FIELD: machine building.
SUBSTANCE: inventive group of inventions relates to methods for estimating levels of a fluid for exhaust gases in a reservoir for storing a given fluid by means of an ultrasonic level sensor. Method of controlling the engine of a vehicle consists in: generating ultrasonic signal in the fluid reservoir for the exhaust gases of the vehicle; in response to the intensity of the received reflected wave of the ultrasonic signal, which is greater than the threshold value, the said reflected wave is filtered based on the dispersion of the received reflected wave and indicates the fluid level based on the filtered reflected wave; in other cases, said reflected wave is not filtered, and indication of the previous most recent fluid level is retained; and limiting the output power of the vehicle engine based on the level indication, wherein the fluid level is further based on the time shift of the reflected ultrasonic signal, and wherein said dispersion is a dispersion of instantaneous level measurements at the last N samples, where N is the number of samples, said dispersion being a measure of the deviation of the received reflected wave from a predetermined number of reflected waves received prior to said received reflected wave, wherein said dispersion is determined based on a probability distribution density function under the condition of random distribution of the received reflected waves. Two more versions of the present method are also disclosed.
EFFECT: proposed inventions allow to make a timely conclusion about the quality of used fluid.
17 cl, 7 dwg
