System, a processing unit, a method and a computer program product for monitoring sensors

• US 9,672,731 B2
• Filed: 12/27/2011
• Issued: 06/06/2017
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: K.Mizra LLC
• Original Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Inventors: Vonder, Matthijs Raymond, Langius, Erik Alle Fokko, Van Der Waaij, Bram Dirk
• Primary Examiner(s): Feild, Joseph
• Assistant Examiner(s): POINT, RUFUS C
• Application Number:
  US13/976,148
• Publication Number:
  US 20130328694A1
• Time in Patent Office: 1,988 Days
• CPC Class Codes: G08B 29/126 of annunciator circuits
• CPC Class Codes: G08C 25/00 Arrangements for preventing or correcting errors; Monitoring arrangements
• CPC Class Codes: H04Q 2209/823 where the data is sent when the measured values exceed a threshold, e.g. sending an alarm
• CPC Class Codes: H04Q 2209/86 Performing a diagnostic of the sensing device
• CPC Class Codes: H04Q 9/02 Automatically-operated arrangements

Abstract

The invention relates to a sensor monitoring system comprising at least one sensor (101, 102, 103) and a processing unit (150), wherein the sensor is arranged to transmit during a plurality of successive time periods data items to the processing unit and the processing unit is arranged to receive the data items from the said at least one sensor, the processing unit being further arranged for: determining for at least some time periods from the said plurality of successive time periods a number of corresponding data items; comparing between the at least some time periods the number of the corresponding data items; deducing for the at least some time periods a parameter associated with a variation in the number of data items per said some time periods. The invention further relates to a processing unit, and a method and a computer program for sensor monitoring.

Claims

1. A sensor monitoring system comprising at least one sensor and a processing unit comprising a buffer, wherein the sensor transmits data items autonomously, each of the data items comprising at least one sensor value, and is arranged to transmit during a plurality of successive time periods data items to the processing unit and the processing unit is arranged to receive the data items from the said at least one sensor and the buffer is arranged to buffer an amount of data items, the processing unit being further arranged for:

determining for two or more time periods from the said plurality of successive time periods a number of corresponding data items received during an expected waiting time;

detecting a duration (Delta) between the successive transmissions of the data items;

setting the expected waiting time for determining the number of data items based on the detected duration and the amount of data items the buffer is arranged to buffer;

comparing between the two or more time periods the number of the corresponding data items; and

deducing for the two or more time periods a measure of change in the number of data items per said two or more time periods.

2. The sensor monitoring system according to claim 1, wherein said determining, comparing and deducing is carried out for each time period forming the said plurality of time periods.

3. The sensor monitoring system according to claim 1, wherein the said measure of change is used for triggering an alarm when the measure of change exceeds a threshold.

4. The sensor monitoring system according to claim 3, wherein a value of the threshold is pre-determined, or wherein a value of the threshold is determined dynamically.

5. The sensor monitoring system according to claim 1, wherein the processing unit comprises a buffer for buffering the data items is an adjustable buffer.

6. The sensor monitoring system according to claim 1, wherein the at least one sensor is configured for transmitting the said data items wirelessly.

7. The sensor monitoring system according to claim 1, wherein a maximum allowable value (Dmax) is defined for the said duration.

8. The sensor monitoring system according to claim 1, wherein a minimum allowable value (Dmin) is defined for the said duration.

9. The sensor monitoring system according to claim 1, wherein the processing unit is further arranged to assign data acquisition window corresponding to a duration of a number of successive data transmission events.

13. The system of claim 1 comprising a previously presented time period having a respective data item receiving rate;

and the processing unit compares the previously presented time period data item receiving rate to a historic rate to calculate a measure of change.

14. The system of claim 1 wherein the processing unit comprises a programmable timer;

and

the programmable timer determines the expected waiting time based on the detected duration and the amount of data items the buffer is arranged to buffer.

15. The sensor monitoring system of claim 1 wherein the processing unit is arranged for:

determining for the two or more time periods from the said plurality of successive time periods sample rate of the sensor as a typical rate at which data items are received from the sensor;

comparing between the two or more time periods the corresponding sample rates; and

deducing for the two or more time periods a measure of change in the sample rates per said two or more time periods.

16. The sensor monitoring system of claim 1 wherein the processing unit is configured for determining, based on the detected duration, a time period for determining the number of transmitted data items.

17. The sensor monitoring system of claim 1 wherein the expected waiting time for determining the number of data items is based on the detected duration multiplied by the amount of data items the buffer is arranged to buffer.

18. The sensor monitoring system of claim 1 wherein the processing unit is further arranged for:

setting the waiting time at a pre-determined value;

determining whether data items have been transmitted during the waiting time; and

if no data items have been transmitted during the waiting time, increase the waiting time.

19. The sensor monitoring system of claim 1 wherein the deducing comprises calculating a changeability value with the equation

changeability value =(N_received—

N_expected)/N_expected;

wherein

N_expected is the number of data items expected to be received during the expected waiting time in a first time period; and

N_received is the received number of data items during the expected waiting time in a second time period, the second time period following the first time period.

20. The sensor monitoring system of claim 1 wherein he data items are packets having a header and a payload, the payload comprising one or more sensor values.

10. A processing unit comprising a buffer, the processing unit for use in a sensor monitoring system comprising at least one sensor, wherein the sensor transmits data items autonomously, each of the data items comprising at least one sensor value, and is arranged to transmit during a plurality of successive time periods data items to the processing unit and the processing unit is arranged to receive the data items from the said at least one sensor being further arranged for:

a. determining for two or more time periods from the said plurality of successive time periods a number of corresponding data items received during an expected waiting time;

b. comparing between the two or more time periods the number of the corresponding data items;

c. detecting a duration (Delta) between the successive transmissions of the data items;

d. setting the expected waiting time for determining the number of data items based on the detected duration and the amount of data items the buffer is arranged to buffer; and

e. deducing for two or more time periods a measure of change in the number of data items per said two or more time periods.

11. A method for monitoring a sensor system comprising at least one sensor and a processing unit comprising a buffer, wherein the sensor transmits data items autonomously, each of the data items comprising at least one sensor value, and is arranged to transmit during a plurality of successive time periods data items to the processing unit and the processing unit is arranged to receive the data items from the said at least one sensor and the buffer is arranged to buffer an amount of data items, the method comprising the steps of:

determining for two or more time periods from the said plurality of successive time periods a number of corresponding data items received during an expected waiting time;

detecting a duration (Delta) between the successive transmissions of the data items;

setting the expected waiting time for determining the number of data items based on the detected duration and the amount of data items the buffer is arranged to buffer;

comparing between the two or more time periods the number of the corresponding data items;

deducing for the two or more time periods a measure of change in the number of data items per said two or more time periods.

12. A computer program product comprising instructions for causing a processor to carry out the steps of the method as is claimed in claim 11.