Micromechanical pressure sensor element and method for using a pressure sensor element of this type

• US 7,305,874 B2
• Filed: 06/20/2006
• Issued: 12/11/2007
• Est. Priority Date: 06/23/2005
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Ullmann, Dirk
• Primary Examiner(s): Allen, Andre J.
• Application Number:
  US11/472,106
• Publication Number:
  US 20060288789A1
• Time in Patent Office: 539 Days
• Field of Search: 737/53, 731/465
• US Class Current: 73/146.5
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00

Abstract

A micromechanical pressure sensor element, in particular for tire pressure measurement. The device has at least: a layer system having a diaphragm underneath which a cavity is formed, which is separated from an external space outside the pressure sensor element; a measuring device for measuring a deflection of the diaphragm; and a seismic mass formed on, underneath, or in the diaphragm. Furthermore, in a method for using such a pressure sensor element, the pressure sensor element is operatable in a sleep mode having lower power consumption and in an operating mode having higher power consumption; in the sleep mode a change in the measuring signals of the measuring device over time is checked, and if a relevant change in the measuring signals is detected, a position change is inferred and a switchover to the operating mode is performed, in which the measuring signals of the measuring device or the analysis signals formed from the measuring signals are transmitted via a transmitter, for example, an antenna.

Claims

1. A method for using a pressure sensor element comprising:

operating the pressure sensor element in a sleep mode having lower power consumption and in an operating mode having higher power consumption;

checking, in the sleep mode, a change over time in at least one measuring signal of a measuring device; and

if a relevant change in the measuring signal is detected, inferring a position change and performing a switchover to the operating mode, in which one of (a) the measuring signal of the measuring device and (b) at least one analysis signal formed from the measuring signal is transmitted by a transmitting device.

2. The method according to claim 1, wherein the transmitting device includes an antenna.

3. The method according to claim 1, further comprising, in the sleep mode, analyzing changes in the measuring signal in a low-frequency range of less than 10 Hz, and recognizing changes in the measuring signal in the low-frequency range as a position change of the sensor element.

4. The method according to claim 1, further comprising, in the sleep mode, recognizing changes in the measuring signal of the measuring device over a limiting value as a position change of the sensor element.

5. The method according to claim 1, wherein the pressure sensor element is used for measuring an internal tire pressure.