4 Mar
2010
4 Mar
'10
5:30 p.m.
On Thu, Mar 04, 2010 at 10:00:09PM +0100, Nick Copeland wrote:
Well, then you need an accelerometer [1]. [2] is said to be in the
iPhone, but you probably want something easier to solder.
With it you could get the inclination angle and then get the applied
force. If you do it right you could even get a crashing sound when
falling...
Actually it does do the trick, Fons doesn't understand the british turn of
phrase: Jon is not implying an attempt to win the 2010 Tour de France
with his contraption, he is going to have fun on the way to work so I am sure
he can extract acceleration (from traffic lights, Fons, he doesn't actually want
to be the King of the Mountains or anything, not even give or take 5%) based
on the rate of change of a signal.
With such noise generating things on your bike you'd be
excluded from the TDF anyway :-)
Of course you can find acceleration from the rate of change
of cadence plus gear ratio etc. And according to Newton,
F = ma and we know m. But that assumes that it is the force
on the pedals that causes the acceleration, which is not
always the case. And the roar of a motor is very dependent
on the work it has to do.
For the simulations I've been working on (Italian cars,
fast, usually red, I can't say more), we used RPM and
throttle position as the inputs to the motor model.
RPM defines the fundamental frequency, but the power
delivered by the moter defines the spectrum.
Ciao,
--
FA
O tu, che porte, correndo si ?
E guerra e morte !
Nick Copeland
suggested simulating the force applied to the pedals by
calculating the rate of change of the cadence. I reckon that might do
the trick.
It doesn't. Just consider going uphill 5% or downhill 5% at
the same and constant cadence. Makes some difference to your
legs and to a motor.