Accelerometer

Immagine two balls being rolled toward each other. Each ball is equipped with a Gadgeteer main board, bluetooth, and an accelerometer . When they balls collide, will the accelerometers provide some kind of measurement to know which ball obsorbed the greatest impact?

The lightest or the one which bounces more.

In terms of acceleration the one with higher drop in acceleration

@ Architect -
Thank you, I appreciate your help. Just wanted to make sure the acelerometer module could measure a sudden drop in acceleration.

While waiting for our build server to do its thing this post got my thinking juices working, and yes you could see the steaming coming out of my ears from across the room…

Making some totally wild assumptions as to Bobs GHI Smart BallsTM I dont think an accelerometer will work as I assume the smarts will be fixed inside the ball and rolling with it (see pic). This means that the accelerometer will be constantly pitching and rolling and since accelerometers measure acceleration with respect to gravity it will be spitting out wild values on all axis as it rolls.

I assume you will need an IMU type arrangement using 3 axis Gyros, Accels and Mags with a DCM or Kalman filter to gain the sensors orientation in space and then check for impact somehow.

If the sensor is not rolling like in a car you can get away with possibly just using an acceleromter even though horizontal motion wont register on the acceleromter as there will be vertical motion on impact. I have seen a graph of this with a toy car which peaked at 40g so you might need a new Gadgetter board as most cheap accelerometers are usually under 11g (not sure on the Seeed version).

I quess you will also need to take into consideration the angle of impact, speed of each ball etc to calculate to energy absorbed.

Again take all this with a grain of salt as I havent had my morning coffee so Im probably spouting a load of rubbish…

PS - i used a Sd Card and not a Blue tooth or Accel module in the picture as Architect has been overly lazy and not created and uploaded them, but thanks for the others :wink:

nice images :slight_smile:

must… restrain… myself… from… making… rude… jokes…

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The accelerometer will measure the shock directly, but gravity will have to be deducted. If the balls move at constant velocity then the accelerometer will measure zero(after gravity is deducted, and if the accelerometer is exactly in the center of the ball).

Once the balls hit, they will experience negative acceleration, ie slowing down.

Whew! Very informative. More to this than I expected! Thank you for your insight.