초록 ▼

In order to determine the contents of a tank fitted with liquid level sensors and metering equipment, a microprocessor is programmed with an algorithm employing a mathematical expression for initially computing data value based on liquid level sensor outputs and tank dimensions, which data values ar

In order to determine the contents of a tank fitted with liquid level sensors and metering equipment, a microprocessor is programmed with an algorithm employing a mathematical expression for initially computing data value based on liquid level sensor outputs and tank dimensions, which data values are compared with actual volumetric amounts of liquid in the tank derived from the metering equipment so as to determine errors in a calibration characteristic for converting the sensor outputs into volumetric amounts. The calibration characteristic is refined by an iterative technique where constants in the mathematical expresson are varied, in accordance with the program so as to make the computed data values closer to the actual volumetric amounts derived from the metering equipment for respective liquid levels in the tank.

대표청구항 ▼

In a system comprising a tank for storing liquid material, sensing means fitted to the tank for sensing liquid level in the tank and providing first output signals, metering means for metering said liquid material and providing second output signals, and processing means having a first input for rec

In a system comprising a tank for storing liquid material, sensing means fitted to the tank for sensing liquid level in the tank and providing first output signals, metering means for metering said liquid material and providing second output signals, and processing means having a first input for receiving said first output signals and a second input for receiving said second output signals, said processing means being operative: (a) to store a first set of data values which represent initial estimates of volumetric quantities of liquid in the tank corresponding to predetermined liquid levels in the tank as sensed by said sensing means, said processing means being programmed with an algorithm which employs a mathematical expression for computing said first data values from said first output signals based on the dimensions of the tank, (b) to store a second set of data values derived from said second output signals, said second set of data values corresponding with actual volumetric quantities of metered liquid, which volumetric quantities are related to said predetermined liquid levels, (c) to compare the first and second sets of data values in order to compute errors in the first set of data values with respect to the second set of data values, (d) to vary the data values in said first set, by varying at least one constant in said mathematical expression, so as to cause new data values to be stored and then to be compared with corresponding data values in said second set to determine if there has been any improvement; the new data value being stored where there is an improvement and the old data value being retained where there is no improvement; the first set of data values which contain the improvements then being employed to provide a corrected calibration characteristic for said sensing means, (e) to refine the corrected calibration characteristic by again varying the first set of data values and repeating a process of comparing the first and second sets of data values and storing a fresh set of first data values containing any further improvements, (f) to compute a correlation between the first and second sets of data values, after each comparison, to determine when there is substantially no further improvement in the calibration characteristic, and (g) to store the refined and corrected calibration characteristic.