Chief Delphi - 2008 and drivetrains

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Re: 2008 and drivetrains

the quick prototype GUI mentioned turned out to be a great success, being a better drivetrain in 2 days than our last year's 6WD in 3 weeks. A designed ackermann steering drive train will perform way better than even the prototype.

As far as our team is concerned, Ackermann steering is the way to go!

Re: 2008 and drivetrains

Kevin is exaggerating. The prototype was nowhere near as good a drivetrain as last year's. something about the steering motor not actually firmly attached to the linkage and the potentiometer mount falling off that doesn't seem to work well...

But the final chassis should be a simpler, lighter design than the previous year's.

Re: 2008 and drivetrains

Quote:

Originally Posted by dtengineering (Post 672003)

What I am looking forward to is the emergence of "car" steering. We are seriously considering setting up just like a sports car... rear wheel drive, front wheel steering. While it doesn't have a "zero" turn radius like tank drive, it should work great for high speed cornering and swerving around other robots heading down the straights.

But we've got a few other tests to run before we commit to that just yet.

Jason

Having completed the tests, we're going to go with 2wd "tank" drive.... traction wheels in front, omnis on back, gyro to go straight.

The deciding factor was, as suggested by others in this thread... Keep it Simple, Finish Early, and PRACTICE.

It is a bit of shame as we had some neat ideas for 4 wheel drive / 4 wheel steering, but as we discovered with our mecanum drive last year, "cool" and "competitive" drive trains are not always the same thing. We're keeping things pretty conservative this year and re-using some COTS wheels from a previous practice robot.

But I'm looking forward to seeing the many cool, competitive and off-the-wall brilliant outside the box ideas that come out this year. I think this must be a pretty good game if after one week there is still no consensus on what the best drive train design is likely to be.

Jason

Re: 2008 and drivetrains

Quote:

Originally Posted by MikeDubreuil (Post 672421)

I can't wait to see the first Ackermann steering robot in competition :D

we just finalized our drivetrain and we are using Ackermann steering:D

Re: 2008 and drivetrains

We are thinking of using ackerman, but we aren't sure that it gives us a huge advantage over two front wheel drive wheels with two omni's in the back, does anyone have any thoughts?

Re: 2008 and drivetrains

We briefly considered using a mecanum set-up for a holonomic system. Strafing could get around the corners quickly but then you have that 40 inch ball to move with you. We are still in testing mode as to whether omni-wheels on the rear will be needed on our basic four wheel drive robot seen here. Comments are welcome.

Re: 2008 and drivetrains

With our prototype, we yound that an Ackermann system is much easier to control than the other bots we were testing. Mostly everyone found the mecanum bot to be confusing to drive due to mecanum's tendancy to drift off course, and if you don't pay attention to how you are oriented it is easy to go the wrong way. With the six wheel drive, we found very finnicky controls, it is very easy to over shoot or undershoot a turn. The ackermann drivebase was very intuitive to drive, and goes where you want it. It can also be driven straight forward easier.

Re: 2008 and drivetrains

team 753's front drive wheels for 2008 we will have these wheels in the front working in conjunction with 2 omni wheels in the rear all driven by 2 small sims with chains and sprockets (through the andymark kit gear boxes)