November 11th, 2011 | | By Ken Mankoff
Following up on my previous post about using the Kinect for earth science applications, I’m documenting the Kinect Go Kit I built for fieldwork.
Kinect Go Kit: Top level
Kinect Go Kit Pelican Case
I travel with two Kinects, two power supplies, and two computers in case one gets damaged or destroyed in the field, although only one computer is in the kit.
The Netbook is a cheap $240 computer running Ubuntu and the libfreenect software stack at a minimum. I have also found it useful to have more advanced data collection software (ROS, RGBDemo, RGBDSLAM), and some analysis software (CloudCompare, points2grid, Viewpoints, etc.). This netbook works fine for raw data dumps from the libfreenect ‘record’ program. It can run the more computationally expensive scene stitching algorithms such as RGBDSLAM, but it takes about 10 seconds per stitch, while a more powerful laptop (but still a few years old) can do it at 0.5 to 1 Hz. Since ‘record’ collects about 1.5 GB of data per minute, it is good to have a lot of free space on the hard drive.
The plugs and cables are shown laid out below, and in addition, some velcro straps are stored in that compartment, used to attach the Kinect to the tripod arm.
The Pelican 1510 case supports two levels, and the lower level looks like this:
Kinect Go Kit: Bottom level
Battery #1 is a 12 V 5 Ah sealed led acid battery. It provides >5 hours of Kinect runtime, about equal to the runtime of the netbook.
Battery #2 is 8 AA batteries (12 V), and underneath is an 8 AA battery holder and a battery charger. If I need to turn the Kinect on for a short amount of time and want to travel lightly, these will do.
Kinect cable layouts
As shown above the cord to the Kinect can be cut and alligator clips or some other electrical termination can be attached. I often have wall power and have attached clips to the detached plug so I can use it as originally intended. However, when in the field, the clips can connect directly to the 12 V battery or the AA battery pack.
Kinect mounted on tripod
The Kinect Go Kit above is close to the minimum necessary for fieldwork. Things that I would like in it, but are not yet, include:
- Tape measure
- Liquid container (tupperwear) and opaque liquid (or additive) so that any scene can have a defined flat surface
- Sling for under tripod to hold battery, netbook, protecting equipment and keeping it off the ground
- Counter weight for tripod arm
Additional tools I have found handy to have with me in the field include, but are not limited to, the following:
- External hard disk for backups
- Zip-ties to complement the Velcro straps
- Spare notebook, perhaps with a more powerful CPU, for scene stitching
- Rope or other ‘image noise’ for scene stitching with RGBSLAM when working in environments that have ‘self similar’ scenes (no good tie points)
- Mounting systems for long term deployment
- Trashbags for environmental protection