Abstract: A multiaddress control system for remotely controlling accessories in a vehicle utilizes a simple encoder and decoders to perform functions previously performed by microprocessors and bus drivers. A transmitter station has an encoder for station addresses and commands that are received from manual switches. The addresses and commands are sent to all of the receiver stations simultaneously on a two-wire common signal bus. The receiver that has been addressed accepts the command and acts upon it. Every word is transmitted twice, and the receivers compare the two transmitted words. Only if the words match does an addressed receiver carry out the command.

Abstract: An automatic map complication system, for deriving information from a pair of stereoscopic photographs by scanning portions thereof which represent homologous imagery comprising:first means for scanning at least portions of a pair of stereoscopic photographs and developing video signals in accordance therewith;second means, including computing means, operable in a sequence of cycles of operation, for estimating for successive cycles of operation, on the basis of at least photogrammetric data related to said pair of photographs, the portions of said photographs which represent homologous imagery and controlling said first means to synchronously scan said portions; andthird means responsive to said video signals for comparing said video signals therein and producing error signals which represent the degree of error in said second means in estimating said portions of said photographs as representing homologous imagery, said second means including means responsive to said error signals for updating the estimate o

Abstract: A position-feedback-control servomechanism for shifting the transmission of a vehicle has both an adaptive proportional-integral-differential controller to compensate for manufacturing variations, etc, and a voltage-compensation system that senses the battery voltage and prevents the gain of a servomechanism drive motor from varying significantly when the battery voltage changes. The motor is preferably a permanent-magnet type to whose terminals the battery voltage is switched on and off. The switching is done by electronic switches that are under the control of a pulse-width-modulated signal. The width of the pulses of the pulse-width-modulated signal is controlled by both a closed-loop position-error signal and a signal derived from an open-loop measurement of the battery voltage.

Abstract: A precharged capacitor connected in parallel with the contacts of an open switch discharges through the switch upon closure. Oxides on the switch contacts are broken through upon closure of the switch to produce a good electrical connection. The capacitor provides sufficient voltage and transient current to clean the switch contacts. A microprocessor having signals of only 5 volts can interrogate a plurality of such switches by multiplexing some semiconductor switching circuits that energize the interrogated switches and by synchronously multiplexing some microprocessor input circuits. The microprocessor's input circuits therefore receive signals indicating the status of each switch in turn.

Abstract: A controller for a relay controls the pull-in time of the armature of the relay by controlling the power applied to the relay coil. To determine the actual pull-in time, the time of closure of the contacts is sensed and the time at which power is applied to the coil is subtracted from it. The actual pull-in time is then compared with a stored value of ideal pull-in time to produce an error signal. The error signal corrects the level of power applied to the relay coil upon the next actuation of the relay, to make the actual pull-in time approximately equal to the ideal pull-in time. In some embodiments to control the level of power on the coil, a Gray-code counter samples a duty-cycle register in a micro-computer and produces a train of pulses that is filtered to provide a DC control signal. The DC control signal controls the duty cycle of a pulse-width-modulated oscillator that rapidly switches (modulates) the power to the relay coil.

Abstract: In a vehicle in which the engine is started from a battery and in which a safety interlock prevents starting if the transmission is not in neutral, the safety interlock is of a type that latches into a condition that enables cranking to continue even when the battery voltage becomes so low that some of the control circuits would not work properly. The interlock is latched when a start command occurs if the transmission is in neutral and the clutch is disengaged. The interlock remains latched until the start command ceases. Limited automatic control of the engine's throttle can also be provided during cranking. If desired, the safe status of the transmission and clutch can continue to be monitored during the cranking and the interlock can be unlatched if the transmission or clutch becomes engaged.

Abstract: A position-feedback-control servomechanism for shifting the transmission of a vehicle has a control algorithm that adjusts the loop gains in a proportional-integral-differential controller to compensate for manufacturing variations in the apparatus as well as for temperature changes and wear. The resulting control system moves the shifting servomechanism into the selected positions accurately and as quickly as possible without permitting excessive overshooting or resonance.

Abstract: An electronic recognition unit indicates that a flow of received information is starting when a desired bi-phased pulsed ratio signal starts to be received. The recognition unit discriminates against both noise and spurious radio signals. Desired signals are made recognizable by reversing, upon transmission, the phase of the carrier for a prescribed pattern of pulses. This technique prevents responding to unqualified continuous-wave signals. The relative phases of adjacent radio-frequency pulses of the desired pulse train convey the recognition information. When the phases of two adjacent pulses are the same a positive audio-pulse output is obtained, and if their phases differ by 180 degrees the output is negative. For a predetermined number of pulses, for example fourteen, the resulting positive and negative audio pulses are added in an audio delay circuit with appropriate inversion of the sign of the intentionally negative pulses.

Abstract: In a communications-receiving system for demodulating phase-coded signals and displaying the resultant information on a cathode-ray tube (CRT), an information code is modulated on a carrier by shifting the phase of the carrier by an integral multiple of predetermined phase step. At the receiver a locally generated reference signal is compared with received pulses to ascertain their phase offsets. The resulting demodulated information is presented in a CRT display that indicates not only the received information but also, by the slope of bright dots, the frequency difference between the local reference and the signal, so that frequency drift can be corrected. The CRT's horizontal sweep represents time and the vertical sweep represents phase angle. The start of each vertical sweep is synchronized with zero-crossings of the locally generated reference signal. The intensity of the CRT beam is controlled by the message.

Abstract: An outer seal for a drive-axle-wheel hub keeps axle-gear lubricant separated from wheel-bearing grease by preventing leakage to and from the wheel-bearing cavity at the outer end of the spindle. A sleeve-like outer-seal journal (50) is pressed into a groove (60) in the outer face of an outer lock nut (38). A seal-carrier ring (62) fits over the wheel hub drive studs (22) between a hub (16) and an axle-shaft cap (42). The ring (62) carries a lip-type resilient outer seal (52) that slidably presses against the outer seal journal (50). Wheel bearing life is extended.

Abstract: A safety method is provided for use with control systems for vehicles such as trucks, and in particular for electromechanical controls (10) that assist the driver in shifting the gears (12), operating the clutch (16), and in actuating the throttle (22, 24, 26) by remote control. The method, which is for use in a vehicle's throttle-actuator subsystem (26A), utilizes a transmission control processor (42A) and a throttle control processor (42B). The method ascertains whether, when the driver of the vehicle removes his foot from the accelerator pedal (24A), control of the fuel pump (26C) returns to the idle governor as it should. The flow of fuel is stopped if it does not return properly. Also, a method is provided that monitors the throttle actuator (26A) to insure that it accurately follows throttle commands such as the position of the accelerator pedal (24A).

Abstract: A computer-controlled apparatus (1) for electrical testing of the make-and-break characteristics of electrical switches (15), including characteristics when the switches are actuated very slowly. The apparatus automatically feeds the switches into a test position (16), "breaks them in" by cycling them through many operations, and tests their switching parameters. The amount of hysteresis (54) between a switch actuator's (38) positions at actuation (30) and deactuation (56) is a criterion for sorting the switches. Switches are automatically classified and marked (14) according to their tested characteristics, and sorted into bins (28, 29). Any undesirable electrical "deadbreak" (an excessive transfer delay) during the operation of a double-throw switch's contacts is detectable by both a Timer Method and a Limit Switch Method, and faulty switches are reliably rejected. The apparatus increases accuracy in the testing of switches and reduces human errors such as those caused by fatigue.

Abstract: An amplitude-control system for a signal generator corrects for variations that occur in the amplitude of output signal upon changing of the specified frequency. It also corrects for errors that occur (due to non-linearity) in the amplitude of its output signal upon changing of the specified amplitude. The amplitude-control system performs both of the amplitude corrections simultaneously and very rapidly by means of an arrangement that employs mostly hardware and very little software. Look-up tables that are stored in memories are read directly instead of by a CPU, and a resulting control signal sets the gain of an amplifier that has voltage-controllable gain. The amplifier amplifies the uncorrected output of the signal generator so as to provide an output signal of corrected amplitude. Calibration is accomplished by automatically or semi-automatically by loading correction data into the memories to form look-up tables.

Abstract: A safety method is provided for use with control systems for vehicles such as trucks, and in particular for electromechanical controls (10) that assist the driver in shifting the gears (12), operating the clutch (16), and in actuating the throttle (22, 24, 26) by remote control. The method, which is for use in a vehicle's throttle-actuator subsystem (26A), utilizes a transmission control processor (42A) and a throttle control processor (42B). The method ascertains whether, when the driver of the vehicle removes his foot from the accelerator pedal (24A), control of the fuel pump (26C) returns to the idle governor as it should. The flow of fuel is stopped if it does not return properly. Also, a method is provided that monitors the throttle actuator (26A) to insure that it accurately follows throttle commands such as the position of the accelerator pedal (24A).

Abstract: Manual override apparatus (38) for use in a vehicle having an automated mechanical transmission (10) or similar transmission, that enables limited driving of the vehicle in the event of a malfunction of the transmission's automatic electronic control system (30). The override apparatus includes a semi-manual arrangement (42, 44, 50, 58) for putting the transmission (10) in gear (46), disabling the electronic logic circuits (48), and actuating the clutch operator (22) from a manual lever-controlled valve (56, 40) in the cab. Another manual device (58) in the cab selectively enables and prevents manual control by the lever-controlled valve of the clutch operator (22).

Abstract: An improved digital data synthesizer has a phase accumulator into which adjustable step increments are clocked. The output of the phase accumulator is connected to address a memory, in which a waveform function is digitally stored. Samples read from the memory at the successive addresses are converted to analog form and filtered to produce a final output signal of a desired frequency. Register stages of the phase accumulator are pipelined to increase their speed. The synthesizer has a plurality of digital-to-analog converters, all on a single chip to equalize the delay times occurring within them. A lookup memory permits a variety of output waveforms to be generated. Several lookup tables for the same waveform are stored with different phase spacing between addresses, and a decoder/addresser automatically selects the lookup table that has been found to result in best performance for a particular frequency. One or more correction lookup table can also be provided.

Abstract: Apparatus for automatically steering a farm crop vehicle between rows of corn by sensing the locations of the rows ahead of the vehicle. The apparatus senses the location of the plants as the crop vehicle approaches them. The data thus obtained are processed by an on-board microcontroller to determine the lateral location of the crop vehicle relative to the rows and provide a feedback signal. Another feedback signal is provided by integrating that lateral error data. In addition to the plant sensors, the harvester has a Doppler radar system on its left side that provides ground-velocity information for the left side, and a similar system on the right side. The radar outputs enable the microcontroller to measure the turning of the vehicle. This is used to produce yet another feedback signal that improves the automatic steering. This turning-feedback signal stabilizes the loop. The microcontroller provides steering commands for automatically tracking the rows.

Abstract: A DC braking system for an inverter-driven induction motor, (e.g., three-phase). When a braking command occurs, the normal gating sequence of the inverter stops. Mode 1 of the braking procedure starts. In Mode 1, two semiconductor phase switches of the group connected with one of the DC buses and the semiconductor switch of the third phase that is connected with the other DC bus are latched in a conducting state. The motor essentially receives DC current, which increases until it actuates a current limit device, clearing the latch. Then all six switches are turned off. That drives the motor current through the back-biased parallel diodes. The negative DC bus voltage is available to suppress motor current despite large motor speed voltages. The apparatus repeats the Mode 1 procedure for a predetermined time interval, after which Mode 2 of the braking procedure starts. In Mode 2, just as in Mode 1, two switches of one bus and one switch of another bus conduct until an overcurrent limit is reached.

Abstract: A tire filter assembly (15, 400) for a central tire inflation system (10) having fluid communication (403) from the exterior to the interior of the pressurized chamber (74) of an inflatable tire (12). The assembly includes filter means (15) mounted to a cylindrical sleeve-type bead lock (400) inside the interior pressurized tire chamber (74). The location of the filter inside the tire permits it to have a relatively large area through which air can flow, and to prevent rubber particles that come off the inside of the tire from entering the central inflation system. The filter assembly is affixed by means of an adhesive (11) or a molding material to a groove (17) provided in the bead lock, and/or by mechanical means.

Abstract: An improved "expanding-shoe" drum brake (100), including an immovable spider member (38) to which brake shoes (18, 19) are pivotally mounted to move into engagement with a rotating annular brake drum (10). As is common, the shoes move in response to motion of a brake-actuating rotatable S cam (12), which is located between first adjacent ends of the brake shoes. The cam applies force to two cam followers (14, 15), which are rollers rotatably fixed to respective brake shoes. At the second end of each brake shoe an anchor pin (30, 31) is fixedly mounted to with webs of the respective brake shoe, as by welding (57A, 57B). In the embodiment described, a corresponding receptacle (43, 45) in the immovable spider has a semicircular surface (49, 51) at its bottom to serve as a bearing. The bearing surface engages the anchor pin, for rotation of the shoe. The brake shoe is resistant to twisting and misalignment.