Backpack PC for a Kinect-v2 on the PR2

This is a small computer for the PR2 robot, in order to install a Kinect v2 (or Kinect One).

The Kinect-v2 needs a USB-3 port, not available on the computers of the PR2.

The driver also needs a GPU capable of running OpenCL.

We have the following configuration installed on Raphael, our PR2:

• AMD A10-7850K APU processor (TDP 95W) link
• ASRock FM2A88X-ITX+ miniITX mainboard link
• CPU cooler: Noctua NH-L9a link
• 16GB DDR3 RAM link or low-profile link
• mSATA 128GB Sandisk X110 solid state drive link
• M350 Mini-ITX case link
• Wall mounting brackets for the M350 link
• Extra FAN for the M350 link
• picoPSU 160W power supply (12VDC) link
• 192W power adapter (230VAC → 12VDC) link

Approximate cost: 600 EUR.

If we had to build the backpack again (as of 22.05.2015), now that the Intel USB3 ports work for the Kinect and the OpenCL support for the integrated GPU is there, we would go for the following configuration (a bit higher performance, and lower power consumption):

• Intel Core i7-4790T, 4x 2.70GHz, tray (TDP 45W) link
• ASUS Q87T Thin-Mini-ITX mainboard link
• CPU cooler: Noctua NH-L9i link
• 16GB DDR3-SODIMM link
• mSATA 128GB Sandisk X110 solid state drive link
• M350 Mini-ITX case link
• Wall mounting brackets for the M350 link
• Extra FAN for the M350 link
• 150W Power supply (230VAC → 19VDC) link

Approximate cost of the new configuration: 750 EUR.

The case could also be a Akasa Euler S Fanless Solid Aluminum THIN Mini ITX Case. Prices here. That would make the computer fanless, but we would require some adapter from the VESA mount to the item aluminum profile.

If the PC should be powered by the internal power supply of the PR2, then a DC/DC converter would be needed to provide the 19VDC. Intel recommends a 150W power supply for the 45W TDP processor PCs. I suggest a Traco Power TEP 150-4815WI. It has a nominal output of 24VDC, but it can be adjusted +-20% with an external resistor. That should be able to feed the 19VDC+-10% needed by the thin-mini-ITX mainboard. For the original configuration on Raphael, with the PicoPSU that needs 12VDC, then the Traco Power TEP 150-4812WI would be appropriate. Both have an input range of 18-75VDC.

Thiemo also suggests a faster i7 (here), but limiting the frequencies to keep it cool. You save a little money and have potentially more performance. But we still think that the suggested i7 should be fine, or even the AMD A10.

We used Item-5 profile from Item. They are extruded aluminum profile, with a size of 20x20mm. We built a “U” and attached it to the mounting ports on the sides of the PR2.

Then we install the wall-mounting brackets to the M350 case, and it is simple to screw the case to the item profile.

The Kinect sensor is installed on the head of the PR2 using a laser-cut plexiglass plate.

Use the driver driver developed by Thiemo Wiedemeyer, hosted at Github. link

We installed Ubuntu 14.04 on the Backpack-PC and run ROS-Indigo. It talks happily to the rest of the PR2 running Hydro.

This extension to the PR2 was done by Alexis Maldonado and Thiemo Wiedemeyer, both working at the Institute for Artificial Intelligence of the University of Bremen