Launch monitor from scratch

[Lihu]

So, I want to build my own launch monitor absolutely from scratch.  Has anyone here ever tried this? I found a thread here about someone that wanted to build their own, but apparently he wanted more of a simulator type of deal and not truly build one from scratch.  I think he later posted another thread on where he could find a launch monitor under $1,000. I know what you guys are probably thinking: "this guy is crazy, there's no way you can build one from scratch..." Well, I am not crazy. So I am calling out all of you geeky golfers out there, which I know there has to be a few.  I am just wondering if anyone has ever tried this.  I am basically looking for an affordable way to obtain a decent radar system with decent range (I tried eBay and craigslist, no luck).  I am looking for something with decent range (I'd like at least 100 yds, but I think I can do it with 50 yds) but I definitely don't think I'd need full shot range measurements.  I'd love something in the levels of the Trackman (they claim it's military-grade stuff) but that would cost me a lot more I think plus it might get me a knock on the door by the FBI... (or at least a phone call and a tail or something like that) A little bit about me (just so you know I'm not crazy), I am a PhD student in aerospace engineering that tracks satellites for a living.  Basically, satellite tracking works by collecting measurements about the satellites flight characteristics, so technically I can do the same with a golf ball.  After all, that's exactly what these companies do anyways.  My programming background is fairly strong and my electronics background is decent enough but not that strong, but I still think I can handle a project like this. Thanks for reading, Ed

If you are working on it, i'm in. I have been working on a 10Ghz patch array. However, based on some crude calculations and measurements, I think 24Ghz would be a minimum for accuracy. Luckily, a simple homodyne circuit should work fine, since we are, generally measuring in one direction. Let me know what you think. Pm me your email.

[Lihu]

I would be interested. I am a 24 year old software engineer who currently works on android integrated with radars.  In my spare time i work with microcontrolers and rasbery pi stuff.  I think this is very doable as long as we have a senor that can detect spin (that i DO NOT know how to do.)  Launch angle and ball speed would be pretty easy.  Lets make this open source so others can also build these things with just a few hundred bucks at most

Spin is detected by the backscatter from the ball. Some type of fft anslysis no doubt. The ball speed would be the main frequency shift with backscatter being in the higher frequency range. I took some crude measurements with my patch array, looks like it should work, but we would need more sensitivity and lower noise on the Lna. Work in progress.

[inthecup]

I understand you are having "fun" but I have to point out.  I bought a functioning Vector Pro Photo based monitor for $900 on ebay.  It measure and calculates in 12" of ball flight.  The obvious benefit being that you can hit into a net in bad weather.

http://www.accusport.com/products/vectorpro

I believe you are after accuracy and for you to dial in your home made unit would take quite a bit of time.  I find the vector pro to be accurate enough to be very useful.

[Lihu]

Originally Posted by inthecup

I understand you are having "fun" but I have to point out.  I bought a functioning Vector Pro Photo based monitor for $900 on ebay.  It measure and calculates in 12" of ball flight.  The obvious benefit being that you can hit into a net in bad weather.

http://www.accusport.com/products/vectorpro

I believe you are after accuracy and for you to dial in your home made unit would take quite a bit of time.  I find the vector pro to be accurate enough to be very useful.

What's the fun in that?

BTW, my radar array is collecting dust as I go play rounds every weekend. )

[inthecup]

Sorry I don't mean to be the fun police.

My monitor does not get the use it gets in the winter.  I have a nice net setup.  Again a photo based solution  is better because it can work in a more compact space.

[Lihu]

Originally Posted by inthecup

Sorry I don't mean to be the fun police.

My monitor does not get the use it gets in the winter.  I have a nice net setup.  Again a photo based solution  is better because it can work in a more compact space.

Your Vector Pro looks pretty nice. I might have to look for one too.

[Scottieat]

RocketSci, I'm interested in this, too. I'm a bit of a novice in the maker community, but I have access to some pretty sharp people in the areas of programming, machine learning and optics. Have you made any progress? Are you tracking the project elsewhere? Are you looking at infrared blasts and vector mapping using a two camera approach? Have you found good imaging software? I noticed these posts are old, but let me know if you are still trying to sort it out. Scott

[Club Rat]

@RocketSci http://www.golf-simulators.com/Future.html

Also, affordable means maybe the use of these items -

Callaway Golf Speed Regime Swing Radar

ES12 Digital Golf Assistant

SwingTalk Golf Swing Analyzer Voice Feedback IOS Android Devices

OPTISHOT GOLF SIMULATOR INDOOR SWING ANALYZER INFRARED 3D VIDEO

Sport Sensors Swing Speed Radar for Golf Swing & Baseball/Softball Bats SSR364

Club Rat

[golftechie]

I'm currently evaluating the 2 different approaches : doppler vs. photometric.  Doppler would provide actual on the course/range distances while photometric provides the theoretical measurements.  I prefer the latter being that I'm sure we've all had 300+ yard drives due to lucky bounds and hard/dry fairways.

Doppler approach - Using a frequency modulated monopulse radar with a 3 receive patch antennas in order to measure doppler shift along the X,Y,Z axes.  Ball radar signature would need to be separated from the club, most likely separating using velocity.  Spin can be possibility be obtained by the backscatter as Lihu mentioned.

Photometric approach - Using an high speed IR LED flash with a reflective laser beam sensor to trigger (which I believe is what Skytrak uses), and taking 2-3 snapshots from 0 to say 10ms.  Rotation with ball spin and spin axis can be calculated using image processing techniques looking at feature extraction and tracking.  I will also be including an overhead camera to track clubhead so that it can measure the golf club and any off-center hits.  This is actually what I am interested in, instead of attaching impact tape to my clubs.

If anyone is still interested, please drop me a line!

[trust_the_golfer]

Came across this thread while doing research on an idea.

I am exploring building a mobile app golf simulator for driving range use.  For example, if I hit a drive 270 on the range, the ball flight/path and distance would be captured and displayed on a virtual course on my phone.   The video below helps explain the idea...

https://vimeo.com/167110209/c914c8ed67

I'm looking for help on how to pull this off technology wise.  I've done a lot of research on different launch monitors, but would definitely like to hear from people who are smarter than me.

Thanks!

[SavvySwede]

29 minutes ago, trust_the_golfer said:

Came across this thread while doing research on an idea.

I am exploring building a mobile app golf simulator for driving range use.  For example, if I hit a drive 270 on the range, the ball flight/path and distance would be captured and displayed on a virtual course on my phone.   The video below helps explain the idea...

https://vimeo.com/167110209/c914c8ed67

I'm looking for help on how to pull this off technology wise.  I've done a lot of research on different launch monitors, but would definitely like to hear from people who are smarter than me.

Thanks!

If someone has a launch monitor they almost exclusively use them at home already complete with the hitting bay, software, projector and screen. There is no market for what you're trying to make.

[trust_the_golfer]

3 minutes ago, SavvySwede said:

If someone has a launch monitor they almost exclusively use them at home already complete with the hitting bay, software, projector and screen. There is no market for what you're trying to make.

Thanks for the response.

The idea is to allow a golfer from one driving range to compete against a golfer from another driving range by playing a "virtual round" on an app.  I do think there is a market for using technology to enhance traditional driving ranges.

I mention the launch monitor because to pull this off there has to be a way to track and visualize ball flight.  Obviously a business model doesn't make sense if I'd have to put a Trackman behind every stall at every driving range.  But I'm here to see if there is more cost effective way to do this.

[SavvySwede]

9 minutes ago, trust_the_golfer said:

Thanks for the response.

The idea is to allow a golfer from one driving range to compete against a golfer from another driving range by playing a "virtual round" on an app.  I do think there is a market for using technology to enhance traditional driving ranges.

I mention the launch monitor because to pull this off there has to be a way to track and visualize ball flight.  Obviously a business model doesn't make sense if I'd have to put a Trackman behind every stall at every driving range.  But I'm here to see if there is more cost effective way to do this.

The launch monitor is where all the cost is and it is absolutely necessary to get the data, no real way around that. But you said you wanted an app to pair with the launch monitor to use the phone as a the display. Your real problem would capturing the very small market of those who...

1. Own a launch monitor
2. Are willing to take it to the range with them.
3. But unwilling to bring their laptop/ use the software that came with their launch monitor

What makes you think that market exists?

[trust_the_golfer]

17 minutes ago, SavvySwede said:

The launch monitor is where all the cost is and it is absolutely necessary to get the data, no real way around that. But you said you wanted an app to pair with the launch monitor to use the phone as a the display. Your real problem would capturing the very small market of those who...

1. Own a launch monitor
2. Are willing to take it to the range with them.
3. But unwilling to bring their laptop/ use the software that came with their launch monitor

What makes you think that market exists?

You are right in that there is no market that exists with your three points. 

In order for this idea to work, there has to be a cost effective way to accurately measure and visualize ball flight and distance at a driving range that is easy for golfers to access.  If there is no real way around that, then the idea isn't feasible. 

But that is the reason I posted to this thread - because it attracts people interested in building things from scratch (who love golf).   Maybe someone will have a great idea. 

[Lihu]

3 hours ago, trust_the_golfer said:

Came across this thread while doing research on an idea.

I am exploring building a mobile app golf simulator for driving range use.  For example, if I hit a drive 270 on the range, the ball flight/path and distance would be captured and displayed on a virtual course on my phone.   The video below helps explain the idea...

https://vimeo.com/167110209/c914c8ed67

I'm looking for help on how to pull this off technology wise.  I've done a lot of research on different launch monitors, but would definitely like to hear from people who are smarter than me.

Thanks!

Funny you should mention this. My launch monitor is getting close to being a prototype. Parts cost is reasonable, and I was thinking of doing this exact same thing.

[Buckeyebowman]

On 3/28/2011 at 7:34 AM, Clambake said:

You might also search the US Patent data bases to get a better understanding of what existing companies have done: http://www.uspto.gov/patents/process/search/index.jsp#heading-1 I've seen quite a few patents from TaylorMade, Callaway, and others on technologies they're protecting for launch monitors, so there is likely so inspiration there on what to do.

 

I think the detecting part is relative easy - it is the algorithmic development to translate either radar or imaging data into something usable that is the hard part.     By the way, here is a list of what Trackman has patented so far to give you an idea of some of the technological problems you'll need to overcome:

 

 

• Comparing a target direction indicated in an image, e.g. by using a camera, with the ball direction determined by radar

• Measuring spin axis orientation of sport balls from trajectory measurements by radar.
• Measuring spin rate of sport balls by radar using multiple harmonic spectrum traces.
• Quantifying golf ball position uncertainty from multipath signal strength.
• Removing multipath signals – for landing spot determination.
• Determining, from a multipath signal from a ball in flight, information relating to a surface over which the ball flies.
• Determining a distance from the ball to the radar using the intensity of reflected radiation at that distance and the intensity of reflected radiation at a known distance.
• Determining information relating to a ball in flight from a deviation between expected multipath oscillation and detected multipath oscillation.
• Determining trajectory information from a flying ball on the basis of a radar-based launch position determination.
• Estimating spin frequency from a plurality of equally spaced, symmetric side band frequencies in a radar signal.
• Including trajectories determined from radar data in images derived from a camera.
• Deriving image data and radar data from an object and providing an altered image wherein the object is rotated.

 

These are just the ones that have already been patented, so one can deduce these are the problems they solved at least 3-4 years ago.    Trackman probably has a lot more patents in the pipeline.

 

Sounds like a fun project....good luck!

So many good replies! In the aggregate they make me wonder how many engineers and programmers Trackman employed in the development of their machine.

[Lihu]

Generally, patents can be worked around. They are not really intended to stifle free inventing. They are more geared to prevent a direct copy.

That's why companys like Ernest Sports and Skytrack can build products in the launch monitor arena even though Trackman, Flightscope and Foresight have lots of patents.

The technology is simple if you are not looking to replace Trackman. Even the Swing Speed radar essentially has a subset of the electronics. Carrier frequencies are different and the power output stages are different, but based upon a simple Doppler radar homodyne and FMCW technology. FMCW for position tracking.

[cnl390]

To quote Penny on the Big Bang Theory, "HUH?"