Decoupling equation mismatch

[plinioMoreno]

@randaz81, is this the line that decouples the eyes position in the firmware? The equation is Vs = L+R
If that is the case, then the wiki documentation does not match the code, which is Vs=(L+R)/2. Then, the control gaze decouples the equation in the wrong way and for large version angles the fixation point is not in the center of the image.

In order to verify the mismatch, we also moved the version to the limit while keeping the vergence at 0. This configuration is supposed to reach the limit (38deg), but after applying the decoupling equation and measuring it, the value is close to half of its actual value. However, the value that we read from the motors control board firmware is 38 deg.

/cc @joao-avelino @ruipimentelfigueiredo

[traversaro]

Other point where that relation is defined:
In the gazebo-yarp-plugins, see https://github.com/robotology/gazebo-yarp-plugins/blob/93644b645efc56ce124e65b80f64b92dcc1a7cdb/plugins/controlboard/src/ControlBoardDriverCoupling.cpp#L81 , it seems that the equation currently used by the firmware is used.
In the paper on the Gaze controller, instead, the wiki version has been used: see https://pdfs.semanticscholar.org/0596/7b8eb45d1a56074f92624e7e808565dbc600.pdf , Equation 1.

cc @alecive @pattacini @triccyx