Forgot to tell the end of this story: Did not sell it. Got a buyer for it and promised to include training. However thought about it for some time and decided it did not feel good. Luckily the buyer understood and allowed me to withdraw.

A lot has happened after that Please keep coming back to read about it....

I'm selling my Trackman MII, it's posted on ebay.fr

Calibration

Received the new IR Leds, $0,75 each so it was time to get started with the calibration rig. However I did not really like the design so I created a new one:


I'm still not 100% happy with it as I would like to include a battery holder into the design but for now it will do. You can download the STL file to 3D print it from here: Putpi Cali V6

Using it is easy. You mark the spot for the ball and place the putter in that position with the correct lie and no shaft lean. Make sure that the face is pointing towards the target, you can use a laser pointer for that. Next the calibration rig is placed against the putter face.

In the software you start the calibration routine. The calibration routine will now measure the position and 3D orientation of the calibration rig. By doing this it can correctly establish how the camera is orientated in relation to the putting line. You then remove the calibration rig and power-on the Marker clip and let the software measure the clip. That's it. The software now knows everything it needs to know in order to correctly measure the putter stroke.

To explain the difference. The following is the measurement of 3 putter strokes. It represent the x/z data (in mm). X being horizontal (left / right direction ) and Z depth (backward / forward direction).


Next image displays the same 3 putter strokes but now the strokes are recalculated using the calibration rig measurement. The calibration rig was oriented differently for each of the three putter strokes.

Conclusion

This project started to improve the TOMI, making it possible to run it on the newer Windows platforms, with improved precision and accuracy, with faster data collection. I think these goals are meet and that all for a sub US $ 35.- price. (without shipment costs and the 3D printed parts)

Exactly a year ago I wrote this on the TOM WISHON FORUM in a thread about 3D printing (TW Forum thread)

Followed by

TWW replied

So what did I read today here : Golf equipment manufacturer Ping produces 3D printed putter ?
and

I tried to login yesterday on the TOM WISHON forum and this message welcomed me


That was a unpleasant surprise! However it seems that I stepped on to many toes when replying to some of the nonsense that was posted there. The reason TOM give me was another one, I'm not respectful enough in my postings. So in short you can say anything you like, be wrong or just straight-out lie as long as you do it respectfully. This is what TOM WISHON wrote when asked why he banned me.

Datum: Thu, 22 Jan 2015 21:35:56 +0000
Van: Tom Wishon 
Aan: Clubfitter73 

Frans

There was a time before in which I had removed your Forum access because your manner of disagreeing with other opinions was beyond what I felt was a respectful tone.  But you said back then you would post in a more respectful manner so I let you back on the Forum.  Since that time and somewhat more recently I have seen and I have heard from several other clubmakers on the forum that you were continuing to adopt a disrespectful tone in some of your posts.   I checked this out and I just feel that your manner of disagreeing with others is just beyond the level of being respectful.  

It is fine to have discussions on Forums in which people with different opinions debate their beliefs.  It is OK to disagree but it is not OK to disagree in a disagreeable manner, which is what you continue to do.  When several other clubmakers email or even call us to say they no longer are going to visit our Forum because of you specifically, I am sorry but there comes a time when the needs of the many outweigh the needs of the few.  

I am sorry but your disrespectful manner just got to be too much for us to accept.  

TOM WISHON

Well, what can I say other then that I don't agree. This is what I wrote back:

Datum: 	Thu, 22 Jan 2015 23:36:36 +0100
Van: 	clubfitter73
Aan: 	Tom Wishon

TOM,

I respectfully disagree. English is not my native language and as such the consequence is that there is a lack of large enough vocabulary. Having less words at your disposal means that tone in which things are being written is perceived differently then when those exact same things would have been said person to person. So I'm not aware of any disrespectful postings except there is a strong aversion against some of the complete BS that some "clubmakers" are posting and they are definitely not doing the clubfitting industry any good! My goals is to improve the overall knowledge and stop misinformation, I'm very passionate about that and that is what you find back in my writings.

Review my posts : There is no-name calling, no personal attacks, only confronting when errors or misconceptions are posted. All I write can be backed by scientific studies and literature!

Please read my TOMI research postings, does providing a diy high speed high precision putter swing monitor sounds like the actions of a person that doesn't care about this industry?

If you do not change your mind then please post your email on the forum to explain that I was banned. I will do the same on the clubfitter.eu website (if you permit me publishing your email)

It's your forum and you can do what you want. Please remember that removing those with a different opinion silences the debate and stops progress.

Frans

He never replied nor did he placed a posting on his forum to explain that I was banned. I do understand however, his main interest is running his business and the forum is a place where clubfitting and clubmaking is promoted. A good forum will increase revenue and if people start complaining and even telling TOM that they are not longer visiting his forum it might cause a possible decrease in revenue.

The ban came shortly after I pointed out that Roy Nix (owner of the AGCP) posted some nonsense about the "club release". (http://wishongolf.com/forum/viewtopic.php?f=1&t=13214) Roy was not really happy and I'm sure he contacted TOM. As TOM and Roy are promoting each others business on their respective websites I think TOM made the decision to ban me to keep Roy happy.

Added 15-12-2015 : Seems that TW removed my remarks from that thread!

Fail!

After testing the PutPi software more then once, re-doing all calculations by hand and using other software club-path, swing direction and all other direction related data seemed incorrect. Not all the time but just now and then.

I build a special "Marker" rail system, allowing almost total control over swing direction and angle of attack.

But still, wrong data.....

Reason!

Then suddenly I started to understand the reason. When the software measures the TOMI marker it knows exactly how the TOMI marker is orientated in relation to the camera but.....the camera has no idea about it's orientated in relation to the target! So impossible to determine the correct swing-direction!

Solutions?

A possible solution is to make sure that the camera is 100% correctly perpendicular to the target or playing line but placing a small camera at 3meters from the target and 1meter from the ball placement 100% correct is impossible.

An other solution is to place the putter with the TOMI marker attached at the ball placement position, measure that position and the move the putter towards the target keeping it on the target/playing line. That might work but leaves enough room for errors and with a objective to measure the swing data within 0.1degree any possible procedure that introduces error should be avoided.

Placing the camera behind the putter in line with the target seems like a good solution but it means that the TOMI marker has to be placed 90degrees turned in relation to it's original position. That "weird" position might influence the putter swing due to the visual distortion such an orientation has for the golfer. Placing the camera at the target has the same visual distortion issue.

Solution

The solution is to introduce a second "marker" allowing the software to measure the direction of the target line. It's a marker that will be placed against the putter clubhead while the putter is placed in the correct position. The marker has 4 leds and those leds are then used to measure the target line direction.

I have already 3D printed this marker, the leds are ordered and I hope those will be delivered within a few days.

To be continued.....

Objective

As mentioned in the "PutPi : The Camera" blog entry it's possible (even very likely) that the lens will cause a distortion of the image.

As the goal is to measure the exact position of the TOMI clip (it's four LEDs) any image distortion will also cause errors in the position measurements.

The objective of this blog entry is to explain how one can calibrate the camera. The final result of this procedure are two files that contains specific lens data with which the distortion can be corrected. Those two files are unique for each and every camera/lens. The PutPi software will load those files and uses them to correct all images received from the camera before try to measure the position of the TOMI clip in those images.

If you want to know more about the theory behind the calibration procedure please visit this link : Camera calibration With OpenCV

The procedure

Step 1 : Preparing the hardware

Print the following image

Use a good printer, white paper, slightly heavier then standard. Print as large as possible.

Find yourself something flat, thick and large enough on which you could glue the chessboard pattern printout. I used a wooden board and by using a metal ruler checked its flatness in all direction.

You could also use glass or a metal sheet, just make sure it's flat!

Place\stick 4 or 5 strokes of double-sided tape on the board. Place them close to each other, not overlapping.

Remove the other protection layer and glue the chessboard pattern printout to the board.

Step 2 : Preparing the software

Download the calibration software from this link : PutPi calibration and run this setup. It will install the calibration software on your system. I assume that you already installed the drivers for the camera as mentioned in "PutPi : The camera" blog entry.

Step 3 : Running the software

As soon as you start the calibration software you just installed it will show a text window and a image window. The text window will inform you about the calibration progress. The image window shows the image recorded by the camera.

If you point the camera in the direction of your chessboard board it will try to "find" all the squares. If it found them it will start drawing dots and lines. This will inform you that the software saw the chessboard and was able to find all the marks.

It will show this image for around 1.5 second before showing a newly recorded image. Because of that 1.5 seconds it seems like the camera is recording very slow.

If the dots are all in the correct position (in between the black and white spaces ) and the lines connection the dots are straight as shown in the image above, press Y or y. This will tell the software that you inspected the image and that it was good enough to be used in the calibration procedure.

Move the camera to record the chessboard pattern from another angle, again check the quality of the dots and lines and press Y or y. You have to do this 10 times. Makes sure that you record images from as much angles as possible and make sure that the pattern is not only placed in one side of the image. Use enough light!

Step 4 : Inspecting the result

After accepting 10 images the software will inform you via the text window that it's calculating the calibration result. This could take some time. When the calculation is finished two things will happen.

In the text window a value with the name "RMS" will be show. This value needs to be as close to zero as possible. Values below 0.3 are good, below 0.2 are better and lower are great. If that value is high then press "escape" and start again!

The image below shows a bad RMS value

At the same time the software shows the RMS value it will also show a second image window. This window is the recalculated and hopefully undistorted image. If the RMS values is high some weird results can be seen


But with a good RMS value you will see that the distortion is almost gone



You're done and can stop the software by pressing "escape"

Step 5 : The final files

The result of a calibration are two files: putpi_Distortion.xml and putpi_Intrinsics.xml These are saved in the same directory as where you have installed the calibration software. PutPi will use those two files to correct any recorded image.

Design

The "new" camera needed a new housing. After designing, testing, adjusting, printing and re-designing, testing etc I ended up with a nice pile of junk


However the final design was rather nice and had extra space for feature options.

But after several extra 3d printing runs I decided that this design was too difficult and took too long to print (more then 6 hours). So I made a new design, easier and faster to print (3 hours), less space but still enough for possible new features.

3D Design Files

These are the three design files you need to print the parts of this housing. If you don't own a 3D printer try to find a Fab lab in your neighborhood and ask them to print it for you. (FabFoundation)

Right side: PutPi HouseV3 R
Left side: PutPi HouseV3 L
Board holder: PutPi Board Holder

Assembly

After printing them this is what you will have:


1) Use the screws with which the board was set in the original housing to connect the board to the new 3d printed board holder.



2) Put the board holder combination in the left side part of the housing.

Pay attention to how you fit the USB cable in the housing and around the board.


3) Click the right side on the left side. Don't force it. It should fit rather good. For permanent assembly you could put some glue around the internal sleeve.

End Result

This is how the end result should look like:

Focusing the new lens:

After mounting the new m12 lens holder on the board and screwing the new IR lens into the lens mount all that is left to do is to get the lens to focus.

Be careful when turning the lens into the lens holder, you do not want to touch the image sensor with the lens and damaging it!

To get the focus correct it's easier when using a focusing aid. One well know aid is the Siemens Start. wiki image

Print this as large as possible and put it flat on the table. Start the "CL-Eye Test software" that was installed together with the driver to see the images taken by the camera. Then slowly start turning the lens until the star becomes as sharp as possible. Don't rush, make tiny adjustments.

When you're 100% sure that the lens is in the best position then secure the lens in place with a spot of glue on the threads. Like this :


With the assembly and focusing finished it's time to put it in his new housing...

The Hardware:

The cheap camera to use and improve the putting fitting data is the Playstation Eye (PlayStation Eye).

This small camera has some great specifications. Not only is the used image sensor sensitive to IR but it also has a resolution of 640x480 with a maximum frame rate of 75fps! When using it at a resolution of 320x240 (the same resolution as the TOMI ) it will even do 187fps. The TOMI can only do 30fps, more then 6 times less frames per second then this rather cheap camera!

The Drivers:

As this camera is intended to be used together with a Sony PlayStation normally no drivers are available for the Windows platform. However Alex Popovich did some fantastic hacking and developed driver for the Windows platform. Those drivers can be downloaded from his website : Code Laboratories These driver will allow any Windows developers to start using this camera in his software. This is why I could use it for the PutPi software as well.

The Lens

Because the image sensor is sensitive to InfaRed Sony used a lens with a IR blocking filter to prevent it from overexposing. The TOMI marker unit is using IR Leds. Without any modifications to the camera lens the IR markers would be visible but rather dim.

Below the same image but now using a lens without any IR filter.

As you can see those IR markers are much more "visible" making it easier for any software to find them and measure their position.

Removing the IR Filter

Removing the IR filter used to be rather easy. See this tutorial PS3Eye Disassembly & IR Filter However Sony has released a new version of the camera and in this new version a new lens configuration is to be found. Removing the IR filter from this lens configuration is not longer possible!

In order to make a camera that can easily see those IR markers it's necessarily to replace the original lens with a new one. Use the above mentioned tutorial to disassemble the camera and to remove the lens configuration. This will be your end result:

Assembling a new Lens configuration

Using the internet it's now time to find a new lens holder, that the plastic holder that connects the lens to the board., and a new lens without any IR filter. The lens holder should have the correct dimensions (M12 x 0.5 , 18mm screw distance) and the lens itself should fit in the holder. I did al that work for you and this is what I found on internet:

Ebay : 5 lens holders M12 x 0.5 (18mm screw distance)
Price? US $3.31(!)

Ebay: M12 x 0.5 Mount 75 Degree View Angle 4.2mm IR Mega Lens F1.8
Price? US $8.85

And if you need a link for the camera, at this moment Amazon is the cheapest : Amazon : PlayStation Eye
Price? US $10.62

So for a total of US $22.78 you will end up with this InfraRed 75fps 640x480 camera.

Ready?

No, not yet. The original lens used by Sony was very good and it's a shame we could not remove the IR filter anymore. The new lens has no IR filter but is of lesser quality. Cheap lenses like this will distort the images:


This "barrel" distortion is not something we can use when trying to measure the markers position as precisely as possible. Luckily we can use software to correct this radial distortion. In a next blog entry I will explain how to remove this distortion using calibration software and provide the software to do this.

to be continued....