New Official Stereo Module?
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With the M0015 Stereo Module being end-of-line, is there a new stereo system that ModalAI is officially supporting? Or has support for stereo vision/computing been dropped?
Thanks! -
@john_t , you can use two AR0144 modules (M0166) in a stereo configuration. When connected to VOXL2 using M0173, the two cameras will be synchronized (start of exposure).
Even though we are not actively using dual AR0144 for DFS, we have tested and it works with
voxl-dfs-serverwith some tweaks.If there is interested in this, we can document how to set it up (using
voxl-dfs-server.)Would you be using your own DFS processing?
Alex
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@Alex-Kushleyev Thanks! Ideally, we would leverage your DFS processing as much as possible.
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@john_t , sounds good. The DFS processing on VOXL2 happens on the DSP, so it's quite efficient and does not use up much CPU or any GPU.
By the way, you could also simulate lower resolution DFS by binning the 1280x800 into 640x400 and it would be very similar to using the older M0015 stereo modules, so that DFS configuration from M0015 stereo could be used without much change.
Since the AR0144 stereo is not a configuration we currently use / support (but we have tested before), we don't have a ready-to-go documentation for setting this up.
This would be kind of experimental test on your end, which we will support. At minimum, you would need:
- voxl2 + APM + power adapter
- M0173
- two AR0144 (M0166) with appropriate coax cable lengths (comes with 80mm cable, but there are other lengths available via custom order)
If you wanted additional cameras, it may be chaper to get a M0173 bundle: such as https://www.modalai.com/products/m0173?variant=48528274424112 or similar (please check cable lengths)
Once you have the hardware, we can set up a similar test (based on your baseline, camera orientation) and help you get started.
Alex
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@Alex-Kushleyev Thanks for the info! It sounds like stereo isn't necessarily the preferred way of obtaining depth information with the VOXL 2's anymore. Is ModalAI's preferred method the ToF sensors now?
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@john_t , I think DFS is tricky on drones because it requires a very good calibration (intrinsics, extrinsics) and the extrinsics cannot change, which is hard to guarantee on the drone. Alternatively, a robust system would be needed that will continuously recalibrate extrinsics over time. This may be the reason why stereo is not easily to use with consistent success on drones.
ToF works well indoors with range up to 4-6 meters, but outdoors the sunlight will severely degrade the performance. Some technical details are available here : https://docs.modalai.com/M0178/
Alex
