Semi-Omni-Arcade Drive

[Chris is me]

This seems "cool" and all, but is it that much more intuitive over a standard arcade or tank drive to warrant so much time being spent coding and debugging such a control algorithm?

[virtuald]

We did it last year with a swerve drive. It works reasonably well. Did not have any problems with gyro drift, it was mostly irrelevant.

Implementation for an omnidrive robot is pretty trivial, its just a little bit of trig. Our code release (see http://www.virtualroadside.com/FRC/) for last year has an implementation by one of our students, he called it 'CompassDrive'. He implemented it for a 2-motor prototype also, and that was a little bit more involved due to trying to correct for drift and such.

What we found is that some people like it, and some people don't. So just make sure you implement both methods of control and see which one works best for your drivers.

[thefro526]

Originally Posted by Chris is me

This seems "cool" and all, but is it that much more intuitive over a standard arcade or tank drive to warrant so much time being spent coding and debugging such a control algorithm?

Chris, I worked with a local team back in 2007 on a similar concept and found that it's an excellent system to have once it's working properly, because it lets less experienced drivers pick up the controls and drive more effectively because they don't have to think as much. At the same time, I didn't like how the system felt, mainly because it was arcade, but also because I felt like there was a layer of sorts between me and the robot.

I personally feel that such a system is only worth spending time on if you have the programming resources though. If your programming resources aren't the greatest then you're time may be better spent elsewhere....

[Adam.garcia]

Yes, team 1388, Eagle Robotics used a gyro for their steering mechanism. I was so impressed as to how it worked. They had a bike tire, with pegs on each side to show the concept.

[Jared Russell]

Originally Posted by Adam.garcia

Yes, team 1388, Eagle Robotics used a gyro for their steering mechanism. I was so impressed as to how it worked. They had a bike tire, with pegs on each side to show the concept.

This is an active gyroscope with a rotating mass. The original poster was referring to a MEMS sensing gyroscope.

But yes, Eagles Robotics' gyro system was very cool.

[byteit101]

Figured out our problem, we thought the gyro was using 0-1, so we were multiplying the results by 360. actual drift was only 0.01 degrees a second.
We also had driver testing, and decided to not use this drive system. They liked Twist joystick Arcade better

[buchanan]

In "real life" I do a lot of work in human-hardware interaction and measuring effectiveness of different ways of doing things. Without reading too much into it with respect to the particular merits of one control paradigm over another, consider some general thoughts:

What seems (or what they say is) easier or more intuitive to people isn't necessarily. When you want to evaluate the effectiveness of alternatives, measure their actual performance on tasks similar to the ones you care about. "Intuitive" often is used simply as a synonym for "familiar", and people with hard-won skills in a difficult task are prone to describing what they do as "easy".

Subjective evaluations like these are notoriously untrustworthy. If you want to find out what works best, measure how well things work. If you want to give people what they like, ask them what they like. Be careful about confusing the two.

[Greg McKaskle]

If you want to give people what they like, ask them what they like. Be careful about confusing the two.

And then give them feedback in the form of a side-by-side test, as blind as can be -- placebo effect doesn't only affect drug tests. Sometimes it takes a skill test and measured data to convince someone of their own performance numbers.

Greg McKaskle