Thomas T Stevenson

US Patent:

44174691, Nov 29, 1983

Filed:

Mar 3, 1981

Appl. No.:

6/277744

Inventors:

Thomas T. Stevenson - Peoria IL
Marios C. Zenios - Peoria IL

Assignee:

Caterpillar Tractor Co. - Peoria IL

International Classification:

G01M 1500

US Classification:

73119A

Abstract:

Apparatus for determining the speed of an engine (10) and the phase shift between first and second shafts (16,19) rotatably driven by the engine (10). First and second fixed magnetic sensors (50,56) generate first and second signals (49,55) in response to movement of magnetically sensible members (47,53) through circular paths at speeds proportional to the speeds of the first and second shafts (16,19), respectively. Clock pulses from a fixed frequency clock (65) are counted to obtain a first count between successive first signals (49) and a second count between successive second and first signals (55,49). The first count is inverted to obtain information as to the instantaneous engine speed. The second count is divided by the first count to obtain information as to the instantaneous phase angle between the first and second shafts (16,19). Successive instantaneous information is averaged to cancel the effects of engine torsionals.

US Patent:

43687059, Jan 18, 1983

Filed:

Mar 3, 1981

Appl. No.:

6/277745

Inventors:

Thomas T. Stevenson - Peoria IL
John F. Szentes - Peoria IL
Marios C. Zenios - Peoria IL

Assignee:

Caterpillar Tractor Co. - Peoria IL

International Classification:

F02D 104
F02D 106

US Classification:

123357

Abstract:

An electronic engine control system (10) utilizing a digital microprocessor (30) for controlling the timing mechanism (13) and fuel pump rack limit (23) to set the engine timing of, and maximum allowable rate of fuel delivery to, an interval combustion engine (11) so that maximum engine performance is obtained with smoke and emissions limited to required EPA levels. A plurality of timing maps (61-64) are provided, for different modes of engine operation, each map having predetermined value timing control signals programmed therein corresponding to the optimal timing advance of a particular engine speed, or particulaoptimoptimal timing advance of a particular engine speed, or particular combination of engine speed and position of the fuel rack (21). A timing map selector (65) identifies the mode of engine operation and selects the appropriate timing map (61-64) to control the timing mechanism (13) by the particular programmed signal for the existing engine speed and fuel rack position. A similar map (71) will output a particular programmed fuel/air signal in accordance with the existing engine speed and timing, the fuel/air signal having been predetermined to correspond to the maximum fuel/air ratio for fuel combustion to meet EPA limits for that engine speed and timing.

US Patent:

48951218, Jan 23, 1990

Filed:

Sep 16, 1988

Appl. No.:

7/245186

Inventors:

Steven R. McCoy - Washington IL
Thomas T. Stevenson - Dunlap IL
Douglas E. Carr - Chillicothe IL
Kevin D. King - Peoria IL

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F02P 514

US Classification:

123425

Abstract:

A method and apparatus is provided for measuring detonation in an internal combustion engine. Vibration sensors located on the engine send signals through a filter which is turned to the cavity resonance of the engine's cylinders. The peaks and valleys of the filtered signals are detected and ratiometrically compared one with another to determine the magnitude of detonation. The detonation information may be used by an engine control to retard timing in response to a predetemined level of detonation.

US Patent:

53377176, Aug 16, 1994

Filed:

May 31, 1991

Appl. No.:

7/956769

Inventors:

Horst Scheel - Peoria IL
Thomas T. Stevenson - Dunlap IL

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F02P 515

US Classification:

123426

Abstract:

An apparatus (8) is provided for controlling ignition in an engine having a ignition system (10), an engine cylinder sensor (48), and a piston disposed in the cylinder and being movable to a top dead center (TDC) position. The cylinder sensor (48) produces a first signal representing the position of the piston within the cylinder and having a frequency responsive to engine speed. The ignition system (10) includes a transformer (24) having a primary coil (26) which is energized in response to a cylinder select signal to produce sparking across an associated spark plug gap (22). A first circuit (98) is provided for sensing a delay between production of the cylinder select signal and the time at which current through a respective primary coil exceeds a preselected current level, and responsively producing a timing error signal. The cylinder selector (36) processes the timing error signal to produce a timing offset signal The cylinder selector then delivers a cylinder select signal as a function of the timing offset and a desired cylinder firing time. In this manner, the apparatus (8) compensates for the timing error introduced by the time required for transformer energization.