METHOD OF CALIBRATING A SENSOR, IN PARTICULAR A YAW RATE SENSOR

• US 20090248346A1
• Filed: 09/01/2006
• Published: 10/01/2009
• Est. Priority Date: 09/02/2005
• Status: Active Grant

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Herbst, Ralf, Fennel, Helmut, Kitz, Rainer
• Granted Patent: US 7,920,981 B2
• Time in Patent Office: Days
• US Class Current: 702/96
• CPC Class Codes: B60T 2250/06 Sensor zero-point adjustment; Offset compensation
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory

Abstract

The invention relates to a method of calibrating a sensor, in particular a yaw rate sensor, in which sensor values (Y_sensor) and associated temperature values (T) are stored in the shape of reference points in a non-volatile memory of the sensor, in which case the values (Y_sensor, T) are determined during a calibration mode in which the sensor is exposed to a predefined temperature profile. In order to further improve the accuracy of the calibration, the invention discloses that the values (Y_sensor, T) determined in the calibration mode are used to determine coefficients (C₀, . . . , C_n-1, C_n) of a polynomial of nth order, and these coefficients are stored.

Claims

1-6. -6. (canceled)

7. A method of calibrating a sensor, the method comprising:

performing a calibration mode in which the sensor is exposed to a predefined temperature profile;

determining sensor values and associated temperature values during the calibration mode; and

storing the sensor values (Y_sensor) and associated temperature values (T) in a non-volatile memory of the sensor;

using the sensor values (Y_sensor, T) determined in the calibration mode to determine coefficients (C₀, . . . , C_n-1, C_n) of a polynomial of nth order; and

storing the coefficients.

8. The method of claim 7, wherein a compensation value Y_Offset is calculated using a polynomial of nth order by means of the determined and stored coefficients (C₀, . . . , C_n-1, C_n) during operation of the sensor.

9. The method of claim 8, wherein an error-corrected sensor value Y_Cluster is determined by means of the compensation value Y_Offset and the measured sensor value during operation of the sensor.

10. The method of claim 7, wherein error-corrected sensor values Y_Cluster and associated temperature values T are determined for calculation of the coefficients of the polynomial of nth order during the operation of the sensor.

11. The method of claim 10, wherein the determined and stored coefficients (C₀, . . . , C_n-1, C_n) are used to calculate a compensation value Y_Offset by means of a polynomial of third order during operation of the sensor.

12. The method of claim 7, wherein the sensor is a yaw rate sensor.

13. The method of claim 12, wherein the sensor is provided in a vehicle.

14. A sensor comprising:

a sensor element (11);

an electronic processing unit (10);

a data bus;

means for mode change-over with at least one calibration mode and one operating mode;

a temperature sensor (12);

a non-volatile memory (14), wherein the non-volatile memory stores sensor values from the sensor element (11) and associated temperature values from the temperature sensor; and

an algorithm which produces coefficients of a polynomial of nth order based on the stored sensor values and associated temperature values.