US 7,031,780 B2 · Sensor system and method for determining system states

Abstract

Method for determining a state variable x from at least one sensor value by a cost function prepared for a measured value y for implementation in an arithmetic unit of a sensor system having at least one sensor and wherein the cost function depends on the respective state x to be measured and gives a deviation of an actual measured value from the calibration as a function of state x in order to determine the sought state x from this minimum. For the cost function, at least one approximation function is set up on the basis of at least one approximation region within the state region x, by which an approximation of the cost function is carried out with approximation functions with negligible error, wherein the sums of the approximation regions cover the entire relevant state region, and at least all local minima are determined on the basis of the approximation, in a selection of approximation regions, wherein optionally a global minimum is determined from the comparison of local minima.

Claims20

Dependent claims

A method for the determination of an unknown state variable (x) of a system (1) from a measured value (y) for implementation in an arithmetic unit (4) of a sensor system (2), said method comprising the steps of:

obtaining a measured value (y) from a sensor system (2);
establishing a cost function which indicates deviation of the measured value (y) from calibration functions as a function of the unknown state variable (x);
establishing a relevant state region from the measured value (y);
establishing approximation regions (30) and establishing for each approximation region at least one predetermined approximation function of the cost function in which a sum of the approximation function covers the entire relevant state region;
determining all local minima (40) of said at least one approximation function of the cost function in each of said approximation regions such that each minimum is determined in a respective approximation region;
and
determining a global minimum (50) by comparing said local minima wherein said global minimum represents the state variable (x) of the system (1).

4 more elements

A method for the determination of an unknown state variable (x) from a measured value (y) for implementation in an arithmetic unit (4) of a sensor system (2), said method comprising the steps of:

obtaining a measured value (y) from a sensor system (2);
establishing a cost function which indicates the deviation of the measured value (y) from calibration functions as a function of the unknown state variable (x);
establishing a relevant state region from the measured value (y);
selecting an approximation function of the cost function from a selection of approximation functions of the cost function;
establishing a selection of approximation regions (30) from the approximation function selected from the selection of approximation functions in which the sum of the approximation regions covers the entire relevant state region;
determining all local minima (40) within the selection of approximation regions within the state region such that each minimum is determined by a sum of a start vector and a weighted difference of the measured value from the calibration as a function of said start vector, and
determining a global minimum (50) by comparing said local minima wherein said global minimum represents the state variable (x) of the system (1).

4 more elements

Dependencies are inferred from the claim text.

Sensor system and method for determining system states

Life of this patent

Sensor system and method for determining system states

Life of this patent

Abstract

Claims20