Varsity tennis player here. I have been using my fitbit bracelet for a couple months now, I have to admit that the device is inaccurate. I am pretty sure it undercounts running distance and number of steps. We are talking about big wide steps that happens in a consistent manner. A players movement on court is much more complicated. Such a bracket for tennis players needs to be much more accurate than my fitbit flexband to be useful. A good tennis player never takes a wide big step, almost all the movements on court are quick small steps. Unlike running, a player changes direction all the time. It would be really cool if the bracelet can give the player data about his footwork but I think the emphasis on this particular product is on the actual technique. Man its not easy. Sure there might some easy wins in the beginning, like counting how many forehands or backhand a player hits or things like how hard have you been hitting the ball. But I think its extremely hard to dig more into it. “How much spin are you giving”, “Are you hitting the ball late or early", “How fast can you recover when you hit the ball(combine it with footwork)”, “How high is the ball when you hit it” “Are you bending your wrist too much, or is you elbow really close to your body”. “Are you hitting the ball just with your arm or your shoulder and your waist follows through with the movement" These would be the questions that an intermediate tennis player would be interested in. However I am afraid these all happen in a fraction of a second and I really doubt a bracelet is accurate enough to give the player insightful data. Sure its a really cool device (still not useful) for people starting to learn or maybe little kids competing against each other, but there is a long way until a serious tennis player can benefit from this. I am a software engineer myself and it was always my dream to do build something about tennis. So go for it man..
I don't tennis, but it looks pretty cool.<p>At the risk of thread hijacking, I have a broader question. My assumption is that most wearable bracelets have the same tech/sensors inside and the difference is in how your software interprets said sensor signals. <i>So why doesn't someone create an open bracelet that people can hack and customize for any sports/fitness application?</i><p>I mean, I would have loved something like this for baseball back in the day (both for pitching and hitting). There are wearables for golf too[0].<p>So, why not just a generic wearable + SDK/app store?<p>[0] <a href="http://mashable.com/2014/05/22/zepp-golf-sensor-review/" rel="nofollow">http://mashable.com/2014/05/22/zepp-golf-sensor-review/</a>
Tennis player here..ummm... As legohead brought up, there are other things to consider like stance. I can see how this thing can be accurate if we had four of them (ankles and wrists). This can show show most of the moving parts, can replay how the body moves (likely hand location and elbow extention), open vs close stance, how fast were moving from point A to point B.<p>I don't know how they're measuring ball rotation, purely by the angle of an upward swing? Don't know if this is accurate. Is this an area it would suggest for improvement? RPM has a large range up to ~5,000rpm (Nadal). What would it even cosider optimal to make a shot?<p>Don't know how the device would know if a ball would land in or not, is this even a major area of concern for the device? Pretty strokes are one thing, but unless the ball lands in, it doesn't matter.<p>Depending on how accurate this device is (probably would need more than one bracelet per person), it can be used for any sports. More importantly, there's a possiblity to measure bad form and increased pressure on certain joints to prevent injuries.<p>Looking forward to see technologies brings forth in the coming years!
Shot Stats[0] is another Tennis related kickstarter currently going on.<p>[0] <a href="https://www.kickstarter.com/projects/laviesak/shot-stats-challenger-make-your-tennis-racket-smar" rel="nofollow">https://www.kickstarter.com/projects/laviesak/shot-stats-cha...</a>
Hi, just thought I'd jump on here and answer a few questions. Thanks all for the interest!<p>You're right in saying the components are pretty ubiquitous, the key part is the algorithms which interpret the data. They would need developing for each sport or particular movement, plus a UI to replay back the insights in a user friendly way. We spent months on this with Smash, it was the real focus of the early work, and will continue to be so. Some kind of platform that allows this to be done easily feels like a great next step...got me thinking :)<p>Rob
Former tennis player here, and builder of a similar device for weightlifting form. Unlike a lot of other wearable kickstarter projects, I think most of the technological claims here are legit. That said, I'm not sure if it does enough to be useful for an avid tennis player. To improve my game, I would like to see:<p>1) Swing form correction<p>2) The angle of the racket relative to an incoming ball (to predict air or ground balls)<p>3) Stance information.<p>Form correction would require position data during the entire swing. Position information is two integrals away from acceleration data collected from the sensors, so it's far too noisy to determine that well enough.<p>I don't know how would you would measure stance with a bracelet, and I'd imagine that racket angle is unreliable.<p>I also question the ball speed measurement for a similar reason to form correction. I'd imagine a possibly effective way to measure speed would be to correlate acceleration data with externally measured velocity data collected in real-life trials. That said, unless you're competing at an advanced level, speed is a vanity metric so I don't care if its a ballpark estimate.<p>Video recording, however inconvenient it may be, addresses all these well. I'd rather see a camera added to tennis courts to record your performance, but that's far less sexy of a product to build.<p>That said, the bracelet looks sexy and the goal of personal training sure beats the hell out of fitbit/fuel/jawbone's capabilities.
Pair wearable tech with future iterations of Tango/Kinect and you're onto something even bigger.<p>Tennis for example -<p>Think about a computer picking up flaws in technique that the human eye would miss; a coach would only be looking at your leg work or arms or upper body but a computer will tell you a multitude of things - wider stance, shoulder's turned to the right a bit more, less follow through, more weight on your front foot etc etc - then imagine it coming straight to your ear every time you place a shot. Pair it up with a ball tossing machine and you've got a coach that knows precisely where you're going wrong, how to fix it and giving you the best possible advice and opportunities to do so (forehand shoddy? that's all your getting until it improves etc).<p>The next decade has just gotten so much more exciting. I'd love to find someone somewhere working on a "complete" system, not separate bits of it - we already have video analysis, wearables, weight sensors (wii fit?), someone just has to slap them all together.<p>Side question - aren't there golf swing analysis places already which use a myriad of tech to give feedback?
I would look into this more. I was watching the French Open just yesterday and I heard Darren Cahill say that top juniors now a days have the technology so that when they walk off the court it will tell them what strategy worked what percentage of the time and what they should have been doing more. Pretty interesting comment, although they never did show an example of it I totally believe it. Babolat[0] pure drive meets Sony[1] racket sensor.<p>The only project I ever built with an Arduino is a wristband with a piezo sensor and it counts the number of balls I hit while was practicing. I thought about expanding it more, but that was the only data point I was really interested in.<p>0. <a href="http://www.tennis-warehouse.com/Babolat_PLAY_Pure_Drive/descpageRCBAB-BPLYPD.html?gclid=CNHb1Yruy74CFa1cMgodRm0ATw" rel="nofollow">http://www.tennis-warehouse.com/Babolat_PLAY_Pure_Drive/desc...</a><p>1. <a href="http://www.theverge.com/2014/1/20/5326558/sony-smart-tennis-sensor-price-and-availability" rel="nofollow">http://www.theverge.com/2014/1/20/5326558/sony-smart-tennis-...</a>
This is a very interesting concept. A side-note: while receiving immediate feedback is useful, a coach is still incredibly useful. They tell you <i>how</i> to improve the one stat and more importantly broader strategy (where to stand, where to hit, etc).<p>I wonder what other sports this can be applied to. My guess is that swimming is a prime candidate and maybe shotput/javelin or baseball pitching.
I made a similar product (albeit a lot less refined) for a hackathon, using the Pebble. It counted number and type of tennis shots, displayed useful HUD data, and then let you see pretty graphs in a desktop webapp. Some problems I ran into:<p>If you have acceleration, to get position, you have to integrate twice, which means two unknown constants, really throwing off your data accuracy. To fix this, the user would have to go back to a defined position (perhaps the tennis 'ready' position) frequently, but that isn't guaranteed or user friendly. They could absolutely work around this with some refined heuristics, but I wasn't able to get one working in the few hours I had.<p>The algorithms are the hard part. I was using naive machine learning techniques to identify swings and such, and they were not nearly adequate; I had many false positives. If they can get all of the stats they claim, I'll be very impressed.
It seems that no one else has a problem with this, but I'm still not completely sold on Kickstarter projects that essentially function as pre-order mechanisms for products in development. Shouldn't this money be coming from investors or lenders?
I am skeptical about this device becoming a game changer in tennis. I played tennis for a while and what really helped me then was video analysis. While data is helpful, it's not as helpful as video. If the wearable could depict my form and technique from data, that'll be a game changer. For game improvement, we don't lack knowledge. After playing any game for a while, we'll know our limitations - but to tide over those limitations you need hours and hours of practice along with a coach. During those rigorous practice hours, your mind gives up and you just want to quit, but your coach won't let you do that :).
As a tennis player I don't see how this is going to help me. At least the video & description of the product don't explain it very well.<p>I've been teaching my daughter tennis, and the issues she has (and that I have as an amateur) need very specific attention -- how you are holding the racquet, follow through, feet position, anticipating ball placement..<p>The description says it gives "tips and advice" - like what? Can it tell me I need to rotate my grip 10 degrees? That my backhand starting swing position is too high? That I am trying to hit the ball too soon or late? etc.
Interesting from a gadget standpoint - I wonder if any "regular" tennis players will be interested. I am reminded of this very clever lean startup experiment about a similar concept (though it was in the racquet, not a wearable).<p>MVP experiment using a walkie-talkie to fake a "smart racquet": <a href="https://www.youtube.com/watch?v=2eJbu4EtHMk" rel="nofollow">https://www.youtube.com/watch?v=2eJbu4EtHMk</a><p>Results of the experiment: <a href="https://www.youtube.com/watch?v=gZzYUW3-JHQ" rel="nofollow">https://www.youtube.com/watch?v=gZzYUW3-JHQ</a>
What I don't understand yet, is what hardware on this band makes it different from other wristbands (besides form factor)? If all the calculations are done on the mobile app, and the wristband is just a data collector, why not implement this app to integrate with existing bands?<p>We've seen so many wristbands (and now watches) releasing, it doesn't make sense to have separate bands for separate tasks. We'll eventually have a similar problem where every website has it's own app.
I was sort of expecting a responsive bracelet that would actively help you. For example by vibrating more or less to help you swing properly (stay on the correct path, buzz until complete follow through etc, buzz when you are at correct spot in serve to help you time the ball etc etc).<p>This looks more like a good, smart application specific flight recorder. Very cool, but not as game changing cool as I first thought it would be.<p>Keep it up though - it is a great game!
Isn't this the same thing - just as a bracelet.<p><a href="http://preorder.moov.cc/" rel="nofollow">http://preorder.moov.cc/</a><p>Apart from the dedicated Tennis application.
I'm a nerd and love data... so I am happy with the response to this question being "because it's cool"... but is anyone actually reaping any reward beyond the basic placebo effect by wearing any of these devices? It might make me want to train more just to see the data... but is the data really helpful?<p>I wonder if we'll be looking at these devices like Nike Pumps in a few years... all gimmick.
I'm hoping that something like the Vidonn X5 ( <a href="http://www.vidonn.com/en/" rel="nofollow">http://www.vidonn.com/en/</a> )gets open sourced - it's $40 device, inc postage, and seems to have everything it needs to do most of what I want... except the app is pretty poor.<p>If you could use this with your OWN apps then it would be a killer device.
I quit working on this same idea about a year ago after concluding that the resolution on (existing) 9-axis IMUs wasn't good enough for serious tennis players.<p>Then again, maybe just being able to see your racquet head speed increase as you improve your technique will be enough for a "quantum of utility" for beginners.<p>Good luck to them!
This is a great idea! I've just pledged 140 AUD. I don't play tennis, but I do play a lot of badminton.<p>My hope is that they'll eventually give software devs access to an API so that I may refine their product to work for badminton.
Really, really, really impressive design. But I think this is a really, really, really small market, and I don't think there will be enough interest to meet the fundraising goal. Hope to be proven wrong, though.
I wonder if it's possible to build Smash for the Google Glass, to get <i>instant</i> feedback instead of looking at the app post-game. Actually, it is possible, and I hope it happens soon.
I'm curious if there are any computer based training tools for tennis that make use of a high speed camera and do image processing to analyse your swing etc.