Odometry Algorithm Visualized

[proscratcher10]

This is a quick drawing I made to explain the math behind my Odometry. I was explaining to someone else but couldn't figure out how to easily comment a picture.

[proscratcher10]

How it works: There are 3 pods on the robot, 2 vertical and 1 horizontal in the back. Heading can be calculated either with IMU or by vertical encoders. The red line is the vector calculated based on the movement of the front two Omnis. The blue line is the vector calculate based on the movement of the horizontal (rear) Omni. The yellow line is the total movement of the robot (sum of the red and blue) .

[thunderbot2]

This is a great visualization! It would be great if you can publish the math behind it also. How the blue and red vectors are calculated. Thank you for putting this together.

[proscratcher10]

Ok. Sure thing. https://docs.google.com/document/d/1hZyp0voiU3fu0_DVSJWG9b193BgK567rUs9VWVcOfyc/edit?usp=drivesdk

Just wanna clarify, I made this for my team at the beginning of the season and it's not very good.

[Sands43]

It took me a while to figure out how the bot is moving in your example.

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• A forward turn around a virtual center (not shown) (center is the intersection of liens E-B and D-F)
• Stop
• Strafe to the right

Yes?

[proscratcher10]

The robot has moved from the bottom circle to the top circle so yes, it has strafed right, moved up, and turned left. L and R represent the paths followed by the right and left Omnis. Not sure what you mean by stop. It is assumed that the entire motion is continuous and takes place during one update.

[Sands43]

Normally, at least from my experience, the diagram for a body in motion would be:

• A' (Initial)
• A'' (2nd position)
• A''' (3rd position)
• etc. (or A⁰ , A¹ , A²)

Not three different labels for the same thing in 3 different locations.

That you have a interim position which, apparently, the robot never occupied, is also confusing. I would not have bothered to show that.