For a current project I'm working on I have to use quaternions to represent the orientation of an object. The piece of code I'm working on now integrates rotation rates to the quaternion representing the orientation. To test it I made a simulink model to simulate a rotating object and compare my result with the one from the simulation.
I noticed that if I compare the quaternion calculated by Simulink's "rotation angles to quaternion" block, it's not the same as the one I calculated, but if I convert both back to rotation angles they are the same.
This leads me to the conclusion that several quaternions can represent the same orientation. But since I'm new to quaternions I thought I might just ask to be sure.