Abstract: A micro-electromechanical optical inertial sensing device comprises a CMOS chip (3), comprising at least one integrated photodiode (6) and analog electronics; an elastically suspended proof mass (1); and a light source (4). A light beam from the light source casts a partial shadow of the proof mass over the photodiode when the proof mass is at rest. When subjected to an inertial movement, the proof mass swings causing the partial shadow to shift and modulate the illumination of the photodiode. An output current signal from the photodiode is processed by the analog electronics to generate measurement results.

Abstract: An apparatus and method for determining the rate of rotation of a body rotating with an angular velocity .omega. about a first axis. The apparatus comprises a housing adapted to be fixed to the body so as to rotate with the angular velocity .omega. about the first axis and a mechanical system within the housing having more than two degrees of freedom. Electromagnetic drive coils are provided for applying a forced vibration to the mechanical system about a second axis substantially perpendicular to the first axis, thereby producing a Coriolis response along a third axis mutually perpendicular to the first and second axes, the forced vibration having a predetermined magnitude and a frequency which is constrained to lie within a predetermined range such that there is produced a coupling between the degrees of freedom whereby the magnitude of the Coriolis response is substantially insensitive to frequency.

Abstract: A gymballess, two axis rate gyroscope in which an inertia rotor is keyed on the electric motor shaft. The motor shaft comprises a flexible part (flexure shaft) adapted to flex upon precession of the inertia rotor in consequence of an angular velocity input around either of two axes normal to each other and both normal to the rotor spin axis, and an end portion extending beyond the inertia rotor in a direction away from the electric motor (delfector). The gyroscope further comprises a non-contacting measuring device in association with the deflector for detecting any deflection thereof.