Ultrasonic Coolant Level Sensor in Vertical Standpipe
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Solution Overview
Problem
Existing coolant level estimation methods in vehicle cooling systems are inaccurate due to temperature fluctuations and sensor degradation, especially at low coolant levels, leading to poor cooling performance and potential engine overheating.
Innovation Solution
A method involving a vertical standpipe fluidically coupled to the coolant overflow container, equipped with an ultrasonic sensor that transmits signals and estimates the coolant level based on echo times, using both raw and processed data to improve accuracy and reliability, and adjusts engine operation accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an ultrasonic sensor is installed at the bottom of the coolant reservoir to estimate fluid level, then the sensor can detect coolant presence, but the dimensions of the reservoir vary based on coolant temperature causing inconsistencies in estimated coolant level
Solution Approach 1:
The patent divides the measurement system into two separate components: a standpipe that maintains constant dimensions and an ultrasonic sensor that measures fluid level. By separating the measurement function from the variable-dimension reservoir, the system achieves consistent measurements despite temperature-induced dimensional changes in the coolant storage container.
Solution Approach 2:
The standpipe acts as an intermediary element between the coolant reservoir and the ultrasonic sensor. It provides a stable, temperature-invariant reference structure that translates the fluid level information from the variable-dimension reservoir into a consistent measurement medium, eliminating the reliability issues caused by thermal expansion and contraction of the reservoir.
2Measurement precision
If the sensor is located at the bottom of the container, then it can detect fluid presence, but at low coolant levels it is unclear whether the fluid level is low or empty
Solution Approach 1:
The patent moves the sensor measurement dimension from a horizontal/planar detection at the bottom to a vertical dimension along the standpipe. The ultrasonic sensor mounted at the top of the standpipe measures downward along the vertical axis, providing clear distinction between low level and empty states through the reflected echo signal strength and timing, which varies predictably with fluid height in the narrow standpipe.
3Adaptability or versatility
If coolant reservoir dimensions vary with temperature, then thermal expansion is accommodated, but inconsistencies in estimated coolant level occur
Solution Approach 1:
The system separates the thermal expansion accommodation function (performed by the flexible reservoir) from the measurement function (performed by the rigid standpipe). This segmentation allows the reservoir to adapt to temperature changes while the standpipe maintains constant dimensional references for accurate level measurement.
Solution Approach 2:
The patent applies different material and structural properties to different parts of the system: the reservoir is designed with thermal adaptability while the standpipe is designed with dimensional stability. This local differentiation of qualities allows each component to perform its specific function optimally without compromising the other.
4Reliability
If processed fluid level data is used for estimation, then data processing reduces noise, but raw echo times contain more information for accurate level calculation
Solution Approach 1:
The system implements feedback by comparing processed fluid level data with raw echo time measurements. The controller uses both data sources to validate and refine the coolant level estimation, cross-checking the processed information against the original ultrasonic echo signals to ensure accuracy and detect potential sensor degradation or measurement errors.
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 enhances the accuracy and reliability of coolant level estimation, reducing engine overheating by compensating for distortions caused by temperature and motion variations, and optimizing sensor power usage for improved data quality.
Implementation Method 1
A method involving a vertical standpipe fluidically coupled to the coolant overflow container, equipped with an ultrasonic sensor that transmits signals and estimates the coolant level based on echo times
Implementation Method 2
estimates the coolant level based on echo times
Data Source
AI summary
Methods and systems are providing for improving engine coolant level estimation to reduce engine overheating. The level of fluid in a coolant overflow reservoir is inferred based on the fluid level in a hollow vertical standpipe fluidically coupled to the reservoir at top and bottom locations, while the fluid level in the standpipe is estimated based on output from an ultrasonic signal transmitted by a sensor positioned in a recess at the bottom of the vertical standpipe. The sensor uses a combination of raw echo times and processed fluid level data to estimate the fluid level accurately and reliably.