US 2017/0122789 A1 · METHOD FOR DETERMINING THE FILL STATE IN A TANK

Abstract

The disclosure relates to a method for determining a level of a liquid in a tank with an ultrasonic fill state sensor and at least two reference surfaces for reflecting an ultrasonic wave transmitted by the ultrasonic fill state sensor. A first reference surface is arranged below a second reference surface. The method includes determining a first propagation speed of an ultrasonic wave to the first reference surface on a first measurement path and a second propagation speed from the first reference surface to the second reference surface on a second measurement path. The method also includes measuring a propagation time of an ultrasonic wave from the ultrasonic fill state sensor to a liquid level of the liquid in the tank, selecting the first propagation speed or the second propagation speed based on at least one selection criterion, and calculating a fill state using the propagation time measured.

Claims20

Dependent claims

A method for determining a level of a liquid in a tank with an ultrasonic level sensor and at least two reference surfaces for reflection of an ultrasonic wave that is emitted from the ultrasonic level sensor, wherein a first reference surface is disposed below a second reference surface, the method comprising the following steps:

a) determining a first propagation speed of an ultrasonic wave in the liquid over a first measuring distance from the ultrasonic level sensor to the first reference surface;
b) determining a second propagation speed of an ultrasonic wave in the liquid over a second measuring distance from the first reference surface to the second reference surface;
c) measuring a propagation time of an ultrasonic wave from the ultrasonic level sensor to a liquid level of the liquid in the tank;
d) selecting the first propagation speed or the second propagation speed depending on at least one selection criterion;
and
e) computing a level with the propagation time measured in step c) and the propagation speed selected in step d).

3 more elements

A motor vehicle having a tank for an operating liquid, the tank comprising an ultrasonic level sensor for determining the level in the tank and at least two reference surfaces for reflection of an ultrasonic wave that is emitted by the ultrasonic level sensor, a first reference surface is disposed below a second reference surface, and at least one controller is arranged for level determination to carry out a method for determining the level of the liquid in the tank, the method comprising the following steps:

a) determining a first propagation speed of an ultrasonic wave in the liquid over a first measuring distance from the ultrasonic level sensor to the first reference surface;
b) determining a second propagation speed of an ultrasonic wave in the liquid over a second measuring distance from the first reference surface to the second reference surface;
c) measuring a propagation time of the ultrasonic wave from the ultrasonic level sensor to a liquid level of the liquid in the tank;
d) selecting the first propagation speed or the second propagation speed depending on at least one selection criterion;
and
e) computing a level with the propagation time measured in step c) and the propagation speed selected in step d).

3 more elements

Dependencies are inferred from the claim text.

Method for determining the fill state in a tank

Life of this patent

Method for determining the fill state in a tank

Life of this patent

Abstract

Claims20