Method and device for detecting the tank filling level in a motor vehicle

• US 9,389,112 B2
• Filed: 12/13/2012
• Issued: 07/12/2016
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Deutz AG
• Original Assignee: Deutz AG
• Inventors: Medina-Sanchez, Gonzalo
• Primary Examiner(s): WILLIAMS, HEZRON
• Assistant Examiner(s): Nguyen, Hoang
• Application Number:
  US13/713,555
• Publication Number:
  US 20130160541A1
• Time in Patent Office: 1,307 Days
• Field of Search: 733/05, 732/90.R, 732/90.V, 702/55
• US Class Current: 1/1
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/30 by floats

Abstract

A method for detecting the filling level in a motor vehicle. A device for ascertaining the tank filling level value of moving vehicles, including at least one tank, at least one filling level sensor, at least one control unit and at least one pump.

Claims

1. A device for ascertaining a tank filling level value of a moving vehicle, comprising:

at least one tank filled with a liquid;

at least one filling level sensor configured for obtaining a tank filling level sensor value;

at least one control unit configured for ascertaining a tank volume value with the aid of a Kalman filter and obtaining a filtered tank filling level value based on the tank volume value; and

at least one pump,

wherein the at least one control unit is configured for ascertaining the tank volume value with the aid of the Kalman filter according to the following formula;

Volk=(1)Volk−

1+(−

d)*mk−

1+wk−

1

where Vol is the tank volume value,

where d is a liquid density in the tank,

where m is the mass injected from the tank,

where w is a stochastic variable, and

where k is a computation cycle.

2. The device as recited in claim 1 wherein the filling level sensor is an ultrasonic sensor.

3. The device as recited in claim 1 wherein the filling level sensor includes at least one floating gauge.

4. The device as recited in claim 1 wherein the liquid is a solution of urea.

5. The device as recited in claim 4 wherein the solution of urea is ADBLUE.

6. The device as recited in claim 1 further comprising a metering module configured for metering the liquid from the tank.

7. The device as recited in claim 6 further comprising a selective catalytic reduction catalytic converter arranged for receiving the liquid from the metering module.

8. A method for ascertaining a tank filling level of a liquid in a tank, comprising the following steps:

ascertaining a state space system;

then ascertaining a tank volume value with the aid of a Kalman filter;

ascertaining a tank filling level sensor value; and

subsequent filtering of the tank filling level sensor value based on the ascertained tank volume value to obtain a filtered tank filling level sensor value,

wherein the ascertaining the tank volume value with the aid of the Kalman filter is according to the following formula;

Volk=(1)Volk−

1+(−

d)*mk−

1+wk−

1

where Vol is the tank volume value,

where d is a liquid density in the tank,

where m is the mass injected from the tank,

where w is a stochastic variable, and

where k is a computation cycle.