Active Grille Shutter Sensor Degradation Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for active grille shutters (AGS) fail to address degradation due to faulty position sensors, leading to unnecessary disabling of the AGS system, which foregoes fuel consumption reduction benefits.
Innovation Solution
A method involving stalling the AGS motor to draw a stall current and calculating fuel economy changes to differentiate between mechanical and sensor degradations, allowing for continued operation and preservation of fuel efficiency advantages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the AGS system is disabled upon detecting degradation, then system reliability is improved, but fuel consumption reduction benefits are lost
Solution Approach 1:
The patent segments the degradation detection into two distinct types: mechanical degradation and position sensor degradation. By differentiating between these two failure modes, the system can apply different response strategies - disabling only when mechanical degradation is detected, while maintaining operation with inferred position when sensor degradation occurs. This segmentation resolves the contradiction by preserving fuel efficiency benefits while ensuring reliability through selective disabling.
2Reliability
If the AGS system is disabled to ensure reliability, then system reliability is improved, but operational continuity is reduced
Solution Approach 1:
The patent implements a dynamic response strategy that adapts the system operation based on the type of degradation detected. Rather than a static disable-all approach, the system dynamically adjusts its behavior: fully disabling for mechanical degradation but maintaining operational continuity with inferred position for sensor degradation. This dynamic approach resolves the contradiction by preserving operational continuity where safe while ensuring reliability when necessary.
3Loss of information
If the AGS position is inferred via engine temperature changes, then position inference is achieved, but reliability decreases at varying ambient temperatures
Solution Approach 1:
The patent replaces the thermal-based position inference method (using engine temperature changes) with an electrical-based method (using AGS motor stall current). This substitution resolves the reliability issue because electrical current measurements are not affected by ambient temperature variations, whereas thermal methods are inherently sensitive to temperature changes. The stall current method provides accurate position inference across all temperature conditions.
4Loss of energy
If the AGS system continues operation with sensor degradation, then fuel consumption reduction benefits are preserved, but measurement precision deteriorates
Solution Approach 1:
The patent introduces an intermediary inference mechanism that estimates AGS position based on motor stall current characteristics when the position sensor degrades. This intermediary approach allows the system to maintain operational benefits by preserving fuel consumption reduction capabilities while compensating for the loss of direct position measurement precision through the stall current-based estimation.
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
Enables the distinction between AGS position sensor and mechanical degradations, allowing the AGS system to maintain operation and fuel consumption reduction benefits, with position inference via stall current being more reliable across varying temperatures.
Implementation Method 1
actuate the AGS motor to move the AGS to a more closed position until a stall current is drawn by the AGS motor
Data Source
AI summary
Methods and systems are provided for a vehicle comprising, during a first condition comprising when an active grille shutter (AGS) position change over a second interval is less than a threshold position change: stalling an AGS motor for a first interval; calculating a fuel economy change over the first interval; and determining a degradation of an AGS sensor based on the fuel economy change being greater than a threshold fuel economy change over the first interval. In this way, various degradation modes of the AGS including faulty AGS position sensors and a mechanical AGS degradation can be differentiated. Furthermore, in the event of an AGS position sensor degradation, the AGS position can be inferred so that operation of the AGS and the fuel consumption reduction advantages conferred therefrom can be preserved.