Method and apparatus for detecting operating state of internal combustion engines

An operating state detecting apparatus for an internal combustion engine for determining whether the internal combustion engine is being accelerated and/or whether it is being decelerated, comprising:

• a pressure sensor for detecting pressures within an air intake pipe of the internal combustion engine,
• a rotational angle sensor for generating a rotational angle detection signal for detecting each of a plurality of rotational angle positions of a crankshaft of said internal combustion engine,
• a pulse generator for generating a reference pulse for detecting a reference rotational angle position of the crankshaft of the internal combustion engine,
• air intake pipe internal pressure sampling means for sampling, at each of the plurality of rotational angle positions detected from said rotational angle detection signal as sampling positions, the pressure within the air intake pipe detected by said pressure sensor at each sampling position,
• storage means for identifying said sampling positions with reference to the reference rotational angle position detected by said reference pulses and storing the pressures within the air intake pipe sampled at different sampling positions, and
• comparative determination means for comparing pressures within the air intake pipe newly sampled at each sampling position with pressures within the air intake pipe sampled at the same sampling position one combustion cycle before and stored by said storage means, determining that said internal combustion engine is being accelerated when the newly sampled pressure within the air intake pipe is higher by at least a predetermined level than the previously sampled pressure within the air intake pipe, and determining that said internal combustion engine is being decelerated when the newly sampled pressure within the air intake pipe is lower by at least a predetermined level than the previously sampled pressure within the air intake pipe.

An operating state detecting apparatus for an internal combustion engine for determining whether the internal combustion engine is being accelerated and/or whether it is being decelerated, comprising:

• a pressure sensor for detecting pressures within an air intake pipe of the internal combustion engine,
• a rotational angle sensor for generating a reference pulse signal for detecting a reference rotational angle position of a crankshaft of said internal combustion engine and a plurality of rotational angle detection pulses for detecting a plurality of rotational angle positions other than said reference rotational angle position,
• air intake pipe internal pressure sampling means for sampling, at each of said plurality of rotational angle positions as sampling positions detected with said plurality of rotational angle detection pulses, a pressure within the air intake pipe detected by said pressure sensor at each sampling position,
• storage means for identifying said sampling positions with reference to the reference rotational angle position detected with said reference pulses and storing the pressures within the air intake pipe sampled at different sampling positions, and
• comparative determination means for comparing a pressure within the air intake pipe newly sampled at each sampling position with a pressure within the air intake pipe sampled at the same sampling position one combustion cycle before, determining that said internal combustion engine is being accelerated when the newly sampled pressure within the air intake pipe is higher than the previously sampled pressure within the air intake pipe, and determining that said internal combustion engine is being decelerated when the newly sampled pressure within the air intake pipe is lower than the previously sampled pressure within the air intake pipe.