Engine State Detection Using Road-Adaptive Mapping

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Solution Overview

Problem

Existing state detection systems for internal combustion engines face challenges in accurately detecting variations in combustion state among cylinders, such as misfires or air-fuel ratio imbalances, due to vibrations from uneven road surfaces, which affect the accuracy of crankshaft rotational behavior analysis.

Innovation Solution

A state detection system that utilizes machine learning-based mapping data classified by road surface conditions to differentiate between rotational speed variations caused by combustion state changes and road surface vibrations, allowing for precise detection of misfires or air-fuel ratio imbalances by selecting appropriate mapping data based on road surface state variables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single detection mapping is used for all road surface conditions, then the device complexity is reduced, but the measurement precision of combustion state variations deteriorates due to road surface vibration interference

Engineering Contradiction:
Improvedetection precision of combustion state variationsVSAvoidcomplexity of mapping structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection mapping is segmented into multiple mappings, each specialized for specific road surface conditions (e.g., paved road mapping, unpaved road mapping). This segmentation allows each mapping to be optimized for its specific condition, improving detection precision without requiring a single complex universal mapping structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects and switches between different detection mappings based on the detected road surface condition. The mapping selection is updated in response to changes in road surface state, allowing the system to adapt to varying conditions and maintain high detection precision across different environments.

Inventive Principle:
Principle #15Dynamics

2Reliability

If road surface vibration effects are not accounted for, then the detection system is simpler, but the reliability of misfire and imbalance detection deteriorates

Engineering Contradiction:
Improvereliability of misfire and imbalance detectionVSAvoidcomplexity of detection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system changes the parameters of the detection mapping based on road surface conditions. Different mappings are selected with different characteristic parameters (such as different frequency ranges or vibration thresholds) that are optimized for specific road surface types, allowing reliable detection while adapting to varying environmental conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system incorporates feedback from road surface condition detection to dynamically adjust the detection mapping selection. By continuously monitoring road surface state and updating the mapping selection accordingly, the system maintains high reliability in misfire and imbalance detection across varying road conditions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11255282B2State detection system for internal combustion engine, data analysis device, and vehicle
Publication Date: 2022.02.22 TOYOTA JIDOSHA KK
  • US11255282B2 patent drawing
  • US11255282B2 patent drawing
  • US11255282B2 patent drawing

AI summary

A state detection system for an internal combustion engine is provided. Rotation waveform variables include information on a difference between cylinders in the rotational speed of a crankshaft during periods in which the respective cylinders generate combustion torque. An obtainment process obtains a value of the rotation waveform variables and a value of a road surface state variable based on an output of a sensor that detects a state of the road surface. A selection process selects, from a plurality of types of mapping data stored in the storage device, the mapping data that is associated with the road surface state variable as the detection mapping. A determination process determines whether the engine is in a predetermined operating state based on an output value of the selected detection mapping that takes the rotation waveform variables as inputs.