Ultrasonic Fill Level Sensor Vertical Reference Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ultrasonic level sensors for determining the fill level in tanks face challenges with changing liquid levels and heights, particularly requiring a large space on the tank bottom for horizontal measurement arrangements, which is inefficient and complicates installation.

Innovation Solution

A method using an ultrasonic fill level sensor with at least two reference surfaces, where the first reference surface is arranged below the second, allowing for the selection of either the first or second propagation speed based on selection criteria to accurately determine the fill level, even when the upper reference surface is not within the liquid, thereby reducing the required space and improving precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a horizontal measuring section is arranged at the bottom of the tank to enable reference measurement, then the propagation speed of ultrasonic waves can be determined, but a relatively large amount of installation space is required at the bottom of the tank

Engineering Contradiction:
Improvepropagation speed determinationVSAvoidinstallation space at tank bottom
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent transitions from a horizontal measuring section arrangement to a vertical arrangement by positioning reference surfaces at different heights (first reference surface below the second reference surface). This dimensional change allows the measuring section to extend vertically rather than horizontally, significantly reducing the horizontal space required at the tank bottom while maintaining the ability to determine ultrasonic wave propagation speed through the liquid.

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

2Adaptability or versatility

If the liquid level fluctuates in the tank, then the fill level changes, but the reference measurement becomes problematic when the liquid level is below the second reference surface

Engineering Contradiction:
Improvemeasurement across varying liquid levelsVSAvoidreference measurement validity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a dynamic selection mechanism that adapts the measurement method based on the current liquid level. The control unit determines whether the liquid level is above or below the second reference surface and selects the appropriate propagation speed accordingly (first propagation speed when liquid level is below, second propagation speed when above). This dynamic adaptation ensures reliable fill level measurement across the full range of liquid levels without requiring the measuring section to remain entirely submerged.

Inventive Principle:
Principle #15Dynamics

3Area of stationary object

If the ultrasonic sensor is arranged vertically to reduce space requirement, then installation space is reduced, but the measurement method becomes more complex requiring selection between multiple propagation speeds

Engineering Contradiction:
Improvesensor installation spaceVSAvoidmeasurement method complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent employs a feedback mechanism where the control unit continuously monitors the liquid level position relative to the reference surfaces and adjusts the propagation speed selection accordingly. Based on feedback about whether the liquid level is above or below the second reference surface, the system automatically selects the appropriate propagation speed (first or second) to ensure accurate measurements. This feedback-driven adaptation manages the complexity through automated decision-making rather than requiring manual intervention.

Inventive Principle:
Principle #23Feedback

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 method enables reliable determination of low fill levels with a vertically arranged sensor, reducing the space needed on the tank bottom and allowing for precise measurement across varying fill levels, including those below the second reference surface, while ensuring accurate and efficient installation.

Implementation Method 1

The transmitter emits an ultrasonic wave that is reflected off a liquid surface within the tank and travels back to the ultrasonic level sensor

Methodology Applied
Scientific EffectUltrasonic wave propagation: Ultrasound

Implementation Method 2

an ultrasonic wave that is reflected off a liquid surface within the tank and travels back to the ultrasonic level sensor

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The propagation speed of the ultrasonic wave in the liquid within the tank is either known or determined using a reference measurement. The fill level in the tank is calculated from the travel time of the ultrasonic wave

Methodology Applied
Scientific EffectSpeed of sound: Speed of Sound

Data Source

PatentEP3169884B1Method for determining the fill state in a tank
Publication Date: 2021.06.16 VITESCO TECHNOLOGIES GMBH
  • EP3169884B1 patent drawingFigure 1~3
  • EP3169884B1 patent drawingFigure 4
  • EP3169884B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for determining the fill state (17) in a tank (4) for a liquid, comprising an ultrasonic fill state sensor (3) and at least two reference surfaces (1, 2) for reflecting an ultrasonic wave transmitted by the ultrasonic fill state sensor (3), wherein a first reference surface (1) is arranged below a second reference surface (2). In method step a), a first propagation speed (9) of an ultrasonic wave is determined from the ultrasonic fill state sensor to the first reference surface (1) on a first measurement path (5) in the liquid. In a method step b), a second propagation speed (10) of an ultrasonic wave is determined from the first reference surface (1) to the second reference surface (2) on a second measurement path (6) in the liquid. In step c), a propagation time (8) of an ultrasonic wave from the ultrasonic fill state sensor (3) to a liquid level (7) of the liquid in the tank (4) is measured. In step d), the first propagation speed (9) or the second propagation speed (10) is selected depending on at least one selection criterion (11, 12, 13). Then in step e), a fill state (17) is calculated using the propagation time (8) measured in step c) and the propagation speed (9, 10) selected in step d).