Abstract: A near-field calibration arrangement for an antenna array determines the phase shifts or attenuation of the elemental control elements of the array. The calibration system includes a probe located in the near field, and a calibration tone generator. The tone generator is coupled to the probe in the case of calibration of a receive antenna, and to the signal port of the array in the case of calibration of a transmit antenna. A code generator generates sets of values, with each set being orthogonal to the others. The codes are applied to the control input port of the array antenna, so that the codes encode the tone passing through the antenna. The encoded tones are applied to a decoder and processor, which processes the signals to determine the phase shift or attenuation associated with each bit of the control signal. A transmit antenna attitude determination or pointing arrangement uses the calibration tone generator in conjunction with a plurality of remote sites.

Abstract: A sigma-delta analog-to-digital feedback converter arrangement (10) achieves low noise and a wide dynamic range by use of a directional coupler (18) as a summing device for generating the difference signal on which the forward sigma-delta analog-to-digital converter (32) operates. The feedback is provided by a digital-to-analog reconstructor (36), which applies the reconstructed analog signal to the tap (18.sub.3) of the directional coupler (18), in which the feedback signal is summed with the analog input signal. A low-noise amplifier (28) is coupled to the output of the directional coupler (18) at which the difference signal appears, so the dynamic range of the signal traversing the low-noise amplifier is small. The high isolation between the tap (18.sub.3) of the directional coupler (18) and the source of analog signals allows the use of an input bandpass filter (16).

Abstract: An installation method for installing machines of different heights at an installation site includes provision of a flexible power cord of particular length, affixed to an upper region of each machine. The power cord is terminated in a power-rated male connector. At the intended installation location, the power cord origination location is identified, which is the location at which the power cord will originate after installation. An interface box having a NEMA female connector is installed at a location such that the female connector is at a radius from the power cord origination location which is less than the length of the flexible power cord. The interface box is installed, connected to a power source, and tested, before physical installation of the machine. At the time of physical installation of the machine, there is no delay attributable to hard-wiring of the power connections to the machine, and it is connected with the flexible power cord.

Abstract: A launch system for plural missiles of different types includes plural launch locations, each adapted for receiving a canisterized missile having a standardized connector, which is coded to indicate the missile type contained within the canister. The system includes an individual fire control unit for each launch location or cell, and power supplies which are available to groups of such cells. An local-area network (LAN), such as Ethernet, interconnects the power supplies, the fire control units, and a central launch control system. Each fire control unit includes a processor for determining the missile type with which it is associated, and an interface card for each different missile type which may be used. The fire control units respond to commands from the central launch control system by interpreting the commands into a parallel form understandable by the missile interface cards.

Abstract: A Vehicle Information and Safety System (VISC) includes a main computer at a vehicle fleet headquarters (HQ) with access over a CDPD data network to a computerized sensor system mounted in each vehicle of the fleet. Sensors which may be used include load sensors coupled to the axles, accelerometers and temperature sensors coupled to the cargo bay, infrared andor pressure sensors monitoring the operator, cameras viewing the cargo bay, cab andor environment, and GPS data. The sensor data are processed by in-vehicle andor HQ computers, to monitor the state of the vehicle and operator, and the security status of the vehicle. PSAP (911) calls can be transmitted from the vehicle under remote control from the HQ for those cases in which the operator is unavailable or unresponsive, and the transmission can be tagged with GPS data. Speech signals from the operator are converted to text, and may be used for control of various functions, or may be data-compressed for transmission over the data network to HQ.

Abstract: Intelligent mobile agents are transmitted to computers at remote sites over a network having a relatively limited bandwidth. In order to provide the mobile agents with extended capabilities, yet to allow them to access information in near-real-time, the intelligent mobile agents dock with docking systems at the network nodes. The docking systems respond to the presence of the mobile agents, and provide extended capabilities to the agent. The extended capabilities, in turn, are made available to the various network nodes at which the agents may dock by loading from portable data storage media, or preferably by occasional loading from the network at off-peak times.

Abstract: A garment or apparatus worn by emergency workers includes an electrically operated source of multiple, mutually diverging laser light beams. The light beams may be modulated to identify the worker and his status. The worker's location in an emergency environment is readily established as the locus of the diverging beams. A smoke-filled environment makes the laser beams more visible to rescuers.

Abstract: A back-to-back locator instrument includes a first portion with an array of two or more magnetic sensors, and an indicator arrangement. A second portion of the instrument includes an array of correspondingly located magnets. Each of the first and second portions includes a marking arrangement, which either allows marking of the underlying surface, or viewing of a mark on the surface for properly locating the instrument portion thereon. When the two portions are congruent or registered, the indicator arrangement gives a maximum indication of corresponding locations. In a particular use, corresponding locations on the inside and outside of a tank are identified. The indicator arrangement may include a separate indicator for each magnetic sensor. A flux concentrator may be associated with each magnetic sensor.

Abstract: A mail-handling tower (10) is associated with a mail container conveyor (12, 312). AC line power is supplied to the tower, which in turn supplies power at low voltage to power the associated conveyor directly by way of two ports (20a, 20b) and indirectly by way of a third, higher-voltage port (20c). A power cut-off switch (8) allows emergency shut-down of the mechanical portions of the tower, and also cuts power from the conveyor (12) powered from the tower ports. The power available at the conveyor energizing ports (20a, 20b, and 20c) allows a maximum run of conveyor. When the conveyor must be run for a greater distance than that which can be powered from the tower, an additional conveyor section (312) is coupled to the remote end (12re) of the first conveyor (12), and a line power source (314) is transformed (320) to a lower voltage, and applied to a power port (240.sub.1, 260.sub.1) of the additional conveyor (312).

Abstract: A method for densifying the LO2 propellant of a vehicle (10) includes providing a heat exchanger (16) including a chamber (22), and an isolated heater (24) and cooler (26) located within the chamber (22). The method further includes the step of pumping propellant (LO2) (with pump 14) from the vehicle (10) to the first port (24i) of the path of the heater (24), to thereby create a flow of propellant (LO2) through the heater (24) path, and from the second port (24o) of the path of the heater (24). In conjunction with the pumping, propellant (LO2) is coupled from the second port (24o) of the heater (24) back to the vehicle (10), to thereby establish a recirculating flow of propellant (LO2). The chamber (22) of the heat exchanger (16) is filled with at least sufficient cryogenic liquid (LN2) to cover at least a portion of the path of the cooler (26), and preferably the entirety of the path of the cooler (26).

Abstract: An eye protection arrangement for protection against multispectral laser threats includes goggles or spectacles with a tunable etalon optical filter. In one embodiment, the optical filter is fixed-tuned to a safe frequency. In another embodiment, light from the laser being used is sensed, and used to set the protective goggles to a different wavelength than the laser. In yet another embodiment of the invention, the protective optical filters have a comb response, and additional protection is provided by optically cascading two filters, each having a somewhat different comb response, so as to reduce the number of transmission spectra.

Abstract: Planishing or stress relief in a welded joint (34) is accomplished with a hammer (12) and a backing bar (26). The hammer is applied on a first side (1) to a first surface (31) of the structure (30). To indicate the proper position of the backing bar, a first magnet (20; 320) is associated with the hammer, and a magnetic sensor arrangement (24; 224; 300) is located on the other side (2) of the structure. In one embodiment, the sensor arrangement is a second magnet (24) which is held in place by the magnetic field (40) of the first magnet. In a second embodiment, the sensor includes a line array (262) of individual sensors, each associated with an indicator of a line array (264) of indicators. In a third embodiment, the sensor includes a line array (300) of two magnetic sensors, which are coupled to a differential indicator (324).

Abstract: A hill-holding arrangement for an electrically driven vehicle includes a vehicle with a "gas pedal" which generates a torque command signal T.sub.CMD. A switch (314) couples T.sub.CMD to a motor controller (316, 14) which drives the motor (40) and therefore the vehicle. When the "gas pedal" calls for zero torque, and the vehicle speed is zero, the switch responds to logic (FIG. 5), and substitutes a position-holding torque command signal T.sub..theta. for the operator-controlled torque command signal T.sub.CMD. Position controlling torque command T.sub..theta. is generated by a controller (312) which receives a position signal representative of the angular position .theta. of the rotor. The position-holding torque control loop then produces such torque as may be required to prevent the rotor of the motor from moving from its commanded position.

Abstract: An electric vehicle is controlled to conform its operation to that of a conventional internal-combustion-engine powered vehicle. In some embodiments, the charging of the batteries by the auxiliary source of electricity and from dynamic braking is ramped in magnitude when the batteries lie in a state of charge between partial charge and full charge, with the magnitude of the charging being related to the relative state of charge of the battery. The deficiency between traction motor demand and the energy available from the auxiliary electrical source is provided from the batteries in an amount which depends upon the state of the batteries, so that the full amount of the deficiency is provided when the batteries are near full charge, and little or no energy is provided by the batteries when they are near a discharged condition. At charge states of the batteries between near-full-charge and near-full-discharge, the batteries supply an amount of energy which depends monotonically upon the charge state.

Abstract: A vacuum pump of the steam-ejector type uses steam generated by the combustion of hydrogen and oxygen. The mass of ejected steam is increased, and the temperature of the ejected steam is reduced, by injection of water into the combustion product. Propellant densification is accomplished by using such a vacuum pump to reduce the vapor pressure of a cryogenic liquid, thereby reducing its temperature. The cryogenic liquid may be the propellant, or it may be a coolant medium thermally coupled to the propellant.

Abstract: A communication system includes a spacecraft which produces a plurality of overlapping spot beams. The spacecraft moves periodically in the N-S direction. Terrestrial user terminals may lie in one spot beam when the spacecraft is in one position, and in another spot beam at a later time. The system also maintains a log of the spot beam location of the user terminals, so all the spot beams do not have to be polled to find the desired one. In order to avoid system loading by location updates resulting from spacecraft motion, the spot beam location of each user terminal is stored in paired form. When a particular user terminal is to be contacted, transmission is performed over both spot beams of the pair. Update occurs only if the user terminal is not in either spot beam of the pair.

Abstract: A spacecraft according to the invention includes a pair of propellant tanks, with the nominal center of mass of the spacecraft located therebetween. Propellant is coupled from the tanks to a velocity-change-inducing thruster by a controllable coupling arrangement. Unwanted torques may occur which tend to perturb the attitude. An attitude control arrangement generates an error signal in response to deviations of the attitude from the desired attitude. The error signal is processed to control the propellant coupling arrangement, to cause propellant to be used preferentially from at least one of the tanks in a manner which tends to move the actual center of mass relative to the axis of thrust or line of action of the thruster. In one embodiment of the invention, the controllable coupling arrangement includes a manifold for coupling propellant from the tanks to the thruster, a tank of pressurizing gas, and a controllable manifold coupling the tank of pressurizing gas to the propellant tanks.

Abstract: Data at 2.4 kbps is to be transmitted over a noisy link having 3 kbps capacity, and made available to ISDN-compatible user devices. The 2.4 kbps data is multiplexed with its control and synchronization signals in a first rate adapter to generate 3 kbps data, organized into 10 msec frames of 30 bits, and transmitted over the link. The signals received from the link are further adapted in a second rate adapter to form 8 kbps, 10 msec, 80-bit, V.110 frames. Not all of the data for each 10 msec, 80-bit frame is available from the corresponding 10 msec, 30-bit frame. Some of the additional data is multiplexed onto plural 30-bit frames, and becomes available to the current 80-bit frame by use of a memory. Other bits of the additional data is stored in a memory in the second rate adapter, and used to fill in the 80-bit frames. The 8 kbps data is further rate adapted to 64 kbps by addition of dummy bits.

Abstract: A controller for a hybrid electric system such as a hybrid electric vehicle includes a load, a battery, and a controllable source of auxiliary electricity. The state of charge (SOC) of the battery is estimated, and an error signal is generated which represents the difference between a desired and actual SOC. The SOC error signal is processed by at least integration, to produce a source signal representing the desired auxiliary source current. A second error signal is generated between the actual current. from the auxiliary source and the desired current from the auxiliary source. The second error signal is processed, at least by integration, to produce a control signal for controlling the auxiliary signal source.

Abstract: A decoder of digital data signals for a message sequence of N symbols from a data source, encoded with a tail-biting convolutional code, and for correcting all combinations of up to a preselected number e of bit errors, operates upon the sequentially-received collection of consecutive-encoded tail-biting data symbols and selects an unmerged decision depth LU(e), a forward decision depth LF(e) and then a decoder decision depth L, before executing in a processor of the Viterbi type, which has a decision depth of L trellis levels, a decoding algorithm for a total of (N+LF(e)+LU(e)) trellis stages to produce a decoded data bit output sequence representative of the N transmitted source digital symbols.