Elaboration takes longer, lower the 'frame_rate'


I’m running a ZED2i on a Jetson nano through ROS1 with a recent version of the ZED software as well as ROS. I get lots of

Elaboration takes longer (0.139038 sec) than the requested FPS rate (0.066666667 sec). Please consider to lower the 'frame_rate' setting or to reduce the power requirements reducing the resolutions

There is no “frame_rate” setting that I can see. There are quite a few rate and freq settings, but none have a value of 15. I have also inspected all the dynamic ones using the parameter server and none have a value of 15. Which am I supposed to change?


The parameter is grab_frame_rate:

The real problem is that your main loop is running at ~7 Hz, which is less than the minimum available ZED frame rate (15 FPS).

What is the resolution that you are using? What modules are you using?
Did you start the jetson_clocks script?

Thank you for confirming which parameter it is. Before answering your questions however, this parameter is set to 10 in my config file (confirmed by rosparam get). Why is it asking for 15?

I use VGA resolution, I have position tracking. I have experimented with mapping or not and that makes no difference.

jetson_clocks shows the power mode is MAXN. Current freqs are all at the max allowed. This is on a Jetson nano.

For grab_frame_rate you must use one of the values allowed by the ZED SDK: 15, 30, 60, 100.

You can instead change the rate of the message publishing: pub_frame_rate

So I can’t specify slower than 15Hz. That explains it. I’m pretty sure my pub_frame_rate is also lower, but I can’t check right now.

But why is it I can’t process faster than 7Hz?

I confirm, pub_frame_rate is set to 10 and point_cloud_freq is set to 8. So I still don’t understand the message.

The message is related to the “grab time”. It says that your configuration is too hard for your hardware because it cannot reach the 15 FPS required for “grabbing”.