the Yuneec Typhoon H motors and are customized for the Intel Aero. There unfortunately is not much documentation on the hardware specifics of this Ready to Fly drone. Thank you again for your help.
00814-2019-03-07_16-59-27.bin (274.2 KB)
00814-2019-03-07_16-59-27.log (540.6 KB)