pic: 3 wheel omni drive concept

[GeeTwo]

Originally Posted by z_beeblebrox

... how damage is avoided when the robot tips over (that's a lot of energy that has to be dissipated).

Originally Posted by s_forbes

Self righting would be done using a versaplanetary winding a strap to move an arm, one on each side of the robot. The arm would return to it's original position when the strap is let back out, using the magic of springs (more latex).

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A damper to lessen the shock when falling over is a really good idea. I'm not sure where the best place to source parts for something like that would be. Some mountain bike spring/damper sets could be used, since they are lightweight by design. Maybe a simple low force gas strut could work, too.

You may also be able to achieve this by partially deploying the self-righting mechanism, and taking up the shock through backdriving the VP.

Originally Posted by s_forbes

Using the toggling style of strafing mechanism is probably a much better application for this, since when it's not in use it leaves the full weight of the robot on the two outside wheels. (I believe this was first used on 148's 2014 robot?) You could probably spend a lot of time playing with the geometry to get it to work just right for a strafing segway robot, since the downforce is dependent on the geometry and how much torque the motor is applying. Would be a fun project!

I did a white paper on the math of this sort of module about two years ago that may give you a good start. Note that this configuration will take more weight off of the wheel you're strafing away from than the one you're strafing towards; it may be easier to keep the balance routines working with a centered, linearly sprung/actuated strafe module.