How Rescue Knows what is 'Level'

In case you do not know something or you are not sure, here is the right place for your question.
Post Reply
CFerry
Posts: 32
Joined: Sun 04. Feb 2018 15:31:41

Hi,
I'm setting up my first Spirit fbl, and first time having a rescue/self level of any kind.
I have not flown yet, but bench testing of Rescue (Acro) give me some odd results.
For example; if I initialize and leave the helicopter in a level position for at least 20 seconds, activating rescue behaves as I would expect (adds pitch and swash tries to orientate the heli to be level). However, if I initialize the heli level, then leave the heli tilted for at least 20 seconds, then activate rescue, it adds pitch and the swash tries to angle the heli at a similar angle that I tilted it at.
So my question is: by artificially holding the heli motionless at an angle, am I fooling the Spirit into thinking that level is at an angle? Is the Spirit always calculating what 'level' is during flight by using it's orientation and acceleration due to gravity?
This is the only explanation I can think of as to the strange behaviour on the bench. If my assumption is wrong and the Spirit 'remembers' level from the point of initialization, then I'd be very confused.

Thanks for any thoughts on the matter :)

Chris
threeDfreak
Posts: 48
Joined: Mon 30. Oct 2017 19:18:22

and what about that situation.

You hover with your Heli around 20 sec backwards. Then you push normal rescue. What is the Spirit doing. Ram the Heli in the field because of wrong level?
CFerry
Posts: 32
Joined: Sun 04. Feb 2018 15:31:41

I have not flown it yet, still building it. But I would like to understand what is happening before I try it out in the air.
ZeXx86
Site Admin
Posts: 12836
Joined: Mon 29. Apr 2013 16:06:44
Contact:

Hi,

trying the rescue on the bench in described way will always result in bad behavior since you are not controlling it and helicopter is not flying.
The rescue is automatically learning from behavior of the model.
So if you will hold it in a steady position and tilted and without a movement and stick input, it mean that it is correct position for making the model steady and without any movement.

This is similar as when you are trying to judge how FBL will fly from movements of the swashplate. You will find that the behavior must be very strange :)
But reality is very different.

So short answer is, that you can't find what will happen in the air.
Unfortunately we can't give you any additional info about how rescue is working.

On the other hand there are ways to verify that it will work all the time correctly without any risk. But basicaly if your configuration is correct and the model is flying, it will work.
Spirit System developer
CFerry
Posts: 32
Joined: Sun 04. Feb 2018 15:31:41

Thank you ZeXx86! I suspected something like that, great to know for sure and nothing is wrong with my Spirit!
I understand there is information you cannot share to protect intellectual property.
But at least I can take from this that the unit is always learning 'level' during flight, not just from the initialization......very interesting.

Thanks for your time!
Chris
CFerry
Posts: 32
Joined: Sun 04. Feb 2018 15:31:41

Just wanted to report back after testing rescue in the air and has always works perfectly.
I practice hitting rescue many, many times over the last few months and it is very reliable, always going perfectly level.

Good job Spirit!
ZeXx86
Site Admin
Posts: 12836
Joined: Mon 29. Apr 2013 16:06:44
Contact:

Thank you for kind words!
Spirit System developer
Post Reply