Compensation of the error of automotive capacitive fuel level sensors when using them on special self-propelled rolling stock
Consumption of diesel fuel by the special rolling stock of Russian Railways per year amounts to tens of thousands of tons, and the issue of reliable accounting and control of its consumption is quite urgent. Currently, part of the special self-propelled rolling stock is equipped with on-board systems for measuring fuel consumption, however, in many units of this equipment, fuel control and accounting is carried out in manual mode. Massive introduction of on-board fuel consumption measurement systems on special self-propelled rolling stock is constrained, on the one hand, by the rather high cost of fuel sensors used on locomotives, on the other hand, by the increased error of relatively inexpensive automotive capacitive fuel level sensors. As part of the laboratory tests of such sensors, it was determined that when they operate on fuel of the same grade, the error corresponds to the passport and is at the level of 1%, and when operating on fuel of different grades without additional recalibration, the error can reach 4% or more. This is largely due to the simplified technology for measuring the amount of fuel in units of volume and insufficient compensation for changes in the density of diesel fuel. To solve this problem, an alternative to standard technology for determining the amount of fuel using automotive capacitive fuel level sensors is proposed, in which the dependence of the readings of these sensors on the fuel density at a standard temperature, once obtained in laboratory conditions, is used. Proposed technology of using automotive capacitive fuel level sensors on a special self-propelled rolling stock will allow keeping its relative reduced error at the level of 1% and will provide measurement of the amount of fuel in units of mass.