Fluid Level Sensor Using Dual Transducers and Deflection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing devices for determining the height of a fluid surface in a container are either inefficient or costly, and struggle with precise measurements at low fill levels and in space-restricted environments.

Innovation Solution

A device with two piezo sound transducers arranged on the bottom section of the container, a deflection element, and a control unit to determine the speed of sound and fluid surface height, allowing for precise measurements at high and low fill levels, and a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single sound transducer is used to measure fluid level, then the device complexity is reduced, but the measurement precision at low fill levels deteriorates

Engineering Contradiction:
Improvenumber of transducersVSAvoidfluid level measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The measurement function is segmented into two specialized transducers: a first transducer for direct vertical measurement and a second transducer for speed of sound determination. This segmentation allows each transducer to be optimized for its specific function, improving overall measurement precision without requiring a single complex transducer to perform all functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second transducer acts as an intermediary element that indirectly contributes to height measurement by determining the speed of sound in the fluid. This intermediary measurement enables correction and calibration of the primary height measurement, improving precision at low fill levels where direct measurement alone is insufficient.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the second transducer is arranged in the same alignment as the first transducer on the bottom section, then the ease of manufacture is improved, but the measurement precision at high fill levels deteriorates

Engineering Contradiction:
Improveassembly simplicityVSAvoidheight determination precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The solution introduces a spatial dimension by positioning the second transducer at a predetermined distance from the first transducer along the bottom section. This spatial separation enables the second transducer to measure speed of sound through a different path, while the first transducer maintains direct vertical alignment for height measurement, resolving the conflict between manufacturing ease and measurement precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If the deflection element is arranged to deflect sound signals toward the reference element, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improvespeed of sound determination precisionVSAvoidnumber of components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The deflection element is integrated with the reference element structure, merging the functions of sound signal deflection and reference positioning into a single structural component. This reduces the number of separate parts while maintaining the precision of speed of sound measurements through the deflected sound path.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If both transducers are arranged on the bottom section in the same orientation, then the ease of operation is improved, but the measurement precision at low fill levels deteriorates

Engineering Contradiction:
Improveinstallation simplicityVSAvoidlow fill level measurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

While both transducers share the same general orientation for ease of installation, the second transducer is positioned at a specific location (predetermined distance from the first) with a specific functional role in speed of sound measurement. This local differentiation in positioning and function enables low fill level measurement precision without compromising overall installation simplicity.

Inventive Principle:
Principle #3Local quality

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 reliable, cost-effective, and efficient determination of fluid surface height with a compact design, maintaining precision across varying fill levels and space constraints.

Implementation Method 1

The system comprises piezoelectric means adapted to emit and receive sound waves in a liquid in order to determine the distance of the wave's path in the liquid on the basis of the time between emission and reception of the wave

Methodology Applied
Scientific EffectSound wave propagation: Sound

Implementation Method 2

determine the distance of the wave's path in the liquid on the basis of the time between emission and reception of the wave

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Implementation Method 3

a deflection element, which is arranged in the fluid chamber for deflecting the second sound signals by a predetermined angle in the direction of the one reference element

Methodology Applied
Scientific EffectAcoustic refraction: Refraction

Implementation Method 4

a control unit which is designed to determine a speed of sound within a fluid in the fluid chamber as a function of the second sound signals

Methodology Applied
Scientific EffectSpeed of sound measurement: Speed of Sound

Implementation Method 5

The sound pulses can be reflected from an interface of the fluid to another medium. Conclusions about the height of the fluid surface in the fluid container can be drawn from the propagation time of the sound pulses

Methodology Applied
Scientific EffectAcoustic reflection: Reflection

Data Source

PatentEP3063512B1Device for determining a height of the surface of a fluid in a fluid container
Publication Date: 2019.12.18 VITESCO TECHNOLOGIES GMBH
  • EP3063512B1 patent drawingFigure 1~2
  • EP3063512B1 patent drawingFigure 3~4

AI summary

The present disclosure relates to a device for determining a height of a fluid surface in a fluid container. In some embodiments, the device comprises: a first sound transducer and a second sound transducer for transmitting and receiving sound signals; a reference element disposed at a predetermined distance from the second sound transducer in a fluid space of the fluid container; a deflection element in the fluid space to deflect sound signals by a predetermined angle in the direction of the reference element; and a control unit. The two sound transducers are adjacent a base portion of the fluid container and aligned similarly. The control unit is configured to establish a speed of sound within a fluid in the fluid space based at least in part on travel of the second sound signals and thereby to establish the height of the fluid surface over the base portion of the fluid container dependent on the first sound signals and the speed of sound within the fluid.