What do you think about when stillstanding?

A few days ago I did a little bit of practise at doing stillstands. I did a 15 second one which is the longest I’ve ever done and I think the fact that I’ve changed the way I view stillstands helped a fair bit. I hadn’t really thought about what I was doing to correct my balance before recently. Now I concentrate on bending my body in the middle so my arms go to the side I’m falling which (somehow?) sends my lower body and the unicycle (which collectively seems heavier) to the opposite side. I also make sure I always have my arms out wide for extra balance. If I need to do a lot of correcting, I sometimes bend over to the side so both my arms are near my body on the side I’m falling to.

What’s your favourite stillstanding method?

Thanks,
Andrew

Re: What do you think about when stillstanding?

and the prize for the weirdest question of the day…

:slight_smile:

nice one

:slight_smile:

Although it is a weird question, I have noticed the same thing. My best stillstands are when I’m totally focused, and have the feeling that my center of gravity is right on top of the wheel, and isn’t going anywhere. Lately I’ve had problems focusing to much on the fact that i’m focused on the fact that i’m focused, and lose focus. Or something.

aaah, yes
the well-known second zen conundrum

:sunglasses:

My attention span is very short. I begin a stillstand, stay in it for perhaps 0.01 seconds, forget what I’m doing, and ride away. Often, during the brief interval of the stillstand, I think about sheep covered with peanut butter ice skating on frozen motor oil.

and the prize for the weirdest answer…
:wink:

and to think, i HAD such a crappy day
:smiley:

‘Holy Crap, I haven’t fallen over yet!’

Re: What do you think about when stillstanding?

Ben Plotkin-Swing <Ben.Plotkin-Swing.w0miy@timelimit.unicyclist.com>

>Although it is a weird question, I have noticed the same thing. My best
>still stands are when I’m totally focused, and have the feeling that my
>center of gravity is right on top of the wheel, and isn’t going
>anywhere. Lately I’ve had problems focusing to much on the fact that
>I’d focused on the fact that I’m focused, and lose focus. Or something.

I agree that being focused on not allowing the centre of gravity to
deviate more than a few mm’s is a great way to do a still stand.

Doing a still stand uses the reflexes that are required to balance
forward/backward in coasting. Unlike coasting, for the still stand
these same reflexes must be adapted for sideways balance as well.

The required reflex is bending the upper body in the direction of the
fall quick enough to regain a position where the centre of gravity is
again very close (or is) over the tire’s point of contact with the
ground.

Sincerely,

Ken Fuchs <kfuchs@winternet.com>

My thoughts in that situation are very similar to Sofa’s. I can’t usually intentionally stand still on the Unicycle, but sometimes I accidentally manage it for 5-10 seconds while getting ready to hop. I think ‘Wow I am still standing’ and then when it’s over, I try to still-stand on purpose and end up sidehopping slightly to correct my balance (after about 2 or 3 seconds).

I think about counting really fast. So instead of counting the seconds slowly like “onethousand one, onethousand two, onethoudand three” I go really fast like “one, two, three, four, five, six, seven, eight, nine, …”. I find my still stands are longer when I count fast. I can make it up to around the count of 20 rather than just the count of 3.

I always think about the nature of truth and virtue, and wonder whether Socrates was right when he argued that it is better to suffer wrong than to commit wrong.

Unfortunately, I’ve never reached a conclusion as I can only still stand for long enough to frame the question.

I think about weight transferal and where I should put my weight. While still standing I often ponder whether it is better to have my weight on the seat or off of it (and generally fall off before I make up my mind).

Most of my focus and thought is about adjusting the pressure on either pedal although I’m probably doing a lot of balancing with my arms it feels like it is all in the foot pressure and that’s what I concentrate on.

wow, realy getting into this still stand thing…bend at the hipps…oh im overbalancing beyond the pont where i can recover…ooo, managed to get it back in controll…ooops doing it again…
…oh, i’ve fallen off.
which probably lasts about 12 secconds

and i normaly wonder what exactly it it that im staring at in the distance.

Re: What do you think about when stillstanding?

Hi Andrew, Ken;

I like Ken’s analogy, but my first impression is that a simple model of still standing is probably impossible from a physics point of view. Where the coasting analogy breaks down is that the tire doesn’t roll laterally in still-standing so there isn’t an easy way to bring the tire patch past the CG to the falling side without hopping. (I’m new to all of this, but I presume hopping is the opposite of still standing.)

So when I get time (probably this weekend) I’m going to model this problem up and try to solve it. For a first cut at the problem I’m considered a double inverted pendulum problem in 2 dimensions with a fixed lower pivot point. The lower pendulum is made from your unicycle and legs, and the upper pendulum is your toros, head and arms. For this first shot I assumed that you kept your arms and head rigid with respect to your torso. The control input is by your abdominal and hip muscles bending at the waist.

Does this simple model make sense, or do I need to consider arm swings too?

My hunch is that the simple double inverted pendulum cannot be stabilized. When the top pendulum is pulled down rapidly in the direction of the fall it creates a counter-torque on the lower pendulum which tends to lever it back up. The overall system CG is lowered, but I don’t think the CG gets moved to the non-fall side of the ballance point, so gravity and the earth continue to apply a torque on the system to make it fall. I could be wrong - there could be some dynamic effects that counteract - however statically it doesn’t work.

Andrew and/or Ken, would you do me a favor and perform an experiment? I have a theory of how this could work.

If the upper pendulum CG is high when throwing the weight to the fall side, but low on the return swing, then I think dynamically the system can be controlled. You can model this by keeping your arms and head high when you flailing in the direction of the fall, but low on the recovery stroke.

Anyhow, if you see an improvement with the “correct high, recover low” method, then I’ll model a third pendulum and see if I can get the system to stabilize.

Thanks,

Tim

PS: The other factor that might make still standing possible is that the tire isn’t exactly a perfectly fixed in place, frictionless hinge. It is possible to apply torques to the earth through the sidewalls, and to mush the rim around with respect to the contact patch. However, I don’t want to add that complication just yet. The first set of puzzles are plenty challenging.

When I stillstand…

I honestly cannot remember having thoughts. My mind is empty – devoid of words and music. Is this a good thing?

Sometimes a single thought comes crashing in – “I can’t believe I’m still standing.”

I just had an idea, but I don’t have the equipment to test it. What if you had a long “stick” to balance with, like what the tightrope walkers use. It’s kind of silly, but maybe it would help one understand the forces and corrections involved in stillstanding. Anyway, it would be cool to be able to stillstand for a few minutes, assuming the stick-thing would allow you to do that.

Dave Lowell (uni57)

Re: Re: What do you think about when stillstanding?

You (well some people anyway) can still stand a pogo stick, so I don’t think these extra complications will be needed.

Joe

Re: What do you think about when stillstanding?

>Ken Fuchs wrote:

>> * Doing a still stand uses the reflexes that are required to balance
>> forward/backward in coasting. Unlike coasting, for the still stand
>> these same reflexes must be adapted for sideways balance as well.
>> *

cyberbellum <cyberbellum.w2bvf@timelimit.unicyclist.com> wrote:

>My first impression was that still standing would be impossible from a
>physics point of view. Ken is right that the basic physics is similar
>to coasting, however the tire doesn’t roll laterally so there isn’t an
>easy way to bring the tire patch to the falling side without hopping.

Sorry, I forgot to mention that one’s feet must keep the wheel from
rolling with respect to the frame. In other words, the pedals and frame
must remain perpendicular (or at a constant angle) at all times. So the
wheel does roll forward/backward only the small amount that the frame
itself does.

One way to learn a still stand would be to use a unicycle with the brake
solidly on with the pedals in the horizontal position. This would
prevent the use of horizontal (pedal) idling to help maintain balance.

The sideways balance reflexes are exactly like those used by wire
walkers, especially those that use their arms and upper body rather than
a balance pole.

Sincerely,

Ken Fuchs <kfuchs@winternet.com>

Re: What do you think about when stillstanding?

uni57 <uni57.w2f43@timelimit.unicyclist.com> wrote:

>I just had an idea, but I don’t have the equipment to test it. What if
>you had a long “stick” to balance with, like what the tightrope walkers
>use. It’s kind of silly, but maybe it would help one understand the
>forces and corrections involved in still standing. Anyway, it would be
>cool to be able to still stand for a few minutes, assuming the
>stick-thing would allow you to do that.

Great idea!

One could use a second balance pole in the forward/backward direction as
well to make balance in that direction easier too.

Try reducing the weight on the ends of each balance pole.

Try using just one balance pole or the other.

Fix the brake so it stays on as I suggested in a previous post.

Sincerely,

Ken Fuchs <kfuchs@winternet.com>

Re: Re: What do you think about when stillstanding?

While driving to work today I got it. It definately does make sense from a physics point of view. A simple thought experiement can show what is going on:

Imagine that someone has taken a unicycle with a relatively massive wheel. Imagine that they have removed the seat and bolted a thin bar to the seat post in a T configuration so that it is parallel to the axle of the wheel. Now if you turn this thing over and set it down on the bar it can flop back and forth in the fore and aft direction, but not side to side.

Now imagine further that this same weird dude has mounted a motor on the unicycle to spin the wheel. If initially the wheel is stopped and the unicycle is perfectly ballanced then it is sort-of still-standing on the T-bar. If it tips a bit then it will tip over unless the motor operator accelerates the wheel so the highest point starts to spin in the direction of the fall. As the wheel spins up the motor applies an equal an opposite torque to the frame of the uni that causes it to stand up - bringing the center of gravity of the whole system with it.

If the motor operator is really quick and starts the spin-up before the inverted pendulum has fallen too far, and if the start-up jerk on the wheel is rapid enough, then the inverted pendulum will tip up past vertical and start falling the other way. When it has fallen a bit the other way the operator can reverse the spin of the wheel and jerk the whole system back.

If this is done right then even though the inverted pendulum is statically unstable, the addition of this active control makes it dynamically stable. It will totter between falling in each direction for as long as the operator keeps up the quick corrections.

So how does this apply to the real Uni world of still-standing? Well, you’re torso and arms are the “wheel”, the quick bend at the waist is the jerk, and your legs and uni are the rest of the inverted pendulum.

I’m still interested in hearing if the “control-high, recover low” strategy of arm waving helps or hurts (or equivalently, ducking and weaving with the torso - as in sit up straight while lunging to the side and skrunch down a bit on the way back). When you wind-mill your arms in this way you are replicating the wheel in the above analogy. I think this is what bull-riders do at the rodeo, and it ought to apply to still standing.

(Personally, I’ll be happy when I master turning around in the parking garage and going back to my start point. Walking back to get on again is getting a little old.)

Cheers,

Tim