Abstract: A container with an inside surface and a mass mounted for oscillation in the container with a pair of bellows in the container each having a bias spring therein and a removable end to expose the interior of the bellows to exchange the spring for easy tuning of the damping characteristics and a plurality of balls, one each positioned in a plurality of troughs around the periphery of the mass proximate the ends there to bear against the inside surface so as to provide low friction oscillation of the mass in the container.

Abstract: A gear drive having a third order damper operating with the antibacklash gear so as to lower the impact of the antibacklash gear at high torques to reduce gear wear while maintaining good contact with the antibacklash gear at lower torques to maintain high accuracy and bandwidth.

Abstract: A constant volume damper which has a very constant damping constant over a considerable range of frequencies by including check valves that prevent cavitation as a piston moves in a chamber. The damper is also sealed for use in space application and is temperature compensated.

Abstract: An acoustic vibration isolator for use in preventing damage to a payload connected to a launch vehicle by removing the air around the payload so that acoustic vibrations do not have a medium to travel through to reach the payload.

Abstract: A vibration isolator which may be constructed in the form of a cube for use in retrofitting a device which is subjected to unwanted vibration present in an attached member which utilizes an active vibration isolator and a passive isolator in series between the members and which may include an overload protection device in the form of a deformable member in parallel with the isolators.

Abstract: A moment control device for positioning a spacecraft which employs a plurality of spinning bodies operable to impart a desired torque to a space craft, the bodies being constructed in a unitary combination and the unitary combination being mounted to the spacecraft to be positioned.

Abstract: An actuator positioned in accordance with two signals, the first being predominant and having a noise portion of magnitude which would mask the second signal and wherein the first signal is filtered to remove the noise and is connected to the actuator independently of the second signal so that the resultant motion of the actuator is additive of the two signals.

Abstract: A vehicle control system is disclosed utilizing a reaction wheel assembly for producing small scanning motions and, in combination, a scissored pair of low-cost control moment gyros is used to produce larger slewing motions.

Abstract: Two wedge-shaped platforms, each rotatable about a different axis, are rotationally mounted together so that a pointing device mounted on one of the platforms can be made to point in a desired direction by predetermined rotational positioning of the two platforms.

Abstract: Disclosed is a vibration damping and isolation apparatus having a passive damping mechanism. The passive damping mechanism includes a piston and first and second elements of magnetic material with a shaft extending therebetween. The piston and shaft are linearly movable relative to one another upon application of forces to the damping apparatus. The shaft is spaced from an axial bore of the piston by a restrictive fluid flow annulus that is filled with a viscous fluid. A resilient seal mechanism, having a static stiffness, couples the first and second elements to the piston to define first and second viscous fluid filled chambers in fluid communication with the annulus. Shearing of the fluid as it is displaced through the annulus dissipates the forces. A magnetic mechanism generates magnetic forces that act on the first and second elements to destiffen the static stiffness of the resilient seal mechanism to improve vibration damping and isolation at low frequencies.

Abstract: A vibration isolator which uses a compressible fluid such as air within a pair of flexible chambers interconnected by a restrictive passage, with one of the chambers connected between a first member which may vibrate and a second member which is to be isolated from vibration so that with vibration of the first member, the compressible fluid is compressed and expanded to force compressible fluid to flow through the restrictive passage between the first and second flexible chambers, and provide desired damping of vibration to the second member.

Abstract: A substantially friction free mounting is presented utilizing a plurality of balls which are placed one each in a plurality of grooves between two members that are relatively movable, and a plurality of magnets are placed near the center of each groove to provide for self centering of the balls in the grooves.

Abstract: A method and apparatus for preventing false nulls in an optical delay line by causing the input optical beam to be frequency modulated or variably time delayed so that the components of the optical signal in the output cannot be of equal magnitude and of opposite phase.

Abstract: A system to determine, from inertial reference apparatus and from GPS receiver apparatus, acceleration signals along a predetermined axis to determine the failure of a GPS satellite signal by comparison of the acceleration signals and to monitor newly acquired GPS satellite signals to determine if a satellite drift was present prior to acquisition.

Abstract: A damping mounting structure for use between two members for isolating motion changes which incorporates a plurality of dampers connected between the two members in a closed geometric shape and which uses cross connections between the dampers located on opposite sides of the geometric shape so that translation motion between the two members is damped less than rotational motion between the two members and an accumulator to provide pressurization of the system but to prevent loss of pressure due to slow rotational vibrations, one-way valves are connected between the system and the accumulator to allow fluid flow only from the accumulator to the system and not from the system to the accumulator and pressure relief or burp valves are used to allow short duration fluid flow from system back to the accumulator when a predetermined system over-pressure is exceeded.

Abstract: A filter for use in an attitude control system which may be subjected to vibrations from disturbances which have frequency contents that vary with time. Sensors on the system produce signals that contain the disturbance frequencies and a calculator connected to the source of disturbance produces a signal which varies as a function of the disturbance. The filter receives these signals and augments the control loop gain at the disturbance frequencies thereby enabling the attitude control devices to null the disturbance effects on the attitude of the system.

Abstract: A calibrate and run bias voltage control method for an optical delay system utilizing a plurality of voltage controlled switches which may experience bias drift wherein during calibration an output optical power error signal of the system is monitored while rapidly changing the bias voltages to the switches according to a desired algorithm and setting the bias voltages at a the level achieved when the output error signal falls below a predetermined tolerance level.

Abstract: A system for use with an inertial reference system and a global position receiver for calculating a position error after a loss of integrity by utilizing the global position system values for position and velocity at a time just before the loss of integrity and by utilizing the inertial reference system position modified by the known error in inertial reference system position as it varies with time and the position error as calculated by the global position system velocity extrapolated over the time since integrity loss.

Abstract: A damping mounting structure for use between two members for isolating motion changes which incorporates a plurality of dampers connected between the two members in a closed geometric shape and which uses cross connections between the dampers located on opposite sides of the geometric shape so that translation motion between the two members is less stiff than rotational motion between the two members.

Abstract: A method and apparatus for use with an aircraft autopilot to prevent an aircraft part from striking the ground during near ground maneuvers by employing a protection circuit between the outer loop and the inner loop of the control chain between the autopilot and the control surface, the prevention circuit producing an output signal when there is a possibility of ground strike which output signal operates to reduce the control surface command signal from the inner loop to the control surface and thus be rapidly responsive to aircraft attitude changes that could produce ground strike.