Imbalance detection device, imbalance detection system, data analysis device, and controller for internal combustion engine

An imbalance detection device applied to a multi-cylinder internal combustion engine, the imbalance detection device comprising:

• memory circuitry;
• and
• processing circuitry, wherein
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the processing circuitry is configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the input to the mapping includes a half order component of a rotation frequency of the crankshaft based on the detection value of the sensor that detects the rotational behavior of the crankshaft,
• the obtainment process includes a process of obtaining a half order component variable that is a variable defining the half order component, and
• the calculation process is a process of calculating the imbalance variable based on the output of the mapping in which the half order component variable obtained by the obtainment process is further included in the input to the mapping.

An imbalance detection device applied to a multi-cylinder internal combustion engine, the imbalance detection device comprising:

• memory circuitry;
• and
• processing circuitry, wherein
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the processing circuitry is configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the input to the mapping includes a road surface state variable that is a variable indicating a state of a road surface on which a vehicle to which the internal combustion engine is mounted travels,
• the obtainment process includes a process of obtaining the road surface state variable, and
• the calculation process is a process of calculating the imbalance variable based on the output of the mapping in which the road surface state variable obtained by the obtainment process is further included in the input to the mapping.

An imbalance detection device applied to a multi-cylinder internal combustion engine, the imbalance detection device comprising:

• memory circuitry;
• and
• processing circuitry, wherein
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the processing circuitry is configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the internal combustion engine includes
• a canister that collects fuel vapor in a fuel tank that stores fuel to be injected from a fuel injection valve,
• a purge passage that connects the canister and an intake passage of the internal combustion engine to each other, and
• an adjustment device for adjusting a flow rate of the fuel vapor flowing from the canister into the intake passage through the purge passage,
• the calculation process includes both of
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the fuel vapor is zero as the input to the mapping, and
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the fuel vapor is greater than zero as the input to the mapping, and
• the response process is a process of, when the flow rate of the fuel vapor is greater than zero, operating the predetermined hardware based on the imbalance variable calculated by having the data obtained by the obtainment process when the flow rate of the fuel vapor is greater than zero as the input to the mapping.

An imbalance detection device applied to a multi-cylinder internal combustion engine, the imbalance detection device comprising:

• memory circuitry;
• and
• processing circuitry, wherein
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the processing circuitry is configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the internal combustion engine includes
• a canister that collects fuel vapor in a fuel tank that stores fuel to be injected from a fuel injection valve,
• a purge passage that connects the canister and an intake passage of the internal combustion engine to each other, and
• an adjustment device for adjusting a flow rate of the fuel vapor flowing from the canister into the intake passage through the purge passage,
• the calculation process includes both of
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the fuel vapor is zero as the input to the mapping, and calculating a first learned value from the imbalance variable and storing the first learned value, and
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the fuel vapor is greater than zero as the input to the mapping, and calculating a second learned value from the imbalance variable and storing the second learned value, and
• the response process is a process of, when the flow rate of the fuel vapor is zero, operating the predetermined hardware by selectively using the first learned value of the stored first learned value and the second learned value.

An imbalance detection device applied to a multi-cylinder internal combustion engine, the imbalance detection device comprising:

• memory circuitry;
• and
• processing circuitry, wherein
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the processing circuitry is configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the internal combustion engine includes
• an EGR passage that connects an exhaust passage and an intake passage, and
• an EGR valve that adjusts a flow rate of exhaust gas flowing in from the exhaust passage into the intake passage through the EGR passage,
• the calculation process includes both of
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the exhaust gas flowing into the intake passage is zero as the input to the mapping, and
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the exhaust gas flowing into the intake passage is greater than zero as the input to the mapping, and
• the response process is a process of, when the flow rate of the exhaust gas flowing into the intake passage is greater than zero, operating the predetermined hardware based on the imbalance variable calculated by having the data obtained by the obtainment process when the flow rate of the exhaust gas flowing into the intake passage is greater than zero as the input to the mapping.

An imbalance detection device applied to a multi-cylinder internal combustion engine, the imbalance detection device comprising:

• memory circuitry;
• and
• processing circuitry, wherein
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the processing circuitry is configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the internal combustion engine includes
• an EGR passage that connects an exhaust passage and an intake passage;
• and
• an EGR valve that adjusts a flow rate of exhaust gas flowing in from the exhaust passage into the intake passage through the EGR passage,
• the calculation process includes both of
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the exhaust gas flowing into the intake passage is zero as the input to the mapping, and calculating a first learned value from the imbalance variable and storing the first learned value:
• and
• a process of calculating the imbalance variable by having data obtained by the obtainment process when the flow rate of the exhaust gas flowing into the intake passage is greater than zero as the input to the mapping, and calculating a second learned value from the imbalance variable and storing the second learned value, and
• the response process is a process of, when the flow rate of the exhaust gas flowing into the intake passage is zero, operating the predetermined hardware by selectively using the first learned value of the stored first learned value and second learned value.

A data analysis device comprising:

• second processing circuitry;
• and
• memory circuitry, wherein
• first processing circuitry, the second processing circuitry, and the memory circuitry configure an imbalance detection system, the imbalance detection system being applied to a multi-cylinder internal combustion engine,
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping constituting a machine learning algorithm, the mapping data including data learned by machine learning, the mapping including a neural network having an input-side nonlinear mapping that nonlinearly converts each output of an input-side linear mapping and an output-side nonlinear mapping that nonlinearly converts each output of an output-side linear mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the first processing circuitry and the second processing circuitry are configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the first processing circuitry is mounted to a vehicle and is configured to execute
• the obtainment process,
• a vehicle-side transmission process for transmitting the data obtained by the obtainment process to the outside of the vehicle,
• a vehicle-side reception process for receiving a signal based on the calculation result of the calculation process, and
• the response process, and
• the second processing circuitry is disposed outside the vehicle and is configured to execute
• an external reception process for receiving the data transmitted by the vehicle-side transmission process,
• the calculation process, and
• an external transmission process for transmitting a signal based on the calculation result of the calculation process to the vehicle.

A controller for an internal combustion engine, the controller comprising:

• first processing circuitry, wherein
• the first processing circuitry, second processing circuitry, and memory circuitry configure an imbalance detection system, the imbalance detection system being applied to a multi-cylinder internal combustion engine,
• the memory circuitry is configured to store mapping data that is data defining a mapping, the mapping constituting a machine learning algorithm, the mapping data including data learned by machine learning, the mapping including a neural network having an input-side nonlinear mapping that nonlinearly converts each output of an input-side linear mapping and an output-side nonlinear mapping that nonlinearly converts each output of an output-side linear mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine,
• the first processing circuitry and the second processing circuitry are configured to execute
• an obtainment process of obtaining the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals,
• a calculation process of calculating the imbalance variable based on an output of the mapping having a value obtained by the obtainment process as the input, and
• a response process of operating predetermined hardware based on a calculation result of the calculation process to respond to a large degree of variations in the air-fuel ratio,
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center,
• the rotation waveform variables and the air-fuel ratio detection variables, which are inputs to the mapping, are respectively time series data within a predetermined angular interval larger than the appearance interval,
• the first processing circuitry is mounted to a vehicle, and is configured to execute
• the obtainment process,
• a vehicle-side transmission process for transmitting the data obtained by the obtainment process to the outside of the vehicle,
• a vehicle-side reception process for receiving a signal based on the calculation result of the calculation process, and
• the response process, and
• the second processing circuitry is disposed outside the vehicle and is configured to execute
• an external reception process for receiving the data transmitted by the vehicle-side transmission process,
• the calculation process, and
• an external transmission process for transmitting a signal based on the calculation result of the calculation process to the vehicle.

An imbalance detection method applied to a multi-cylinder internal combustion engine, the imbalance detection method comprising:

• storing mapping data that is data defining a mapping by memory circuitry, the mapping constituting a machine learning algorithm, the mapping data including data learned by machine learning, the mapping including a neural network having an input-side nonlinear mapping that nonlinearly converts each output of an input-side linear mapping and an output-side nonlinear mapping that nonlinearly converts each output of an output-side linear mapping, the mapping having a rotation waveform variable and an air-fuel ratio detection variable as an input, the air-fuel ratio detection variable being a variable corresponding to an output of an air-fuel ratio sensor in each of a plurality of first intervals, and the mapping outputting an imbalance variable that is a variable indicating a degree of variations in an air-fuel ratio of the internal combustion engine;
• obtaining by an processing circuitry the rotation waveform variable based on a detection value of a sensor that detects a rotational behavior of a crankshaft, and the air-fuel ratio detection variable in each of a plurality of first intervals;
• calculating the imbalance variable based on an output of the mapping having the rotation waveform and the air-fuel ratio detection variable as the input;
• and
• operating a predetermined hardware based on the imbalance variable to respond to a large degree of variations in the air-fuel ratio, wherein
• the rotation waveform variable is a variable indicating a difference between instantaneous speed variables that are variables corresponding to a rotational speed of the crankshaft in each of a plurality of second intervals,
• the first interval and the second interval are both angular intervals of the crankshaft smaller than an appearance interval of a compression top dead center, and
• the rotation waveform variables and the air-fuel ratio detection variables that are inputs to the mapping are respectively time series data within a predetermined angular interval larger than the appearance interval.