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Unread 27-05-2015, 08:15
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Re: about the torque calculation of a mecanum wheel

While Matsinos does decompose the "driving force" Fi into Fi,p and Fi,t improperly because he assumes that it is transverse to the wheel axis (it is not), this error is inconsequential, as when he performs experiments, he does not control torque or force, but angular speed.

The problem I related above is consistent throughout the work. Though the photograph of figure 1 and the overhead diagrams of figures 2 through 6 all depict the proper roller orientation, When he decomposes the force parallel to the roller axis into x and y, he depicts the axis of a roller at the top of the wheel, not one in contact with the floor.

The consequence of this error is recognized within the paper in the paragraph below equation 14 on page 8 (Matsino's emphasis):
Quote:
if the track and the wheelbase are chosen in such a way as to satisfy the condition tan α = Ly =Lx, the resulting net torque
always vanishes irrespective of the magnitudes of the applied forces and of the direction of the rotation of the Mecanum wheels!
I have not yet had a chance to review the experimental data to see if the wheels were installed as pictured or as analyzed (or perhaps some other way).
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