Robot Suspension System Design

The problem with a typical suspension system is that its very complex and involves many parts.

As a solution, I invented a new type of robot suspension consisting of one single flexible part.

To learn more about my design, check out my tutorial at:
http://www.societyofrobots.com/mechanics_robot_suspension_system.shtml

Category:

Science & Technology

Tags:

• robot
• suspension
• system
• ERP
• experimental
• platform
• finite
• element
• analysis
• FEA
• CAD

[TheChickenLoop]

Tires achieve a nearly identical result. Whether you can argue the benefits of this design is moot - neither tires nor this design provide damping to the degree that is necessary to achieve an effective suspension system. With no way to extract the energy from an impact, a bump can send this design airborne, unlike a traditional suspension. Keep going, though - I'm sure you can incorporate an equally simple solution to achieve damping.

[palmisano]

@TheChickenLoop It's a suspension system to help keep all four wheels on the ground when on uneven terrain . . . it's not for high speed damping . . .

[pomeroy600287]

I like the front wheels that can roll sideways as well. I suppose castors would be too innacurate?

[palmisano]

@pomeroy600287 They are called 'omni-wheels' =P

[SvenOkonomi]

Those designs might be a little concerning when it comes to lateral bend though. I have a feeling the center hub would pop out of alignment too easily when reasonable load is applied or when some sort of sideways motion is forced upon the unit like an uneven surface. The hook prong omniwheel suspenders are quite good though, you might even find its latteral bend could work WITH your design rather then against it. Interesting work! Thanks for sharing

[palmisano]

@SvenOkonomi Yeap I also analyzed lateral bend, even though you don't see it in the video. You can limit the bend by selecting appropriate material thickness.

[theonelinerkid]

those wheels would be brilliant for my friends diy scooter he made from boxes and wood cos you dont need srpings cos theyre in the wheel

[RustyNex]

@kubarebo lol well it sounds like you have a beast of a car, because my car is very much affected by extra weight, i bought some alloy wheels of the same diameter as the original steel wheels but a lot heavier and it slowed the car right down, add extra passenger and its very noticeable. so maybe engine torque is what it comes down to, i know bikes with low engine torque but high RPM, weight makes a huge difference.

[Jesus45U]

@kubarebo

The volume of fluid in a shock absorber is less important than the viscosity of the fluid and the size of the gap/holes in the piston that moves trough the fluid. Hence how they can use magnetically enhanched newtonian fluids to enhanche shock absorbing without adding more volume.

And yes, it's a big deal - Try and take off the shockabsorbers (keep the springs offcourse) of a car and drive down a road with potholes. At 10 mph, no problem, at 60mph, you will be all over the place.

[kubarebo]

@RustyNex The moment of inertia of wheels on my car adds about 200kg of equivalent weight to the car per m_eq=I*(1/r)^2, so it's not as horrible as it'd sound. I don't feel much difference in acceleration with 3 extra adults in the car... I don't exactly do WOT every 20 minutes. Well, maybe every 40 minutes ;)

[RustyNex]

@kubarebo of course rotational mass is an issue, the more weight the engine has to rotate the more torque it needs. Rotational mass, over all mass and unsprung mass, all dictate how the car performs, but few components are in all 3 areas, wheels are one of them. But you are right that wheel weight is more of an issue to how the suspension performs, but its also an issue to acceleration, anyway in my experience with mechanics, this design wouldn't be effective on a larger scale with larger forces

[kubarebo]

@TheChickenLoop This design does not provide damping because it was designed with no damping at all. It can be easily modified to add damping, and that's what I was saying all along :) So we agree.

[kubarebo]

@Jesus45U The active volume of a hydraulic damper in a typical passenger car suspension is on the order of 10 cubic inches. This "quite a lot of dampening" is very compact. You make it seem like a much bigger deal than it really is :)

[kubarebo]

@RustyNex Rotational mass is not an issue. Overall mass is an issue in cars. The real issue is really unsprung mass -- that's why the wheels have to be light, not because they rotate, but because the heavier they are, the poorer the car's response to shocks. Since this is a composite wheel, not all of it is unsprung mass. The parts that are rigidly coupled to the shaft are stuck to the body of the car and can be as heavy as you wish, pretty much.

[Jesus45U]

@kubarebo

Whoa .. a blast from the past, someone reply to a 2 year old post. :)

Anyways, the problem with speed, is that it doesn't scale liniearly.

Old Swordfighters found this out by experimentation.

If you swung a sword, double the weight, and you double the impact.

Double the speed however, and you quadruple the impact - hence why most swords weigh only 3-4 pounds.

This means that you need quite a lot of dampening at higher speeds, and that becomes a problem in designs like this.