Engineering Marvel of the Winter Olympics: A Broom | Hacker News Reader

Engineering Marvel of the Winter Olympics: A Broom

nytimes.com

130 pointsmontrose39 comments

> Each SmartBroom has four sensors in the broom head that relay data to a small display unit. Hamilton took one for a spin down the ice, and the data was instantaneous — line graphs along with a slew of numbers that showed his force in pounds and his stroke rate in hertz. Hamilton also pointed to a figure that he described as his “sweeping performance index,” or S.P.I., a metric that combines power and speed in one easy-to-digest figure.

Is there an obvious true way to reach that SPI metric? Is it possible that optimizing for the broom-provided SPI gives you non-optimized performance? I would assume that you would need temperature measurements from the ground/ice since the article implies that's the function of sweeping:

> A quick primer on sweeping: It is important. The science behind it is much more complicated than people think. The simplified version is that sweeping slightly increases the temperature of the ice while creating micro-scratches on the surface. The result is that players are better able to control for distance and trajectory as the rock travels down the sheet. The sport hinges on precision, so every brush stroke counts.

Am I missing something?

You could gather empirical data in controlled settings and make a model that relates the things you can measure easily (speed and downward force) to the things you care about (rock distance and control). I don't know for certain, but I'd guess that's what's been done here.

I would guess that maximizing the number would not always provide optimal results. I don't curl but if you ever watch curling you can see that they aren't always trying to provide full force all of the time. I'm sure that having a quantifiable number that gives an indication of how hard they're sweeping at any given point could be useful.

Yeah, it's all about fine tuning the speed of the rock so it lands exactly where you want it to go. Curling is basically shuffleboard but you can adjust the slipperiness of the track while the rock is in motion. If the rock is already slowing down at the right rate (or not enough!) you definitely don't want to be sweeping.

I do wonder where the sport originated. Ice shuffleboard is straightforward enough, but who was the genius that figured out you could sweep the ice to control the rock better. Why were there no killjoys yelling that it was cheating? How can this be an Olympic sport but dart throwing isn't?

> I would guess that maximizing the number would not always provide optimal results. I don't curl but if you ever watch curling you can see that they aren't always trying to provide full force all of the time.

Sure, absolutely.

> I'm sure that having a quantifiable number that gives an indication of how hard they're sweeping at any given point could be useful.

This was the part I was debating. How they're weighing frequency against force to reach a unified metric.

When and how much they apply that within a game is a separate issue.

I thought this would be about the ban a few years ago: Brooms with certain bristles were banned, as it made it "too easy".

From the same paper a few years back: https://www.nytimes.com/2015/11/20/sports/facing-control-iss...

Hey, some of us are still fuming about brushes. The couple of days after a bonspiel used to hurt.

What did people use before brushes?

(I love that the user complaining about curling minutiae has the username "stan_rogers", by the way. Possibly the most Canadian thing ever.)

Proper brooms, as opposed to push brooms. You might occasionally see a skip using one just to call shots these days. It took a lot of effort to sweep effectively with a corn broom.

(I can sing all of his stuff as a party piece, but I had the name a long time before he became famous, and Stan is a really common name in my family going back many generations. Probably related if you go all Mormon on the genealogy, but that's more effort than fun.)

I'm interested to see how the curling federation handles this - the last I heard they banned brooms with directional bristles as they provided too much of an advantage. I can see this being an invaluable training tool, but ultimately banned in competition

From my reading it is only meant as a training tool.

That is also my understanding. In fact the end of the article states they'd like to get the

> hardware light enough to embed in brooms used in competition so that real-time statistics can be broadcast on television.

but currently it's solely a training tool.

Using those sensors in competition wouldn't alter the skill/athleticism required of the athletes like the directional bristle broom. It would simply increase the amount of data that broadcasters / journalists have to work with, increasing the visibility of the sport.

Yes.

> last I heard they banned brooms with directional bristles as they provided too much of an advantage.

Odd, could they not just give everyone brooms with directional bristles? then it would no longer be an advantage.

If it makes things too easy then it can compress results to the point where the luck vs. skill balance in any sport is tilted too heavily towards luck. A lot of these improvements also have an impact downstream from the top-tier competitors; a $2000 broom may be nothing compared to the cost of fielding a top team, but can become pay-to-win at amateur levels and be something the governing bodies of a sport may want to avoid.

The new brooms fundamentally changed the nature of the game, greatly diminishing the importance of the skill of the thrower and the strength and athleticism of the sweepers.

The cat is now out of the bag. The techniques learned from using directional brooms have now created a completely different style of sweeping, based mainly on manipulating scratches in the ice rather than heating it. Directional fabric broom heads are banned, but the directional sweeping technique they spawned is here to stay. Not everyone in curling is happy about that.

http://www.cbc.ca/sports/olympics/curling/curling-s-broom-co...

If a sport or activity can be undermined by learning more about it, maybe it’s not much of a sport.

Yup

A sport is defined by the artificial limitations placed on it. I could break the world record for the mile run if I were allowed to drive a car or use a bicycle instead of my legs. At some level there is a subjective evaluation of what the sport is about, and an evolving attempt to allow technological improvements to enter where they are in the spirit of the sport (like grippier gloves in football) and ban them when they change the nature of the sport too much (like superchargers in F1).

Except that in this case the previous poster was simply saying that the technique alone is the issue, not the tools.

Fair point, I concede. I took your statement to be wider in applicability than was clear from the context.

All games are played by an arbitrary set of rules designed to encourage a particular kind of competition. New equipment, new tactics or simply increasing skill levels may undermine critical aspects of the balance or challenge of those games. Practically all sports have tweaked their rules over time to ensure that the game remains fair, challenging and enjoyable to watch.

In the early 1950s, the NBA had a serious problem with boring, low-scoring games. Once teams had achieved a lead, they tended to run out the clock by passing the ball between each other and playing very defensively. In 1954, they introduced the shot clock, which effectively prohibited these stalling tactics and was widely credited with saving the game as a spectator sport.

Golf has regularly changed the rules to preserve the integrity of traditional courses. Better clubs, better balls and greater athleticism were making many holes almost trivial for professional players. Rather than destroying their heritage by abandoning iconic courses, they chose to regulate the equipment. They haven't just banned new developments - in many cases, they prohibited equipment that had been used in competition for many years.

In the case of curling, the directional brush heads revealed a new way of using old equipment. Traditional bristle brush heads were thought to be obsolete, but turn out to be extremely powerful if they are brand new, very stiff and used in a specific way. This combination of factors may be detrimental to the game as a whole. I think that it's entirely reasonable for the World Curling Federation to consider a ban on certain types of bristled brush head.

It's worth contemplating the fact that the ban on directional brush heads came entirely from the players themselves - prior to the ban, 34 elite curling teams signed an open letter saying that they would not use the new technology.

http://www.cbc.ca/news/canada/manitoba/top-curling-teams-say...

A real nice, fictional example is the one in Quidditch through the ages by Kennilw... er, JK Rowling. A whole section is devoted to stooging, a tactic to overpower the goalkeeper that was eventually banned because it made the game too boring (not to mention dangerous for the goalies).

Can you imagine if the sweeping part didn't exist and someone came out and started doing it today? There would be rules against it so fast you wouldn't even be finished saying "neat trick" before it was banned. Stopping at directional bristles seems a little bit arbitrary.

As an Electrical Engineering student at North Dakota State University I curled. Our team won the North Dakota State Championship. One of my friends was training for the Korean Olympics. It appears that I overlooked the market for brooms...

It's great to see technology being used to make athletes better even if it means changing technique.

Nice to see a small NodeMCU in the picture there - just goes to show that even hobbyist-grade hardware can be used to solve real problems, and be experimented with usefully.

The blue board on the perf board is an Arduino Nano, I don't see any NodeMCU. Although that would have been nice to be able to use bluetooth.

You're absolutely right, and it is obvious now I look again. I must have gotten forgetful between reading the article and commenting!

The Dutch short track ice skating team did something similar with Samsung: they developed a suit that measures the angle of the athlete and sends the data to the trainer.

https://www.sammobile.com/news/samsung-created-a-smartsuit-t...

We are the only people who care so much about speed-skating - everyone in our country knows what a clap skate[0] is, I doubt that is true anywhere else.

Makes me wonder how many hyper-specialised niches of technology like this exist out there.

[0] https://en.wikipedia.org/wiki/Clap_skate

Cool idea and great execution. Must also be a fairly small market for such brooms, and competition.

It is like selling kit that is only used in Formula 1 and no other formulas. McLaren sell lots of telemetry kit that is mandated by the FIA, they also sell other bits and bobs where there can only be ten buyers in F1. In all fairness they do have sidelines for NASCAR and Formula E so it is not that niche.

Essentially these parts are not mass produced, they are tailor made from a pattern rather than fully bespoke. A different business model with different profit margins.

The thing is that you have to get this kit from somewhere to be in the sport, either you make it yourself or you buy the pricey semi-customer specialist kit from someone else in the game. So the teams such as Red Bull and Force India buy from McLaren, they can't run the cars without the telemetry.

With the broom it also creates this situation, you can't be in the sport without the telemetry. So the niche is a good one, like what MacLaren have, a de-facto monopoly that does not rule out rival teams cloning their own solution if they really want to. (In the automotive analogy Ferrari do not buy from McLaren as much as other teams, they roll their own.)

https://www.mclaren.com/appliedtechnologies/products/list/fo...

Looks really cool, does anyone want to speculate on how it works? They say they have four sensors in the broom head? what do you think they are? pressure sensors maybe? do you think they have an accelerometer in addition to these sensors?

I'd imagine that (like the bathroom scale that they referenced, even if they're using different hardware) they have four 3-axis force sensors which connect the sweeping head to the broom, letting them calculate the forces while allowing for different angles.

From the article:

  > Was there a way to take a pedometer (to measure
  > stroke rate) and a miniature bathroom scale (to
  > measure force) and fuse them to a curling broom?
  >
  > “So Andrew looks at me like I’m an idiot and
  > says, ‘No, you’d use, like, four sensors and an
  > accelerometer,’ ” Hamilton recalled.

Given that he wanted to measure stroke rate and force, it stands to reason that the accelerometer handles the stroke rate and the four sensors measure the force.

I think it was a mistranscription, and should read as "force sensors" (a.k.a. load cells) rather than "four sensors."

"Canadians get a discount" I wonder how much money they're passing up on for their curlingist patriotism

These kinds of things tend to be labors of love anyway.

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