Armir,
Understand you need to get the altitude controller dialed in before you can proceed. Just wanted you to know about terrain. It’s a great feature and is very good with an accurate terrain model.
Good luck,
Dave
Yes that is correct.
Hi David,
Thanks man. It surely is a great feature and i will be making use of it more often.
Cheers
I intend to to tune Hobby-Wing Arris agri-drone which is in Quad layout. The total weight is 22Kg with Tank capacity of 10Kg. I start auto tune i need a PID parameters from a similar tuned drone. can someone lend his PID parameters so that i something to satrt with.
Unless someone has exactly the same aircraft then nobody can give you any parameters that are much better than the defaults and you are left to following the instructions anyway:
https://ardupilot.org/copter/docs/tuning-process-instructions.html
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We build an endurance VTOL that carries a quite a bit of fuel so we experience a similar weight change over the course of the flight.
I’ve recently done a fair amount of work in Ardupilot on my own branch that lets me tune the aircraft at empty then full, then I linear interpolate between the values based off the fuel in the tank.
I think you could probably do the same thing with the P, I, and D values on the quads. I’m sure it wouldn’t be perfect but it might be a lot better than just settling for one set of values.
We would just have to create a duplicate set of parameters for the heavy tuning then blend between the two as the tank level reduces.
You would of course have to have a reliable way to sense the amount of fluid in the tank.
-Shane
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A bit like the MOT_BAT_VOLT min and max values that scale the PIDs for battery voltage…
You want another PID modifier based on some configurable input like a tank capacity used.
Are you talking about the plane PID loops here or the Copter PID loops?
The tricky thing about multirotors is the payload varies in location significantly. For example my large multirotor can hard mount a 20 kg payload under the aircraft between about 10 cm and 50 cm from the centre of lift of the rotors. It is also set up to carry that payload with a tether. So you can’t just change the tune based on the take off weight.
In the case of a fuel take, it is necessarily very close to the CG and therefore CL point of the aircraft. It is also a fluid rather than a solid so it has a lower inertia than a solid payload. I would expect it to have minimal impact on the tuning required in multirotor mode if everything else is done correctly.
@Shane_R how much variation in PID parameters are you seeing?
I didn’t change the PIDs based on the fuel load.
I changed minimum airspeed, TECS climate, Q assist speed and some roll limiting stall prevention stuff that becomes more aggressive with heavier fuel loads.
We carry a gallon of fuel in a 25 lb airframe so the difference in weight has a pretty significant impact on performance.
being able to change the aggression of some of these things was really nice because we can take advantage of lighter fuel loads and we don’t have to choose a number that works for all conditions.
I don’t know enough about the quad tuning to be sure if it’s possible one way or the other. I was just suggesting it might be possible to have a lightweight and heavyweight tuning and to blend between the two based on the amount of fluid in the sprayer tank.
-Shane
Yep, it is definatly possible and can benefit some payload configurations. The trick is dealing with the complexity of this for the variety of configurations that could be mounted on a multirotor. At this stage I have not seen a strong argument to justify the additional complexity.
It sounds what you have done is potentially really useful for plane! Well done!
And thank you very much for offering up this suggestion. This is how we make the project better!
I have the same problem.
The altitude drops while flying in automode.
The cause is unknown.
Hello,
I have similar doubt. I want to change of the quad mass (i.e. weight) for do a simulation (I know thi’s will make unstable my quad, but this’s the idea).Which is parameter that do I can do it?
Second question: It’s possible change control law of vehicle on the mission planner, by placing other kind of controller?
altitude drops and/or increases in automode when breaking are due to barometer noise (prop and wind).
Protect your barometer with foam and the problem will go away.
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You can change the mass in the SITL. Should be one of the SIM_* parameters.
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Nope, not in mission Planner. You need to change the vehicle firmware, recompile and upload.