Simulating kicking a ball.

BIG TOE!!!!!!
You have obviously never kicked a soccer ball in a real game.

There are two areas of the foot commonly used for striking the ball.
a) The top face of the foot e.g. where the laces of your shoe are, but slightly nearer the toe.
b) The Instep, the area of the foot which touches the other foot if you stand with your feet together, this gives more control and slightly less power.

Exponents of curving free kicks commonly use a bit of a) and b) together kicking across the line of intended flight to impart spin.

You need to get the fundamentals correct.
Only occasionally will a 'toe poke' will be used as a last resort to nudge the ball away from an opponent or over the goal line.

A goal kick for maximum distance will be (a),.
The power applied is such that in winding up for the kick, the heel of the striking foot can hit your backside, and the follow through is such that the knee of the striking leg can hit the opposing shoulder

Del

Thanks for the soccer advice Del, but it's not important to me where the foot contacts the ball, you're right, I'm not a soccer player. The gist of my query has to do with the the components and their configuration. Got any ideas?

An accelerometer on the foot could detect the kick.
I don't think you could realistically simulate the feeling without exerting quite a bit of force pretty quickly which may have safety implications....so...
Simplest to give some feedaback would be a rumble motor (like in a standard game pad) on the appropriate part of the foot. Maybe attached with a rubber strap or Velcro that could be put over your foot, with the motor on top of your foot.
Del _{(the footabll snob...who has at least played the game)}

Does the motor respond to movement?

I imagine that we could make you a sensor for one million 440 dollars and 32 cents, more or less.

However I do have doubts about where to put it.

An imaginary place for it may not work out.

The sensor may have to be real, and the ball real on a spring mount so you kick the ball and the sensor knows if it is a good kick or not.

In one really rich guys compound he had a room where he could whack at golf balls that hit a screen that represented the fairway and landed balls for the next set of whacks.

P.S. you might want to look at that sort of system. Rich guys have it for golf.

Ok, a soccer ball is too much in terms of the feedback impact with the toe, how about reducing it to the feel to the impact of the putter in a 6 foot putt with a golf ball?

Assuming that you want to do more than just kick the ball any which way, I think you need a tethered ball with the bells and whistles inside it. If you play billiards, it is as though you are putting the sensor in the cue tip, but that doesn't tell you about the "English" or the top or bottom spin you put on the cue ball. The boot does similar things to the football (the real football, not the pointy one).

" ... a sensor which can detect the end of the swing of the foot as a person "kicks" an imaginary soccer ball ...." - this is your first big problem. There is nothing to sense - it's an imaginary ball!

Forget the ball forget the kick, I'm not trying to sense the kick or the ball simply "DETECT THE END OF THE SWING OF THE FOOT".

" ... as a person "kicks" an imaginary soccer ball"

When a ball is kicked, the swing of the foot does not end when the foot contacts the ball - there is always follow-through.

Detecting the end of the swing is certainly possible¹. The fragment of the OP I've quoted and the title of the thread were unnecessary distractions.

¹ using, eg, an accelerometer as has been suggested, or possibly some kind of inertially-operated switch.

Wouldn't a pedometer do that for you, it might give a click at the start and finish of the kick but it would be cheap.

"Wouldn't a pedometer do that for you, it might give a click at the start and finish of the kick but it would be cheap."

That's interesting, hack a pedometer. Very clever! Thanks.

Hi corelite,

Del had it right in suggesting an accelerometer. With one of these placed on the foot, at the end of a kick, the acceleration will suddenly drop to zero and then reverse. You must select an accelerometer of the right range. You must also be aware that accelerometers are axis (direction) specific.

You will spend some time programming to determining how the output of the accelerometer will give you the desired effect in the game.

There are many accelerometers out there. Here are some:

http://www.sparkfun.com/commerce/product_info.php?products_id=758

http://www.analog.com/en/mems/products/index.html

http://www.radioshack.com/product/index.jsp?productId=2909788&CAWELAID=124299652

Good luck on your project!

Mike

Thanks for the links, Mike.

Hi corelite

Your purpose seem to return signals to the athlete to improve his performance. And your problem would be to interpret / calibrate the sensor(s)

Consider using a high speed video recorder, a sensitive microphone , strain gauges etc to determine the impact velocity and to calibrate your device.

You could also use the video to determine the result of the effort.

Your final product could be a keypad to punch in the desired distance, wind and other values and the club used.

For feedback you could use an earphone with a tone beep to indicate increasing or decreasing power.

Then you should also consider the rules of the game (A woman sprinter may not use ball bearings or casters - etc)

For light striking of the ball I see no problems per se. My issue would come into play during a powerful kick. Not only is the problem with where on the foot the ball makes contact, but also the position of the arc of the leg. Ie, Did I strike it too early or late? Did I nick the ball rather than get a clean strike, or did I hit the ball too low or not high enough. Nothing worse than going to give a powerful kick to the ball and having someone tackle the ball and you miss. OOOOh my aching groin!
Seems to me you may need a object to absorb and record the strike.

"(A woman sprinter may not use ball bearings or casters - etc)"

This gives me an idea. Perhaps a ball bearing rolling loose in a linear race or cage like a metal or plastic tube attached to the shoe can be used as a kinesthetic cue as the ball bearing rolls inside the tube and contacts the ends of the tube during the leg swing. Good lead! Thanks Hendrik.

I want to thank everyone for your input and spirited discussion on my question. The responses veer off at times in directions which are not in the realm of my original idea, but I see now that the way I proposed the project could have been better conveyed. I was trying to be concise but I see now that I could have been more precise. So here goes:

A friend of mine has Parkinson's disease and has trouble walking. However he discovered that when he kicks a soccer ball, or rock, or whatever (with the point of his foot) just lightly, it somehow organizes his stride and he is able to walk a few strides forward. He did play soccer so I think there is muscle memory involved.

He's tried just imagining kicking a ball but that doesn't work, he needs the kinesthetic feedback such as the feel of the "Tap" at the point of his foot when he contacts the ball. Since it would be inconvenient to walk around kicking a ball in the supermarket, or, movie theater, etc. the idea of a device which can be attached to the shoes simulate feel of the toe "tapping" the ball (I understand now that "kick" was a poor choice of a word), came to mind. Again, I apologize for the misdirection.

Certainly I now have a better grasp of the problem and what you are attempting.

Your friends discovery is interesting, and it may well be that a tube taped to the side of his shoes with a ball bearing in it may provide the feed back that he finds helpful.

I imagine this is fairly low tech, and it could be that the tube would need to be filled with multiples of ball bearings, and the tube to be in the shoe, next to the skin to provide the sense he apparently finds of aid.

Possibly a system could be created to provide thump roll pulse feedback within the shoe.

You may want to repost the question with more of the detail in the BioMech & BioMed section. This may be sort of against the CR4 rules, but your original question implied a game sort of set up. Those in BioMech may already be familiar with the sensory aids those with your friends affliction have, and if not, may have curiosity about it.

It is implied that should you create or find an aid for one, it would aid others in similar circumstances.

It is good to help your friends.

Light!

Maybe it's worth looking a bit harder at what's happening, here. Sounds to me as if perhaps the feedback needs to come from the relative position of the feet - perhaps when one foot is sufficiently in front of the other that it's time to put it down & transfer the load to that leg and start swinging the the other leg.

Just a thought ...

One question, not necessarily the last is: is this "tap" to simply occur at the point where he stops moving his leg, or is it a signal to tell him to stop moving the leg, similar to what happens when you dribble the ball?