Editing Gimbal lock (section)

{{Short description|Loss of one degree of freedom in a three-dimensional, three-gimbal mechanism}}
{{Refimprove|date=March 2013}}
[[File:Gimbal Lock Plane.gif|thumb|Gimbal-locked airplane. When the pitch (green) and yaw (magenta) gimbals become aligned, changes to roll (blue) and yaw apply the same rotation to the airplane.]]
[[File:Gimbal lock still occurs with 4 axis.png|thumb|Adding a fourth rotational axis can solve the problem of gimbal lock, but it requires the outermost ring to be actively driven so that it stays 90 degrees out of alignment with the innermost axis (the flywheel shaft). Without active driving of the outermost ring, all four axes can become aligned in a plane as shown above, again leading to gimbal lock and inability to roll.]]

'''Gimbal lock''' is the loss of one [[degree of freedom (mechanics)|degree of freedom]] in a multi-dimensional mechanism at certain alignments of the axes. In a three-dimensional three-[[gimbal]] mechanism, gimbal lock occurs when the axes of two of the gimbals are driven into a parallel configuration, "locking" the system into [[rotation]] in a degenerate two-dimensional space.

The term can be misleading in the sense that none of the individual gimbals is actually restrained. All three gimbals can still rotate freely about their respective axes of suspension. Nevertheless, because of the parallel orientation of two of the gimbals' axes, there is no gimbal available to accommodate rotation about one axis, leaving the suspended object effectively locked (i.e. unable to rotate) around that axis.

The problem can be generalized to other contexts, where a [[coordinate system]] loses definition of one of its variables at certain values of the other variables.