That is a good question. Even better question is what is actually patented on that patent? I read it, but don't understand what exactly they have patented. Gyro stabilized gimbals have existed long before 2005 they have the priority date.
That was my thought, after re-reading the claims several times, it sounds like it is fundamentally describing the "Rotatably coupled 3-Axis" design of a stabilized gimbal. including sensors to calculate angle, very abstract.
"a first frame rotatably coupled to the base on a first pivot axis, including a first actuator disposed to torque the first frame about the first pivot axis responsive to a first motor signal, and a first rotational sensor having a rotation-sensitive sensor axis and producing a first sensor signal representing the rotation of the first frame with respect to the base"
further down describing the sensor orientations:
"the rotation-sensitive sensor axis of at least one of the rotational sensor plurality is disposed at a fixed angle with respect to the corresponding one of the pivot axis plurality."
very detailed, perhaps overly detailed, allowing people to design around the patent?