Abstract: For an antenna on a satellite in an inclined orbit about the Earth, cross-track motion resulting from the rotation of the Earth can be reduced in antenna coordinates by yawing the antenna (preferably by yawing the entire satellite, for example, by using a reaction wheel system) by an appropriate angle, which varies throughout the orbit.

Abstract: A system and method for eliminating pointing error in a beacon tracking system due to uncontrolled differences in passive loss or in amplification of the separate signals involved in creating a pilot signal. A locally generated reference signal (30) is radiated onto a set of feed horns (14), at least three (20, 22, 24) of which are used to track a pilot signal (18). The reference signal (30) is detected and used in an automatic gain control feedback loop (44, 46, 48) to maintain equal gain on the separate feed horn channels. The equalized signal is processed (62) to produce precision tracking signals.

Abstract: A hybrid electric vehicle powered by a combination fuel cell and a gas turbine driven generator. The fuel cell is sized relative to the gas turbine and the vehicle such that up to about 50 percent of the vehicle's maximum sustainable power is supplied by the fuel cell electrical power output. This relative power source size achieves improved fuel consumption compared to vehicles powered by combustion engines without the cost penalty associated with a fuel cell large enough to power the vehicle. At low power requirements, the fuel cell efficiently provides all or most of the vehicle's power requirements. As the power requirements increase, additional fuel is burned in the gas turbine.

Abstract: A flywheel assembly for storing energy and rotatable in response to the rotation of a shaft includes a hub having a transition portion having a constant stress intermediate region operatively coupled to the shaft and an outer connecting portion forming a flexible cylinder, wherein the shaft and the flexible cylinder are substantially coaxial, and an outer cylinder wherein a majority of the mass of the flywheel assembly is concentrated. The flexible cylinder includes connecting pads disposed at opposing edges of the outer side of the flexible cylinder thereby permitting connection to the outer cylinder. The outer cylinder increases radially responsive to a corresponding increase in rotational speed of the flywheel assembly, while the diameter of the transition portion of the hub follows the radial increase of the outer cylinder.

Abstract: A flywheel safety support system isolates the flywheel and its motor-generator from the driving environment of an electrically powered motor vehicle. A suitable liquid, placed between the outer and vacuum housings of the flywheel assembly, provides buoyancy and damping to the vacuum housing, cooling of the motor-generator, and serves as one of the barriers to rotor energy and angular momentum transfer in the event of an accident or failure. During normal operation, a shearable mechanical gimbal system keeps the vacuum housing centered in the outer housing, reacts the spin moments generated by the motor-generator, and provides a path for the electrical leads into the vacuum housing. In the event of bearing seizure or rotor failure, the mechanical gimbal will shear and allow the vacuum housing to gradually spin down against the fluid. A fiber barrier provides an additional layer of protection to passengers.

Abstract: A bearing system for positioning and supporting a rotor having a vertical shaft (20) coincident with a main rotation axis included in a flywheel (10) used for energy storage and high surge power in vehicular applications. The bearing system includes upper and lower radial force generators (110, 210) containing only electromagnets, and upper and lower axial force generators (120, 220) including an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the bearings includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a preferred bearing stiffness. The bearing system also includes upper and lower touchdown ball bearings (130, 230) which are engaged only when the radial force generators are unable to maintain the rotor in a predetermined cylindrical volume within the flywheel (10).

Abstract: A capacitive sensor system for an active magnetic bearing supporting a rotating shaft and flywheel in a flywheel energy storage system integrates sensor elements into the bearing stators, thereby conserving valuable space within a vacuum housing enclosing the flywheel energy storage system. High frequency resonant processing provides intrinsic linearity and noise immunity while permitting fast response times. Simple design of the sensor system permits all sensor electronics to be readily packaged within the vacuum housing.

Abstract: The invention provides a method for controlling the precession of a spinning spacecraft (20) which allows the spacecraft body to respond to an input torque without the nutation normally attendant when an input torque is applied about one transverse axis to accelerate a spinning spacecraft about that one axis. Dynamic decoupling eliminates nutation through the impression of additional derived feedback torques (44,46) to the input torque control of a spinning spacecraft to oppose or cancel the intrinsic cross-coupling terms (34,36) of the spinning spacecraft's gyrodynamics that give rise to the nutation.

Abstract: A field control system for a wound rotor synchronous motor-generator used in electrically powered automobiles is capable of optimizing the performance of the motor-generator for all driving conditions. Using a rotary transformer to transmit power across the rotational boundary, it has no wearing parts and is silent. Preferably, the field control system has common elements with the controller which generates the stator currents of the synchronous motor-generator.

Abstract: A flywheel support system isolates the flywheel (11) and its motor-generator (21) from the driving environment of an electrically powered motor vehicle. A suitable liquid (9), placed between the outer (8) and vacuum (10) housings of the flywheel assembly, provides buoyancy and damping to the vacuum housing, cooling the motor-generator, and serves as one of the barriers to rotor energy and angular momentum transfer in the event of and accident or failure. During normal operation, a shearable mechanical gimbal system (80) keeps the vacuum housing centered in the outer housing, reacts the spin moments generated by the motor-generator, and provides a path for the electrical leads into the vacuum housing. In the event of bearing seizure or rotor failure, the mechanical gimbal will shear and allow the vacuum housing to gradually spin down against the fluid. A system of angular-contact oil-lubricated ball bearings (12, 13) supports the rotating assembly including the rotor (21b) of the motor-generator.

Abstract: A bearing system for positioning and supporting a rotor having a vertical shaft coincident with a main rotation axis included in a flywheel used for energy storage and high surge power in vehicular applications includes first and second radial force generators disposed in a first plane perpendicular to the rotation axis of the rotor, the first and second force generators including only electromagnets, third and fourth radial force generators disposed in a second plane perpendicular to the rotation axis of the rotor, the third and fourth force generators including only electromagnets, and upper and lower axial force generators each containing an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the force generators includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a desired bearing stiffness.

Abstract: A method of and system for applying single gimbal control moment gyros to spacecraft attitude control employing two control moment gyros with nominal spin axes anti-parallel and gimbal axes displaced at a fixed angle in the plane normal to the nominal spin axes to achieve two orthogonal body fixed control torques using two wheels. If the gimbal axis displacement of each of three wheels is 120 degrees, two wheels provide independent uncoupled orthogonal two-axis control, and the third can substitute, in the event of failure, for either of the two requiring no change in control law or performance.

Abstract: A flywheel rotor used in a flywheel energy storage system providing a high energy storage capacity while providing an ample volume for a high power motor-generator within its envelope includes an outer, primarily cylindrical body having conically tapered end sections, a conical hub section attached to the outer body, and a relatively short inner cylinder, which cylinder connects shaft to the inner portion of the conical hub section. In an exemplary case, the individual components are predominantly constructed of filament wound fiber composites while allowing material choices to be driven by both cost and performance. According to one aspect of the rotor, the inner portion of the inner cylinder can be a slotted aluminum cylinder.

Abstract: A satellite-based communication system providing high rate transfer of data between linked terminals. The system comprises a plurality of user terminals (VSAT's) that are linked by and that communicate with each other by way of a satellite-based relay system. A network control center provides configuration signals that control the satellite relay system and coordinate linking of terminals to each other. Frequency division multiplexing uplinks are used from the terminals and the network control center to the satellite relay system. Time division multiplexing are used on downlinks from the satellite relay system to the terminals and the network control center. Each user terminal comprises a data compression and decompression circuit, a transceiver, and an antenna for transmitting and receiving data to and from the satellite relay system. The satellite relay system comprises a satellite, a wide area antenna, a plurality of receive antennas, a plurality of transmit antennas, and a signal processor.

Abstract: A flywheel rotor used in a flywheel energy storage system providing a high energy storage capacity while providing an ample volume for a high power motor-generator within its envelope includes an outer, primarily cylindrical body having conically tapered end sections, a conical hub section attached to the outer body, and a relatively short inner cylinder, which cylinder connects shaft to the inner portion of the conical hub section. In an exemplary case, the individual components are predominantly constructed of filament wound fiber composites while allowing material choices to be driven by both cost and performance. According to one aspect of the rotor, the inner portion of the inner cylinder can be a slotted aluminum cylinder.

Abstract: In a shared process control system for a power train of a hybrid electric vehicle operating responsive to operation of an accelerator pedal and a brake pedal and including a gas turbine powering a first motor-generator, a flywheel powering a second motor-generator, and a traction third motor-generator operatively coupled for selectively driving and being driven by vehicle wheels, each of the first, the second and the third motor-generators being commonly connected to a high voltage bus via respective rectifier-inverters controlled by a single controller, the control system is operated by a method including steps for operating of accelerator pedal to produce a substantially instantaneous increase in output torque with an increase in load on the bus by the traction motor to thereby produce a voltage drop, initiating increased power output from the flywheel motor-generator in response to the voltage drop to hold up bus voltage, thereby decreasing flywheel shaft speed, and subsequently producing a proportional in

Abstract: A flywheel support system isolates the flywheel and its motor-generator from the driving environment of an electrically powered motor vehicle. A suitable liquid, placed between the outer and vacuum housings of the flywheel assembly, provides buoyancy and damping to the vacuum housing, cooling of the motor-generator, and serves as one of the barriers to rotor energy and angular momentum transfer in the event of an accident or failure. During normal operation, a shearable mechanical gimbal system keeps the vacuum housing centered in the outer housing, reacts the spin moments generated by the motor-generator, and provides a path for the electrical leads into the vacuum housing. In the event of bearing seizure or rotor failure, the mechanical gimbal will shear and allow the vacuum housing to gradually spin down against the fluid. A system of both active and passive axial and radial magnetic bearings supports the rotating assembly including the rotor of the motor-generator.

Abstract: Frequency reuse and data coding methods for use in a high data rate satellite communication system. The frequency reuse method provides for dual polarization and spatial reuse of transmit and receive beams to provide for a twelve-fold increase in the effective bandwidth and number of users that may be supported by the system. Transmit and receive antennas provide multiple, interleaved transmit and receive antenna beams. Digital input data at a source user terminal is coded and transmitted from a source user terminal on one of the plurality of receive antenna beams. The received data is demodulated and is routed so that it may be transmitted to a destination user terminal. The data is then remodulated, multiplexed, and transmitted to the destination user terminal on one of the plurality of transmit beams. The transmitted data is decoded at the destination user terminal to produce the output data.

Abstract: The attitude of a spinning spacecraft (20) whose spin axis is substantially in the plane of the orbit is controlled without the use of reaction control thrusters. A two-axis gimbal (24) on which a momentun wheel (26) is mounted is secured to a central body (21). Two actuators (40, 42) are used to selectively pivot the gimballed momentum wheel (26) about each gimbal axis (x, y) in order to apply a control moment to change the attitude state of the spacecraft (20).

Abstract: A system and related method is provided for rapidly repointing spacecraft through the application of a high torque, of a gyroscope in which braking means (20, 22) provided on a gimbal (16, 18) is actuated simultaneously with the actuation of the torque motor (24, 26) to achieve amplification of the control moment imparted to the gyroscope (10). Because only one brake (20, 22) may be actuated at a time in a double gimbal gyroscope system having a single spin wheel (12), actuation of the brake ( 20, 22) for each of the two axes is sequential. However in a system having redundant torque motors (24, 26), re-pointing of the spacecraft may be achieved using the simultaneous braking and torque application method of the present invention without increasing the repointing time by applying torque to a gimbal (16) rotating about one axis of the first spin wheel (12) at the same time that torque is applied to a gimbal (18) rotating around the orthogonal axis of the redundant spin wheel (12).