PX4 vs ArduPilot - when to choose what

dagar · March 10, 2021, 10:05pm

They run PX4 and they’re fully supported upstream.

PX4/PX4-Autopilot/blob/3ad0da51c4841fb20ced4d8e205d9abb5541e889/ROMFS/px4fmu_common/init.d/airframes/4071_ifo#L1-L120


#!/bin/sh
#
# @name UVify IFO
#
# @type Quadrotor x
# @class Copter
#
# @output MAIN1 motor 1
# @output MAIN2 motor 2
# @output MAIN3 motor 3
# @output MAIN4 motor 4
#
# @maintainer Hyon Lim <lim@uvify.com>
#
# @board px4_fmu-v2 exclude
# @board px4_fmu-v3 exclude
# @board px4_fmu-v4pro exclude
# @board px4_fmu-v5 exclude
# @board px4_fmu-v5x exclude
# @board bitcraze_crazyflie exclude

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soldierofhell · May 27, 2021, 8:54pm

Recently I had to implement custom LQR controller in PX4 and I must say that I like uORB messaging. Pub/sub to topics concept is very familiar to those working in ROS or Gazebo. Also the modules that are like ROS packages or Gazebo plugins that you can add easly to the core system. Plus CMake as build system. In general, I must say that for newcomer, especialy for someone with ROS background it’s easier to modify or replace particular component without detailed knowlege of the whole system.

space_sailor · June 4, 2021, 12:22pm

Didn’t see your answer before but it confirms my thoughts.
Interesting since I actually work extremely closely with Airbus…

dkemxr · July 10, 2021, 6:22pm

Cool, Russell Brand is posting on the forum.

lordvon · July 12, 2023, 5:11am

henlo wonder what ppl think of this thread nowadays. which has better attitude n altitude controller?

does px4 have this issue? AP_MotorsMatrix: prevent altitude loss when thrust-to-weight is less than 2 by 117-MasterChief · Pull Request #23512 · ArduPilot/ardupilot · GitHub

code is totally different; will need to dig in sometime.

rollys · July 12, 2023, 1:34pm

I believe so but you can post your question here.

Good luck.

lordvon · July 12, 2023, 10:40pm

thanks. what makes you think that has the same issue?

i will post there when i get around to using it.

rollys · July 14, 2023, 1:50pm

If I’m thinking it right, it’s part of the blending program. But first off, I have in quadplanes, I use a 2:1 thrust to weight ratio. I go more like 1.6-1.7:1 with higher kV quadmotors, i.e. enough to lift to altitude to hover for a short period of time. That’s enough to keep the altitude while it transitions to FW mode. You fix FW throttle percentage and ramp up period via params while the quadmotors’ throttle auto adjusts to maintain altitude and yaw corrections regardless of the throttle position on the Tx, during the transition.

I had built one several years ago that it started to dive during the transition. After making some changes to the blending params, I was able to almost get rid of the diving tendency.

Good luck.