Intake Manifold Pressure Sensor Responsiveness Diagnosis at Idle

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Solution Overview

Problem

Conventional methods for diagnosing pressure sensor responsiveness in intake manifolds of spark-ignition engines require driver operation, leading to unstable diagnosis execution rates and reduced accuracy due to the difficulty in reproducing fixed acceleration conditions.

Innovation Solution

A method that measures pressure pulsation amplitude during engine idling, extracts maximum and minimum values from pressure sensor signals, and performs calculations using pre-stored normal values to diagnose responsiveness without driver input, incorporating crank angle sensing and digital conversion for high accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If driver operation (accelerator pedal stepping) is required for diagnosis, then diagnostic method can be implemented, but diagnosis execution rate becomes unstable and diagnostic accuracy deteriorates

Engineering Contradiction:
Improvediagnosis execution rate stabilityVSAvoiddriver operation requirement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The diagnosis system performs self-diagnosis automatically during engine idle operation without requiring driver intervention. The ECU autonomously monitors pressure sensor signals and executes diagnostic routines, eliminating dependency on driver actions while maintaining stable and repeatable diagnostic conditions through controlled idle operation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system prepares diagnostic conditions in advance by utilizing the engine idle state, which naturally occurs during normal operation. By pre-establishing the diagnostic environment through idle operation rather than requiring transient acceleration events, the system ensures consistent and reproducible measurement conditions

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If driver operation is required to reproduce fixed acceleration conditions, then diagnosis can be performed, but it becomes difficult to reproduce fixed acceleration and fixed vehicle speed every time

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidrepeatability of acceleration conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system pre-establishes diagnostic conditions by utilizing engine idle operation, a stable and easily reproducible state. By preparing the diagnostic environment through controlled idle conditions rather than requiring repeated acceleration events, the system ensures consistent pressure sensor signal characteristics for accurate and repeatable measurements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes the operational parameter from transient acceleration states to steady-state idle operation. This parameter change transforms the diagnostic condition from one that is difficult to reproduce (variable acceleration profiles) to one that is inherently stable and easily repeatable (controlled idle speed and load conditions)

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If diagnosis is performed during transient acceleration state, then pressure sensor responsiveness can be assessed, but diagnosis depends on driver operation and execution rate is unstable

Engineering Contradiction:
Improvepressure sensor responsiveness measurementVSAvoiddiagnosis execution rate
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The diagnosis system performs autonomous self-diagnosis during engine idle operation without requiring driver participation. The ECU automatically monitors pressure sensor signals and executes diagnostic routines, eliminating dependency on driver actions while maintaining stable and repeatable diagnostic conditions through controlled idle operation, thereby improving both measurement precision and execution rate

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system enables continuous diagnostic capability by utilizing the engine idle state, which occurs frequently during normal operation. This allows the diagnostic function to be executed continuously whenever idle conditions are present, rather than being limited to occasional acceleration events, thereby improving diagnosis execution rate while maintaining measurement precision

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP4603694A1Method of diagnosing responsiveness of pressure sensor of intake manifold
Publication Date: 2025.08.20 NIKKI CO LTD
  • EP4603694A1 patent drawingFigure 1~2
  • EP4603694A1 patent drawingFigure 3~4
  • EP4603694A1 patent drawingFigure 5(1)~5(5)

AI summary

An object of the present invention is to provide a method of diagnosing responsiveness of a pressure sensor (10) provided in an intake manifold (4), which is capable of achieving both of not depending on an operation by a driver and improving diagnostic accuracy. A method of diagnosing responsiveness of a pressure sensor (10) provided in an intake manifold (4) of a spark-ignition engine (1), includes: measuring, by the pressure sensor (10), a pressure pulsation amplitude generated by intake pulsation when the engine (1) is idle; extracting a measurement maximum value (MAP_H) and a measurement minimum value (MAP_L) from measured pressure sensor signal information; performing a calculation with reference to a normal maximum value and a normal minimum value stored in advance in a control device of the engine (1) when the pressure sensor (10) is normal, the measurement maximum value (MAP_H), and the measurement minimum value (MAP_L); and judging that the responsiveness of the pressure sensor (10) deteriorates when a result of the calculation satisfies a predetermined responsiveness deterioration condition.