Woodward Governor Company

Daniel C Garvey

James R Bowers

Larry L Adams

George E Parker

Richard D Fiolkoski

Bruce G Bailey

A wheel slip controller for a locomotive is disclosed that utilizes PID controllers to control the traction wheels during normal locomotive operation. The controller monitors several independent wheel slip indicators to provide rapid detection of excessive wheel slip. Upon detecting excessive traction wheel slip, motor control from the operative PID controller is suspended and a wheel slip compensator assumes command of the traction wheel drive motors. The wheel slip compensator then dynamically compensates the motors depending upon the amount of wheel slip that is detected. Once the wheel slip condition has been corrected, control of the traction motors is transferred back to the interrupted PID controller.

Locomotive wheel slip controller

Methods and apparatus, preferably carried out with the aid of a programmed digital computer for iteratively determining the actual speed of an engine and iteratively updating a fuel rate command signal so as to govern and correctively remove any errors from the set point speed. Jumps to a program subroutine are triggered by sensing the engine crankshaft to generate a predetermined number Q of pulses during the span of one revolution (where Q is an integer greater than 1), and each pass through the subroutine determines the actual engine speed as an average over the last whole revolution of the crankshaft. There are thus Q iterations per revolution but each interation signals the speed over one whole revolution. This results in wholly eliminating torsionally induced speed fluctuations, or the like, from the determined speed signal. Each pass through the program subroutine also determines the speed error and updates the fuel rate command signal as a PID function of such error. Because this iterated updating occurs, not at a regularly timed rate, but at intervals which vary inversely with speed, the instructions of the subroutine program can be made very short and simple while nevertheless causing effective automatic tuning adjustments of the integral gain, stability and compensation factors.

Method and apparatus for iterated determinations of sensed speed and

A control system is provided for a combine or other vehicle having an engine for driving both the ground wheels of the vehicle and at least one auxiliary mechanism, such as the crop-processing mechanisms of a combine. The engine is coupled to the ground wheels through a hydrostatic transmission, and the power takeoff for the auxiliary mechanism is located on the engine side of the transmission. A speed droop governor regulates the fuel input to the engine in response to changes in the engine speed. Transmission control means adjusts the setting of the hydrostatic transmission, and thus the load applied to the engine via the transmission, in response to changes in engine speed or another parameter that varies with engine load so as to control the speed changes effected by the droop governor. The combined effect of the speed droop governor and the transmission control means is to gradually reduce the operating speed of the engine as the fuel input to the engine is increased, with the total speed reduction over the full load range of the engine comprising from about 1% to about 5% of the no-load speed.

Engine and transmission control system for combines and the like

An electromagnetic actuator has a stator and an armature both made of magnetically permeable material and each having a plurality of projecting poles spaced apart from each other. The armature poles and stator poles cooperate with each other so that each pair of opposed pole faces of an armature pole and a stator pole form a narrow working air gap for passing magnetic flux between the opposed pole faces. An electrically energizable coil produces magnetic flux which passes through the poles of the armature and stator and across the working air gaps. Selected pairs of the opposed armature and stator poles form a substantially constant air gap so that the attracting magnetic force on the armature increases as the armature moves in a first direction relative to the stator and decreases as the armature moves in the opposite direction, and other pairs of the opposed armature and stator poles form a variable air gap so that the attracting magnetic force on the armature decreases as the armature moves in the first direction and increases as the armature moves in the opposite direction.

Electromagnetic actuator with torque-compensating poles

An electromagnetic actuator characterized by a pivotally connected stator and rotor (armature) forming a magnetic path linked by the coil and containing an air gap between the extremities of the stator and rotor. One such extremity is formed as a tapered arcuate tooth having inner and outer arcuate surfaces, and the other extremity is shaped to define a tapered arcuate mouth which fits complementally onto the tooth as the rotor pivots to a closed position. The coil mounted on the stator is formed with an arcuate passageway which receives the two extremities, coil thereby substantially surrounding the air gap while permitting the extremities to swing in a closing or opening sense relative to one another.

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Fort Collins, CO, United States of America

Daniel C Garvey