It is said that the value of “MOT_THST_HOVER” must be between “0.2 and 0.8”. Is it difficult to maintain altitude if this value is low?
The param simply says that your vehicle hovers with 20 to 80% thrust (or total throtle if you prefer).
Thus if your hover thrust is 0.8 your vehicle most propably is underpowered and will not have enough room for manuvres. On the opposite side if you hover with just 20% of your available thrust, the vehicle is overpowered and it will be jumpy and difficult to tune. …Or it means you’ve done a great job with your airframe weight and you have plenty of room for batteries to increase flight time.
In short, most of the times heavy is bad, light is good or managable
It is not good if the value of MOT_THST_HOVER is too low
The current value for MOT_THST_HOVER is 0.23.
It’s neither good nor bad it’s just a higher thrust to weight. Tune for it or add a heavier/ higher capacity battery.
If there is higher thrust against weight, are there any drawbacks?
They can be more challenging to tune. But I have a small quad with a MOT_THST_HOVER value of .125 and it is very well tuned and flies great.
Guys, I try to figure out what value I should I use for MOT_THST_HOVER to properly set notch filter, but after setting MOT_HOVER_LEARN = 2 and hovering flight I read MOT_THST_HOVER = 0.17. It seem to be wrong value because my quad is reasonably powered and at hovering sends to ESCs servo value around 1420uS. If I interpolate 1420 between 1000uS (0%TH) and 1900uS (100%TH) it’s about 47% of TH, which is reasonable but far from 17% saved in MOT_THST_HOVER. What value should I use? Why is autolearnt throttle so strange?
Throttle is not linearly mapped to PWM, see:
trying to calculate in the XLS sheet, but values still doesn’t fit together. Obviously my real hover thrust is somewhere between 40-50% and in this area are corrections by MOT_THST_EXPO very small - just in few % range. This doesn’t explain so big difference between MOT_THST_HOVER = 0.17 (17%) and real hover thrust (around 45%).
I’m becaming confused of this and notch filter setup isn’t very clean here. Can you please maybe using my hover log here tell me what is correct MOT_THST_HOVER value in my case to use for the notch filter setup?
I repeat that my quad isn’t any crazy overpowered beast as discussed above hovering with the TH stick at the bottom, but reasonably powered quad hovering with TH stick just a hair under the middle.
Edit: I tried to add some balast weight to my quad, do another hover and check whether MOT_THST_HOVER has changed - and yes - slightly. Adding 20% extra weight to my quad changed the value from 0.17 to 0.20. From it I guess that the value gets updated, but still I’m curious how such a big difference is possible. Any more explanations or ideas wellcome!