Controlling px4 witj pwm

PX4 Autopilot Flight Controllers 💻
1

Hi, I’m beginner to PX4 autopilot.

I’m trying to find a way to control each motor of the multicopter.

But, currently, all I could find is controlling the multicopter through changing velocity.

So, I’d like to ask if there’s a way to control each motor.

Thanks!

+I apologies if I wrote in the wrong category. I wasn’t rly sure about which category to write this question in.

2

That’s not so easy because there are generally other control paths working. Can you describe what you actually want to achieve high level?

4

I’m currently trying to train a drone agent with reinforcement learning, and to do so, I have to create an offline (rule-based) dataset. I’ve already succeeded in training it using high-level information such as using position.

But since my goal is to train it with low-level data, I’ve tried using angular velocity first. But the problem is since PID is applied, I could not get the exact angular velocity value given to the drone (before PID is applied) when creating an offline dataset. Also, since there’s no API to get throttle value, I could not create an offline dataset using angular velocity. So that’s why I was trying to use pwm to train my drone.

The way how I create my offline dataset is:

  1. Using ‘MoveToPosition’ API, move drone from initial position to a random goal.
  2. Collect the data that I want to train the drone with (e.g. position, pwm, etc.) using the API, while drone is conducting the movement commanded by MoveToPosition API.
    (This is the step where I said that I could not get the throttle value)
  3. Repeat this process until I collect sufficient amount of data.

Thanks!

5

I would consider rate inputs rather than setting the motors individually. The reason is that you need to have a high rate / low latency control signal to the motors and I doubt that will work properly.

6

Oh I see… Thanks for the reply. I’ll have to change it to rate inputs :slight_smile: