Crank Pulser Rotor Inter-Gear Teeth Error Removal

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Solution Overview

Problem

Existing inter-gear teeth error removal methods for crank pulser rotors are not applicable to non-uniform interval explosion engines or single cylinder engines, hindering accurate misfire decision-making in these engine types.

Innovation Solution

A method and device that detect angular velocity at each crank angle, calculate relative angular velocity, integrate it within a given range, remove inertia and pumping torque components, and learn an inter-gear teeth error coefficient to accurately remove inter-gear teeth errors from misfire parameters, applicable to non-uniform interval explosion engines or single cylinder engines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the inter-gear teeth error removal method of PTL 1 is applied to non-uniform interval explosion engines or single cylinder engines, then the device complexity is reduced, but the measurement precision deteriorates because the technology cannot be applied to these engine types

Engineering Contradiction:
Improveerror measurement complexityVSAvoidmisfire decision accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The invention changes the approach from measuring physical tooth errors to calculating error coefficients through angular velocity analysis. By detecting angular velocity at each crank angle and integrating relative angular velocity, the system derives inter-gear teeth error coefficients without requiring direct error measurement, making the method applicable to various engine types while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces direct mechanical error measurement with a computational approach using angular velocity detection and integration. Instead of physically measuring tooth position errors, the system uses rotational velocity data processed through mathematical operations to determine error coefficients, enabling application to non-uniform interval engines.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If angular velocity is detected during combustion, then the measurement time is reduced, but the measurement precision deteriorates due to combustion torque interference

Engineering Contradiction:
Improveerror detection timeVSAvoidangular velocity measurement accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The invention performs angular velocity detection during a fuel cut period before normal combustion occurs. This preliminary measurement captures the baseline angular velocity without combustion torque interference. The system then uses this baseline to calculate relative angular velocity and error coefficients, ensuring measurement precision while completing the process within an acceptable time frame.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention utilizes the periodic fuel cut operation in multi-cylinder engines to perform measurements during specific cycles when combustion is suppressed. By detecting angular velocity during these periodic fuel cut periods, the system obtains accurate baseline data that can be applied to misfire detection across all cylinders.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3604779B1Engine vehicle, inter-gear teeth error removal method for crank pulsar rotor, and device
Publication Date: 2021.04.14 HONDA MOTOR CO LTD
  • EP3604779B1 patent drawingFigure 1
  • EP3604779B1 patent drawingFigure 2~3
  • EP3604779B1 patent drawingFigure 4

AI summary

It is made possible to remove an inter-gear teeth error of a crank pulser rotor from a misfire parameter to achieve accurate misfire decision also in a non-uniform interval explosion engine or a single cylinder engine. A crank angular velocity measurement unit (5) detects an angular velocity at each crank angle. A relative angular velocity calculation unit (7) calculates a relative angular velocity at each crank angle with respect to a reference angular velocity detected in the proximity of the compression top dead center of an engine. An integration angular velocity calculation unit (8) integrates the relative angular velocity within a predetermined crank angle range to calculate an integration angular velocity. An inertia torque component removal unit (9) and a pumping torque component removal unit (11) remove an inertia torque component and a pumping torque component from the integration angular velocity to calculate a post-removal integration angular velocity. An inter-gear teeth coefficient learning unit (10) calculates and learns an inter-gear teeth error coefficient from the post-removal integration angular velocity. An inter-gear teeth error component removal unit (12) calculates an inter-gear teeth error component at each engine speed using the inter-gear teeth error coefficient and removes the inter-gear teeth error component from the post-removal integration angular velocity.