Motor Specification and Sizing for Android

[akhter]

Hie,

I want to build my own Humanoid robot. I am new in this field and I can not select the motors that I needed.

I do not know how to calculate the torque (N-m) for the motors. I found some papers they calculate the motor power in Watt or Oz-in. How to calculate them?

Here is my calculation process. Do not know is it the right way of wrong.

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Motor Position: Knee (Pitch)
     Total weight, W = 9Kg (weight of upper torso of the knee.)
     Length form the Knee to Head of the Robot, L = 0.914 m
     So, Force,    F = (W x 9.81) = 88.29 N (Newton)
           Torque, T = (F x L) = (88.29 x 0.914) = 80 N-m
=====================

Please give me a suggestion about my calculation, right or wrong?
Please tell me the right way of the calculation.
Please tell me how to select good and appropriate motors.

I will be so much grateful to you.

Regards,
Akhter

[Admin]

http://www.societyofrobots.com/mechanics_statics.shtml
http://www.societyofrobots.com/robot_faq.shtml#select_motor