Bitcraze Forums

Hello, I'm a newbie for Crazyflie. Recently I have tried some motion commander to control Crazyflie. However, everytime that Crazyflie take off, it isn't smooth enough. It's always like a two-step for lifting itself up. And this makes the position of Crazyflie changes a little bit(sometimes not just a little). Then, when the Crazyflie does any commands, the final position of it will change according to the last position after they take off.

So, I would like to ask if there's any possible way to take off Crazyflie smoothly so that it can perform the command and return results as we want correctly.

Hi!

First important question:

• What kind of positioning system are you using? The flowdeck, lighthouse, LPS ? It is important to know if you are using a relative positioning system or a external one.

Usually for quadrotors, taking off is always difficult since it needs to be done quickly. If it goes too slowly, the quadcopter is affected by the ground effect which makes it unstable. In general, taking off should happen as quickly as possible and it might overshoot when it does.

Anyway, let us know what you are using for positioning so that we know what we are dealing with.

I assume you are using high level controller.
another trick is to zero the state estimate x,y after takeoff.

@kimberly
Now, I simply use a flow deck and multi-ranger deck. For LPS, I will try in the future.

@wydmynd
So far, I haven't tried a high level commander yet. Just using a simple motion commander.

Btw, from your suggestion to set the state_estimate to be [0,0], if I understand right, the crazyflie will move back to the initial position after it takes off, right?

Might be a good idea to try the latest firmware. There are some improvements made to the flowdeck's implementation.