Frame rate vs Scan Detail?


#1

I’m curious about the exact interaction between frame rate and scan detail.

From the documentation, I understand that there are High, Medium, and Low detail levels. Is there any way to quantify those levels of detail? Are they different degrees of interpolation applied to the basic 185 x 105 grid? Or, are fewer sensels being scanned?

There is a theoretical maximum frame rate of 2000Hz. Low Detail == up to 1000Hz, Medium Detail == up to 250Hz, and High Detail == ???. It doesn’t seem like 2000Hz is possible at any of these levels of detail. Is there a way to get to that?

The Morph page lists full resolution mode (125 Hz) and High Speed Mode (500Hz). How do those relate to API calls? Can I replicate to performance of the Drum Overlay using API calls?

Thanks.


#2

Hello, thank you for contacting us.

  1. The force image will always be 185 by 105 and we can still offer high accuracy tracking with interpolation. The thing that will change is the two point discrimination (how close you can put two points next to each other) and the frame rate. With lower detail we can offer higher frame rate but you may not be able to separate two fingers adjacent to each other. With high detail you can distinguish two points very close together but it has a slower frame rate.
  2. 2000 Hz is the current API maximum so that if we push our hardware to higher frame rates, the software does not need to change. Yes, the Morph currently does not go to 2000 Hz. The fastest is between 500-1000 Hz in high speed mode.
  3. Full resolution is the high detail mode so it runs around 125 Hz.
  4. The Drum Overlay is running in high speed mode with the maximum frame rate. We are doing some additional processing in firmware but nothing I can go into detail on the forum.
  5. We list high speed mode as 500 Hz and up to 1000Hz because if you set the frame rate to be 500 in low detail mode, then it will remain 500. If you set the frame to be 1000Hz, then it will vary depending on the number of contacts and forces applied to the surface in the 600-1000Hz range.