I have written the code for converting Euler Angles to Rotation matrix and back below:
Rzc = -0.0030; Ryc = -2.4788; Rxc = 0.0180;
eul_seq_c_in = [Rzc, Ryc, Rxc];
rotm_c = eulerToRotationMatrix(eul_seq_c_in);
eul_seq_c_out = rotationMatrixToEuler(rotm_c)
function R = eulerToRotationMatrix(seq_in)
alpha = seq_in(1);
beta = seq_in(2);
gamma = seq_in(3);
Rz = [cos(alpha) -sin(alpha) 0;
sin(alpha) cos(alpha) 0;
0 0 1];
Ry = [cos(beta) 0 sin(beta);
0 1 0;
-sin(beta) 0 cos(beta)];
Rx = [1 0 0;
0 cos(gamma) -sin(gamma);
0 sin(gamma) cos(gamma)];
R = Rz * Ry * Rx;
end
function seq = rotationMatrixToEuler(R)
beta = -asin(R(3,1));
if abs(cos(beta)) > 1e-6
alpha = atan2(R(3,2), R(3,3));
gamma = atan2(R(2,1), R(1,1));
else
alpha = atan2(-R(2,3), R(2,2));
gamma = 0;
end
seq = [alpha, beta, gamma];
end
To elaborate, you can see that the operation to convert "Rotation Matrix" to "Euler Angles" completely depends on the original "Rotation Matrix", and hence you would need to brute force this check. Moreover, in the original conversion of Euler Angles to Rotation Matrix, you can see that the "cos" or "sin" of the values are being stored, hence your period or phase information is being lost.
If you are very strict that you want a one to one mapping, you might have to trace back to writing code for the exact mathematical constraints to convert "Euler Angles" to the desired "Rotation Matrix".
Theese functions try to achieve the required result in the simplest way possible and hence goes about it this way.
The workaround for your solution might be to conver all your original "Euler Angles" to "Rotation Matrix" and convert it back and then store the same. The Euler Angles after conversion show the "one to one mapping" you require.
Hope this answer helps!
