Gimbal lock is the loss of one degree of freedom within a gimbal system in a three-dimensional space that occurs when two out of three gimbals line up in a parallel configuration, "locking" the system into a rotation in a degenerated two-dimensional space. The term "lock" is misleading: no gimbal is restrained, all three can still continue rotation among their suspended axis, but with the parallel orientation of two gimbals, there is no gimbal available to accommodate the rotation along it's axis
Gimbal lock in flight is a common problem: Planes & spacecraft are considered to be the center of the ring system, leading a rotation on three axes. Perfect examples of gimbal lock in aircraft dynamics is when the pitch gimbal is in a perfect 90 degree angle of the center of the plane, this forces it into lining up with the yaw gimbal. Ultimately, in this example, the roll gimbal is unusuable because the 90 degree alignment will have no rotational effects on the plane during it's increase or decrease of altitude. The roll gimbal ends up only spinning the system in 2D space until one of the two gimbals is moved. Another example is when the pitch gimbal is aligned with roll at 0 degrees in altitude, this gimbal lock keeps the yaw gimbal for rotating.
Risks in flight dynamicsEdit
Prevention & indicationsEdit
In Andromeda spacecraft, in the CM & PM are gimbal indicators, known as the 8 balls. The 8 balls are labeled with a white & black side & have angles marked on them & they have two nickel sized red dots, spaced 180 degrees apart from each other. These two regions indicate the alignment of the gimbals. When the red dot begins to float into the window, the angles are close to lining up & when the red dot moves to the center of the window, the gimbals are locked & the attitude reference is lost & in terms of navigation, the ship itself is also lost.