Fully Active Pneumatic Suspension Build Completed

[pvfjr]

Hey guys, I've finally completed a senior project I've been working on . Check it out and let me know what you think.

https://sites.google.com/site/pvfjr1/aleas

It's a modified SCX10 Honcho that has small pneumatic cylinders for shocks. It has a control system that I designed with an accelerometer, gyroscope, force sensors, and cylinder position encoders. Servos operate small air valves, and two lightweight tanks store compressed air from a bike pump.

Using open differentials, I have more than doubled RTI test performance, added 7* of rollover resistance, and improved dynamic ditch escaping abilities. Check out a couple of the videos below, or just visit the site for more information.

https://www.youtube.com/watch?v=V_fctmLv1VM

https://www.youtube.com/watch?v=_9AArzLKP0E

[Fauker]

That is a very cool project! I will have to remember to watch the videos when I get home from work.

[1r3land]

Wow. Very cool. That's amazing work. Give yourself a pat on the back.
I wish I had the knowledge and time to do that!

Very cool.

[pvfjr]

Originally Posted by 1r3land

Wow. Very cool. That's amazing work. Give yourself a pat on the back.
I wish I had the knowledge and time to do that!

Very cool.

Thanks. This is the project where I get to show off five years of learning electrical, computer, and mechanical engineering. I'm pretty pleased with how things turned out--particularly the dynamic ditch escape. It was an interesting problem that's never really been done before, and I had no idea if it would even work.

[Liv3mind]

That is seriously one of the coolest self built systems I haver ever seen in rc, awesome.

[alpine4x4]

Thats a pretty nifty setup. Very creative. Question, what is the weight of the stock rig as tested and what is the weight of the modified rig?

[rockhugger]

Love it. Nice work.

[braceysdad]

That is too cool, very inventive

[rockhugger]

Originally Posted by pvfjr

Thanks. This is the project where I get to show off five years of learning electrical, computer, and mechanical engineering. I'm pretty pleased with how things turned out--particularly the dynamic ditch escape. It was an interesting problem that's never really been done before, and I had no idea if it would even work.

Was this project for personal achievement, or are you submitting it for something? Before I read about your five years of Education, I immediately thought you were either a student or graduate in the videos. Bravo again!!!

I think it has actually been tried before on rcc, but never finished iirc. In 1x1 there was a load leveling system for crawlers based on air bags and a central brain. It never got popular for some reason.

I'm also curious of the weight difference between these two test vehicles.

[micro racer]

That is really cool! Your website says that is a proof of concept, so I hope you can continue working on it and get it into bigger and better things! ie. 1:1 rigs!

[pvfjr]

Originally Posted by alpine4x4

Thats a pretty nifty setup. Very creative. Question, what is the weight of the stock rig as tested and what is the weight of the modified rig?

The stock rig is 5 lbs, the modified one is 5.8 lbs. Not much weight added overall.

[pvfjr]

Originally Posted by rockhugger

Was this project for personal achievement, or are you submitting it for something? Before I read about your five years of Education, I immediately thought you were either a student or graduate in the videos. Bravo again!!!

I think it has actually been tried before on rcc, but never finished iirc. In 1x1 there was a load leveling system for crawlers based on air bags and a central brain. It never got popular for some reason.

I'm also curious of the weight difference between these two test vehicles.

This was for a senior design project. I'll graduate in June with a bachelor's in ECE (electrical and computer engineering) and one in ME (mechanical engineering). Instead of doing a project for each degree, they're letting me do a multidisciplinary project instead. If I can find time this term, I might have to write a conference paper about it.

Do you think you could find a link to the 1:1 system you're talking about?

[pvfjr]

Originally Posted by micro racer

That is really cool! Your website says that is a proof of concept, so I hope you can continue working on it and get it into bigger and better things! ie. 1:1 rigs!

Yeah, I have a Nissan Pathfinder, some 16" cylinders, and a set of Mercedes Unimog axles that I'd like to try this with.

[WHITE-TRASH]

Originally Posted by pvfjr

Do you think you could find a link to the 1:1 system you're talking about?

Pretty sure he's talking about the air rock suspension system. I talked to the owner of a winch rope company one year at a big rock crawling event that had the system. The next year he brought his Jeep back with coilovers instead of air bags. I asked him why the change and he said it was great until you went around a long S turn on the highway and the suspension compensated for the side load. When you hit the next corner quickly the weight was already shifted outwardly not in or centered so it was spooky to drive.

[Wicked Monkey]

Eventually will you be able to do all the setup at the transmitter instead of having to touch the truck to adjust for the ditch escape for example?

[pvfjr]

Originally Posted by WHITE-TRASH

Pretty sure he's talking about the air rock suspension system. I talked to the owner of a winch rope company one year at a big rock crawling event that had the system. The next year he brought his Jeep back with coilovers instead of air bags. I asked him why the change and he said it was great until you went around a long S turn on the highway and the suspension compensated for the side load. When you hit the next corner quickly the weight was already shifted outwardly not in or centered so it was spooky to drive.

That's why I have a six-axis accelerometer/gyro on board. I can distinguish between static load differentials and those due to centripetal acceleration.
Too bad they abandoned the system for a fixable problem.

[pvfjr]

Originally Posted by Wicked Monkey

Eventually will you be able to do all the setup at the transmitter instead of having to touch the truck to adjust for the ditch escape for example?

There is a lot of programming that I could have done, but I was gathering a lot of data from the thing as it operated and didn't want to worry about packet loss, so I went with a dedicated UART/USB connection rather than a wireless connection. It would take very little work to hook it up with an Xbee or something though.

[rockhugger]

Originally Posted by WHITE-TRASH

Pretty sure he's talking about the air rock suspension system. I talked to the owner of a winch rope company one year at a big rock crawling event that had the system. The next year he brought his Jeep back with coilovers instead of air bags. I asked him why the change and he said it was great until you went around a long S turn on the highway and the suspension compensated for the side load. When you hit the next corner quickly the weight was already shifted outwardly not in or centered so it was spooky to drive.

That's the one. It was Air rock. It was a great idea, but in the end, I don't think it was fully thought out.

Originally Posted by pvfjr

That's why I have a six-axis accelerometer/gyro on board. I can distinguish between static load differentials and those due to centripetal acceleration.
Too bad they abandoned the system for a fixable problem.

This was quite a few years ago, so maybe the problem was not so fixable then... or cost to much, either way, you're right... and I say, why waste the money going to market if it's not a sound design and will ultimately fail.

I'm also sure Accelerometers have shrunk in size, and / or are more readily available for such uses now.

good stuff on the degrees.

[o0wiz0o]

Land Rovers have a similar system. My Discovery 2 had it.

[WHITE-TRASH]

Originally Posted by pvfjr

That's why I have a six-axis accelerometer/gyro on board. I can diprogrstinguisheen static load differentials and those due to centripetal acceleration.
Too bad they abandoned the system for a fixable problem.

In the end the product was abandoned because it was an over complicated answer to a problem that really didn't exist. Properly tuned suspension flat out works. The vehicle will be as stable as its center of gravity will allow for and be comfortable to drive. Most importantly it'll be stone simple and easy for anyone mechanically inclined to fix.

Some people build nice stuff and get around just fine. While others are in engineering programs and think they can build the best mouse trap. Look up chainlink and chainlinks retarded cousin for perfect examples of a super complicated answer to the non problem. I'm not playing down the knowledge or skills needed to build an rc with active suspension so don't get me wrong. I'm just saying enjoy it for what it is, your kick ass project.