This is an early draft, need to define the weight of pib, motor torques and speeds
In this document, we outline the features and capabilities required for the knee of pib, our humanoid robot. By understanding these requirements, we can determine the appropriate transmission ratio and method of transmission to ensure effective movement and stability.
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Where T_motor is the torque output of the motor. Depending on the motor specifications, we will choose a transmission ratio that balances both torque requirements and movement speed to achieve the desired performance for the knee joint.
2-Stage Transmission
To achieve a transmission of 36 as assumed in the table below, 2 stages seem to be useful:
Planetary gear-stage with ration 1:7
belt-drive with 1:6.25 (75/12 teeth)
Summary Table of Movement Speeds and Torques
State | Torque Knee (Nm) | Torque Motor (Nm) | Speed Knee (rad/s) | Speed Motor (rad/s) | Transmission Ratio (r) | Power | |
|---|---|---|---|---|---|---|---|
Static | 72.6 | To be determined 2 Nm | 2.36 | To be determined | To be determined Goal: 85,7 @22V: 209 (no-load) | Calc: 36.3 Real: 43,75 | 0.171 |
Dynamic | 435.6 | To be determined 2 Nm | 2.36 | To be determined | To be determined | 1.028 |