Great, thank’s Randy.
Little question on Terrain Following: so, if you are flying with Lidar, you setup correctly your Lidar and program a mission as usual? or We have to choose Altitude type “Terrain” in Mplanner too?
@cala2,
Yes, that less step, “selecting Terrain” from the drop-down on the Mission Planner’s Flight Plan screen and then upload the mission is important too. Ah, I didn’t make it clear that that drop-down must be selected before you upload the mission. Maybe I’ll recheck the wiki page.
Thanks!
Thank,s from me too Randy. I am using Heli FW 3.3.3 at the moment in a Align 700E with LIDAR. I also would love to try Terrain Following. But to read what happend to Rob Lefebvre on 13. August I am just not brave enough to try the 3.4rc2. And I wonder who would?
Have you received the log file or other evidence from Rob to confirm it is such a bug in there as he claims?
Fred,
Yeah, I agree that for tradheli users, it’s probably best to wait for -rc3.
Tridge is also actively flying the tradheli and he’s submitted some fixes to master to add additional checks. I have to say that I’ve mostly left this particular issue in their capable hands. I think we will release -rc3 next week.
Randy, I’m confused about a step on the autotune wiki. “For large copters set the Rate Roll and Pitch filters to 10hz”.
What is considered a large copter? Why 10hz? I have looked for info about that parameter and I find no clear explanation about it. Can you explain how to correctly find a filter value? Again, what is considered a large copter? Or point me to the right information.
@adolfotregosa,
We should probably put this into a different thread but in any case, my understanding from Leonard is that if the propellers are larger than 13" diameter (i.e. 33cm) then it should probably be considered a large copter. A regular copter (like an IRIS or Solo) has 9" (24cm) props it seems.
I’ve just updated the autotune page to clarify this definition of “large copter”. Hope that makes it more clear for the next person and thanks for bringing this up!
@adolfotregosa, I don’t think it needs to be exactly 10hz… but in general, what this filter does is smooth the vehicle’s rotation rates before they’re sent into the PID controllers. A higher filter value (like the default 20hz) smooths the rotation rates less, a lower value (like the 10hz recommended for larger copters) smooths them more. With a small copter you want to keep it responsive and it’s motors can react more quickly, so you don’t want much smoothing so a higher filter value is better. For big copters though, they can’t react quickly anyway (big inertial from the vehicle and props) so you can smooth the rotation rates more so a lower filter value is better.
As for the Terrain Following Wiki with range finder use there are no other obscure parameters to set from default to receive performance like shown in the 2m Ski Mountain mission video? EK2_RNG_USE_HGT remains at -1?
That’s right, no need to tell the EKF to use the range finder altitude.
I guess the only thing that I might add is that you may find the mission doesn’t start if you’re starting the mission while the vehicle is on the ground (i.e. first command is a takeoff command) but the range finder is reporting itself as unhealthy while on the ground. This can happen if, when on the ground, the range finder reports it’s distance as less than the value of the RNGFND_MIN_CM parameter. The default is 20 but for my little IRIS it was reporting something less (like 15) while the vehicle was on the ground so I reduce the parameter value. Another alternative of course would be to initiate the mission while the vehicle is already in the air (flying in Loiter mode or something similar).