pic: Air Suspension

[dtengineering]

Originally Posted by Al Skierkiewicz

Joe,
...using mechanical force to move a piston and create pressure was deemed illegal under the robot rules.

Al makes a good point... but it got me thinking that a system like this could be tied in to the robot's pneumatic system and you could actively raise or lower the pressure in the system to achieve different ground clearances... when you want to hold position and not be pushed around, just lower the robot frame right down on to the ground!

But regardless of FRC legality, this is a cool project on its own right.

Jason

[NickE]

Originally Posted by dtengineering

Al makes a good point... but it got me thinking that a system like this could be tied in to the robot's pneumatic system and you could actively raise or lower the pressure in the system to achieve different ground clearances... when you want to hold position and not be pushed around, just lower the robot frame right down on to the ground!

One thing I can think of to do this is have this pneumatic system on a secondary regulator and use a servo to actively change the pressure of the secondary regulator. I'm not sure if this is legal but it'd be interesting for sure. You could adjust how springy your suspension would be. Another idea would be to use a center-closing solenoid and close the solenoid when the piston is wherever you want it to be.

[Al Skierkiewicz]

Creating pressure using mechanical force on legal pneumatic component has been deemed illegal in the past. Reasoning behind such a rule is the possibility of a pneumatic system already at full pressure, with flow restrictors, could conceivably exceed system pressure of 125 PSI if pushed on with enough force.

Also, until last year, pressure modulators were not allowed. Last year, a few changes in the rules did allow them and I remember seeing one robot that had somehow controlled a pressure regulator to achieve a desired effect. I don't remember if it proved advantageous or not.

[Rion Atkinson]

I am loving the idea. It would prove very advantageous for anything. It has true real world potential. If legal it FIRST I would love to see it on a bot.


I agree with Gary, bumpers could cause a problem..

[joeweber]

I agree with Gary, bumpers could cause a problem..

As shown on our other post http://www.chiefdelphi.com/media/photos/34389? we would attach the bumpers to each section of the drives which would allow them to move up and down with the wheels keeping them at the correct height. The only problem I see is the bumpers could be called articulating which would be illegal.

Far as the pneumatics I Like the idea of having a pressure relief valve and a pressure regulator to make it legal.

[Rion Atkinson]

Originally Posted by joeweber

As shown on our other post http://www.chiefdelphi.com/media/photos/34389? we would attach the bumpers to each section of the drives which would allow them to move up and down with the wheels keeping them at the correct height. The only problem I see is the bumpers could be called articulating which would be illegal.

Far as the pneumatics I Like the idea of having a pressure relief valve and a pressure regulator to make it legal.

That makes perfect sense. A very good idea. And the argument of if the bumpers are articulating or not could be argued every which way.. Technically I would say they wouldn't be. What is the difference between a robot with center drop and this when it comes to the bumpers? They are moving up and down (Now yes not as much, but none the less. They are moving) so couldn't that technically be called articulating? The bumpers would only move with the wheels, which would go with the level of the ground, so wouldn't they technically never go above or below the rule book's allowance?

Just my thoughts. I may be misinterpreting something..

-Rion

[Al Skierkiewicz]

Eric,
Pneumatic vacuum using cylinders was allowed in 2007 after some discussion, in 2004 it was not. The only legal vacuum devices prior to 2007 were venturis which create vacuum but not by mechanical force. However, even these were not legal in most years.

From 2004 Robot Pneumatic section rules <R54> revised...

• A device that creates a vacuum is not considered to be a pneumatic device, and is allowed. This includes, but is not limited to, venturi-type vacuum generators and off-the-shelf vacuum devices (as long a they are powered by one of the Kit motors).

Some teams used vacuum pumps that were COTS items, removed the motors and replaced them with KOP motors. The FP was the motor of choice that year.

[EricH]

Originally Posted by Al Skierkiewicz

Eric,
Pneumatic vacuum using cylinders was allowed in 2007 after some discussion, in 2004 it was not. The only legal vacuum devices prior to 2007 were venturis which create vacuum but not by mechanical force. However, even these were not legal in most years.

From 2004 Robot Pneumatic section rules <R54> revised...

• A device that creates a vacuum is not considered to be a pneumatic device, and is allowed. This includes, but is not limited to, venturi-type vacuum generators and off-the-shelf vacuum devices (as long a they are powered by one of the Kit motors).

Some teams used vacuum pumps that were COTS items, removed the motors and replaced them with KOP motors. The FP was the motor of choice that year.

Then two teams were using illegal mechanisms in 2004; a pair of West Coast teams used a setup similar to 386's 2007 one to try to create suction on the 2X ball.

[Al Skierkiewicz]

Eric,
That is a possibility particularly if this was a week one or two event. I did not look into which Q&A prompted which Team Update, I merely quoted the final robot rules revision.
I do remember at least one team, buying a cheap vacuum cleaner and replacing the motor with an FP. It worked fairly well as I remember.

[Brandon Holley]

Originally Posted by EricH

Then two teams were using illegal mechanisms in 2004; a pair of West Coast teams used a setup similar to 386's 2007 one to try to create suction on the 2X ball.

Not to mention Baxter's bot that year....that was a thing of beauty.

[joeweber]

Installed the air suspension. It does work but requires too much work to make it usefull. Keeping the correct pressure and all the systems needed is no justifiable.

[Elgin Clock]

It's not just your bumper zone you can throw out of whack with a design like that, it's your whole profile!
We had a drop down wheel this year that raised the front of our robot up ever so slightly, & when we measured it, the bot was out of profile with the wheel in the down position. We had to cut our frame depth (front to back) a bit so that when it leaned back it was still in profile.
Just one more thing to consider.

[EricH]

IIRC, Al, it did not extend to the generation of vacuums. I know of three separate instances where a team used 100% FRC-legal pneumatics to generate a vacuum via mechanical means. (2 in 2004 and 1 in 2007). All three were judged legal. It is possible to argue that this system creates 2 vacuum systems.

You could also make the argument that this effectively creates 2 closed-loop gas shocks, which have a rather off-and-on legality if I remember the past rules correctly. (Of course, then that begs the question of "Why not just do that on one cylinder instead of two?", but that's beside the point.)

And remember, now that we are in a bit of a rules discussion: 2010 rules may forbid pneumatics altogether or otherwise make this design either legal or illegal, so anything said here may or may not apply after 1/9/2010.

[Rion Atkinson]

Originally Posted by EricH

And remember, now that we are in a bit of a rules discussion: 2010 rules may forbid pneumatics altogether or otherwise make this design either legal or illegal, so anything said here may or may not apply after 1/9/2010.

Seeing as the rookie teams KOP will come with a Air Compressor I have reason to believe that pneumatics will be legal.

[EricH]

Originally Posted by Formerly Famous

Seeing as the rookie teams KOP will come with a Air Compressor I have reason to believe that pneumatics will be legal.

Don't tell them, but that's the ballast next year. The pneumatics come back in 2011.