Many optical systems include components mounted on board a gimbal, such as a roll/nod gimbal, that is used to point or steer the field of regard of the optical system. Measuring the gimbal position and angle using traditional on-gimbal position encoders and/or angle resolvers has several drawbacks. For example, optical on-axis position encoders are bulky and expensive, and angle resolvers tend to impart non-linearity errors into the control systems using the resolver data. Additionally, these components take up much-needed space on the gimbal platform. Furthermore, since a roll/nod gimbal spins freely in the roll axis, an expensive data slip ring is typically required to transfer the data signals from on-gimbal position encoders or angle resolvers to other off-gimbal (non-rotating) components, such as line-of-sight or beam steering devices, or other control devices, for example. Slip rings are electromechanical structures that are commonly used for passing electrical signals, such as power and/or data, between a rotating component and a stationary component. Data slip rings tend to be more expensive and noisy than power-only slip rings due to requirements to support the relatively high data rates necessary for effective transfer of data signals.
USPTO Backgrounds
USPTO Backgrounds