METHOD FOR AUTONOMOUS DETERMINING GROUND VEHICLE SPEED Russian patent published in 2017 - IPC G01C22/00 

FIELD: measuring equipment.

SUBSTANCE: scale factor of the mechanical speed sensor is calibrated in case of reading deviations of the mechanical and optoelectronic speed sensors exceeding the certain level, according to the information of the mechanical and optoelectronic speed sensor, in which the delay time is measured, when taking it by the light-sensitive elements of the signals reflected from the road surface irregularities, when illuminated with miniprojectors of this sensor. Herewith not all the set of pulses, coming from the sensitive elements, is estimated, but only individual characteristic pulses, that fall within the predictable time intervals defined by the mechanical speed sensor. The measurement periodicity by the highly-accurate measurer is determined by comparing the signal levels of the second channel relative to the first highly-accurate measurer channel, and when the deviations exceed the threshold level, the most highly-accurate measurer is disabled.

EFFECT: improving the accuracy.