S2 (Scribbler II) Object Overview

Phil Pilgrim (PhiPi)

I've attached the "Documentation" view of the S2 object I've been working on for the Scribbler II. During the last few weeks, I've concnetrated on motion control and drawing commands. All motion in the S2 is coordinated and tied to the motor encoders. What that means is this: if you slow or stop one wheel with your hand, say, the other will slow proportionally or stop so as not to distort the motion profile.

Hopefully, the embedded comments will be self-explanatory. If not, I'll be happy to answer any questions you might have. Although this object is nearly finished, it should sitll be considered a work in progress.

Thanks,
-Phil

hover1

Thanks Phil. This is going to be a powerfull little robot!
Jim

erco

Nifty, looks terrific Phil!

The initial S2 specs called for "more powerful motors" than Scribbler. I sure hope this means lower gearing for better low-speed control. Most of Scribbler's 255 different "speeds" were unusable since the motor was just stalled at low speed, even on a smooth flat floor. I've read posts describing this same problem on another new robot, touted as "fast". A silly situation, to be sure...

One of my first mods on my Scribbler was to change the gearmotors to lower the ratio, which made it slower and far more controllable. High-end speed without fine motor control is useless on a robot that shows this much potential.

My two cents!

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·"If you build it, they will come."

erco

BTW, one of my early Retrobot feedback demos on Youtube shows just what you described above: one wheel slows down to sync with the other as·a load is applied: http://www.youtube.com/ercost60#p/u/9/VzbKlwc4GWs

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·"If you build it, they will come."

Whit

@Phil,

This is very impressive! When the new S2 is ours, will the full code be accesible?

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Phil Pilgrim (PhiPi)

erco,

The gear ratio is 126.85:1. But, more importantly, the encoder feedback provides much finer control than a PWM duty cycle alone could afford, especially at low speeds. (But you knew that. )

Whit,

Absolutely! The S2 object source will be available to use (and modify) in any way you see fit.

-Phil