Smallest / lightest VOXL 2 camera stack for RGB + thermal + navigation on sub-250 g UAV

[ישראל בן שלמה]

Hi ModalAI team,

I’m developing a sub-250 g UAV and am trying to determine the lightest practical VOXL 2 / VOXL 2 Mini camera and sensor architecture for the aircraft.

The target payload functions are:

• Daylight RGB video / imaging
• FLIR Boson+ 320 thermal video
• Camera input required for reliable VIO / navigation
• Lowest possible total camera, adapter, cabling, and interposer mass

I am specifically trying to avoid carrying unnecessary stereo, ToF, or additional cameras if they are not required.

Could you recommend the exact minimum hardware stack you would use for this application?

In particular:

1. For reliable VIO, can we use a single tracking camera, or is a stereo pair required/recommended?
2. Which current ModalAI tracking camera/module would give the lowest installed mass?
3. For RGB imaging, what is the lightest currently supported color camera/module that can provide useful daylight video?
4. For a Boson+ 320, is the current recommended connection still:
   Boson → M0201 → coax → M0181 → VOXL 2 J8?
5. Can the Boson, RGB camera, and minimum VIO camera configuration operate simultaneously on one VOXL 2 / VOXL 2 Mini?
6. If yes, could you provide the exact ModalAI part numbers/interposers/cables required and, if available, approximate individual masses?
7. Is there a supported camera configuration close to this, or would it require a custom voxl-camera-server configuration?

The aircraft has a very tight mass budget, so I am trying to establish the absolute minimum viable sensor stack rather than starting from one of the larger development-kit camera configurations.

Thanks,
Yisrael

[Alex Kushleyev]

Hello @ישראל-בן-שלמה ,

Please see some options below and the recommendations at the end.

• For reliable VIO, we recommend dual tracking cameras. The tracking cameras are very light, so the extra 3 grams will give you lots of safety margin
• AR0144 is probably the best option since this is what we use. 2.2g with 80mm coax cable
  • OV7251 camera (M0014) is probably the smallest (it is lower resolution also 640x480 vs 1280x800 for AR0144). ov7251 is EOL but it looks like we have some in stock. the weight of M0014 module is 0.5g (with the flex cable). However, to connect it to VOXL2 / mini, you would need an interposer like M0076 (0.6g) ( or M0135 (1.0g)
• IMX214 (M0025 module, https://docs.modalai.com/M0025/ ) may be the lightest 4K camera we have (0.7g with flex cable), but it is very old and sensor + lens quality is very far from our newer (and heavier) IMX412- and IMX664-based camera modules.
• Flir Boson 320 is a bit heavy too. The one i have with lens is about 23g. Most of the weight is the lens, i think.
  • for connecting Boson to a Voxl2 Mini, you should use M0194 ( https://www.modalai.com/products/m0194 )
• Boson → M0201 → coax → M0194 → VOXL 2 Mini J6 or J7?
• you can plug in another camera into M0194, such as AR0144 (coax version) or the IMX412 (coax version)

The best option in terms of support (no EOL components) and hardware quality, would probably be:

• VOXL2 Mini (11g)
• M0195 (5.0g) -- see C43 configuration : https://docs.modalai.com/M0195/
• Boson + M0201 + coax -> plugs directly into M0195. weight of M0201 + 80mm coax is 1.7g + 0.7g = 2.4g. Need to add weight of Boson!
• one or two AR0144 (M0166) -- 2.2g with 80mm cable (each)
• hires camera (IMX412) M0161 : 8.5g with 800mm coax cable

Minimal Config

• VOXL2 Mini (11g)
• M0194 plugged into J7 (1.4g) + 80mm coax (0.7g) + M0201 (1.7g) + weight of Boson
  • M0166 AR0144 (2.2g with 80mm coax) plugged into M0194
• M0076 (0.6g) plugged into VOXL2 mini J6
  • M0025 IMX214 camera (0.7g) plugged into M0076
    ** note that this is mixing the coax and non-coax cameras, but i think this should work. we would need to give this a quick test to make sure.

Alex