TriPed-Robot / trip_kinematics

Python package for inverse kinematic calculations of hybrid serial parallel robots
https://trip-kinematics.readthedocs.io/en/main/
MIT License
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Group init stuck in infinite loop #78

Closed liquidcronos closed 2 years ago

liquidcronos commented 2 years ago

The following code snippet gets the init function of the KinematicGroup stuck:

import trip_kinematics as trip

first_joint = trip.Transformation(
    'q1', values={'rz': 0}, state_variables=['rz'])
first_link = trip.Transformation('l1', values={'tx': 1}, parent=first_joint)
second_joint = trip.Transformation(
    'q2', values={'rz': 0}, state_variables=['rz'], parent=first_link)
second_link = trip.Transformation('l1', values={'tx': 1}, parent=second_joint)

def get_noisy_from_true_value(state):
    return {'q1': state['q1']['rz'],
            'q2': state['q2']['rz']}

def set_noisy_to_true_value(state):
    return {'q1': {'rz': state['q1']}, 'q2': {'ry': state['q2']}}

noisy_model = trip.KinematicGroup('noisy_model',
                                  [first_joint, first_link,
                                      second_joint, second_link],
                                  actuated_state={'q1': 0, 'q2': 0},
                                  actuated_to_virtual=set_noisy_to_true_value,
                                  virtual_to_actuated=get_noisy_from_true_value)

When interrupting the code execution the following terminal output appears:

File "C:\Users\USER\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\trip_kinematics\KinematicGroup.py", line 139, in __init__
    self._chain_keys.append(current_key)
KeyboardInterrupt

This suggests that the bug is caused within the while loop in line 134.

liquidcronos commented 2 years ago

changing the names of the actuated state to be different than the names of the transformations does not solve this problem

liquidcronos commented 2 years ago

The error seems to be caused by multiple transformations having the same name, leading to a infinte loop while ordering