Caterpillar Inc.

Paul M Young

Paul C Gottshall

Gerald N Coleman

Travis E Barnes

Michael S Lukich

Steven R McCoy

Larry E Schmidt

Gregory L Williamson

Wendell Dean Stahl

Scott E Nicholson

Ronald J Penick

Errol W Davis

John J Wunning

Mohamad Z Deiri

Lawrence E Schmidt

The present invention is an apparatus for controlling a variable geometry turbocharger (VGT) in closed loop and open loop modes, and a switching mechanism for determining whether open loop or closed loop control laws should be used. In the closed loop mode, a correction factor, obtained from a pressure correction map based on engine speed and atmospheric pressure, is subtracted from the desired boost pressure to prevent overspeed of the turbocharger at lower atmospheric pressures. The actual boost pressure is then compared to the desired boost pressure after correction to obtain a boost pressure error signal. The boost pressure error signal is used as an input to a proportional integral differential control law that responsively produces a desired VGT vane position. A minimum limit on the desired VGT vane position is based on engine speed and fuel quantity, whereas a maximum allowable vane position may be a predetermined constant or function. A linearization map is used to obtain a VGT current signal that is transmitted to an actuator for moving the vane position.

Device for controlling a variable geometry turbocharger

A circuit for digitally monitoring a duty cycle of a pulse width modulated signal is provided. The circuit includes a counter portion, a digital filter, and a data storage device. The counter portion is connectable to receive the pulse width modulated signal and is operable to monitor the pulse width modulated signal for a predetermined time period during which a count value is established. The digital filter is connected to receive the count value established by the counter portion and is also connected to receive a stored count value from the storage device, the digital filter being operable to establish a filtered count value based upon the count value and the stored count value input thereto. The storage device is connected to receive the filtered count value established by the digital filter. Multiple pwm signals may be also be monitored by including multiple counters, multiple storage devices, and one or more multiplexers.

Apparatus and method for digitally monitoring a duty cycle of a pulse

An apparatus for determining the timing of an internal combustion engine having a crankshaft, a camshaft, and a plurality of cylinders each having an electronically controlled fuel injector is disclosed. A crankshaft sensing device monitors the rotation of the engine crankshaft and responsively produces a crankshaft pulsetrain. Additionally, a camshaft sensing device monitors the rotation of the engine camshaft and responsively produces a camshaft pulsetrain. An engine control receives the crankshaft and camshaft pulsetrains, and responsively determines the period of each pulse, determines the rotational position of the crankshaft and camshaft, and produces an inject signal relative to one of the crankshaft and camshaft pulsetrains to the fuel injector in order to initiate fuel injection.

Engine timing apparatus and method of operating same

A digital communication circuit that avoids bit collisions between an external communication device and a controller that communicate to each other through a bi-directional serial communication link is disclosed. The digital communication circuit includes digital circuitry that receives and transmits a digital communication signal. A detection circuit detects when a digital communication signal is being received. And delay circuitry receives the transmitted digital communication signal and responsively produces a delay signal to delay the detection of the received digital communication signal.

Programmable bit-collision adjustment circuitry for a bi-directional

An apparatus for communicating with an electronic control module on an engine of a machine from a remote location is disclosed. The apparatus includes an electronic controller associated with a power supply on the electronic control module. A sensor is connected to the electronic controller for sensing an engine parameter indicative of the operating state of the engine. A communications interface for transmitting and receiving a communication signal is associated with the electronic controller. An ignition switch is connected to the power supply, such that when the ignition switch is in the off position, the electronic controller is powered down. The electronic controller is subsequently powered up if a communication signal is received from the remote location. This in turn allows a sensed engine parameter to be communicated to the remote location, and further allows machine information to be downloaded from the remote location to the electronic control module while the ignition switch remains in the off position.

Apparatus for communicating with a machine when the machine ignition is

A fuel injector control circuit is disclosed. The circuits can be used with a plurality of different fuel injectors and can be programmed to produce a plurality of different injector current waveforms. The control preferably includes a microprocessor with memory connected to a multiplexer and an application specific integrated circuit. The control can also be used to increase the current rise time of a specific injector current waveform.

Programmable fuel injector current waveform control and method of

In one aspect of the present invention, a method determines the rotational position of a crankshaft of an internal combustion engine. The method includes monitoring the rotation of the crankshaft and responsively producing a crankshaft pulsetrain. A clock signal is produced having a predetermined frequency. The clock signal and the crankshaft pulsetrain are received. Each pulse of the crankshaft pulsetrain is sampled, and responsively the period of each sampled pulse is determined. Signals representative of the determined pulse periods are produced. The method further includes receiving the determined pulse period signals, and responsively determining a value which is predictive of a period of the next pulse to be produced. A signal representative of the predictive value is produced, and the predictive value signal is received. An intermediate position signal based on the predictive value is produced. The intermediate position signal is representative of a predetermined angular rotation of the crankshaft.

Method for determining the rotational position of a crankshaft of an

A control system for an internal combustion engine having a plurality of cylinders and a rotatable crankshaft. Each cylinder has an electronically actuatable intake valve, exhaust valve and fuel injector. The control system includes a sensor which monitors the rotation of the crankshaft and responsively produces a crankshaft pulsetrain. A computer produces operator parameter signals. The operator parameter signals including one of a plurality of operating modes of the engine. A first microprocessor receives the crankshaft pulsetrain, responsively determines the speed of the engine and produces a signal representative of the determined engine speed. A second microprocessor receives the operator parameter signals and the engine speed signal, responsively determines valve and injection events for each cylinder to responsively achieve the one engine operating mode. The second microprocessor produces signals representative of the determined valve and injection events.

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Peoria, IL, United States of America

Paul M Young