Classmate Video Lagging

[lkearley]

We have been having trouble with using our classmate and the driver dashboard, the video feed has been seriously lagging. With teleop enabled, the video is around 5 fps and has a 2 second lag, but with teleop disabled, the video is around 20 fps and it's 1 second behind. Obviously, that would be a huge problem for driving and autonomous goal recognition. Has anyone else been having these issues? Does anyone know how to fix it? Thanks in advance.

[EricH]

What is the resolution you're using on the camera?

[lkearley]

Originally Posted by EricH

What is the resolution you're using on the camera?

320x240, but we have the same problems at 160x120. The compression also has no effect.

[SenorZ]

We had this issue last year. We even had some sort of overload of the network that forced our cRio to reboot! Running full stream video from the Axis through the router is very taxing on the classmate.

I would highly recommend not doing that unless you REALLY need a live video.

[lkearley]

So we sort of solved it. We now just open the driver station on the classmate, but the dashboard on a second laptop. We didn't have everything on the second laptop before because it has connection issues and isn't too reliable. Thanks for the help!

[Alan Anderson]

Running full stream video from the Axis through the router is very taxing on the classmate.

That's definitely the case for the E09 Classmate. The E11 does a little better.

Look at the diagnostics window on your Driver Station. Do you see any error messages when you enable the robot in Teleoperated mode? Dealing with error conditions could be keeping your Classmate busy enough that it can't do a good job showing the video from the camera.

[Greg McKaskle]

The lag is caused by sending more images than can be displayed. Images flow from the camera through its TCP stack, to the bridge, to the laptop and its stack. any buildup and it will start to lag.

If you watch the laptop CPU and identify the speed that it is displaying, you probably want to set the camera framerate to a value no faster. At that point, the laptop CPU should drop below max and the lag should reduce and minimize at a 100ms or so.

Updating the laptop or splitting the duties will allow for higher framerate without lag.

I also don't really see how this could cause a cRIO to reboot since the cRIO isn't at all involved in the display to the dashboard.

Greg McKaskle