Abstract: An apparatus for sensing and measuring changes in inclination and providing a digital readout. By sensing pulse width changes rather than amplitude, the apparatus provides improved immunity to instability and environmental changes. A variable frequency scale factor oscillator allows choice of readout units. Any preset angle may be selected as a zero reference. The capability is provided to hold any reading displayed for any desired period of time. An overrange indicator is actuated when the linear range of the sensor has been exceeded. Digital output signals derived from the sensor are applied to gate an angle generator which is responsive to correction factor signals to adjust the digital count in accordance with stored offset data. The digital signal count is incremented or decremented in accordance with a signal representing the sign of inclination, derived from the sensor pulse widths and applied to gate the angle generator accordingly.

Abstract: An apparatus for removing correlated clutter introduced in radar video by standard video enhancers. A differencing network provides the difference between an enhanced radar video signal and the previous enhanced radar video signal appropriately weighted. This difference is a video signal with decorrelated clutter.

Abstract: A magnetic head slider for supporting a flying head on a magnetic disk has a plurality of rails extended longitudinally between the slider and the disk which provide the air bearing surface and define a channel parallel to the motion of the data track. A flexible beam is affixed to the leading edge of the channel providing a cantilever structure. A magnetic head is mounted on the free end of the cantilever. A pair of oppositely polarized piezoelectric crystals are mounted on the cantilever assembly. When energized by an electrical driving source, the cantilever beam is flexed upwards or downwards thereby changing the distance of the magnetic head from the disk. A capacitive proximity sensor is coupled to the magnetic head for sensing the height of the head above the data track. The output of the sensor is fed to the driving source and energizes the piezoelectric crystals in the polarity desired for the corresponding deflection of the cantilever structure.

Abstract: A fluid sphere gyroscope is used as the north-seeking sensing element in a gyrocompass. A sensor responsive to angular deviation of the gyroscope from the horizontal provides a tilt signal which is used to energize heating elements located along the independent spin axis of a rotating fluid mass. Application of a thermal gradient along the spin axis of the fluid mass causes a controlled precession of the gyroscope, thereby compensating for bias and acceleration sensitive drift errors and precessing the gyroscope about a vertical axis in a controlled manner. Rotary transformers permit inductive coupling of the heating elements to the tilt signal and to a power source with minimal disturbing torques.

Abstract: During a transition of a VTOL aircraft such as a helicopter, from one altitude held without its ground effect zone to another to be held within its ground effect zone, or vice versa, a collective stick position synchronizer which can memorize the proper trim condition at the previous altitude in conjunction with the stick force sensor out-of-detent logic and a low vertical speed sensor, together constituting a ground effect zone detector, is used to drive the collective stick trim actuator in a direction which relieves any force being exerted by the pilot in order to maintain the new commanded altitude.

Abstract: A full time three-cue (roll control, pitch control and collective control) for helicopters flight director and/or autopilot wherein the collective control cue is automatically activated when airspeed is below a predetermined low value or above such value when path errors naturally or manually produced, or airspeed errors exceed predetermined values in magnitude or time.

Abstract: An apparatus for determining an angle of incidence of a received signal utilizes two widely spaced interferometers with equal length crossing baselines. The time differential of a signal arrival between the two elements of each interferometer is established and the difference between the two time differentials is determined. Multiplying this difference by a predetermined constant provides the desired angle.

Abstract: An apparatus for sensing acceleration utilizes a multimode input optical fiber to provide an output of light which passes through a grating, and is collimated by a grinrod lens. The collimated light is reflected from a double faceted reflecting surface in two beams. Absent acceleration, the two beams are focussed by the grinrod lens onto portions of the grating covering, respectively, the input faces of two multimode output optical fibers, and provide 1/2 the maximum possible amount of light to each of the output optical fibers, with a balanced output. In response to acceleration, the reflection surface tilts, the beams move, and the outputs of the output optical fibers change, representing the acceleration.

Abstract: A stroke writing character generator pauses between the generation of vectors, which may meet at sharp corners, so as to reduce deflection bandwidth. A stroke state machine having a plurality of states controls the generation of the vectors. The plurality of states includes a time pause state. A vector length counter provides an end of vector signal that causes the stroke state machine to enter the time pause state for inserting a time pause between the generation of the vectors. The video of the CRT on which the vectors are written is blanked in coincidence with the time pause.

Abstract: A windshear warning apparatus which separately compares a plurality of signals derived from horizontal and vertical inertial acceleration and air mass acceleration components to indicate incipient windshear. The compared signals are substantially equal under normal wind conditions but are significantly different under windshear conditions. A signal proportional to the product of the magnitude and rate of change of the total or resultant inertial acceleration of the aircraft is used to provide a warning of a significant windshear condition.

Abstract: An input/output (I/O) system and method for coupling a host computer to a plurality of peripheral devices in which data destined for peripheral devices is transferred to an output data buffer whose locations are paired with output channel addresses stored in an output device table. A microcomputer performs any processing required on data stored in the output data buffer by reading the address and a function code in the output device table then distributes processed data to an output device block whose locations are addresses of output channels. An input data buffer and input device table similarly arranged, collects and processes input data continuously, which input data buffer can be transferred to the host computer, on command, in a high speed burst.

Abstract: A hermetically sealed quasi-planar integrated circuit suitable for millimeter-wave transmission. The circuit is enclosed within a module having a metal frame soldered to a quartz window. Active elements, such as beam-lead diodes, are mounted on a conductive layer housed within the frame. The assembly is evacuated and may be filled with an inert gas to avoid condensation in humid operating conditions. The invention is particularly adaptable to use in a cross-bar signal mixer at frequencies up to 140 GHz. The structure is adaptable to cooling to reduce circuit losses and improve performance and operating efficiency. Resonant cavities are provided to permit tuning the mixer to fixed frequencies.

Abstract: An aircraft speed control system for use with an automatic throttle position control system and automatic flight control system permits capturing and maintaining a commanded airspeed during the capturing of a desired altitude from either climbing or descending flight. The system manipulates the throttles at a variable rate dependent on the difference between the actual thrust of the aircraft and the desired cruising thrust at the selected airspeed and inversely proportional to the actual altitude rate. A signal derived from thrust error and altitude rate signals is utilized to generate a limiter control signal which is combined with an engine pressure ratio signal to generate a drive signal for urging the aircraft to capture precisely the commanded airspeed.

Abstract: A method and apparatus for entering data in a random access memory with a fixed orientation independent of the heading vector of the carrier vehicle. The data remains positionally fixed in the memory and is addressed for readout in a manner to present a heading-up display for all vehicle heading vectors.

Abstract: A buffer comparator receives input pulses and produces buffer output signals that drive first and second output comparators arranged to operate as an amplitude-sensitive logic circuit that produces a high level output signal when and only when the internal driving signals have an amplitude between first and second threshold levels. In one embodiment, the output of the buffer comparator is applied directly to the non-inverting input terminal of the first logic circuit comparator and through a low resistance resistor to an R-C network and the inverting terminal of the second logic circuit comparator. The remaining input terminals on the logic comparators are connected to a multiple voltage divider that provides lower and upper threshold voltages to the respective comparators. An input pulse applied to the buffer comparator initiates an internal driving signal that charges the capacitor in the R-C network exponentially.

Abstract: A multiple microcomputer system in which each microcomputer can execute independent programs, transfer data at high speed to or from the memory of any microcomputer in the system, and signal between microcomputers that data has been transferred and the action to be taken on the transferred data.

Abstract: A microwave phase shifter for use in waveguide transmission line employs a piezoelectric cantilevered bimorph member mounted on the waveguide and a thin wafer of dielectric material mounted on the free end of the cantilever above a slot in the waveguide. Voltages applied to the bimorph member cause this member to distort so as to insert the wafer into the waveguide slot and alter the phase of the microwave signal being transmitted.

Abstract: An apparatus for generating halos about CRT display symbols, to distinguish them from background video, reads, from an image memory, video Bit signals corresponding to a CRT picture element P.sub.I,J, and the immediately surrounding CRT picture elements. A digital signal is generated therefrom representing a first Boolean Function. The intensity of the background illumination at P.sub.I,J, is unaltered, in response to a digital signal of zero, and is diminished by one-half, in response to a digital signal of one.

Abstract: A null-adjusting tool for aligning a tilt sensor of the electrolytic liquid type to the vertical is provided. A sensor mounting plate with a tilt-sensing element attached thereto is rotated about a pivot pin by the rotation of a coarse and fine adjustment screw. The coarse adjustment screw acts directly on the sensor mounting plate. The fine adjustment screw provides a high degree of position resolution control through a combination of screw thread and lever type mechanical advantage. A digital readout containing a liquid crystal display and self-contained power source is mounted on the null-adjusting tool to provide a visual indication of the angular deviation of the tilt sensor from the vertical during the alignment process.

Abstract: An apparatus for protecting computer memory utilizes a parity matrix to generate an n-k check bit signal of an extended linear (n,k,4) code from a k data bit signal. Exclusive-OR gates add the n-k check bit signal to an n-k tag bit signal selected from a predetermined class, to form, when concatenated with the k data bit signal, an element of a code of a certain class. The element comprising the k data bit signal is written in memory. A correction matrix or And gate cooperating with exclusive-OR gates detects an attempt to access the k data bit signal with an n-k key bit signal belonging to the same class as the n-k tag bit signal, but which does not match it.