Slow throttle response on PX4 rover

PX4 Autopilot
1

I’m using PX4 on Pixhawk to drive two motors independently in a tank-drive-like configuration. One motor speeds up and slows down considerably faster than the other, and, after a lot of trouble shooting, I’m certain that it’s an issue with my signal output from the Pixhawk. When I hook up both Pixhawk signal outputs to my oscilloscope, one PWM signal changes its pulse width (therefor the voltage out of my motor controller) way slower than the other. I can’t find any information online about this, anyone who has had a similar problem, and I’ve tried changing so many parameters to get a less sluggish throttle response. Does anyone have any recommendations? Thanks!!

Here’s a link to a Google Drive link to a video that explains what I’m talking about:

2

Hi @rocketman , which version of PX4 are you using? Could you also share your parameter configuration?

3

Hi @Benja , I’m using PX4 Pro Stable Release v1.13.3.

Attached is a PDF of my modified parameters. Let me know if you need my total parameter configuration; the website won’t let me upload it, but I could send a Google Drive link if you need it. Thanks!

1Apr23ModifiedParams.pdf (850.8 KB)

1 Like
4

Could you share the log as well? You can upload to https://logs.px4.io/ and share the link!

5

Thanks so much for helping with this. Link below:

https://review.px4.io/plot_app?log=9eb0f2da-475b-412a-b40e-714b553a83b2

6

Analysis

So for your configuration (differential steering), you should use the appropriate airframe (read more about types of rovers here: Rovers (UGVs) | PX4 User Guide).

Currently, the one you are using is a generic rover (linked below) with steering & throttle control, which doesn’t match your vehicle’s configuration.

What you should use instead is a differential driver rover, like this:

Suggested Solution

Therefore, you can select the Aion Robotics R1 airframe in the airframe selection tab, and connect the motors appropriately to check if they operate as expected.

1 Like