Method and arrangement for indirectly determining fill characteristics of a fluid tank on a marine vessel

• US 20040149003A1
• Filed: 01/31/2003
• Published: 08/05/2004
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: AB Volvo
• Original Assignee: AB Volvo
• Inventors: Nestvall, Per
• Granted Patent: US 7,059,167 B2
• Time in Patent Office: Days
• US Class Current: 73/1.73
• CPC Class Codes: G01F 23/802 Particular electronic circuits for digital processing equipment
• CPC Class Codes: G01F 25/0084 for measuring volume
• CPC Class Codes: G01F 25/22 Checking proper indicating of discrete level by floats

Abstract

Method and arrangement for accommodating indirect ascertainment of fill-characteristics of fluid tanks on marine vessels. The invention includes providing an experientially-based mapping of volume characteristics of a fluid tank positioned on a marine vessel that are correlated with respect to measurable fluid surface positions within the fluid tank. In consideration of this volume characteristic mapping, fluid fill condition information is output for operator use based on quantification of a parameter other than sensed fluid level in the fluid tank. While it is contemplated that the other parameter may be any characteristic that readily reads back to the volume characteristic mapping, it is particularly advantageous, and a preferred embodiment of the invention, that the other parameter be a volumetric quantification of fluid consumed out of the tank that can be compared to an earlier ascertained tank volume.

Claims

1. A method for accommodating indirect ascertainment of fill-characteristics of fluid tanks on marine vessels, the method comprising the steps of:

providing an experientially-based mapping of volume characteristics of a fluid tank positioned on a marine vessel correlated with respect to measurable fluid surface positions within the fluid tank; and

outputting fluid fill condition information for operator use based on quantification of a parameter other than sensed fluid level in the fluid tank based on a function of that other parameter being compared to the experientially-based mapping of volume.

2. The method as recited in claim 1, further comprising:

calibrating the accuracy of the output of fluid fill condition information by occasional adjustment of the map of volume characteristics versus measured fluid surface position; and

assuring accuracy of the calibration by limiting performance of the calibrating step to when vessel conditions are amenable thereto.

3. The method as recited in claim 2, further comprising:

limiting execution of the calibration process to instances when the vessel is at a standstill.

4. The method as recited in claim 2, further comprising:

limiting execution of the calibration process to travel periods when the attitude of the vessel is substantially constant.

5. The method as recited in claim 2, further comprising:

limiting execution of the calibration process to periods when fluid in the fluid tank is substantially static.

6. The method as recited in claim 5, further comprising:

considering vessel attitude when performing the calibration process.

7. A method for accommodating indirect ascertainment of fill-characteristics of fluid tanks on marine vessels, the method comprising the steps of:

mapping volume characteristics, that have been obtained on an experiential basis, of a fluid tank positioned on a marine vessel; and

outputting fluid fill condition information for operator use based on quantification of a parameter other than sensed fluid level in the fluid tank based on a function of that other parameter being compared to the experientially-based mapping of volume.

8. The method as recited in claim 7, further comprising:

correlating the volume characteristics versus sensable fluid surface level positions within the fuel tank and thereby enabling corrective calibration of the output of fluid fill condition information to the operator.

9. The method as recited in claim 8, further comprising:

causing corrective calibration of the output of fluid fill condition information to automatically occur at preselected intervals.

10. The method as recited in claim 8, further comprising:

requiring corrective calibration of the output of fluid fill condition information to be operator initiated.

11. The method as recited in claim 7, further comprising:

basing the experientially based mapping of volume characteristics of the fluid tank on a known fluid volume contained within the fluid tank and a correlating sensed fluid surface level position within the fuel tank.

12. The method as recited in claim 11, further comprising:

sensing the fluid surface level position within the fuel tank utilizing a mechanically-based detector.

13. The method as recited in claim 11, further comprising:

sensing the fluid surface level position within the fuel tank utilizing a wave-based detector.

14. The method as recited in claim 13, further comprising:

utilizing a wave-based detector that optically senses the fluid surface level position within the fuel tank.

15. The method as recited in claim 13, further comprising:

utilizing a wave-based detector that utilizes sound waves to sense the fluid surface level position within the fuel tank.

16. The method as recited in claim 7, further comprising:

utilizing fluid consumption as the parameter upon which the outputting of fluid fill condition information is based.

17. The method as recited in claim 16, further comprising:

measuring fuel consumed thereby enabling operator readings of remaining fuel quantity in an on-board fuel tank.

18. The method as recited in claim 16, further comprising:

measuring water consumed thereby enabling operator ascertainments of remaining water quantity contained within an on-board water tank.

19. A calibrating liquid-level measurement arrangement for a marine vessel comprising:

a liquid storage tank positioned on a marine vessel;

a liquid surface position sensing device in communication with a processor and adapted to provide position-indicating data regarding a sensed position of a liquid surface in said liquid storage tank to said processor;

an operator input to said processor adapted to accept quantitative information regarding liquid amounts added to said liquid storage tank;

a liquid withdrawal arrangement in fluid communication with said liquid storage tank, said liquid withdrawal arrangement having a capability for measuring a volumetric amount of liquid withdrawn from said liquid storage tank via said liquid withdrawal arrangement; and

said processor adapted to compare the sensed position of the liquid surface in said liquid storage tank with the measured volumetric amount withdrawn from said tank thereby enabling correlation between an amount of liquid stored in said liquid storage tank and a corresponding sensed position by said liquid surface position sensing device.

20. A method for calibrating a liquid-level measurement arrangement for a marine vessel comprising:

sensing an initial position of a liquid surface in a marine vessel'"'"'s liquid storage tank that is at least partially filled with an amount of liquid;

measuring an amount of liquid withdrawn from said liquid storage tank and sensing a subsequent position of the liquid surface in said liquid storage tank thereby enabling an assignment of the volume of liquid stored in said liquid storage tank defined between said initial and subsequent positions; and

repeating a series of such sensing and measuring steps thereby enabling a mapping of stored liquid volume inside said liquid storage tank with respect to an axis defined by a series of detectable liquid top surface position.

21. The method as recited in claim 20, further comprising:

utilizing, in a following sensing and measuring step, said subsequent sensed position as an initial sensed position of the liquid top surface thereby enabling a substantially continuous mapping of stored liquid volume inside said liquid storage tank.

22. The method as recited in claim 20, further comprising:

quantifying an amount of liquid added to a liquid storage tank positioned on a marine vessel; and

correlating said quantified amount of liquid added to said liquid storage tank with a map-derived amount using sensed positions of the liquid surface in said liquid storage tank before and after the addition of said quantified amount of liquid.

23. The method as recited in claim 20, further comprising:

correcting said map-derived amount to said quantified amount thereby calibrating the mapping of stored liquid volume inside said liquid storage tank.

24. The method as recited in claim 20, further comprising:

initializing said mapping of stored liquid volume inside said liquid storage tank with respect to said axis along which said liquid surface positions are taken sensing an initial position corresponding to an essentially empty tank having substantially no liquid surface therein;

filling, to a substantial extent, said liquid storage tank with a measured mount of liquid; and

sensing a subsequent position of the liquid surface in said substantially full liquid storage tank and thereby enabling an assignment of a substantial total volume of said liquid storage tank defined between liquid surface positions corresponding to essentially empty and substantially full tank conditions.

25. The method as recited in claim 20, further comprising:

enabling accurate readings of tank contained volumes based on liquid surface position along said axis based on an historically-based and calibrated mapping of tank volume with respect to axis position of sensed liquid surface position therealong.

26. The method as recited in claim 20, further comprising:

enabling the utilization of non-uniformly shaped tanks with respect to said axis along which said liquid surface positions are taken.

27. The method as recited in claim 20, further comprising:

enabling the utilization of non-uniformly shaped tanks with respect to said axis along which said liquid surface positions are taken and non-matched liquid surface position sensors thereby increasing the universality of a pre-configured liquid storage tank arrangement positioned on a marine vessel.

28. The method as recited in claim 27, further comprising:

enabling the utilization of non-rigid liquid storage tanks that are influenced in shape, at least partially, by the environment in which said tanks are placed for operation.

29. The method as recited in claim 20, further comprising:

causing the sensing of the liquid surface positions in the marine vessel'"'"'s liquid storage tank to preferentially be taken when the marine vessel has been traveling at a substantially constant speed for a predetermined period of time.

30. The method as recited in claim 20, further comprising:

causing the sensing of the liquid surface positions in the marine vessel'"'"'s liquid storage tank to only be taken when travel conditions of the marine vessel have satisfied a predetermined criteria.

31. The method as recited in claim 20, further comprising:

permitting the sensing of liquid surface positions in the marine vessel'"'"'s liquid storage tank only when travel conditions of the marine vessel have satisfied a predetermined criteria.

32. The method as recited in claim 20, further comprising:

permitting the sensing of liquid surface positions in the marine vessel'"'"'s liquid storage tank preferentially when the marine vessel is stopped.

33. The method as recited in claim 20, further comprising:

permitting the sensing of liquid surface positions in the marine vessel'"'"'s liquid storage tank preferentially when a longitudinal axis of the marine vessel is off-set no more than a predetermined amount from horizontal.

34. The method as recited in claim 20, further comprising:

permitting the sensing of liquid surface positions in the marine vessel'"'"'s liquid storage tank preferentially when a longitudinal axis of the marine vessel is off-set no more than a predetermined amount from a static floating inclination of the marine vessel.

35. The method as recited in claim 20, further comprising:

configuring the liquid storage tank on the marine vessel as a fuel tank for a propulsion system of the vessel.

36. The method as recited in claim 35, further comprising:

permitting non-measured draws on the fuel tank containing liquid storage tank for consumption other than by propulsion systems of the vessel.

37. The method as recited in claim 36, further comprising:

blending out the effects of consumption by non-measured draws from the fuel tank on mapped tank volumes corresponding to liquid surfaced positions sensed along said axis.

38. The method as recited in claim 20, further comprising:

displaying a mapped amount of liquid remaining in said tank in a conventional manner thereby avoiding confusion by an observing operator.