Engine control system and methods
Embodiments describe a method of controlling a two-stroke internal combustion engine is shown. The method includes selecting one set of two or more sets of engine parameter inputs or a weighted value of two or more sets of engine parameter inputs, determining an engine output parameter from the selection, and utilizing the determined engine output parameter to control one or more engine operations; re-selecting one set of two or more sets of engine parameter inputs or a weighted value of two or more sets of engine parameter inputs during engine operation, utilizing the reselected output parameters to adjust one or more engine operations. Each set of engine parameter inputs includes a direct measurement of crankcase pressure and engine speed and optionally one or more of barometric pressure, exhaust valve position, air temperature, engine coolant temperature, exhaust temperature, boost pressure, crankshaft position and direction of rotation, humidity, fuel pressure, fuel temperature, detonation sensor level, exhaust oxygen content, and throttle valve angle.
1 . A two-stroke internal combustion engine system, comprising:
a crankcase including a piston and crankshaft;
an ignition system in-contact with a combustion chamber;
a fuel injection system in fluidic communication with the combustion chamber;
an air intake passage in fluidic communication with the crankcase;
an exhaust passage in fluidic communication with the combustion chamber;
an air intake valve positioned within the air intake passage;
an exhaust valve positioned within the exhaust passage;
one or more pressure sensors positioned within the crankcase;
a turbocharger in fluidic communication with both the air intake passage and the exhaust passage; and
an engine control unit,
wherein the one or more pressure sensors includes an absolute pressure sensor positioned to measure crankcase pressure during a compression phase of the crankcase,
wherein a first crankcase pressure is measured during the compression phase and wherein a second crankcase pressure is measured at a second crankshaft position, and
wherein the engine control unit compares the first crankcase pressure to the second crankcase pressure to calculate a reference value for fuel injection,
wherein the one or more pressure sensors measure the crankcase pressure at multiple crankshaft positions per compression cycle, wherein a location of the multiple crankshaft positions that the one or more pressure sensors measure the crankcase pressure is determined by the engine control unit based on one or more engine input parameters.
2 . The system of claim 1 , wherein the one or more pressure sensors are coupled with one or more walls of the crankcase to measure the crankcase pressure within a crankcase area, wherein the crankcase area is positioned between the air intake valve and the exhaust valve.
3 . The system of claim 1 , wherein the one or more pressure sensors are integrated with the one or more walls of the crankcase.
4 . The system of claim 3 , wherein the multiple crankshaft positions that the one or more pressure sensors measure the crankcase pressure are processed into an average by the engine control unit.
5 . The system of claim 1 , wherein the engine control unit compares the first crankcase pressure to the second crankcase pressure to calculate a slope of pressure change, wherein the reference value for fuel injection is based on the slope of pressure change.
6 . The system of claim 1 , further comprising a pressure management system positioned between the turbocharger and an engine throttle, wherein the pressure management system determines an upstream pressure measured between the turbocharger and the engine throttle.
7 . The system of claim 6 , wherein the engine control unit compares the upstream pressure to the crankcase pressure.
8 . The system of claim 1 , wherein a direct measurement of crankcase pressure during the compression phase of the crankcase is received by the engine control unit, wherein the engine control unit uses the direct measurement of crankcase pressure to control a fuel injection parameter.
9 . The system of claim 8 , wherein the fuel injection parameter includes one or more of an fuel injection duration, a fuel injection amount, fuel injection timing, ignition timing, an exhaust valve position, and an electronic throttle valve position.
10 . A method of controlling a two-stroke internal combustion engine, comprising:
providing an engine, including:
a crankcase including a piston and crankshaft,
an ignition system in-contact with a combustion chamber,
a fuel injection system in fluidic communication with the combustion chamber,
an air intake passage in fluidic communication with the crankcase,
an exhaust passage in fluidic communication with the combustion chamber,
an air intake valve positioned within the air intake passage,
an exhaust valve positioned within the exhaust passage,
one or more pressure sensors positioned within the crankcase, wherein the one or more pressure sensors includes an absolute pressure sensor,
a turbocharger, fluidly connected to both the air intake passage and the exhaust passage, and
an engine control unit,
measuring crankcase pressure during a compression phase of the crankcase with the one or more pressure sensors;
determining an engine load based on measured crankcase pressure; and
measuring the crankcase pressure at multiple crankshaft positions per compression cycle with the one or more pressure sensors,
wherein a location of the multiple crankshaft positions that the one or more pressure sensors measure the crankcase pressure is determined by the engine control unit based on one or more engine input parameters.
11 . The method of claim 10 further comprising:
providing a wastegate;
providing a throttle body; and
providing an air bypass valve, wherein the air bypass valve includes a plurality of valve positions;
measuring an upstream pressure of the throttle body;
utilizing a combination of the measured crankcase pressure and the measured upstream pressure to determine a reference value for wastegate valve position and air bypass valve position.
12 . The method of claim 11 , wherein the upstream pressure is measured between the turbocharger and the throttle body.
13 . The method of claim 10 , wherein the one or more pressure sensors are integrated with one or more walls of the crankcase to measure the crankcase pressure within a crankcase area, wherein the crankcase area is positioned between the air intake valve and the exhaust valve.
14 . The method of claim 10 further comprising:
processing the multiple crankshaft positions that the one or more pressure sensors measure the crankcase pressure are into an average with the engine control unit.
15 . The method of claim 10 , wherein a first crankcase pressure is measured during the compression phase and wherein a second crankcase pressure is measured at a second crankshaft position.
16 . The method of claim 15 further comprising:
comparing the first crankcase pressure to the second crankcase pressure to calculate a reference value for fuel injection.