Method and system for monitoring a tire air pressure

• US 20030079536A1
• Filed: 09/10/2002
• Published: 05/01/2003
• Est. Priority Date: 09/10/2001
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Fischer, Martin, Fischer, Frank, Hillenmayer, Franz, Prenninger, Martin, Fuessel, Dominik
• Granted Patent: US 6,748,799 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: B60C 23/0401 characterised by the type of alarm
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

A method of monitoring a tire pressure, comprises the steps: measuring at least one parameter that influences the tire pressure, calculating the optimum tire pressure ρ_opt on the basis of the at least one measured parameter, comparing a measured tire pressure p with the optimum tire pressure ρ_opt in order to generate a deviation signal in the event of a predetermined deviation.

Claims

1. A method of monitoring a tire pressure, comprising the steps:

measuring at least one parameter that influences the tire pressure;

calculating an optimum tire pressure on the basis of the at least one measured parameter;

comparing a measured tire pressure with the optimum tire pressure in order to generate a deviation signal in the event of a predetermined deviation, the predetermined deviation being defined by an upper and lower limit and, in each case when the deviation signal generated exceeds the upper limit or falls below the lower limit, a deviation value is increased in order to generate an alarm signal when the deviation value reaches a predetermined threshold value, and the deviation value is reduced when no deviation signal is present.

2. The method as claimed in claim 1, wherein the optimum tire pressure includes a vehicle-specific parameter.

3. The method as claimed in claim 1, wherein the optimum tire pressure depends on a first parameter, which changes as a function of the ambient air pressure.

4. The method as claimed in claim 1, wherein the optimum tire pressure depending on a second parameter, which changes as a function of the speed of a vehicle which has at least one tire whose tire pressure is to be monitored.

5. The method as claimed in claim 1, wherein the optimum tire pressure depending on a third parameter, which changes as a function of the loading of a vehicle which has at least one tire whose tire pressure is to be monitored.

6. The method as claimed in claim 1, wherein the optimum tire pressure depending on a fourth parameter, which changes as a function of the inflation of the tire.

7. The method as claimed in claim 1, wherein the upper and/or lower limit of the predetermined deviation depends on at least an ambient air pressure, a vehicle speed, a vehicle loading and/or a tire inflation.

8. The method as claimed in claim 1, wherein the alarm signal generated will be output only when the gas tank cover of a vehicle is opened.

9. The method as claimed in claim 1, wherein the alarm signal generated being output only when refilling the vehicle having at least one tire whose tire pressure is to be monitored is detected.

10. The method as claimed in claim 1, also comprising a step for calculating a still permissible loading of a vehicle having at least one tire whose tire pressure is to be monitored, from a predetermined value and the currently measured tire air pressure, and for displaying the still permissible loading of the vehicle.

11. The method as claimed in claim 10, wherein the predetermined value is the calculated optimum tire pressure.

12. A system for monitoring a tire pressure, comprising

at least one tire to be monitored;

at least one sensor for measuring at least one parameter of the at least one tire that influences the air pressure;

an air pressure sensor for measuring a current tire air pressure; and

an evaluation unit, which receives the at least one parameter measured by the sensor and measured data from the air pressure sensor and wherein the evaluation unit calculates an optimum tire pressure on the basis of the at least one measured parameter and compares the measured tire pressure with the optimum tire pressure in order to generate a deviation signal in the event of a predetermined deviation, wherein the predetermined deviation is defined by an upper and lower limit and, in each case when the deviation signal generated exceeds the upper limit and falls below the lower limit, a deviation value is increased in order to generate an alarm signal when the deviation value reaches a predetermined threshold value, and the deviation value is reduced when no deviation signal is present.

13. The system as claimed in claim 12, wherein the evaluation unit receives at least one parameter out of a plurality of parameters consisting of a vehicle-specific parameter, the ambient air pressure, the speed of a vehicle, the loading of a vehicle, the inflation of the tire.

14. The system as claimed in claim 12, further comprising a sensor for detecting when the gas tank cover of a vehicle is opened, wherein the evaluation unit only generates the alarm signal upon detection of said opening.