Internal combustion engine control system

Patent metadata

Field	Value
Publication number	US-11118527-B2
Application number	US-202016938388-A
Country	US
Kind code	B2
Filing date	Jul 24, 2020
Priority date	Jan 26, 2018
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

A control unit controls a combustion state of an internal combustion engine in accordance with a drive torque requested by a driver. The control unit performs a switching control to switch at least a combustion state between lean-burn combustion and stoichiometric combustion. A monitor unit performs torque monitoring to determine abnormality of a request torque, which is requested to the internal combustion engine, and a generated torque of the internal combustion engine based on the request torque and an estimation torque, which is an estimation value of an actual torque of the internal combustion engine. A combustion state determining unit determines whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion. A computing unit computes the estimation torque in accordance with the combustion state determined by the combustion state determining unit.

First claim

What is claimed is:

1. An internal combustion engine control system comprising:
a control unit configured
to control a combustion state of an internal combustion engine based on a drive torque of the internal combustion engine requested by a driver and
to perform a switching control to switch at least the combustion state between lean-burn combustion and stoichiometric combustion; and

a monitor unit configured to perform torque monitoring to determine abnormality of a request torque, which is requested to the internal combustion engine, and a generated torque of the internal combustion engine based on the request torque and an estimation torque, which is an estimation value of an actual torque of the internal combustion engine, wherein
the monitor unit includes:
a combustion state determining unit configured to determine whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion; and
a computing unit configured to compute the estimation torque in accordance with the combustion state determined by the combustion state determining unit, wherein
the monitor unit includes an injection amount regulating unit that is configured
to regulate an injection amount of fuel to the internal combustion engine on determination of abnormality in the torque monitoring in a state where the combustion state determining unit determines that the combustion state in the control unit is the lean-burn combustion and
not to regulate an injection of fuel to the internal combustion engine on determination of abnormality in the torque monitoring in a state where the combustion state determining unit determines that the combustion state in the control unit is not the lean-burn combustion.

2. The internal combustion engine control system according to claim 1 , wherein
the combustion state determining unit is configured to determine whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion based on at least one of
a sensor signal from a sensor that measures a physical amount, which is assured in the monitor unit and contributes to combustion of the internal combustion engine and
a drive signal for driving an actuator that controls a physical amount, which is assured in the monitor unit and contributes to combustion of the internal combustion engine.

3. The internal combustion engine control system according to claim 2 , wherein
the control unit is configured to control the combustion state while driving and controlling at least a fuel injection device, and
the combustion state determining unit is configured
to acquire, as the drive signal, an injection drive signal to drive the fuel injection device,
to compute a fuel injection amount of the fuel injection device based on the injection drive signal,
to acquire, as the sensor signal, a flow rate signal correlated with an air flow rate by which air is supplied to a cylinder of the internal combustion engine, and
to determine whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion based on a relation between the fuel injection amount and the flow rate signal.

4. The internal combustion engine control system according to claim 3 , wherein
the combustion state determining unit is configured
to acquire a fuel pressure of an accumulator that accumulates fuel in a high pressure state and to be supplied to the fuel injection device and
to compute the fuel injection amount based on the injection drive signal and the fuel pressure.

5. The internal combustion engine control system according to claim 3 , wherein
the flow rate signal is output, as the sensor signal, from the sensor including at least one of an air flow meter, an intake pressure sensor, a throttle opening angle sensor, and an accelerator position sensor.

6. The internal combustion engine control system according to claim 2 , wherein
the combustion state determining unit is configured
to acquire, as the drive signal, an injection drive signal of a fuel injection device
to acquire, as the drive signal, a cam angle signal according to a rotational position of a camshaft of the internal combustion engine and a crank angle signal in accordance with the rotational position of the crankshaft of the internal combustion engine,
to compute a positional relation between an injection timing of fuel to the internal combustion engine and a compression stroke top dead center of the internal combustion engine based on the injection drive signal, the cam angle signal, and the crank angle signal, and
to determine whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion based on the positional relation.

7. The internal combustion engine control system according to claim 1 , wherein
the monitor unit includes an intake amount regulating unit that is configured to regulate an intake amount of air to the internal combustion engine on determination of abnormality in the torque monitoring in a state where the combustion state determining unit determines that the combustion state in the control unit is the stoichiometric combustion.

8. An internal combustion engine control system comprising:
a control unit configured
to control a combustion state of an internal combustion engine based on a drive torque of the internal combustion engine requested by a driver and
to perform a switching control to switch at least the combustion state between lean-burn combustion and stoichiometric combustion; and

a monitor unit configured to perform torque monitoring to determine abnormality of a request torque, which is requested to the internal combustion engine, and a generated torque of the internal combustion engine based on the request torque and an estimation torque, which is an estimation value of an actual torque of the internal combustion engine, wherein
the monitor unit includes:
a combustion state determining unit configured to determine whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion; and
a computing unit configured to compute the estimation torque in accordance with the combustion state determined by the combustion state determining unit,

the monitor unit includes an injection amount regulating unit that is configured to regulate an injection amount of fuel to the internal combustion engine on determination of abnormality in the torque monitoring in a state where the combustion state determining unit determines that the combustion state in the control unit is the lean-burn combustion,
the combustion state determining unit is configured to determine whether the combustion state in the control unit is the lean-burn combustion or the stoichiometric combustion based on at least one of
a sensor signal from a sensor that measures a physical amount, which is assured in the monitor unit and contributes to combustion of the internal combustion engine and
a drive signal for driving an actuator that controls a physical amount, which is assured in the monitor unit and contributes to combustion of the internal combustion engine,

the control unit is configured to control the combustion state while driving and controlling at least a fuel injection device, and
the combustion state determining unit is configured
to acquire, as the drive signal, an injection drive signal to drive the fuel injection device,
to compute a fuel injection amount of the fuel injection device based on the injection drive signal,
to acquire, as the sensor signal, a flow rate signal correlated with an air flow rate by which air is supplied to a cylinder of the internal combustion engine, and
to determine whether the combustion

Assignees

• Denso Corp

Inventors

• Nodera Masato

Classifications

• F02D11/106

  Detection of demand or actuation · CPC title

• F02D2200/0618

  Actual fuel injection timing or delay, e.g. determined from fuel pressure drop · CPC title

• F02D41/18

  by measuring intake air flow · CPC title

• F02D2200/1004

  Estimation of the output torque · CPC title

• F02D41/009

  using means for generating position or synchronisation signals · CPC title