Quote:
Originally Posted by Foster
Since this popped to the list today, there were a number of teams that were looking / got this board to support vision for next year.
How are your boards working out for you?
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I haven't seen too many teams actively talking about their development on these here on CD but we now have 3 of them for our students to test/play with (4 of them if you count the mentor owned one). So far, most of the challenges have been around getting the students acclimated to C++, getting a C++ program on the board to communicate over the network to LabView, and then getting LabView to understand that communication.
Our impressions of the board are favorable though (thus why we now have 3 of them). Running X11 on them can be unstable at times but not bad most of the time. We will disable X11 for competition. One of our student programmers suggested switching to wayland... sadly, he became an example for the other students and was shot.
The boards run linux but they do require some system knowledge to enable certain features (USB 3.0 is not enabled by default). You have to update the image using dd or some similar commands. You will encounter driver issues inevitably with USB devices or other things.
C++ is the way to go if you are going to use these boards since you are paying for the GPU and writing OpenCV code in any language other than C++ doesn't seem to give you access to it. You of course gain all of the pain associated with C++, including memory management and that problem is doubled with the GPU because you have to swap images to and from it.
We have not touched on optimization with our students yet but we will soon. When we do, we are going to start them down the road of threading and running the network on a different thread than the image grabbing thread. We also have not started to look at optimizing the offload to the GPU, though we are using it now, which is cool.
We have not put this board on a robot yet. We are still doing bench-top testing with pre-recorded videos. We will be putting one on a robot before too long. The power draw from one of these board is capable of overloading the VRM but it is doubtful that it will based on calculations.
Our intent will be to post a paper sometime before the end of the season about our efforts. If you have specific questions then feel free to ask or PM me. I'm always happy to chat.
All of the above being said, the following is my personal opinion and not necessarily shared by my team:
I think the vision challenges from the last 5+ years can be done without this board using the new RoboRIO and a cheap-ish USB webcams (We are also a beta team) and the examples that WPI/NI/FIRST provide along with some dedicated students/mentors looking at the problems and writing some clever color filters.
These boards can do substantially more than that. Vision processing with OpenCV is capable of doing object recognition (Think: looking for and recognizing the bumpers of other robots and playing automated defense: "No, I didn't pin them for 5 seconds, it was exactly 4.99 seconds and I have logs to prove it"
). If you are going to use this board then I suggest you plan on doing something above and beyond the basic vision challenge of tracking an object by color alone or determining if a goal is simply hot/cold. Granted, I'm a bit of an ambitious dreamer and not always a realist but my students keep surprising me.
EDIT: In no way take my above comments as negative or that teams shouldn't try to do awesome stuff with OpenCV. Please, try everything. I want to be amazed and I know all teams will continue to impress upon me how awesome FRC is for that. I just want to be clear that these boards are both expensive and powerful and can be used for some awesome stuff.