For the geeks

This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
I have an young employee that needs an engineering project. He plays TT at the basement or garage level but he needs a senior project. I have offered to sponsor or pay for a recording device. It would record yaw, pitch and roll and the acceleration in 3 axis. The idea is that this device would weigh about 40-45 gm or about the same amount as a cut sheet of rubber. It would be mounted to one side of a paddle. To be useful the device would need to take 6 readings, yaw, pitch and roll and 3 accelerometer readings 4000 times a second but it would best if it could take all 6 readings 10K times a second. This would allow one to monitor the swing and also monitor when the ball hits the paddle and how long it is in contact with the paddle.

This hasn't been done before. I think it would be a good senior project.

The big problem is finding accelerometer devices like you have in your modern cell phones that are 100 times faster.

Can you imagine seeing your swing in 3D?
 
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
http://www.wilcoxon.com/vi_index.cfm?PD_ID=383

About the accelerometer, something like this? :)

Sent from my T1X Plus using Tapatalk
That is way too big. Think about what is in your cell phone but better
http://www.designworldonline.com/6dof-sensors-improve-motion-sensing-applications/#_
The device(s) must be small. Remember the total weight with battery can only be that of cut rubber, about 40-45gm so it can be mounted on the back side of a paddle.
The new Apple watch probably has one of these small chips in it.
So far none of these 6DOF mems devices are fast enough for TT....yet.
The technology will improve as there are more needs for wearable devices, drones, and other remote vehicles.

This is a good start but it would need to be faster , with less noise and much smaller.
This one is too big but he uses better and faster filtering.
 
  • Like
Reactions: BeGo
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
I/we have ordered an 6DOF accelerometer/gyroscope. The kit costs about $100 and it includes an Atmel Arm CPU and software. This kit may not be as good as I want but it will be a start. I am going to sacrifice an LKT Instinct Plus blade to mount the 6DOF sensor and CPU on. Hopefully this combination will be about 40-45 gm.
 
  • Like
Reactions: BeGo
This user has no status.
This user has no status.
Member
Feb 2015
55
18
145
This sounds really interesting, be sure to keep us all updated!

Sent from my XT1068 using Tapatalk
 
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
This is what we are getting

This sounds really interesting, be sure to keep us all updated!

Sent from my XT1068 using Tapatalk
http://store.invensense.com/ProductDetail/EV_INVARM_G-InvenSense-Inc/425140/

http://store.invensense.com/ProductDetail/MPU6500EVB-InvenSense-Inc/488434/
The two parts should weigh less that 45 gm with the additional battery. I just hope the communications between the sensors and the CPU are fast enough. We are trying to buy as much off the shelf as possible. When we really know what we are doing we will design a board optimized for sports.

If this works out should be able to monitor golf and base ball bat swings.
 
  • Like
Reactions: BeGo
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
There has been no progress except for me spending money on the development kits and programming materials. I have just been informed that the student will not be allowed to do this project for his senior project because he would be working on his own instead of working in a group. The teacher wants the student to experience the frustration of working in a group. Most of the students have no practical experience at taking on a project and don't know where to begin. The student that has been working for us has been functioning as an electrical engineer for a couple of years now and has experience in designing and programming CPU circuit boards.

I still think the student will be able to work on the swing analyzer but I doubt we will get to the part where the final product is designed.

Professors are clueless.
 
This user has no status.
This user has no status.
🏆 Top 1% Commenter
Well-Known Member
Jul 2015
1,697
1,976
6,397
Read 1 reviews
What if just attach a few LEDs to a paddle and record their movement with a camera, like what Airflight Simulator gadgets do? For example: http://www.free-track.net/english/ .This will require some tricky math/geometry, but there could be useful libraries to do that.
 
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
Multiple cameras would be required to triangulate the location of a LED. It would take a long time to setup to get all the coordinates. I am hoping to take this to the club and capture a few strokes from my coach.

The initial goal is to just get the software done. I think we can still do that. After that I wanted the student to design a small circuit board with much more expensive and faster chips. I would like to get 10K samples/second on all 6 channels.
The student already design circuits at our company so this wouldn't be a big stretch for him.
 
This user has no status.
Watch "A 7 DOF arm, ping pong robot playing with human, Zhejiang University" on YouTube -



I knew it why chinese players are the best. Coz they practice with this bot.
I will understand you all. The thing is, humans can have upto 6DOF rotation of arm, dof-degree of freedom.
But chinese have made a robot that has 7DOF, where 1DOF is redundant. In short if you play with god and play quite good against him(though don't win) they you can atleast play against humans and taste your boot sand!!
Guys,this is something you all must understand.

Sent from my XT1068 using Tapatalk
 
This user has no status.
This user has no status.
🏆 Top 1% Commenter
Well-Known Member
Jul 2015
1,697
1,976
6,397
Read 1 reviews
Multiple cameras would be required to triangulate the location of a LED. It would take a long time to setup to get all the coordinates. I am hoping to take this to the club and capture a few strokes from my coach.

The initial goal is to just get the software done. I think we can still do that. After that I wanted the student to design a small circuit board with much more expensive and faster chips. I would like to get 10K samples/second on all 6 channels.
The student already design circuits at our company so this wouldn't be a big stretch for him.

FreeTrack is 6DOF and works with a signle web camera. For 6DOF mode it works with 3 LEDs, not a single one. All you need is a cheap web camera, 3 LEDs, a cap and some wires. I was able to make it work within a day with investment of 30$ and it worked amazingly. Is tracking a TT paddle different from tracking a head?

This demo is for TrackIR, a commercial variant of a similar system. TrackIR is slightly different, but the principle is the same.

 
Last edited:
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
Good news. The student's assigned project is almost done. This student that works for me has experience that most students don't have so he said the professor's assigned project was trivial. The student will now be able to work on the swing analyzer.

The PC simulators and capturing data at video frame rates are not fast enough.
 
  • Like
Reactions: achalwins94
This user has no status.
This user has no status.
This user has been banned.
Nov 2010
367
135
502
This thread reminds me of this one...

I love it!
On the the high school foot ball team I was called four point Pete. That was a long time ago. I was in special advanced classes but so was half of the front line of our football team. We were a team of geeks but we were not pencil neck geeks. I was also freshman wrestling champion of Portland Oregon. Our coach used the term pencil necks but he didn't include the term geek because half the football team were in the advanced classes and thought is was great it was so because few of us would play college football and even fewer would play professional football. However our foot ball coach repeatably said "get tough or tie". My mother was just as tough as the foot ball coach and said "the world does not revolve around you" and "the world does not owe you a living". I short I was not raised to be a pencil neck geek.
I am a conservative. I believe in survival of the fittest. I/my company competes against the like of Siemens and Bosch/Rexroth. These a giant companies but we win where we compete.

The OP doesn't know what real stress is. I have said this before on any forum but I was a reactor controls officer on a nuclear submarine and also in charge of top secret crypto gear. That is stress. There are many that freak out during training and of the 3 of us from OSU that went into the Adm Rickover's nuclear navy, I was the only one the made it.

TT is not stressful. Try sailing a small sail boat far out in the ocean when something strange happens or the weather gets bad. Try writing the procedure for starting up a nuclear reactor after refueling. Actually I didn't write a procedure. I had to look through many previous startups and copy as much as I could because the nuclear navy doesn't like originality when precedent is available. Still my equipment was new and the procedure had to be right. That is stress.

When you are writing, copying as much as possible, the procedure to start up a nuclear reactor. When people ask you to sail out in the ocean because you are one of the few that have ocean experience. When people ask you to do their geeky control applications because you are the best at industrial applications. That is when you know you have the trust of others.

So, have any of you been in charge of a a nuclear reactor instrumentation? Have any of you held plutonium in your hand? Have any of you been in charge of top secret crypto gear? Have any of you been ask to sail with them because you know how to sail in the ocean?

I am tired of this shit. What the other forums haven't figured out is that really am a expert in motion and how and why things move. I really can do the math and the physics behind how TT balls move.

When any of you make a few million dollars play TT I will start to listen to what you have to say.

I am a hard ass. I don't like liberals. I don't like musllims. In the end it is the survival or those that really want to survive. When will the liberal relent to reality?
 
Last edited:
Top