SYSTEM, METHOD, AND DEVICE FOR MEASURING AND REPORTING CHANGING LEVELS OF LIQUIDS IN STORAGE TANKS

• US 20140347194A1
• Filed: 08/11/2014
• Published: 11/27/2014
• Est. Priority Date: 09/13/2006
• Status: Abandoned Application

• Current Assignee: Florida Power & Light Company (NextEra Energy, Inc.), TrackPoint Systems, LLC (Truck-Lite Holdings 2 Corp.)
• Original Assignee: Florida Power & Light Company (NextEra Energy, Inc.), TrackPoint Systems, LLC (Truck-Lite Holdings 2 Corp.)
• Inventors: Schnitz, Benjamin A., Masters, Claude T., Survant, George D.
• Application Number:
  US14/456,661
• Publication Number:
  US 20140347194A1
• Time in Patent Office: Days
• US Class Current: 340/870.05
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30
• CPC Class Codes: G01F 23/80 Arrangements for signal processing
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 20/203 Inventory monitoring
• CPC Class Codes: G08B 21/182 Level alarms, e.g. alarms responsive to variables exceeding a threshold
• CPC Class Codes: G08C 17/02 using a radio link

Abstract

A system for measuring and reporting changing levels of liquids in a storage tank includes a sensing device having a fluid level sensor, an accelerometer, a wireless transceiver, and a microcontroller for detecting the volume of liquid in the storage tank in response to determining that the storage tank is not moving and sending an alert message if the volume of liquid in the storage tank has changed from a previous volume by a threshold amount. The system also includes a central tracking computer having a tracking database and being interfaced to the Internet, and a master control unit attached to the storage tank. The master control unit is for: receiving the alert message from the sensing device; obtaining the location of the storage tank; and communicating the alert message and the location of the storage tank to the central tracking computer for storage in the tracking database.

Claims

1. A method of operating an autonomous fluid level sensing device, comprising:

detecting, using a fluid level sensor, a level of liquid in a storage tank, in response to determining that the storage tank is not moving; and

sending, using a sensing device transceiver, a message based on the level of liquid in the storage tank.

2. The method of operating an autonomous fluid level sensing device of claim 1, wherein determining that the storage tank is not moving comprises:

taking a plurality of samples of at least one of an x-axis, a y-axis, and a z-axis of an accelerometer;

determining a standard deviation of the plurality of samples of the at least one of the x-axis, the y-axis, and the z-axis of the accelerometer;

determining that the storage tank is not moving when;

the standard deviation of the plurality of samples of the at least one of the x-axis, the y-axis, and the z-axis of the accelerometer is less than a predetermined constant value and the storage tank was previously determined to be still;

or

the storage tank was previously determined to be in motion but a percentage of the plurality of samples of the at least one of the x-axis, the y-axis, and the z-axis of the accelerometer indicating motion over a plurality of sample cycles is less than a stillness threshold percentage value.

3. The method of operating an autonomous fluid level sensing device of claim 1, further comprising initializing the fluid level sensor and the sensing device transceiver in response to detecting, using a magnetic detector, that a magnet has been positioned in proximity to the magnetic detector.

4. The method of operating an autonomous fluid level sensing device of claim 1, further comprising converting, using a sensing device microcontroller, the level of liquid in the storage tank into a volume of liquid in the storage tank.

5. The method of operating an autonomous fluid level sensing device of claim 4, wherein the message based on the level of liquid in the storage tank is the volume of liquid in the storage tank.

6. The method of operating an autonomous fluid level sensing device of claim 4, wherein the message based on the level of liquid in the storage tank is an alert message that the volume of liquid in the storage tank has changed, and wherein sending the alert message is performed when the volume of liquid in the storage tank has changed from a previous volume of liquid in the storage tank by a threshold amount.

7. The method of operating an autonomous fluid level sensing device of claim 4, further comprising sending, using the sensing device transceiver, a status report message with the volume of liquid in the storage tank when the volume of liquid in the storage tank has not changed for a predetermined amount of time.

8. The method of operating an autonomous fluid level sensing device of claim 4, further comprising:

detecting, using a temperature sensor, an ambient temperature value of the autonomous fluid level sensing device; and

adjusting the volume of liquid in the storage tank based on the ambient temperature value.

9. The method of operating an autonomous fluid level sensing device of claim 1 wherein the sensing device transceiver is a wireless transceiver.

10. An autonomous fluid level sensing device comprising:

a fluid level sensor for detecting a level of liquid in a storage tank; and

a means for determining whether the storage tank is moving;

a sensing device transceiver; and

a sensing device microcontroller in communication with the fluid level sensor, the means for determining whether the storage tank is moving, and the sensing device transceiver, the sensing device microcontroller executing instructions for;

detecting, using the fluid level sensor, the level of liquid in the storage tank, in response to determining, using the means for determining whether the storage tank is moving, that the storage tank is not moving; and

sending, using the sensing device transceiver, a message based on the level of liquid in the storage tank.

11. The wireless autonomous fluid level sensing device of claim 10, wherein the means for determining whether the storage tank is moving comprises an accelerometer, and wherein the sensing device microcontroller executes further instructions for:

taking a plurality of samples of at least one of an x-axis, a y-axis, and a z-axis of the accelerometer;

determining a standard deviation of the plurality of samples of the at least one of the x-axis, the y-axis, and the z-axis of the accelerometer; and

determining that the storage tank is not moving when;

the standard deviation of the plurality of samples of the at least one of the x-axis, the y-axis, and the z-axis of the accelerometer is less than a predetermined constant value and the storage tank was previously determined to be still;

or

the storage tank was previously determined to be in motion but a percentage of the plurality of samples of the at least one of the x-axis, the y-axis, and the z-axis of the accelerometer indicating motion over a plurality of sample cycles is less than a stillness threshold percentage value.

12. The wireless autonomous fluid level sensing device of claim 10, wherein the sensing device microcontroller executes further instructions for converting the level of liquid in the storage tank into a volume of liquid in the storage tank.

13. The wireless autonomous fluid level sensing device of claim 12, wherein the message based on the level of liquid in the storage tank is an alert message that the volume of liquid in the storage tank has changed, and wherein sending the alert message is performed when the volume of liquid in the storage tank has changed from a previous volume of liquid in the storage tank by a threshold amount.

14. The wireless autonomous fluid level sensing device of claim 12, wherein the sensing device microcontroller executes further instructions for sending, using the sensing device transceiver, a status report message with the volume of liquid in the storage tank when the volume of liquid in the storage tank has not changed for a predetermined amount of time.

15. The wireless autonomous fluid level sensing device of claim 12, further comprising a temperature sensor in communication with the sensing device microcontroller, the temperature sensor for detecting an ambient temperature value of the wireless autonomous fluid level sensing device, wherein the sensing device microcontroller further executes instructions for adjusting the volume of liquid in the storage tank based on the ambient temperature value.

16. The wireless autonomous fluid level sensing device of claim 10, further comprising a sensing device battery for use as a power source, and a power management circuit in communication with the sensing device battery and the sensing device microcontroller, the power management circuit providing voltage level detection, regulation, and control, and power switching for autonomous operation of the wireless autonomous fluid level sensing device.

17. The wireless autonomous fluid level sensing device of claim 10, further comprising a magnetic detector in communication with the sensing device microcontroller, wherein the sensing device microcontroller further executes instructions for initializing the fluid level sensor and the sensing device transceiver in response to detecting, using the magnetic detector, that a magnet has been positioned in proximity to the magnetic detector.

18. The wireless autonomous fluid level sensing device of claim 10, wherein the sensing device microcontroller further executes instructions for configuring a variable parameter in response to receiving, using the sensing device wireless transceiver, a configuration message.

19. The wireless autonomous fluid level sensing device of claim 10, further comprising an intrinsically safe barrier device for providing intrinsically safe communications between the sensing device microcontroller and the fluid level sensor.