Author Topic: Walking: Sparc vs Robogames rules  (Read 1995 times)

daggius

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Walking: Sparc vs Robogames rules
« on: January 04, 2016, 07:46:35 pm »
I have an idea and wanted to check if it is ok.

I think that is OK to do a non wheeled robot via sparc rules that uses 2 servos to control 2 legs.  It is similar to a cam except that that it is not "continuous" motion -- because it is connected to a servo which only rotates ~120 degrees, you have to reload the cam yourself every time by moving the servo back to start position.  Basically the leg pushes the bot forward when the servo goes one way, then the leg just drags back along the ground when the servo goes the other way to reload (you have a joint in the leg to let it drag the 1 way).  So to walk you have to wiggle your controller stick back and forwards to toggle the servo alot.  You can walk forwards (not backwards) and also turn by only using 1 of the 2 legs at a time.  You might have other skids to the ground in order to balance better too so maybe its more like dragging than walking since its resting on these when the leg is dragging along.

I think this qualifies for the 2x weight allowable by sparc rules but not by robogames rules.  Because robogames specifically says Linear actuator and a servo does not count as that.  Am I right?

And also, has anyone else made walkers recently that follow either of these rule sets (curious what they did)?

Thanks!

Sparc rules

Quote
Non-wheeled: non-wheeled robots have no rolling elements in contact with
the floor and no continuous rolling or cam operated motion in contact with the
floor, either directly or via a linkage. Motion is “continuous” if continuous
operation of the drive motor(s) produces continuous motion of the robot.

Robogames rules
Quote
Walking: Walking robots are defined as those with linear-actuated legs which operate independent of each other. That is, any given leg must be able to move laterally and vertically with no cause and effect from another leg.
« Last Edit: January 04, 2016, 07:51:13 pm by daggius »

daggius

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Re: Walking: Sparc vs Robogames rules
« Reply #1 on: January 04, 2016, 08:19:41 pm »
also it seems that jumping, hopping, flying, and hovercrafts all qualify for 2x weight according to sparc.  pretty sweet.

MikeNCR

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Re: Walking: Sparc vs Robogames rules
« Reply #2 on: January 04, 2016, 09:22:47 pm »
also it seems that jumping, hopping, flying, and hovercrafts all qualify for 2x weight according to sparc.  pretty sweet.

Anything within those categories (including weight bonus) is left to the discretion of the specific event organizer if they're legal at all.
« Last Edit: January 04, 2016, 09:24:46 pm by MikeNCR »

AmbientChaos

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Re: Walking: Sparc vs Robogames rules
« Reply #3 on: January 05, 2016, 08:22:13 am »
Quote
Walking: Walking robots are defined as those with linear-actuated legs which operate independent of each other. That is, any given leg must be able to move laterally and vertically with no cause and effect from another leg.

My interpretation is that the design you are describing would still fit the Robogames rules. If i understand you correctly you are using a servo to create two separate linear motions, on the forward stroke the leg is pushing laterally backward and vertically down, and on the reverse stroke the leg is pulled laterally forward and has to recoil vertically up to allow it to return without pushing you backward.  I think that the two key parts that make this qualify where a shuffler does not is that unlike a shuffler the legs aren't linked so that one leg moving forward doesn't by definition mean that another leg is moving back as part of the linkage, and it sounds like the vertical movement of the leg is perpendicular to the axis of rotation of the motor instead of all of the movement being concentric to the axis of rotation as with a rolling or shuffling bot.

I may be putting words in their mouths, but my basic interpretation is that the intention of the Robogames rule was not to restrict walking robots to using linear actuators but that the robots' legs have to move independently on multiple axes and not be entirely dependent on just rotation.
« Last Edit: January 05, 2016, 08:25:57 am by AmbientChaos »