casainho wrote: ↑Jan 08 2020 5:47am

So master is now updated.

Thank you!

casainho wrote: ↑Jan 08 2020 5:47am

I have a question to you, since you are experienced with the torque sensors, etc.

...

I don't know, if I understand your questions in the right way.

First you have to be careful with the physical quantities.

energy = work = force * distance. The physical unit is (N*m) = (J). As you see from the units, a torque is already an energy.

power = energy / timeinterval. The physical unit is (N*m/s) = (J/s) = (W).

For our electric motor:

electrical power = U_batt*I_batt = mechanical power + losses (heat

)

mechanical power = 2*PI*torque_motor*erps/(no. of polepairs)

torque_motor = km * I_motor (1), where km is a motor constant, see e.g.

here.

We define for the motor power:

P_mech_motor = Assistlevel*P_human

2*PI*torque_motor*erps/(no. of polepairs) = Assistlevel*2*Pi*torque_human*cadence

with (1) you get:

**2*PI*km * I_motor*erps/(no. of polepairs) = Assistlevel*2*Pi*torque_human*cadence **
I think this is the relation you were looking for?!

Some more math:

For the TSDZ2 the gear ratio cadence/erps is always constant. Other way round, you can write

cadence = constant_ratio*erps. (2)

with (2) follows:

2*PI*I_motor*km*erps/(no. of polepairs) = Assistlevel*2*PI*torque_human*constant_ratio*erps

If you bundle all constants in one:

I_motor*erps = constant * Assistlevel*torque_human*erps

as you see, erps can be cancelled out of the equation:

**I_motor = constant * Assistlevel * torque_human**
I hope this helps ?!

regards

stancecoke