Using a Kinect as a primary camera for drivers

[ekapalka]

Hello! I was wondering how we would go about streaming images from a Kinect which is plugged into an on-board computer to the driver station. I've been looking at TCP (using C++, because we're using C++ OpenCV) for sending both targeting data (just three floating point numbers) and video, but I'm not entirely sure where to begin. What have other teams done? Do they use 3rd party TCP/UDP/___ libraries or do they write their own? I guess if all else fails we can use the Axis Camera for the driver and simply send targeting data to the cRIO via NetworkTables (or the C++ equivalent). It's bugging me. All the vision processing I've learned so far has just been on my personal computer, because I know that actually sending that information to the cRIO is going to be a challenge of it's own. Any thoughts on the matter would be greatly appreciated!

[Invictus3593]

I've been working on C# code to get kinect depth camera and color camera and I've gotten success in recieving the feeds in an onoard computer, but I'm having trouble with networking as well.

I know TCP is the protocol used by the axis camera and the port it uses is 80.If you were going to use just the kinect and no axis camera, you could use port 80 for the data. If you needed another port, look in the manual for guidelines on which ones you can use and select one that is bidirectional, same as 80.

If you can't write your own TCP libraries, i'd definitely find a third-party client to work with.

Hopefully this helps!

[curtTheGreat]

Last year when we used a Kinect sensor, we ran into some troubles with a network based solution. That being said we chose to use the serial port on our CRio. Going serial allowed us to get an uninterrupted signal from our onboard computer to the CRio.

[Domtech]

I played around with using the kinect as a driver camera last year, and I managed to get it working with just some of the shelf freeware:

1. KinectCam, a driver to make the kinect work as a USB webcam.

2. yawcam, a small aplication to host the camera feed over the network.

It worked quit well, but at about a second of lag with the classmate on the robot transmitting over wifi, it was too slow to be useful, and we didn't have any weight allowance left.

Cool part is that KinectCam was able to place a BMP crosshair at a certain "depth" into the image, which was great for aiming.

[Greg McKaskle]

There are numerous threads asking how to communicate between devices on the robot.

I've attached an image to show how the networking can be accomplished in LV.

The TCP and UDP icons are in the Data Communication/Protocols directory. When you don't need to receive all data, and are sending smallish amounts, I prefer to use UDP. It is really simple to use. You need to identify how to encode the data. You can use json, xml, or flattened binary. Just have the read side match and have it check for timeout errors.

TCP is similar -- but different. Large amounts of data, above a few Kbytes will typically use TCP instead of UDP, and if you are sending a protocol where all elements must be processed in order, TCP is your friend.

Greg McKaskle

[ekapalka]

Originally Posted by Greg McKaskle

I've attached an image to show how the networking can be accomplished in LV.
[small, elegant LabView code]

sigh... I really hope it turns out to be like that in C++... or even Java. Actually it wouldn't be too much of a learning stretch (formatting wise) to use java.

[yash101]

Originally Posted by Domtech

I played around with using the kinect as a driver camera last year, and I managed to get it working with just some of the shelf freeware:

1. KinectCam, a driver to make the kinect work as a USB webcam.

2. yawcam, a small aplication to host the camera feed over the network.

It worked quit well, but at about a second of lag with the classmate on the robot transmitting over wifi, it was too slow to be useful, and we didn't have any weight allowance left.

Cool part is that KinectCam was able to place a BMP crosshair at a certain "depth" into the image, which was great for aiming.

This post just solves half the problems that I am having with OpenCV and hacking the kinect

[ekapalka]

Originally Posted by Invictus3593

I know TCP is the protocol used by the axis camera and the port it uses is 80.

[...] If you can't write your own TCP libraries, i'd definitely find a third-party client to work with.

Thanks! That really does help. I've been looking all over, and I've gotten the impression MJPEG just passed java by, and wasn't really picked up and developed by the java community (which makes finding useful resources a pain...). I've found great libraries for streaming straight JPG images via UDP, but I have a feeling that the DriverStation is pretty locked down and resistant to change. I've also found a few promising and "robust" third party TCP libraries, but I'm almost certain we would end up having to write our own program to encode the series of JPEG images to MJPEG video (I can't find info on this ANYWHERE). Are there any other options for streaming video through port 80 to the driver station (without creating a custom dashboard or something like that)? Thanks!

[yash101]

Since I am familiar with PHP, can I have nginx and php serve a file to the cRIO? How would I do this?

[Invictus3593]

Originally Posted by ekapalka

Thanks! That really does help. I've been looking all over, and I've gotten the impression MJPEG just passed java by, and wasn't really picked up and developed by the java community (which makes finding useful resources a pain...). I've found great libraries for streaming straight JPG images via UDP, but I have a feeling that the DriverStation is pretty locked down and resistant to change. I've also found a few promising and "robust" third party TCP libraries, but I'm almost certain we would end up having to write our own program to encode the series of JPEG images to MJPEG video (I can't find info on this ANYWHERE). Are there any other options for streaming video through port 80 to the driver station (without creating a custom dashboard or something like that)? Thanks!

If you're trying to use the driver station to connect, it is gonna be locked down, but the dashboard isn't. If you need help programming a custom dashboard, there are white papers all over the internet that can help or you can post in NI Labview!

If you're completely shut down to the custom dashboard idea, you can try writing a seperate program that you can run on the driver computer that only gets what you need from the stream, but I don't think it would be easily integrated into driver-side vision processing.

[yash101]

If NI redesigns the driver station with the new control system, it would be a great idea to add an SDK for the driver station; in other words, they should allow macros, scripts and ability to add controls to the driver station

[Greg McKaskle]

Can you explain what you mean by "add controls"?

Greg McKaskle

[yash101]

Yes, sir, indeed.
What I mean by controls is add features to it, like multiple cameras, or buttons within the driver station or anything else you could possibly think of

[ekapalka]

Originally Posted by Greg McKaskle

Can you explain what you mean by "add controls"?

You seem like the right person to go about making suggestions to regarding the DriverStation. What I want is a full-fledged DriverStation SDK that gives programmers straightforward and simplistic control over the entire atmosphere (not only the SmartDashboard, but the look and feel of the DriverStation app, as well). Also easy two way control between the DriverStation and an onboard computer. What I'd really love would be to have things like dynamic apps that can change depending on the task and non-standard I/O, custom buttons, custom sliders, particle affects, colour changing text, OpenGL simulations, realtime graphs, and simple video streaming procedures for non-IP cameras. I think I've set my expectations wayy too high :P I would at least like a change of DriverStation colours... I always feel like I'm using Windows 98... I'm so sorry for complaining... I'm just working on a custom dashboard, and I've set a lot of really high goals... thanks!

[yash101]

I will have to agree with that. I think that that is one of the "dreams" of many Driver Station users