This is a U.S. national stage of application No. PCT/EP2004/05 1054, filed on 8 Jun. 2004. Priority is claimed on the following application: Country: Germany, Application No.: 103 29 500.3, Filed: 30 Jun. 2003.
The invention relates to a rotation rate sensor having a vibration gyro with circuits which are used for operation of the vibration gyro and for emission of a rotation rate signal and which access variable data, having a nonvolatile memory which can be written to and in which the data is stored, and having means for reading the data from the nonvolatile memory after switching on the rotation rate sensor, with the data being subdivided into groups on the basis of its use, and measures for data protection being taken for in each case one group.
By way of example, U.S. Pat. No. 5,226,321 discloses rotation rate sensors in which a vibration gyro is excited on two axes which are aligned radially with respect to a major axis, for which purpose a primary and a secondary control loop having appropriate transducers are provided on the vibration gyro. These control loops may include various analog and digital circuits, with the analog circuits and the vibration gyro having tolerances, so that adjustment is necessary, at least during the production of the rotation rate sensor. The individual circuits then access the stored data during subsequent operation.
Furthermore, EP 1 189 025 A2 and U.S. Pat. No. 5,313,835 have disclosed data such as this being stored in an EEPROM. For safety reasons, the data is stored in a duplicated (redundant) form in EP 1 189 025 A2, so that the correctness of the data that is read can be checked by comparison. In addition, only one data storage process is provided during the production of the rotation rate sensor.
In the case of a rotation rate sensor which has been disclosed in U.S. Pat. No. 5,826,204, a non-volatile memory is provided in an associated electronic controller and has written to it table values which change as the “learning success” of the controller progresses. There is therefore fundamentally a risk that, in poor circumstances, incorrect data may also be written to the volatile memory.
Furthermore, it may be necessary to match characteristics of the rotation rate sensor to the respectively intended purpose, for example by presetting parameter sets for filters.
The rotation rate sensor according to the invention is characterized in that the memory is arranged such that the data for in each case one group can be written and read independently of the data of the other groups, and in that a checksum is formed over the data for in each case one group, is stored in the non-volatile memory, and is used for checking during reading. The non-volatile memory is preferably an EEPROM or a flash EEPROM.
The invention makes it possible to write the data in each of the individual groups to the non-volatile memory, and to edit it, in a mutually independent manner, at different times. By way of example, the adjustment data can thus be stored in the nonvolatile memory towards the end of the production process, while parameter sets which relate to the use of the rotation rate sensor, for example the vehicle type in which the rotation rate sensor is intended to be installed, are stored later, by the user.
All of the data which in any way governs the operation of the rotation rate sensor can be stored in the non-volatile memory. In particular, provision is made in the case of the rotation rate sensor according to the invention for the adjustment data and/or parameter sets for filters and/or value limits for self-testing of the rotation rate sensor to be stored.
One development of the rotation rate sensor according to the invention comprises a software emulation program also being stored in the non-volatile memory.
The invention allows numerous embodiments. One of these will be described in the following text and is illustrated schematically in a number of figures in the drawing, in which:
The example of use shown in
Since this is not necessary for understanding of the invention, the vibration gyro 1 and the sensor module 2 will not be explained in any more detail. Since the rotation rate sensor is relevant to safety, monitoring is provided for correct operation of the microcomputers 3, 5, in particular the program execution.
For safety reasons, monitoring is carried out continuously in the rotation rate sensor during operation, for example by variables being monitored to determine whether they have overshot or undershot their value ranges. The limits of these value ranges may differ from one application to another. Limits L1 to Ln such as these are therefore likewise stored with an associated identifier IL and a checksum ChSL in the EEPROM 8. Finally, a program for software emulation is also stored in the EEPROM 8.
Number | Date | Country | Kind |
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103 29 500 | Jun 2003 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2004/051054 | 6/8/2004 | WO | 00 | 12/28/2005 |
Publishing Document | Publishing Date | Country | Kind |
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WO2005/001383 | 1/6/2005 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5226321 | Varnham et al. | Jul 1993 | A |
5313835 | Dunn | May 1994 | A |
5617176 | Matsuzawa et al. | Apr 1997 | A |
5826204 | Ulm | Oct 1998 | A |
6647301 | Sederlund et al. | Nov 2003 | B1 |
20050022596 | Lehureau et al. | Feb 2005 | A1 |
Number | Date | Country |
---|---|---|
43 40 719 | Jun 1995 | DE |
42 42 557 | Oct 1997 | DE |
0 461 761 | Jun 1994 | EP |
1 189 025 | Mar 2002 | EP |
Number | Date | Country | |
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20060195290 A1 | Aug 2006 | US |