- posted
14 years ago

engineer. This is not a homework problem, but I am trying to figure

out how to determine the angle between two cables attached to two

rigid structures. Please let me explain what I am talking about. I

have two vectors (2 cables attached to a fixed beam - they will always

have tension and will never deform out of shape of a line) and the

other end they both are attached to a non-fixed box (I guess you can

think of it as rubber cords on the wall attached to a box). I will

always know the orientation of one cable (CABLE A) that is, the angle

relative to the box (coordinate system of the box). I know the

INITIAL angle of the second cable (CABLE B), however, the angle is the

angle relative to the beam. I would like to know if there is a way to

solve the angle of CABLE B in the boxes coordinate system at 1) the

initial position and 2) if the box is moved to a new location. This

seems like it would be simple, but I don't know how to solve this.

So, I started it by trying to transform the vector of CABLE B into the

coordinate system of the box (going from the fixed beam to the box).

I think that would give me the initial position/angle of CABLE B in

the boxes coordinate system. I really do not know how to write the

transformation matrix to do this, but think it would be something

CABLE B

X

Y * [Rotation Matrix] = CABLE B's new XYZ coordinates

Z

Then how would I need to get the angels with respect to the boxes

coordinate system.

Then if the box moves, how would this all work as well? Please help!