damping.rst

.. currentmodule:: trep.forces

:class:`Damping` -- Damping on Configuration Variables

:class:`Damping` implements a damping :class:`Force` on the generalized coordinates of a system:

F_{q_i} = -c_i\ \dq_i

where the damping constant c_i is a positive real number.

One instance of :class:`Damping` defines damping parameters for every configuration variable in the system. You can specify values for specific configuration variables and have a default value for the other variables.

Implemented Calculations

Calculation	Implemented
f	Y
f_dq	Y
f_ddq	Y
f_du	Y
f_dqdq	Y
f_ddqdq	Y
f_ddqddq	Y
f_dudq	Y
f_duddq	Y
f_dudu	Y

Examples

damped-pendulum.py, extensor-tendon-model.py, forced-pendulum-inverse-dynamics.py, initial-conditions.py, pccd.py, pend-on-cart-optimization.py, puppet-basic.py, puppet-continuous-moving.py, puppet-moving.py, pyconfig-spring.py, pypccd.py, radial.py

Create a new damping force for the system. default is the default damping coefficient.

Damping coefficients for specific configuration variables can be specified with coefficients. This should be a dictionary mapping configuration variables (or their names or index) to the damping coefficient:

trep.forces.Damping(system, 0.1, {'theta' : 1.0})

.. attribute:: Damping.default

   The default damping coefficient for configuration variable.

.. method:: Damping.get_damping_coefficient(config)

   Return the damping coefficient for the specified configuration
   variable.  If the configuration variable does not have a set value,
   the default value is returned.

.. method:: Damping.set_damping_coefficient(config, coeff)

   Set the damping coefficient for a specific configuration variable.
   If *coeff* is :data:`None`, the specific coefficient for that
   variable will be deleted and the default value will be used.