Apparatus and method for determining liquid levels

An apparatus for determining the quantity of a liquid in a liquid-containing tank, the tank having at least first and second attitudes relative to the gravity vector, comprising:

• at least N liquid-level sensing probes in a liquid-containing tank, each probe having a first and at least a second probe-specific liquid-quantity profile for a first and at least a second attitude of the probe relative to the gravity vector;
• stored-program controlled processor means for determining a value representative of the fraction of each of said N probes immersed in the liquid;
• and
• memory means containing N and N' sets of M sequential storage locations containing liquid-quantity profile information for respective ones of said N liquid-level sensors for their respective first and second attitudes;
• said processor means addressing said memory means to determine liquid-quantity information for each of said N liquid-level sensing probes, said processor means addressing said memory means at a specific probe-quantity address, said probe- quantity address being defined as a function of a first address offset representative of the first or second attitude of the tank, a second probe-specific address offset representative of a relative position of the probe in a series of N probes, and a third address offset representative of the fraction of a respective probe immersed in the liquid multiplied by the M sequential storage locations, said probe-quantity address being equal to the sum of said first, second, and third address offsets.

A method for determining the quantity of a liquid in a liquid-containing tank whereby the tank has at least first and second attitudes relative to the gravity vector and at least N liquid level sensing probes, comprising the steps of:

• immersing a first and at least one other liquid-level sensing probe in a liquid-containing tank, each probe having a first and at least a second probe-specific liquid-quantity profile for a first and at least a second attitude of the tank;
• determining a value representative of the fraction of each of said first and other probe immersed in the liquid;
• storing liquid-quantity profile information in a memory for the first and the other liquid-level sensor for their respective first and second attitudes, the stored information arranged as first and second sets of first and second sets of liquid quantity profile information;
• addressing the memory to sequentially determine liquid-quantity information for the first and the other liquid-level sensing probes, said liquid-quantity information for each of said respective probes being located at a probe-quantity address, said probe-quantity address being determined by the steps of:
• determining a first address offset representative of the first or second attitude of the tank,
• determining a second probe-specific address offset specific to the first or other probe,
• determining a third address offset representative of the fraction of a respective probe immersed in the liquid multiplied by the M sequential storage locations, and
• summing the first, second, and third address offsets;
• and
• summing the liquid-quantity information from the first and other liquid-level sensing probes.