Abstract: An accelerometer comprising a frame having an input axis (y) and a cross axis (x) orthogonal to and co-planar with the input axis. The accelerometer has a flexible beam coupled to a proofmass. The beam is supported at a pivot location. A rotator coupled to the frame provides a restoring force having a first or second polarity to the beam. The restoring force is applied in a direction parallel to the input axis (y) to restore the proofmass to a reference position in response to an absence of acceleration along the input axis. A position signal sensor provides an error signal proportional to the displacement of the proofmass from the reference position. A servo responds to the error signal by applying a drive signal to the rotator which applies a restoring force to the flexible beam to restore the proofmass to its reference position.

Abstract: A hydrofoil apparatus for attachment to a marine vessel having a first pivot means for positioning the rotational axis of a gooseneck shaft parallel to the yaw axis of the hull and a trailing load support arm having a forward end coupled to the gooseneck. A planing surface sensor or planing foil rides on the water surface. The planing surface provides a hydrodynamic force to hold the planing surface sensor on surface as the vessel moves with forward velocity. An elongated body member is pivotally coupled to rotate on a first pitch axis with respect to said planing surface sensor. The elongated body member is pivotally coupled to the trailing load support at its aft end. A vertical fin is coupled to support the elongated body member. The fin maintains the planing surface sensor forward of said second pitch axis. A lifting foil raises the bow of said marine vessel by provide a lifting force via the fin.

Abstract: An analog-to-digital conversion system of the incremental pulse-width modulation type for generating a digital representation of the amplitude of an input analog current to be converted comprising a current integrator, a precision unipolar current source, means for switching current from that source in opposite directions to and from a current summing terminal at the input to the integrator, a timing source, and pulse-width control circuit which controls the means for switching current and which controls a clock signal gating circuit on and off to obtain the output digital representation.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. In a preferred embodiment, forcing along the longitudinal axis of the proof mass is provided by a single helical coil disposed in a magnetic field directed radially relative the proof mass longitudinal axis. The polarity of the magnetic field is fixed around the periphery of the helical coil.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. The array of filaments becomes relatively compliant in all six degrees of freedom when loading exceeds a selected design load. This provides overload protection since the proof mass can be brought to a practical mechanical stop for support before excessive stress can fracture a filament.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. An improved transition device provides a relatively simple, controllable and inexpensive means for temperature stabilizing the elastic suspension.

Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. Means are provided in the accelerometer for dynamically nulling the bias.

Abstract: A dithered ring laser gyro in which the effects of mode locking, or frequency locking, at low rotation rates are reduced by producing an oscillatory flow of the ionized gas in the gain section of the laser. The envelope in which the laser is sealed includes a pair of closed-end bellows. The bellows are extended and retracted in push-pull to pump the gas. There is thus created a dynamically varying pressure differential and oscillatory gas flow along the bore of the gain section of the laser which induces a corresponding oscillatory bias in the gyro output.

Abstract: In a ring laser type gyro, laser optics adjustment means comprising a duo-mode bimorph device for separately controlling each of the optical length and alignment of the gyro laser optics.