Let me make sure one thing:
Please provide the following information:
1. Dimension of the system (at least r1,r2,r3)
2. Does the outer most one can only rotate in YAW AXIS?
3. Is it a static system, only need to be able to set the angle for Pitch, Roll and Yaw angle?
Or there is(are) initial angualr velocity for a dynamic system? What are those values? What are the differential equations according constraints for your system.
Because I have never play with such device before, I do not have any ideas about the physics model (constraints) for the system. I need physics model to create the simulation.
The rotation axes for the following two images are not the same. Which one is similar to your gimbal?
The following is a static version. Click [eye]