Intercooler-Based Ambient Temperature Estimation for Sensor Diagnostics

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Solution Overview

Problem

Engine control systems face challenges in accurately determining ambient air temperature, leading to false diagnostic failures when the air intake mechanism is blocked, as they cannot distinguish between outside and inside air temperatures, causing erroneous notifications and disrupting temperature models.

Innovation Solution

A system that determines an estimated ambient air temperature using the cooling capacity, ambient air flow rate, and cooling flow rate of the intercooler, comparing it with the ambient air temperature sensor value to trigger error notifications only when the difference exceeds a threshold, thereby reducing false failures and determining the state of the air diverter valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engine control system uses ambient air temperature sensor readings for diagnostics, then temperature-based diagnostics can be performed, but false diagnostic failures occur when the air intake mechanism is blocked and the air diverter valve changes state

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidfalse diagnostic failures
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intermediary estimation mechanism that uses intercooler efficiency calculations as a mediator between the ambient air temperature sensor and the diagnostic system. This intermediary layer provides a reference temperature value derived from thermal physics principles (intercooler heat exchange efficiency) to validate whether sensor readings are physically plausible, thereby filtering out false diagnostics caused by blocked air intake without adding hardware sensors

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously comparing the ambient air temperature sensor reading against the estimated temperature derived from intercooler efficiency. This feedback loop allows the diagnostic system to detect when the sensor reading diverges from the physically estimated value, indicating a blocked air intake condition, and adjust diagnostic thresholds accordingly to prevent false failures

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the system triggers error notifications based on temperature differences, then sensor failures can be detected, but erroneous notifications are generated when air intake blockage occurs

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoiderroneous error notifications
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent dynamically changes the diagnostic parameter (temperature difference threshold) based on the operational state of the air diverter valve and intercooler efficiency. When the air diverter valve is in a position indicating potential blockage, the system adjusts the threshold for triggering error notifications, allowing larger temperature differences without generating erroneous alerts, while maintaining strict thresholds when the valve indicates normal operation

Inventive Principle:
Principle #35Parameter changes

3Reliability

If additional hardware or sensors are added to improve temperature sensing accuracy, then diagnostic reliability can be enhanced, but device complexity and cost increase

Engineering Contradiction:
Improvetemperature sensing accuracyVSAvoidhardware requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses self-service by leveraging existing vehicle components (intercooler, air diverter valve, and basic temperature sensor) to generate the estimation reference. The intercooler's inherent thermal exchange function is repurposed as a temperature estimation device, and the air diverter valve's position information is used to contextualize sensor readings, eliminating the need for additional dedicated temperature sensors or complex hardware while maintaining diagnostic reliability

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces false diagnostic failures by accurately determining the air diverter valve state, adjusting diagnostic thresholds, and enhancing the robustness of air temperature sensing without requiring additional hardware or sensors, allowing for effective retrofitting of existing vehicles.

Implementation Method 1

a cooling capacity of an intercooler associated with the vehicle is determined... a cooling flow rate of the intercooler associated with the vehicle is determined

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP3967864B1Estimating ambient air temperature and diagnosing sensor failure using intercooler efficiency
Publication Date: 2024.07.03 PACCAR INC
  • EP3967864B1 patent drawingFigure 1
  • EP3967864B1 patent drawingFigure 2A
  • EP3967864B1 patent drawingFigure 2B

AI summary

Examples of the present disclosure describe systems and methods for determining an estimated ambient air temperature in an environment in which a vehicle is operating. The estimated ambient air temperature may be compared to an ambient temperature sensor value. The comparison may be used to determine whether an ambient air temperature sensor of the vehicle is functioning properly or if an error notification or fault code should be triggered.