Granted Patent B2

US 8,942,958 · App. 13/249,256 · Granted Jan 27, 2015

Abstract

Claims (43)

1. A method of calculating at least one sensor modelling coefficient for multiple sensor regions of operation, the method comprising:

defining a first sensor region of operation and at least one further sensor region of operation;

defining a first set of sensor modelling equations that comprise at least one sensor modelling coefficient for the first sensor region of operation, and at least one further set of sensor modelling equations that comprise at least one sensor modelling coefficient for the at least one further sensor region of operation;

calculating the at least one sensor modelling coefficient for the first sensor region of operation;

deriving at least one derivative equation for the at least one further sensor region of operation based at least partly on at least one defined inter-region boundary constraint, the first set of sensor modelling equations, and the at least one further set of sensor modelling equations;

calculating the at least one sensor modelling coefficient for the at least one further sensor region of operation based at least partly on the at least one derivative equation; and

storing the calculated coefficient for the first sensor region and the calculated coefficient for the at least one further sensor region in a sensor system for converting a digitized sensor signal to an estimated sensor output signal.

2. The method of claim 1 , wherein the method comprises defining as the first sensor region of operation a region comprising a tighter specification than a specification of the at least one further sensor region of operation, wherein the tighter specification means that the at least one sensor modelling coefficient for the first sensor region of operation is required to be more accurate than the at least one sensor modelling coefficient for the at least one further sensor region of operation.

3. The method of claim 1 , wherein the at least one inter-region boundary constraint comprises at least one of:

a sensor modelling equation for the first and at least one further sensor region of operation that are set to be equal at a junction between the two sensor regions; and

a rate of change in a plurality of curves for the at least one sensor modelling equation in relation to at least one sensor measurement is set to be equal.

4. The method of claim 1 , further comprising:

calculating the at least one sensor modelling coefficient of the at least one further sensor region of operation additionally based at least partly on at least one from a group of:

at least one data reading;

at least one mean coefficient reading; and

at least one further constraint based on a higher order differential.

5. The method of any claim 1 , wherein the method comprises calculating at the least one sensor modelling coefficient for the first sensor region of operation by way of:

taking at least one data reading;

establishing at least one equation using the at least one data reading in a form of at least one unknown coefficient; and

solving the at least one equation for the at least one unknown coefficient to establish a curve fit.

6. The method of claim 1 , wherein the method comprises a method of calculating at least one sensor modelling coefficient for multiple sensor regions of operation for at least one of a temperature sensor and a pressure sensor.

7. The method of claim 1 , further comprising:

reading the stored coefficient for the first sensor region and the stored coefficient for the at least one further sensor region calculated;

estimating at least one estimated sensor output signal using the read stored coefficients; and

outputting an at least one estimated sensor output signal.

8. An apparatus comprising at least one signal processing module arranged to calculate at least one sensor modelling coefficient for multiple sensor regions of operation, the at least one signal processing module being arranged to:

define a first sensor region of operation and at least one further sensor region of operation;

define a first set of sensor modelling equations that comprise at least one sensor modelling coefficient for the first sensor region of operation, and at least one further set of sensor modelling equations that comprises at least one sensor modelling coefficient for the at least one further sensor region of operation;

calculate at least one sensor modelling coefficient for the first sensor region of operation;

derive at least one derivative equation for the at least one further sensor region of operation based at least partly on at least one defined inter-region boundary constraint, the first set of sensor modelling equations, and the at least one further set of sensor modelling equations;

calculate the at least one sensor modelling coefficient for the at least one further sensor region of operation based at least partly on the at least one derivative equation; and

store the calculated coefficient for the first sensor region and the calculated coefficient for the at least one further sensor region for use in converting at least one digitized sensor signal to an estimated sensor output.

9. The apparatus of claim 8 , wherein the apparatus is an integrated circuit device.

10. A sensor system, comprising:

an analog to digital converter that receives a temperature voltage signal and a pressure voltage signal and converts the temperature and pressure voltage signals to digital temperature and pressure voltage signals; and

a signal processor that receives the digital temperature and pressure voltage signals and converts the digital temperature and pressure voltage signals to temperature and pressure values using at least first and second modelling equations having respective first and second sets of coefficients,

wherein the first set of coefficients is generated by calculating at least one sensor modelling coefficient for multiple sensor regions of operation, comprising:

defining a first sensor region of operation and at least one further sensor region of operation;

defining a first set of sensor modelling equations that comprise at least one sensor modelling coefficient for the first sensor region of operation, and at least one further set of sensor modelling equations that comprises at least one sensor modelling coefficient for the at least one further sensor region of operation;

calculating the at least one sensor modelling coefficient for the first sensor region of operation;

deriving at least one derivative equation for the at least one further sensor region of operation based at least partly on at least one defined inter-region boundary constraint, the first set of sensor modelling equations, and the at least one further set of sensor modelling equations; and

calculating the at least one sensor modelling coefficient for the at least one further sensor region of operation based at least partly on the at least one derivative equation.

11. The sensor of claim 10 , further comprising a memory for storing the first and second sets of coefficients.

Assignments (26)