The topics covered in this section include:
Setup File and XML Tag Definitions
The settings file is an XML file whose tags specify properties to be used by OpenSim for the inverse dynamics analysis. The XML tags used are defined in the following sections.
Note: The following setup file example can be found in examples/Gait2354_Simbody.
Example: XML file for an inverse dynamics setup file
The properties for the analyze tool, which is responsible for performing the inverse dynamics analysis, are enclosed inside the opening and closing tags <InverseDynamicsTool> and </ InverseDynamicsTool >. The name attribute name="subject01_walk1" specifies the execution name. The name of the results file generated will be prefixed with this name.
The <model_file> tag specifies the OpenSim .osim file used to construct a model. This file typically defines the OpenSim musculoskeletal model scaled to the dimensions of the subject by the Scale Tool.
Forces to Exclude/Include
The <forces_to_exclude> allows the modification of the forces defined in the model file for the purpose of InverseDynamics. Forces can be specified either individually or as groups, the default behavior is to exclude "Muscles" and leave all other forces (e.g. Bushing forces or contact) in effect.
Results Directory and Precision
The <results_directory> tag specifies the directory where results should be written.
Initial and Final Times
The <time_range> tag specifies the time interval over which the inverse dynamics analysis is to be performed. The initial and final times may be adjusted to the nearest frames of data available.
Coordinates and Filtering
The <coordinates_file> tag specifies the time histories of kinematics (e.g., generalized coordinates) that describe the movement of the model. For example, this file may be generated by the inverse kinematics tool. The <lowpass_cutoff_frequency_for_coordinates> tag specifies the low-pass cutoff frequency for filtering the kinematics. If the kinematics have already been filtered, specify a negative cutoff frequency to prevent filtering.
The <external_loads_file> tag specifies the XML file containing the external loads applied to the model during an inverse dynamics analysis. Detailed description of the contents of this file are given above.