Doppler radar vehicle speed sensing system including means for checking system operation based on the detection of low frequency Doppler frequency components

摘要: A vehicle speed sensing apparatus with means for checking its operation comprises a Doppler radar unit producing signal related to and from the signal, first section extracting low frequency components in second connected an check signal. The extracted correspond vertical motion of are considerably lower than which corresponds minimum speed. If these corresponding not present, it is indication that system operating properly.