Commanding Position#

In this tutorial, we’ll show you how to control your open-source leg in position mode usin the opensourceleg library.

Import the OpenSourceLeg Class#

To use the OpenSourceLeg class, we first need to import it from the opensourceleg.osl module:

import as units
from opensourceleg.osl import OpenSourceLeg

Add a Joint Object#

Once we have imported the OpenSourceLeg class, we can create an instance of the class with the desired frequency and joint configuration:

osl = OpenSourceLeg(frequency=200)  # 200 Hz

In this code, we create an OpenSourceLeg object named osl with a frequency of 200 Hz and a joint with a gear ratio of 9.0.

Controlling Joint Position#

To control the position of a joint, we can use a with block to ensure that the OpenSourceLeg object is properly opened and cleaned up after use:

set_point = units.convert_to_default(45, units.position.deg)

with osl:
    osl.knee.set_motor_position(osl.knee.motor_position + set_point)

    for t in osl.clock:

In this code, we enter a with block that sets the mode of the knee joint to “position”, and set the motor position of the knee joint to the current position plus the set_point value. We then loop over the osl.clock generator, which generates a sequence of timestamps at the specified frequency, and log the motor position of the knee joint to the console at each timestamp. We then call the osl.update() method to update the state of the OpenSourceLeg object.


This code assumes that the OpenSourceLeg object is properly configured and calibrated, and that the joint is properly connected and functioning.

Code for this tutorial:#

 1import as units
 2from opensourceleg.osl import OpenSourceLeg
 4osl = OpenSourceLeg(frequency=200)  # 200 Hz
 7set_point = units.convert_to_default(45, units.position.deg)
 9with osl:
10    osl.knee.set_mode(osl.knee.control_modes.position)
11    osl.knee.set_motor_position(osl.knee.motor_position + set_point)
13    for t in osl.clock:
15        osl.update()