Walker rule clarification? Unusual design.

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AntRoboteer
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Re: Walker rule clarification? Unusual design.

Post by AntRoboteer »

Without the bristles in that scenario, there would be no movement from the robot; the bristles are the moving legs.

It's like saying walkers like Drumbledore aren't walkers because they use a motor which rotates more than 180 degrees spinning a cam shaft which would not make sense.

I would classify this machine as more of a shufflebot but if anything is certain, it is definitely not a 'roller'.
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DieGracefullyRobotics
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Re: Walker rule clarification? Unusual design.

Post by DieGracefullyRobotics »

No, because the mechanism on, say, Drumbledore translates the circular output of the motor into a walking motion. It is the mechanism that turns it from one to the other. A bristlebot doesn't do that. It has no mechanism, just vibration, which is caused by circular motion. No, it's not a roller, but robots aren't split exclusively into rollers or walkers/shufflers. By this logic, I could put a mobile phone in the arena set to vibrate and ring it and it would be classed as a walker. Which I think is nonsense.

Obviously I'm the only one to think this way so I'm happy to shut up about it. I just think it's a slippery slope away from what the walker rule is supposed to represent.

In tangent, the wording that Peter posted would outlaw Wrecks as a walker as its back "foot" rotates through 360 degrees. So to get back to George's original question about his design, I think the key will be the pivot that the robot performs. Purely by the wording of that rule as it stands and disregarding my personal opinion, it would definitely qualify for the walker allowance.
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Shakey
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Re: Walker rule clarification? Unusual design.

Post by Shakey »

I don't agree with bristle bots being walkers. I consider the final drive output to be the last directly driven component in the drive, not just a part that vibrates. Bristlebots in my mind have a final output that is rotating through 360 degrees.
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AntRoboteer
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Re: Walker rule clarification? Unusual design.

Post by AntRoboteer »

The final output would be the contact surface with the arena.

Wheels are the contact surface of any roller and rotate more than 360 degrees. Legs are the contact surface of most walkers and they rarely rotate, merely move up and down (although you could class as an approx 90 degree movement of the foot as it walks).

Bristlebots utilise vibration motors in order to agitate bristles. The bristles tend to move in a leg like movement, and as such have a similar type of movement to a conventional walker. They would border on being walkers.

Another way to think about this is as follows:

An example walking spinner robot has legs and a cam shaft system to drive it. When the spinner spins up, there is a gyroscopic force applied to the robot. If one of the sets of legs were to lock up, the robot would likely still be able to 'gyro dance' using one set of legs and the spinner.

So,

a) Under current rules, that would be fine and the robot would be considered as mobile and competition legal as it can still move around the arena in a controlled manner.

b) Through the classification that any part of final drive output must not rotate more than 180 degrees, since the spinner is providing a significant component of the robot's final movement at that point, it would not be classified as competition legal despite clear mobility.

Clearly, a) is the sensible option. However, if the final output were not to be classed as the contact surface, b) would come into play and disqualify the robot. This is why it is clear the rules mean that the contact surface should not be rotating more than 180 degrees.
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Lincoln
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Re: Walker rule clarification? Unusual design.

Post by Lincoln »

your not the only one that thinks that way Dave just the most vocal.
having designed what i believe to be one of the most effective walking mechanisms implemented in antwights. i would agree that a bristle bot should not get the extra wight allowance of a walker, without getting into anything about how much the "final drive" rotates. it simply should not get the extra wight because a bristle bot mechanism would require less wight than just having wheels. even with a 2 sided system to have control, a tiny offset wight on a small fast motor and a tooth brush head seems like less wight and less effort than putting wheels on the end of heavy metal gear-motors. whereas my walking mechanism is about 10 grams per motor heaver than using wheels.

however, i think people may be scared of bristle bots becoming a thing because of hex-bugs and things, or as Dave said a vibrating phone. but theses are already addressed by the no commercial product without significant modification rule. if someone builds a bristle bot and proves that it takes more wight than wheels ill change my opinion but for now, bristle bots are neither roller or walker, they are bristle bots and such do not count to get the extra wight allowance.

but back to the original question, what i think George is describing would count as a walker and a pretty cleaver one at that. imagine a cube with 2 giro effect spinning masses inside. suddenly speeding up or slowing down of these would cause the cube to tilt up on one side then as the other spinning mass was moved would cause the cube to pivot round on one corner. doing this repeatedly would make a definite walking motion.
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GeorgeR
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Re: Walker rule clarification? Unusual design.

Post by GeorgeR »

Yeah that kind of describes it Lincoln, although in the motion I envisage the motor torque and gyro forces work together to lift and turn the bot in one motion. To be honest I don't know why I asked this now, I've still got to fix my current bots, build my conventional cam driven walker, and maybe make a beetleweight before I get on to weird and wonderful stuff like a gyro walker.


As for bristlebots, maybe they should be defined as neither roller or walker, but as a separate category of "bristlebot". Then we can move on to the important task of arguing about whether they can count for the 4th spot, or if they get a weight bonus!
For what it's worth, I think it depends on the purpose of the rules. I was under the impression that the 4th spot rule was to encourage different/unusual designs, in which case I say bristlebots are in.
There seems to be different views on the purpose of the weight allowance. Is it a reward for building a complex design? Is it to allow for the increased weight of the walking mech? Or is it to make the otherwise uncompetitive design viable? If it's the latter then bristlebots get the weight, but if it's either of the former then they don't.
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DieGracefullyRobotics
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Re: Walker rule clarification? Unusual design.

Post by DieGracefullyRobotics »

Thanks Shakey and Lincoln!

As I said before, the rule was originally implemented to reward the complex task of building a walker, not to just generally reward any creativity. Creativity and the walker rules are entirely separate issues and don't really involve each other.

Don't get me wrong, I think rewarding creativity is hugely important and sorely lacking currently. I have tried in the past to come up with things that do reward creativity but they have been largely unsuccessful. It's just not an issue connected to the 4th slot ruling as it currently stands.

Regardless, your concept shouldn't meet any opposition if you ever decide to build it, George. I guess that's the key thing, ha.
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Re: Walker rule clarification? Unusual design.

Post by peterwaller »

I had forgotten how much more lively the discussions were with you on here Dave.
I am still not convinced though that a bristle bot does not meet the rule.
I am not saying it deserves to get the the extra weight but it is the bristles that convert the vibration into linear motion and there is nothing in the rules to say the final drive output has to move. :wink:
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Re: Walker rule clarification? Unusual design.

Post by AntRoboteer »

Lincoln wrote: Thu Jun 07, 2018 9:26 pm it simply should not get the extra wight because a bristle bot mechanism would require less wight than just having wheels. even with a 2 sided system to have control, a tiny offset wight on a small fast motor and a tooth brush head seems like less wight and less effort than putting wheels on the end of heavy metal gear-motors. whereas my walking mechanism is about 10 grams per motor heaver than using wheels.
Firstly, moving 250g or even 150g around on bristles using vibration motors is not an easy thing to do; two coreless motors and tiny offset weights won't do anything for you. You'd need sizeable motors with sizeable weights to get that moving. I have tried similar experiments and needless to say I was not impressed enough with the drive to even consider entering such a machine. About 25g per motor was the figure I got to in order to move around 130g.

Secondly, your drive system Lincoln is more than capable of shoving machines around (very impressive given the size and weight); a bristlebot of any size is generally labouring moving its own weight, let alone pushing other machines around so a comparison there is not quite right and definitely cannot be used to deny bristlebots the extra weight allowance just because it appears that the mechanism could be lighter.

It is plainly clear that a bristlebot would completely qualify for walker allowance under the current ruleset as detailed in my previous post (final output = contact surface) and there is no reason for that to change; the engineering challenge is more than enough to contend with.
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Re: Walker rule clarification? Unusual design.

Post by Shakey »

AntRoboteer wrote: Fri Jun 08, 2018 7:02 pm It is plainly clear that a bristlebot would completely qualify for walker allowance under the current ruleset as detailed in my previous post (final output = contact surface) and there is no reason for that to change; the engineering challenge is more than enough to contend with.
The issue is that it is not plainly clear hence why the debate exists. It's not something that could ever by objectively argued by the word to a conclusion as there is still interpretation. For instance I don't even agree with your interpretation of the final output equals contact surface.

If going purely by word of the interpretation that walkers are defined by their contact surface not rotating through more than 180 degrees the following are also walkers: Drones (The landing gear), hovercraft (The skirt).

Now clearly a drone is not. This is the issue we have with many rules debates is that a conclusion won't be reached arguing by the word as it is still open to too much interpretation but instead community consensus needs to be reached on the spirit of the rule and then the rule rewritten to clarify.

Not that any of the rules changes get recorded anyway.
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