search

ethz-asl / rotors_simulator

RotorS is a UAV gazebo simulator
1.2k stars 756 forks source link

Unstable drone on faster than real time simulations #694

Open markostamos opened 2 years ago

markostamos commented 2 years ago

Drone gets unstable and falls when update rate of gazebo goes above 2x real time.

Jaeyoung-Lim commented 2 years ago

@markostamos I think this issue is lacking context / details to decide whether if this is a real issue.

How are you controlling the vehicle? Could you provide instruction can we reproduce your problem?

markostamos commented 2 years ago

@Jaeyoung-Lim i set a position (x,y,z) using the lee controller. As expected this works and the uav stays in that position but if i try to do the same thing with a faster update rate ( more than 2x the real time) the uav gets unstable and eventually falls.

tbanus commented 2 years ago

I am having a similar issue. I tried it with both Lee Controller and the PID controller I implemented. Both causes issues. My observation is that when the RAM usage reaches %99, the drone falls. However, I haven't tested this. I also suspect the ros time acts differently under these conditions since it messes with the derivative (dt) term of the PID controller. Has anyone reached a solution for this?