This air suspension is to be used with our third try drive. Through testing we found that you could add just enough air to hold the front of our robot at the desired height. When transitioning up a ramp on a angle one side would rise forcing air into the other side to push down. We could also add air as needed to raise or lower the front as needed for a game or stiffen the suspension.
Clever… since the pistons are all connected and of the same bore, the pressure and therefore the force on each wheel must be the same.
But since the weight distribution in your robot is not 100% even, do you8 have a problem with it sitting at a funny angle? Also is there a benefit to using double-acting pistons or could you save hose, fittings, and weight and go with single acting pistons?
Neat idea!
-q
Alec Issigonis, the designer of the original Mini, had similar designs for a hyrdraulic suspension back in the day.
Neat Idea although there are often added complexities to adding suspension. Chain tension can be problematic.
We are using this design to replace our curent design. The old design cuts off the front of the robot and would create design problems with game collection peices. The new design clears the front and also makes it stronger.
Below is the old designhttp://www.team1322.org/new%20drive008.JPG
Joe,
I would just like to make you aware that in the past, using mechanical force to move a piston and create pressure was deemed illegal under the robot rules. Each year pneumatic rules change but before you dedicate your design, please wait for kickoff and then ask the question through the Q&A.
Regardless of legality, have a few students write white papers on these different approaches. Make them thoroughly research and explain them, and include pictures of the beasts. It will make applying to college and getting scholarships into a cakewalk.
Very cool designs!
I don’t think the rules have ever been quite that specific and restrictive. In many applications, the robot mechanisms “push back” on the pneumatic cylinders and can potentially pressurize the system. In my experience, the main thing the inspectors have watched for in such cases is that a relieving regulator prevents overpressurizing things.
You wouldn’t be permitted to use a totally closed pneumatic system as shown in the drawing. You’ll want to put a regulator on it to maintain the desired pressure anyway, and that ought to take care of it.
You have to watch what this does to your bumper zone, should bumpers be required again this year.
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
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.
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.
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…
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.
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.
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
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.
:p:rolleyes::D:rolleyes:
Just like airbag systems on low riders. Get some big rims and underglow next :).
I realize that this is of no help at all, but trucks are my other hobby than robotics.
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.