I want to build a robot that is not confined to a single, perfectly flat area, so I want it to be able to handle stairs.
I invoke the creative powers of LMR to brainstorm the design for a staircase handling robot drive system.
Here are some of the design criteria:
It has to work for a fairly large robot. Something the size of R2-D2 or larger. (at least 1m tall, with a weight of 20-30 kg)
The stair climbing ability must not come at a cost to the agility of the robot on flat ground.
The drive system must be robust enough to survive real world stairs and pavement, maybe even carpets.
Why not a bigger version of the RoverX’s wheels?
Why not a bigger version of the RoverX’s wheels?
Whegs are cool
… but I think they might be a bit impractical for a tall robot. Plus, I’m not sure about their ability to carry a large weight.
Maybe wheels with retractable legs would be better?
How about wheels on an arm
How about wheels on an arm that will allow you to change the center of gravity.
** This. This is a winner!**
This. This is a winner!
Tank tracks are awesome, they work on just about every surface (grass, carpet, tile, gravel), strong (Steel tank tracks are indestructable for hobbyists) and can be easy to implement (two wheels with tracks over them). They also can be heavy (can be a pro or a con). Depending on the configuration of the tracks, the robot can have excellent mobility or excellent stability, but rarely both. It's a trade off, but sometimes necessary. This is the iRobot Talon (or something like that). It has a 2nd set of tank tracks that can pivot and rotate around, allowing it to traverse stairs.
Posum!
The Talon and the Shrimp are very interesting. I guess my fallback solution would be tank treads but I would like to try something more lightweight first. The shrimp drive system looks like a very clever design, but I would like something more compact. Maybe something similar to the shrimp but without the passive obstacle climbing features. Like Shawnesy said, wheels on actuated arms (actually legs). Hmmm… maybe a 4 wheeled bot with the capability to balance on a pair of wheels while raising the others onto the next step.
Following that thought pattern
A balancing robot that maintains vertical around a central point of a pair of arms that have a drive wheel on each end would allow for 4WD when it is on level ground and then when climbing stairs would rotate the wheels on said arms to climb the stairs. I will attempt to draw something if my words fail at conveying my idea.
In the first episonde of SW,
In the first episonde of SW, R2D2 climbs some stairs. Of course, it’s CG. But this made me think, would it be possible to actually do it? Let’s see…
The robot has 3 legs terminated with wheels. It can go 2 leg or 3 leg position. What if you make the legs extendable? The middle one is already retractable, so just the outer legs need to be extendable. To climb a step, the robot would align itself with the step, then retract the middle leg and extend the outer legs until the base of the robot is higher than the step. Then quickly lean forward and land on the step on the middle leg just barely extended. Retract the outer legs, place them on the step, extend and continue to the next step. It should be possible.
BTW, what do you mean when using the word Posum? Anything related with the possum animal? The only idiom I found was “play possum” that means play dead, ignorant, not interested. Is that what you mean?
Nice…
That robot goes over rocks almost as fast as a human, possibly even faster.
Unfortunately I need something that won’t wobble as much. I’m trying to built a robot butler so I need it to be fairly steady when carying my drinks 
In the end I think I will use 6 wheels with 3 axles, 3 whels on each side, similar to a tank. Each axle will be mounted on some kind of lif mechanism. The robot will have a stair sensor in front of it. When going upstairs, the robot will start with all the wheels extended. When the first set of wheels approaches or touches the first step the robot makes sure his center of gravity falls between the middle and back axles then it lifts up his fron axles and places it on top of the next step. It moves forward, lifts up the middle axis, places it firmly on the higher step, changes its center of gravity to fall between the first two axles and then lifts his back axle. Then the process repeats.
HelloI think is possible,
Hello
I think is possible, but as you will see in this video, the mechanics needed for central leg took significant amount of internal space.
http://www.youtube.com/watch?v=UBhOSHtnBtQ&feature=bf_prev&list=PLEF90ABAF7544899F&lf=results_main&index=41
I’ll go without middle leg and put robot on the next step on it’s belly. The rest of the process is like Robotx said.
