US 2006/0218998 A1 · Stroke determination unit and method of measuring stroke in a multi-cylinder four-cycle engine

Abstract

A stroke determination unit for a 4-cycle engine uses intake pressure as a parameter to provide accurate stroke determination. A combined pressure combines the detected pressures of intake ports of the first to third cylinders, and stroke determination is carried out by recognizing, within a combined pressure waveform based on a detection value for the combined pressure, shapes of the combined pressure waveform for a specified phase period of a crankshaft. The pressure pattern recognition is carried out by storing variation patterns of pressure values measured within the specified crankshaft phase period, and collating patterns with a data map stored within an ECU. Alternatively, the pattern recognition is carried out by collating with condition equations representing “rising” or “upward peak”. With the latter, pressure variation due to contamination such as electrical noise to the pressure sensor is made negligible, and noise suppression of the stroke determination unit is improved.

Claims18

Dependent claims

A stroke determination unit for a multiple cylinder, 4-cycle engine, said stroke determination unit comprising:

a crank angle detection device for detecting an angular position of a crankshaft,
an intake pressure detection device for detecting respective intake pressures corresponding to each of a plurality of the multiple cylinders,
an intake pressure variation generating device for causing variation so that an intake pressure waveform of at least one cylinder becomes different relative to the intake pressure waveforms of other cylinders;
an intake pressure waveform combining device for combining detected intake pressure waveforms;
a pattern recognition device for recognizing a pattern of the detected intake pressure waveform;
and
a stroke determination device for determining a stroke of each cylinder using the crankshaft position and a recognized pattern.

4 more elements

A method of determining the stroke of an engine using a stroke determination unit, the engine comprising multiple-cylinders, a crankshaft, and four-cycle operation, the stroke determination unit comprising

a crank angle detection device for detecting a stage of a crankshaft, the crank angle detection device configured to segment a single revolution of the crankshaft into plural stages,
an intake pressure detection device for detecting an intake pressure of each of the multiple cylinders,
an intake pressure variation generating device for causing variation so that an intake pressure waveform of at least one cylinder becomes different relative to the intake pressure waveforms of other cylinders;
an intake pressure waveform combining device for combining detected intake pressure waveforms to form a combined intake pressure waveform;
a pattern recognition device for recognizing a pattern of the detected intake pressure waveform;
and
a stroke determination device for determining a stroke of each cylinder using the crankshaft phase and a recognized pattern,
wherein the method comprises the following method steps:
detecting a stage of the crankshaft using the crank angle detection device;
defining a crank reference position;
setting a stage count to a value corresponding to a stage associated with an inflection point of the combined intake pressure waveform;
specifying a stage count period which begins from the stage that corresponds to the stage count value;
recognizing a pattern of the combined intake pressure for each stage within the stage count period based on combined input pressures, which form the combined intake pressure waveform,
recognizing a pattern of the combined intake pressure of the specified stage count period;
and
defining the stroke based on the recognized pattern of the combined intake pressure of the specified stage count period.

13 more elements

Dependencies are inferred from the claim text.

Stroke determination unit and method of measuring stroke in a multi-cylinder four-cycle engine

Life of this patent

Stroke determination unit and method of measuring stroke in a multi-cylinder four-cycle engine

Life of this patent

Abstract

Claims18