Passive Torques#

Passive torque models for joint stiffness and damping effects.

class biosym.model.actuators.actuator_models.passive_torques.PassiveTorques(joints_dict)#

Bases: BaseActuator

Passive torque actuator model.

forward(states, constants, model)#

get_actuated_joints()#: Returns the list of actuated joints.

get_n_actuators()#: Returns the number of actuators in the model.

get_n_constants()#

get_n_constraints(*args, **kwargs)#

Get the number of constraints defined by this actuator model.

Returns:: Number of constraints. Default is 0.
Return type:: int

Notes

The default implementation returns 0. Actuator subclasses that define constraints (e.g., activation dynamics, force equilibrium) should override this method to return the correct number of constraints.

get_n_states()#

Get the number of states associated with this actuator model.

Returns:: Number of states defined by this actuator model.
Return type:: int

Notes

The default implementation returns 0. Actuator subclasses that define internal states (e.g., muscle activation, fiber length) should override this method to return the correct number of states.

get_nnz()#

Get the number of non-zero entries in the Jacobian of the actuator model.

Returns:: Number of non-zero entries in the Jacobian. Default is 0.
Return type:: int

Notes

The default implementation returns 0. Actuator subclasses that define constraints or dynamics should override this method to return the correct number of non-zero entries in their Jacobian matrices.

process_eom(model)#

Process the equations of motion for the actuator model.

This method is called during the symbolic equation generation phase to integrate actuator dynamics into the overall system equations.

Parameters:: model (biosym.model.model.BiosymModel) – The biomechanical model containing the actuator.

Notes

The default implementation does nothing. Actuator subclasses should override this method if they need to add additional equations of motion, constraints, or symbolic relationships to the model.

Examples of when this is needed: - Muscle activation dynamics - Force-length-velocity relationships - Internal state evolution equations

reset()#: Resets the actuator behaviour.