Crankcase Ventilation Flow Estimation for Filter Clogging Detection

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Solution Overview

Problem

Diagnosing engine wear and detecting clogging status of filter elements in internal combustion engines with closed crankcase ventilation systems is difficult, leading to potential damage and increased costs due to inaccurate timing of filter replacements.

Innovation Solution

A method and control arrangement that estimate the flow rate of gas through the crankcase ventilation outlet using data from existing components, such as a pump unit's pumping rate, to determine wear status and clogging of filter elements, thereby providing timely replacements and preventing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional crankcase ventilation systems are used without flow rate monitoring, then the system structure remains simple, but the ability to detect wear status and filter clogging is lost

Engineering Contradiction:
Improveflow rate measurementVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pump unit serves dual purposes: it performs its primary function of moving crankcase gases while simultaneously providing data (pumping rate, power consumption) that enables flow rate estimation. The system uses existing components and their operational parameters to achieve measurement without adding dedicated sensing hardware.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control arrangement acts as an intermediary that processes readily available data from the pump unit (pumping rate, power consumption) and converts it into useful flow rate information. This mediator transforms existing operational data into diagnostic insights without requiring direct physical measurement of gas flow.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If filter elements are replaced based on fixed intervals, then maintenance scheduling is simple, but premature or delayed replacement occurs leading to increased costs

Engineering Contradiction:
Improvefilter performanceVSAvoidmaintenance timing
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system continuously monitors gas flow rate through the crankcase ventilation outlet and provides feedback about the actual operating conditions. This feedback enables dynamic adjustment of maintenance scheduling based on real-time system state rather than following a rigid time-based schedule, optimizing both reliability and resource utilization.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The maintenance strategy transitions from static (fixed intervals) to dynamic (condition-based). The system adapts maintenance timing based on actual filter loading conditions reflected in gas flow rate measurements, allowing extensions or accelerations of maintenance intervals as needed to maintain optimal performance.

Inventive Principle:
Principle #15Dynamics

3Difficulty of detecting and measuring

If no flow rate estimation is performed, then diagnostic capabilities remain simple, but wear status and filter clogging cannot be detected

Engineering Contradiction:
Improvediagnostic capabilityVSAvoidoperational information
Core Design Contradiction:
Difficulty of detecting and measuringVSLoss of information

Solution Approach 1:

The system replaces direct mechanical measurement of gas flow rate with a computational approach. Instead of using complex flow meters or sensors, the control arrangement calculates flow rate by substituting mechanical measurement with mathematical processing of electrical parameters (power consumption, pumping rate) from the pump unit.

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

Data Source

PatentEP4400696B1Method of estimating an operational aspect of an engine, computer program, computer-readable medium, control arrangement, engine, and vehicle
Publication Date: 2026.02.25 SCANIA CV AB
  • EP4400696B1 patent drawingFigure 1~2
  • EP4400696B1 patent drawingFigure 3~4

AI summary

A method (100) of estimating an operational aspect of an internal combustion engine (10) is disclosed, wherein the engine (10) comprises a crankcase (4) enclosing at least part of a crankcase volume (V), a crankcase ventilation outlet (1) connected to the crankcase volume (V), and a gas cleaning assembly (6) comprising an oil separator unit (7) and a pump unit (8) configured to pump gas from the crankcase volume (V) to the oil separator unit (7) via the crankcase ventilation outlet (1). The method (100) comprises the steps of obtaining (110) data indicative of a pumping rate of gas pumped by the pump unit (8) and estimating (120) the flow rate of gas through the crankcase ventilation outlet (1) based on the data. The present disclosure further relates to a computer program, a computer-readable medium (200), a control arrangement (21), an internal combustion engine (10), and a vehicle (2).