Clipped sensor data estimator

• US 20060052925A1
• Filed: 08/26/2005
• Published: 03/09/2006
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Siemens VDO Automotive Corporation (Siemens AG)
• Inventors: Andres, Robert M., McConnell, Douglas A.
• Granted Patent: US 7,643,921 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A method of estimating values beyond sensor limits accurately and simply includes the initial step of determining an actual slope utilizing measured data. An estimated slope is then determined as a percentage of the actual slope to provide an estimation of data values outside of the sensor limits until measured values return to within sensor limits. The estimation method according to this invention increases sensor range without sacrificing resolution with a desired accuracy.

Claims

1. A method of estimating values outside of sensor limits comprising the steps of:

a. determining an actual slope from measured data values within sensor limits;

b. determining an estimated slope based on the actual slope; and

c. estimating data values outside of the sensor limit based on the estimated slope.

2. The method as recited in claim 1, wherein data values are estimated according to the estimated slope until an actual measured data value falls within the sensor limits.

3. The method as recited in claim 1, wherein data values are estimated according to the estimated slope until reaching a desired limit value.

4. The method as recited in claim 1, wherein said estimated slope is a percentage of the actual slope.

5. The method as recited in claim 1, wherein the percentage of the actual slope is less than 100% of the actual slope.

6. The method as recited in claim 1, wherein the estimated slope is approximately 50% of the actual slope.

7. The method as recited in claim 1, wherein the estimated slope is determined in real time.

8. The method as recited in claim 1, wherein the estimated slope is determined after actual measured data returns to within sensor limits such that the estimated data values are symmetrical within a period where actual data values exceed the sensor limits.

9. A method of sensing vehicle acceleration comprising the steps of:

a. measuring vehicle acceleration with a sensor having limits less than an expected upper limit of acceleration values for measurement;

b. determining an actual slope based on values within the senor limits; and

c. estimating data outside of the sensor limits based on the actual slope.

10. The method as recited in claim 9, wherein said step of estimating data outside the sensor limits comprises determining an estimated slope beyond the sensor limits based on the actual slope.

11. The method as recited in claim 10, wherein the estimated slope is a fraction of the actual slope.

12. The method as recited in claim 11, wherein the estimated slope is approximately 50% of the actual slope.

13. The method as recited in claim 10, wherein the estimated slope is determined in real time.

14. The method as recited in claim 10, wherein the estimated slope is determined after an actual measured value is detected within the sensor limits.

15. The method as recited in claim 14, wherein the estimated slope is determined between a first time where an actual measured value is beyond the sensor limits and a second time where an actual measured value returns to within the sensor limits.

16. The method as recited in claim 15, including an ascending estimated slope and a descending estimated slope.

17. An occupant restraint system comprising:

an occupant restraint device;

a sensor to measure data indicative of vehicle operating conditions, wherein the sensor includes at least one limit beyond which no data is measured; and

a controller to receive signals from the sensor and to determine conditions that require actuation of the occupant restraint device, wherein data indicative of vehicle operating conditions beyond the at least one limit of the sensor are estimated such that the determination of conditions that require actuation of the occupant restraint device can be made beyond the at least one limit of the sensor.

18. The system as recited in claim 17, wherein the controller estimates the data outside the sensor limit by determining a slope of measured data within sensor limits and determining an estimated slope beyond the at least one sensor limit based on the estimated slope.

19. The system as recited in claim 18, wherein the estimated slope is a fraction of the determined slope to estimate data outside the sensor limit.