Abstract: In an electric vehicle, the traction motor is driven from a battery by way of a controllable electric power switching arrangement. In normal operation of the switches of the switching arrangement, the power losses or heating of the switches depends upon the power being handled; during hard acceleration the power is high, and at constant speed on level ground the power is relatively small. Thus, the power “dissipated” by the switches varies with time. A cooling system transfers heat from the switching arrangement to ambient. During acceleration, the cooling system may not be able to limit the instantaneous temperature of the switches to the desired value. A phase-change heat “sink” coupled to the switches absorbs heat from the switches during hard acceleration, and returns the heat to the cooling system under more constant-speed conditions.

Abstract: An electric motor vehicle includes an electric motor driving a step-down differential, axles, and drive wheels. An operator control produces torque command signals, which are applied to a controller to command application of electric power to the motor in response to the torque commands, to achieve the desired torque. The low friction of the electric drive, in conjunction with the rotational compliance or imperfect stiffness of the axles, may result in low-frequency surges or jerky motion, especially at low speeds. A damping arrangement includes a differencing circuit coupled between the operator control and the controller, for taking the difference between the operator-commanded torque and a damping torque signal. The damping torque signal is produced by differentiating the electric motor speed to produce a motor-acceleration representative signal.

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 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 method for fabricating a printed-circuit board includes the steps of loading components onto the printed circuit board, and placing a pin array over the components. Each pin is free to move "downward," and each component has at least one pin pressing on it to hold the component in place. Each component also preferably has a pin on each side of it, to hold it against lateral movement. The pin support arrangement is dimensioned so that a gap or space exists between the support and the component side of the board. Heat is applied to the gap, and flows through the interstices between the pins to heat the solder on the upper side of the board to fuse the solder and make the desired connections.

Abstract: A number N of AC machines, such as motors or generators, are independently controlled by a control system having 2N+1 phases, having N orthogonal sets of phase components. In a particular application, a hybrid vehicle including a generator and an induction motor are independently controlled by a five-phase controller having two independent sets of mutually orthogonal components. Each set of components controls one of the machines, and has no net effect on the other machine(s).

Abstract: An electric vehicle (10) includes a traction motor (26) which drives the wheels (30a, 30b) by way of a differential (28), if desired. The traction motor (26) is controlled by a controller (24) which responds to torque command signals, to cause the motor (26) to produce the commanded torque. An accelerator pedal (12) is coupled to a position transducer (16) which converts pedal position into digital signals. The digital signals representing pedal position are applied as addresses to a memory (22) to access the stored signals. The memory is preprogrammed with torque signals representing the torque desired at a given pedal depression. In a preferred embodiment, the preprogrammed signals represent torques which are monotonically related to the pedal position, although some deviation may be acceptable in small portions of the operating range. The memory signals resulting from a given pedal position are applied to the controller, for causing the controller to command the motor to produce the specified torque.

Abstract: A heat transfer arrangement for one or more heat-generating components (18a) on a printed-circuit board (16) includes a heat transfer plate (316) defining an aperture (416) registered with the components. A "vertically" movable heatsink adapter (410) is adjusted to juxtapose its "lower" surface with the "upper" surface of the components to be heat-sunk. A heat-transfer pad (318) may be used between the heatsink adapter (410) and the component (18a). In various embodiments, the heatsink adapter takes the form of circular (410) or rectangular (410R) plugs, a draw-tube (808) arrangement, or a bellows (1010).

Abstract: A hybrid electric vehicle includes a traction motor driven by a traction battery, and a supplemental or secondary electrical source for charging the traction battery. In order to warm the passenger compartment during cold weather, heat is applied from the traction motor and the secondary source. Under some conditions, there may be insufficient heat to adequately warm the passenger compartment. The traction motor efficiency is lowered, so that more heat is generated, to aid in supplying the deficiency. In an embodiment in which the traction motor is an ac motor, the efficiency is lowered by applying a direct current to the motor. In an embodiment in which the ac motor is an induction motor, the efficiency is lowered by increasing the average slip frequency.

Abstract: A controller (400) for a variable-speed induction motor (498) includes field-oriented control (410, 476), which in a feedback (402) arrangement senses motor parameters to form field and torque error signals. The field error signals are processed by a first limited-state PI processor (490a), which individually limits the magnitude of the proportional component of the field voltage to no greater than the bus voltage. The field error signals are also processed by a state-limited integrator (426a) which limits the integral component of the field voltage to the difference between the proportional component and the bus voltage. A first summer (432a) sums the proportional and integral components to make the field voltage command. The torque error signals are processed by a further limited-state PI processor (490b) which individually limits the proportional component of the torque voltage to a value not greater than the available bus voltage, after the first PI processor has been given preference.

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: 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: 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: In a time division multiple access spacecraft communication system, each ground station determines when to send its information packets to arrive at the spacecraft at the beginning of a time slot. The calculation is based upon knowledge of the locations of the spacecraft and the transmitting ground station. A master ground station determines the location of the spacecraft by the use of the propagation delays between the various ground stations (including itself) and the spacecraft, together with knowledge of the locations of the ground stations. The spacecraft location is then transmitted back to the various ground stations. The determination of propagation delay by each ground station is performed by repeatedly transmitting a ranging signal containing a multiple-bit unique word to the spacecraft, and counting spreading code chips until the next unique word is received from the spacecraft.

Abstract: A hybrid electric vehicle includes a lead-acid traction battery made up of a plurality of series-connected modules. During operation of the vehicle, the traction battery is discharged for acceleration, and charged by an ancillary power source. To maximize the capacity of the traction battery to accept regeneration charge current from dynamic braking, and to produce useful traction motor current, the modules of the traction battery are equalized during normal operation of the hybrid electric vehicle.

Abstract: In a time division multiple access spacecraft communication system, each ground station determines when to send its information packets to arrive at the spacecraft at the beginning of a time slot. The calculation is based upon knowledge of the location of the spacecraft. A master ground station determines the location of the spacecraft by the use of the propagation delays between the various ground stations (including itself) and the spacecraft, together with knowledge of the locations of the ground stations. The spacecraft location is then transmitted back to the various ground stations. The determination of propagation delay by each ground station is performed in two major steps. The first step determines coarse time delay to within one bit interval by repeatedly transmitting a multibit unique word to the spacecraft, and counting bits until the next unique word is received from the spacecraft.

Abstract: A control system for the uplink transmitter of a ground station communicating with a spacecraft includes an antenna located at the ground station, pointed toward the spacecraft for receiving downlink signals transmitted therefrom. The received signals are accompanied by noise attributable to ambient, sky and ground temperatures. A low-noise receiver is coupled to the output port of the antenna, for establishing the receiver noise temperature. A processor is coupled to the low-noise receiver apparatus and to the power control input port of the uplink transmitter, for responding to changes in the received noise power attributable to the presence or absence of precipitation in the downlink. The processor does this by producing an estimate of the attenuation attributable to the rain in the downlink, and generates the control signal in response to the estimate of the attenuation.

Abstract: Improved throughput is provided in a spacecraft TDMA cellular communications system by in-call signalling without the need for flag bits, while still allowing the in-call signaling to be differentiated from other traffic. The terrestrial locations include mobile user terminals and gateways which provide connections to the land telephone line system. The spacecraft includes a transmitter and receiver, and an antenna which forms a plurality of spot beam footprints, in which the terrestrial terminals are located. Each of the terrestrial terminals transmits signals to, and receives signals from, the spacecraft. Each of the terrestrial terminals includes an encoder/decoder, for encoding at least call maintenance control signals, for temporarily interrupting the traffic signals to allow another action. The control signals may have bit content which exceeds the bit-carrying capability of the TDMA bursts, so transmission of the control signals must extended over a plurality of bursts.

Abstract: A communications system includes first and second ground stations and a spacecraft repeater. Data signals are transmitted between ground stations by way of the repeater, together with spread-spectrum ranging signals. Uplink rain attenuation is compensated for changing the transmitted power at the ground stations. The amount of downlink attenuation is determined by measuring the total carrier-to-noise ratio in three paths, station 1 to station 2, station 2 to station 1, and station 1 to station 1. With these three values of total attenuation, the two downlink attenuations and the number of active signals traversing the repeater can be determined. The downlink attenuations are converted to uplink attenuations, and used to control the transmitters.