Converting Frenet TNB Coordinates to Cylindrical Coordinates

[caejournal]

Hi all,

I have a circular helix with any point on the helix defined using the Frenet tnb triad.
t- tangent, b- binormal and n-normal acting towards the axis of the host circular cylinder.

The tangent of the helix t is oriented at angle A with respect to the base of the cylinder.

Now I want to convert the tnb coord system to the cylindrical coordinate system, RTZ. I need it because the cylinder has to be defined in terms of RTZ.

I came up with this:
R = -n
T = t cos(A) - b sin(A)
Z = T sin(A) + b cos(A)

Is this correct? (T is implicit in RTZ for representing a helix in cylindrical CSYS). I am confused. Any help would be appreciated. Thanks

-C

 

[caejournal]

Anyone? Please...