Abstract: An anti-backlash gearing system which includes first and second drive gears hich mesh with a driven gear to provide torque and rotational motion to the driven gear. The drive gears are each driven by a motor, while the driven gear drives a load. The anti-backlash gearing system uses a microprocessor to control the command voltage R to each of the drive motors. The command voltage R provided to each drive motor also includes an offset .delta. which may be positive for one motor and negative for the other motor. The torque provided by one motor and its associated drive gear to the driven gear may be in the positive direction (clockwise direction), while the torque provided by the other motor and its associated drive gear to the driven gear is in the negative direction (counterclockwise direction). The motors are driven in opposite directions to control the backlash on the gears.

Abstract: A tracking system including an acquisition sight for use by a pilot of an rcraft to acquire a target. Once the pilot acquires the target an operator uses a track handle to take control of tracking the target. The operator monitors the target utilizing narrow and wide field of view monitors. When the target is visible within the narrow field of monitor, the operator can switch tracking of the target to an automatic video tracking system which tracks the target by contrasting the target and its surroundings. A computer, which receives azimuth and elevation data from the tracking device, processes the data and provides azimuth and elevation angle signals to a gimballed mirror to steer the mirror to the target. The gimballed mirror receives image forming light from the target and then directs the light to a wide field of view camera and a zoom telescope.

Abstract: An apparatus for the error free transmission of PCM/FM telemetry data. The pparatus comprises a first mixer for receiving an RF signal which has a first frequency and which is the carrier for the PCM/FM telemetry data. A variable frequency oscillator provides a local oscillator signal to the first mixer which is an offset for the RF signal. The first mixer then mixes the RF signal with the local oscillator signal resulting in the RF signal having a second frequency. This RF signal is supplied to a second mixer which mixes the RF signal with a fixed frequency signal provided by a fixed frequency oscillator. The RF signal provided by the second mixer now has a third frequency and is supplied to a bandpass filter. The frequency of the local oscillator signal is adjusted so that the offset to the RF signal provided by the first mixer is approximately one half of the intermediate frequency bandwidth of the bandpass filter.

Abstract: An outdoor scene simulating apparatus for testing an infrared imaging dev comprising an infrared source, which emits infrared energy along a first optical path. Positioned downstream from the infrared source along the first optical path is a metallic substrate which has on its front surface a simulated outdoor scene. The simulated outdoor scene is formed by coating a portion of the metallic substrate with a black ink which absorbs infrared radiation. A thermal mass abuts the substrate to provide a cooling path between the thermal mass and the substrate. The thermal mass cools the metallic substrate and black ink of the simulated outdoor scene to temperatures below ambient temperature reducing infrared emissions from the metallic substrate and black ink of the simulated outdoor scene. Infrared energy reflected from the metallic substrate is directed along a second optical path to a collimator.

Abstract: A countermeasure system, adapted for use on board an aircraft, for confus an incoming missile as to the location and heading of the aircraft. The countermeasure system generates for each side of the aircraft at least two infrared energy images which are projected onto the aircraft's fuselage and then swept across the aircraft's fuselage to confuse the incoming missile's infrared seeker. Each infrared energy image is generated by at least two lasers operating at different frequencies within the infrared region of the electromagnetic spectrum. A beam combiner combines the beams of infrared energy from each laser forming a single collimated beam of infrared energy having multiple frequencies which is then directed to a beam former. The beam former spreads the collimated beam of infrared energy which it then directs to a scanner.

Abstract: A doppler video signal conditioning circuit comprising first, second and rd buffers which respectively receive a voltage controlled oscillator signal, a second intermediate frequency signal and a second local oscillator signal from a missile' radar receiver. The buffered voltage controlled oscillator, second intermediate frequency and second local oscillator signals are then supplied to a doppler processing circuit. The doppler processing circuit processes these signals, providing at its output a reconstructed doppler video signal which includes a marker which is 20 kHz above the frequency the missile's radar is tracking. The doppler processing circuit provides the reconstructed doppler video signal to an analog-to-digital converter. The analog-to-digital converter digitizes the reconstructed doppler video signal before supplying the digitized signal to a frame controller.

Abstract: A digital conversion circuit for receiving a Non-Return to Zero Level Data tream and then converting the Non-Return to Zero Level Data stream to a Bi-Phase Data stream. Combinational logic including an EXCLUSIVE-NOR circuit, three D-type Flip-Flops, AND gates, a NAND gate and inverters are utilized to convert the incoming Non-Return to Zero Level Data stream to the Bi-Phase Data stream while eliminating from the Bi-Phase Data stream any undesirable spikes or noise.

Abstract: A signal converter for converting a bi-phase-level data stream to non-ret-to-zero-level data. The bi-phase-level data stream is input to a detector circuit. When the detector circuit detects a high level for more than half of a bit period, the detector circuit provides a logic zero pulse at a state S7. If the high level is not at the logic one state for a sufficient time period the detector circuit will not reach state s7. If the time period is to short than the detector circuit is reset to state s0. This high level pulse occurs whenever the second half of a bit period is high followed by a high in the first half of the following bit period. A sample is taken on the first half of every bit period. A low at the detector circuit keeps the detector circuit at state s0. A clock signal generating circuit receives the logic zero pulse and then proceeds through its states s0-s10. When state S1 is reached a clock pulse is provided by the clock signal generating circuit.

Abstract: An interface circuit which receives a PCM telemetry data stream comprising waveform divided into 100 words including a three word frame sync signal. The PCM data stream is supplied to a comparator which converts input telemetry signal to a TTL compatible signal. When the PCM data is unencrypted, the PCM data stream is supplied to a de-randomizer circuit which de-randomizes the randomized data. A bit sync circuit which also receives the PCM data stream generates a 320 kHz clock signal which is synchronized to the incoming PCM data stream. The de-randomized PCM telemetry data stream which is in a serial format and the 320 kHz clock signal pass through a digital multiplexer to a universal synchronous asynchronous receiver transmitter. When the receiver transmitter detects a PCM frame sync signal for a frame of PCM data, it interrupts a master microprocessor which then retrieves each word of PCM data from the frame. The master microprocessor writes the frame of PCM data into one bank of a dual Port RAM.

Abstract: An electronics circuit for frequency shift keying a continuous-running caer, such as a sinewave, which allows the user to vary two closely spaced frequencies from a personal computer. The electronics circuit of the present invention comprises a microcontroller which has stored therein a lower frequency and an offset frequency. After the electronics circuit is powered up the microcontroller enters the MAIN program and generates control and address signals to effect a transfer of thirty two data bits representing the lower frequency from the microcontroller to a pair of eight bit RAMS. A programmed array logic device, which receives addresses from the microcontroller, decodes the addresses and then provides chip select and output enable signals to the RAMs to allow the thirty two data bits to be written into the RAMs with the write signal being provided by the microcontroller.

Abstract: A self-propelled remotely controlled pilot vehicle adapted for use on raiad tracks to monitor hazardous conditions and obstacles on the railroad tracks. The pilot vehicle precedes a train along the railroad tracks at a distance which will allow the train to come to a complete stop in the event the pilot vehicle encounters a hazardous condition on the track. The pilot vehicle is equipped with a sensor array which measures a variety of different parameters such as the presence of noxious gases, moisture in the atmosphere or at ground level, and breakage in one or both rails of the track. The pilot vehicle is also equipped with a television camera which provides a visual image of the railroad track ahead of the pilot vehicle to the engineer of the train.

Abstract: A missile launch simulator for testing the launch of a missile from a mise launcher on board an aircraft. The missile launch simulator emulates the functions of the missile's on board turbo generator by utilizing microprocessor controlled relays to provide phase A, phase B and phase C gyro drive signals to the missile's gyro when the umbilical cord connecting the missile to the launcher is opened during an emulated launch. The missile launch simulator also provides high voltage power to the missile's on board electronics after an emulated launch by utilizing microprocessor controlled relays and the missile launcher filament power to emulate the turbo generator's high voltage power signal which powers the missile's on board electronics after the missile is launched from the aircraft.

Abstract: A self-propelled remotely controlled pilot vehicle adapted for use on raiad tracks to monitor hazardous conditions and obstacles on the railroad tracks. The pilot vehicle precedes a train along the railroad tracks at a distance which will allow the train to come to a complete stop in the event the pilot vehicle encounters a hazardous condition on the track. The pilot vehicle is equipped with a sensor array which measures a variety of different parameters such as the presence of noxious gases, moisture in the atmosphere or at ground level, breakage in one or both rails of the track and orientation with respect to the force of gravity as well as the yaw, pitch and roll of the tracks upon which the pilot vehicle is riding. The pilot vehicle is also equipped with a television camera which provides a visual image of the railroad track ahead of the pilot vehicle to the engineer of the train. An infrared camera which is mounted on the front of the pilot vehicle generates an infrared image of the tracks.

Abstract: A miss distance scoring system comprising four antennas which are configu to provide for an optimal radiation pattern of pulsed radio frequency energy to determine a missile's miss distance and miss direction from a target. Reflected pulses from a missile are received by each of the four antennas and then supplied by a radio frequency switch to a scalar scoring system which provides an analog video signal to four analog switches. The four analog switches are also connected to a controller which provides control signals to the switches to separately activate each switch. The activated analog switch then samples and holds the analog video signal with the sample being provided to an associated bandpass filter of the switch which is one of four bandpass filters. The sampled portions of the analog video signal are provided to a multiplexer and then passed sequentially through the multiplexer.

Abstract: An interface circuit for receiving an analog PAM telemetry data stream from missile's telemetry unit. The PAM data stream comprises a waveform divided into 64 channels and includes a sync signal. The PAM data stream is supplied to a filter which removes from the PAM data stream subcarrier channel oscillator frequencies. The filtered data stream is next supplied to an analog-to-digital converter which converts each sample of the data stream to an equivalent twelve bit PAM data word which is supplied to a slave microprocessor. The slave microprocessor processes each of the sixty four PAM channels by utilizing a 25.6 kHz PAM clock signal generated by a PAM signal processing circuit. The slave microprocessor first checks for the sync signal. When the sync signal is decoded, the slave microprocessor sends a message to a master microprocessor via a dual port RAM indicating that the sync signal was located. The master microprocessor will respond with an acknowledgement message to the slave microprocessor.

Abstract: Accordingly, the preferred embodiment of the present invention includes ft and second pontoons; a plurality of removable connector modules located in pockets on each end of the pontoons for absorbing impacts and for locking together joined pontoons; a plurality of retractable, resilient alignment pins located in the ends of the pontoons for initial alignment of the pontoons; and a winch operated bridal line attached to the alignment pins, via guide bores, for drawing together the pontoons in a joined fashion. Each connector module includes, on one end, a compressible locking pin that may be slidably located in the extended position (for joining and locking together with another pontoon) or in the retracted position (for storage). The other end of the connector module includes a receiver bore for receiving the locking pin of a mating pontoon.

Abstract: A radar encoder comprising a delta modulation circuit which receives analog adar video data from a radar and then converts the data to digitized NRZL video data. The radar encoder also has an encoder circuit which receives the digitized NRZL video data as well as a trigger pulse signal and analog synchro signals from the radar. The synchro signals are provided to a Synchro-to-Digital Converter which converts the synchro signals to sixteen digital synchro data bits which are then latched into the converter. The synchro data bits are next parallel transferred to a pair of shift registers and then clocked in a serial format to a multiplexer. The multiplexer also receives the digitized NRZL video data supplied to the encoder circuit. A state machine, in response to the trigger pulse signal, generates control signals to latch the synchro data bits into the converter and then effect the parallel transfer of the synchro data bits from the converter to the shift registers.

Abstract: A control signal generator for generating a plurality of control and timing ignals which are supplied to a scan converter. The control and timing signals are utilized by the logic elements of the scan converter to process the incoming pixel data from a missile's seeker allowing the data to be supplied to a video monitor for viewing. The control signal generator includes a state machine which generates four state variable signals and a cycle counter which generates a binary count thirty one signal which allows the state machine to cycle through six predetermined states until the scan converter completes processing of incoming pixel data from each detector of the missile's seeker. The count thirty one signal and the four state variable signals are decoded by five decoders which generate the timing and control signals for the logic elements of the scan converter.

Abstract: An electronics circuit for digitizing an analog audio data signal into a ital equivalent signal and then introducing digitized nyquist dither data into the digital equivalent signal to substantially eliminate the need for removing the nyquist dither data from the digital equivalent signal prior to its conversion to an analog signal which is a substantial replica of the incoming analog audio or like data signal. The electronics circuit comprises a first pseudo-random number generator which generates a series of digitized nyquist dither bits for addition to the digital equivalent signal. The digitized nyquist dither bits are, in turn, provided by an external computer using a computer program which first generates a pseudo-random sequence of positive integers over a first predetermined range.

Abstract: A wear resistant and impact tolerant plow blade comprising a plurality of ternate layers of wear resistant and impact resistant materials. Each layer extends from the leading edges of the plow blade rearwardly and is fabricated of a homogeneous material. Each layer has substantially parallel sides and abuts an adjacent layer or layers to form a substantially seamless plow.