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Hi,

I have some query regarding RRA.
1. In "RRA Control Constraints" file there are "default_min" and "default_max". How to decide these values ?
2. In the "RRA Actuators" file how to decide the "optimal_force" ? and what is "PointActuator", "TorqueActuator", "CoordinateActuator" ?

1) Control constrains encodes any external knowledge of the muscle excitation patterns. For example you may know the maximum control values of a muscle during walking and you can constrain the redundant solution based on your measurements.

2) Since these are residual actuators, that compensate for the inability to generate the appropriate force or torque to reproduce the movement. You can start with some value, and through iterations try to reduce these as much as possible. Different type of "Actuators" represent the internal hierarchy of actuators that is supported by OpenSim.

PointActuator: apply a force on a body
TorqueActuator: applies equal and opposite torques on the two bodies (body A and B) that it connects
CoordinateActuator: applies a generalized force to along a generalized a generalized coordinate, which is proportional to its input control

CoordinateActuator should be your choice since you are interested to compensate for the inability of the muscles to generate the appropriate generalized force on a joint.

Hi
Thanks for the reply. It is helpful actually.

I have a 3D data set where the participants is standing on both the legs and then after some time they are standing on single leg. I have run the scaling and inverse kinematics part. However I am bit confused about RRA.

1. How to get the pelvis x coordinate in PointActuator in "RRA_Actuators.xml" file ?
2. What is the "RRA_task file is all about ? what is "CMC_Joint" ?
3. If I use the same "gait2354_RRA_setup.xml" (walking related) file in my case then after some time opensim is crashing ? What could be the possible reason for that ? Kindly help me.

1. How to get the pelvis x coordinate in PointActuator in "RRA_Actuators.xml" file ?

If you look at the model folder you will find a set of default .xml files that you can consult on how to define the coordinate actuator.

2. What is the "RRA_task file is all about ? what is "CMC_Joint" ?

RRA tracks the motion through a set of tasks. In the task file you define how well you would like to track the tasks. Again you can consult the .xml files.

http://simtk-confluence.stanford.edu:80 ... +Algorithm

3. If I use the same "gait2354_RRA_setup.xml" (walking related) file in my case then after some time opensim is crashing ? What could be the possible reason for that ? Kindly help me.

If OpenSim crashes you can look into err.log and out.log files in the installation directory.

Best

Thank u