Engine Air Supply Diagnostic via Mass Flow Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing air supply systems for internal combustion engines lack effective diagnostic capabilities, particularly for detecting leaks and ensuring the reliability of mass flow sensors and air duct tightness during ongoing operation.
Innovation Solution
The proposed solution involves a novel assignment of air ducts to cylinders and a heater in the exhaust system, allowing for a mutual plausibility check of measured signals. This includes comparing mass flows through different air ducts to expected values, checking the oxygen content in exhaust gases, and evaluating pressure signals to diagnose leaks and ensure system reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple air outlets are provided at the air filter box for separate air paths to cylinders and heater, then air supply flexibility is improved, but installation space requirements increase
Solution Approach 1:
The patent merges the air outlets for the cylinder air path and heater air path into a single air outlet at the air filter box. The control device selectively directs air to different destinations (cylinders or heater) based on operational requirements, eliminating the need for separate physical air outlets and reducing installation space while maintaining air supply flexibility.
2Measurement precision
If mass flow sensors are installed in both first and second air ducts for monitoring, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The control device acts as an intermediary that indirectly monitors air flow in the second air duct by measuring the mass flow in the first air duct and calculating the difference. This eliminates the need for direct mass flow sensors in both ducts while maintaining monitoring capability through computational deduction based on the principle of mass conservation.
Solution Approach 2:
The patent replaces physical mass flow sensors in the second air duct with a computational approach using the control device to calculate air flow based on measurements from the first air duct and operational data. This substitutes mechanical sensing with electronic computation, reducing device complexity while preserving measurement functionality.
3Reliability
If comprehensive diagnostic capabilities are implemented to detect leaks and sensor reliability, then system reliability is improved, but diagnostic complexity increases
Solution Approach 1:
The control device continuously monitors mass flow measurements from the first air duct and compares them with expected values based on operational conditions. It provides feedback on system reliability by detecting deviations that indicate leaks or sensor failures, enabling proactive maintenance while using simple comparison logic rather than complex diagnostic algorithms.
Data Source
AI summary
An air supply to an internal combustion engine, which includes at least one cylinder and a heater. A first air duct is provided for supplying air to the at least one cylinder of the internal combustion engine for operating the internal combustion engine and a second air duct is provided for supplying air to a heater for heating an exhaust system of the internal combustion engine. The first and second air ducts are connected by a third air duct to an air filter, for providing filtered ambient air to the internal combustion engine. The first and second air ducts in each case have at least one control element for controlling the amount of air flowing through. The second and third air ducts in each case have a mass flow sensor for measuring a mass of the air flowing through the relevant air duct. Methods and devices for diagnosing the air supply are also described.