Method for correcting non-linearities of an output signal of an electrical component, particularly a measuring transducer

• US 20030163270A1
• Filed: 02/04/2003
• Published: 08/28/2003
• Est. Priority Date: 02/04/2002
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Opitz, Bernhard, Wieja, Thomas
• Granted Patent: US 6,901,355 B2
• Time in Patent Office: Days
• US Class Current: 702/86
• CPC Class Codes: B60T 2250/06 Sensor zero-point adjustment; Offset compensation
• CPC Class Codes: F02D 2041/283 the sensor directly giving at least one digital reading
• CPC Class Codes: F02D 41/2496 the memory being part of a closed loop
• CPC Class Codes: F02D 41/28 Interface circuits
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory

Abstract

A method for correcting non-linearities of an output signal of an electrical component with the aid of a characteristics map that is defined by discrete interpolation points. In this context, the adjacent interpolation points of the characteristics map are ascertained as a function of at least one signal influencing the non-linearities of the output signal. Interpolation is carried out between these interpolation points, and a corresponding correction signal is ascertained as a function of the or each signal by an interpolation. The output signal of the electrical component is corrected as a function of the correction signal. To improve the correction of non-linear transfer characteristics and/or temperature responses of the electrical component, it is proposed that the or each signal for addressing the characteristics map be high-pass filtered, and the correction signal be ascertained as a function of the or each signal by the interpolation and a subsequent low-pass filtering.

Claims

1. A method for correcting non-linearities of an output signal of an electrical component with the aid of a characteristics map that is defined by discrete interpolation points, comprising:

ascertaining the interpolation points of the characteristics map that are adjacent as a function of at least one signal influencing the non-linearities of the output signal, wherein the at least one signal is for addressing the characteristics map;

performing an interpolation between the ascertained adjacent interpolation points;

determining a corresponding correction signal as a function of the at least one signal by the interpolation;

correcting the output signal of the electrical component being corrected as a function of the correction signal;

high-pass filtering the at least one signal; and

ascertaining the correction signal as a function of the at least one by the interpolation and a subsequent low-pass filtering.

2. The method as recited in claim 1, further comprising:

oversampling the at least one signal.

3. The method as recited in claim 1, wherein:

the high-pass filtering of the at least one signal is performed in accordance with a delta-sigma modulator.

4. The method as recited in claim 1, further comprising:

reducing a sampling rate of the at least one signal.

5. The method as recited in claim 1, further comprising:

reducing a sampling rate of the correction signal.

6. The method as recited in claim 4, wherein:

the reducing of the sampling rate of the at least one signal is performed by a decimation filter.

7. The method as recited in claim 5, wherein:

the reducing of the sampling rate of the correction signal is performed by a decimation filter.

8. A digital sensor evaluation circuit of an electrical component for correcting non-linearities of an output signal of the electrical component, the evaluation circuit comprising:

a characteristics-map memory in which discrete interpolation points of a characteristics map are stored;

an arrangement for ascertaining the interpolation points of the characteristics map that are adjacent as a function of at least one signal influencing the non-linearities of the output signal, the at least one signal being capable of addressing the characteristics map;

an arrangement for ascertaining a corresponding correction signal as a function of the at least one signal by an interpolation;

an arrangement for correcting the output signal of the electrical component as a function of the correction signal;

an arrangement for performing a high-pass filtering of the at least one signal; and

an arrangement for ascertaining the correction signal as a function of the at least one signal by the interpolation and a subsequent low-pass filtering.

9. The evaluation circuit as recited in claim 8, further comprising:

an arrangement for oversampling the at least one signal.

10. The evaluation circuit as recited in claim 8, further comprising:

a delta-signal modulator for performing the high-pass filtering of the at least one signal.

11. The evaluation circuit as recited in claim 8, further comprising:

an arrangement for reducing a sampling rate of the at least one signal.

12. The evaluation circuit as recited in claim 8, further comprising:

an arrangement for reducing a sampling rate of the correction signal.

13. The evaluation circuit as recited in claim 11, further comprising:

a decimation filter for performing the reducing of the sampling rate of the at least one signal.

14. The evaluation circuit as recited in claim 12, further comprising:

a decimation filter for performing the reducing of the sampling rate of the correction signal.

15. A measuring transducer for converting one of physical quantities and chemical quantities, detected by a sensor, into an electrical output signal, comprising:

a digital sensor evaluation circuit for correcting non-linearities of an output signal of the measuring transducer, the evaluation circuit including;

a characteristics-map memory in which discrete interpolation points of a characteristics map are stored,

an arrangement for ascertaining the interpolation points of the characteristics map that are adjacent as a function of at least one signal influencing the non-linearities of the output signal, the at least one signal being capable of addressing the characteristics map,

an arrangement for ascertaining a corresponding correction signal as a function of the at least one signal by an interpolation,

an arrangement for correcting the output signal of the electrical component as a function of the correction signal,

an arrangement for performing a high-pass filtering of the at least one signal, and

an arrangement for ascertaining the correction signal as a function of the at least one signal by the interpolation and a subsequent low-pass filtering.

16. A storage medium for storing a computer program that when executed on a computing element achieves a performance of:

ascertaining interpolation points of a characteristics map that are adjacent as a function of at least one signal influencing non-linearities of an output signal of an electrical component, wherein the at least one signal is for addressing the characteristics map;

performing an interpolation between the ascertained adjacent interpolation points;

determining a corresponding correction signal as a function of the at least one signal by the interpolation;

correcting the output signal of the electrical component being corrected as a function of the correction signal;

high-pass filtering the at least one signal; and

ascertaining the correction signal as a function of the at least one by the interpolation and a subsequent low-pass filtering.

17. The storage medium according to claim 16, wherein:

the computing element includes a microprocessor.