Caterpillar Inc.

Siamak Mirhakimi

Walter Earle Earleson

Stephen C Nofsinger

Eric W Ohlson

Raymond G Evans

A control system for controlling an internal combustion engine is disclosed. The control system employs closed loop engine speed control and includes a primary and secondary engine speed sensor. An electronic control module detects a failure of the primary or secondary sensor and causes the other sensor to be used as the engine speed feedback signal in the closed loop control.

Redundant speed sensor for engine control

Phase detection apparatus and method

An apparatus for controlling dynamic braking in a vehicle having at least one drive motor of the type having an armature and a field. The motor is adapted to function as an alternator during dynamic braking for dissipating power through a resistor grid. The vehicle includes a field current controller for regulating the level of dynamic braking by controlling the current level through the motor field. A brake level selector is provided for producing a desired braking level signal. A field current sensor senses the current level in the motor field and produces an actual field current signal. A grid current sensor senses the level of current flowing through the resistor grid and produces an actual grid current signal. A controller receives the desired brake level signal, the actual field current signal, and the actual grid current signal. The controller produces a first desired field current signal and a desired grid current signal in response to the desired brake level signal. The controller further produces a second desired field current signal in response to the actual field current, actual grid current, and desired grid current signals, compares the first and second desired current field and produces a final desired field current signal responsive to the compared signals. The field current through the motor is controlled in response to the final desired field current signal.

Locomotive dynamic brake control

In the subject invention an electronic control unit is used to control the air/fuel ratio in an engine combustion chamber in response to sensed engine parameters. More particularly, a magneto interface produces an ignition signal which is delivered to a spark plug. The spark plug is disposed essentially in the center of a combustion chamber, and it ignites an air/fuel mixture in the chamber in response to the ignition signal. A sensor such as an ion probe, for example, is further disposed in the combustion chamber longitudinally from the spark plug. The sensor produces an ionization signal in response to a flame front propagating past the sensor. A buffer circuit receives the ignition and ionization signals and produces a combustion signal in response to a time difference between the reception of these signals. The electronic control unit receives the combustion signal and calculates a combustion signal air/fuel ratio in response to the combustion signal. Both the combustion signal and the combustion signal air/fuel ratio are responsive to changes in the quality of the fuel in the combustion chamber. Subsequently, the control unit calculates a volumetric air/fuel ratio. The volumetric air/fuel ratio is indicative of the volume of air and fuel in the combustion chamber, and it does not account for fluctuations in fuel quality. Finally, a wastegate is controlled in response to the volumetric and combustion signal air/fuel ratios.

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Peoria, IL, United States of America

Siamak Mirhakimi