Engine Controller Adaptive Intake Air Calculation

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Solution Overview

Problem

Existing engine control systems face challenges in accurately calculating intake air amount due to intake air pulsation, which can reduce the detection accuracy of air flow meters, leading to reduced control accuracy of engine operations, especially when the responsivity of the air flow meter is temporarily reduced.

Innovation Solution

An engine controller that employs multiple calculation methods for intake air amount based on the output of an air flow meter and additional sensors, such as intake pipe pressure and throttle opening degree, to determine intake air pulsation, switching between mass flow, speed density, and throttle speed methods to maintain accurate control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the mass flow method is used to calculate intake air amount based on air flow meter output, then calculation accuracy is improved during steady operation, but measurement precision deteriorates when intake air pulsation is great

Engineering Contradiction:
Improveintake air amount calculation accuracyVSAvoiddetection accuracy under pulsation conditions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system dynamically switches between mass flow method and speed density method based on detected intake air pulsation levels. When pulsation exceeds a threshold, the system transitions from mass flow method to speed density method, ensuring accurate intake air amount calculation under varying operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the calculation method parameter based on pulsation detection. By monitoring pulsation magnitude and adjusting the calculation approach accordingly, the system maintains measurement precision across different engine operating states.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the speed density method or throttle speed method is used during high pulsation, then measurement precision is improved, but device complexity increases due to multiple calculation methods

Engineering Contradiction:
Improveintake air amount calculation accuracy under pulsationVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control device dynamically selects between calculation methods based on real-time pulsation detection. A determination process evaluates pulsation magnitude and automatically switches the calculation approach, managing complexity through adaptive control rather than fixed multi-method architecture.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the air flow meter output is used for pulsation determination, then measurement precision is improved, but reliability deteriorates when the air flow meter responsivity is reduced due to collected deposit

Engineering Contradiction:
Improvepulsation detection accuracyVSAvoidpulsation determination reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system uses intake pipe pressure as an intermediary parameter to detect pulsation when air flow meter reliability is compromised. By monitoring pressure fluctuations in the intake pipe, the system can determine pulsation magnitude without directly relying on air flow meter output, ensuring continuous reliable operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If multiple sensors are used for pulsation determination without air flow meter output, then reliability is improved when air flow meter responsivity is reduced, but device complexity increases

Engineering Contradiction:
Improvepulsation determination reliabilityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses intake pipe pressure sensor for dual purposes: measuring intake pipe pressure for speed density calculation and detecting pulsation magnitude. This multi-functional use of existing sensors improves reliability without adding dedicated pulsation sensors, managing complexity through versatile sensor utilization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3783217B1Engine controller, engine control method, and memory medium
Publication Date: 2025.07.30 TOYOTA JIDOSHA KK
  • EP3783217B1 patent drawingFigure 1
  • EP3783217B1 patent drawingFigure 2~3
  • EP3783217B1 patent drawingFigure 4~5

AI summary

An engine controller, an engine control method, and memory medium are provided. A second calculation process (P2) calculates an intake air amount without using an output of an air flow meter (13). A second determination process (P4, P11, P21) determines whether an intake air pulsation in an intake passage (11) is great without using the output of the air flow meter (13). When the intake air pulsation is determined to be great by at least one of a first determination process (P3) and the second determination process (P4, P11, P21), a calculation method switching process (P5) selects the calculated value of the intake air amount obtained by the second calculation process (P2) as a calculated value of the intake air amount used to determine an operation amount (Q) of an actuator (15, 18, 21) (Fig. 2).