Vehicle speed detection method for satellite-based vehicle navigation system, involves comparing engine speed with estimated vehicle speed of global positioning system and selecting final vehicle speed accordingly

摘要

The power supply noise frequency is detected and converted to an engine speed, and an acceleration value is detected and processed to get an estimated vehicle speed. The engine speed is compared with an estimated vehicle speed of global positioning system (GPS) after performing gearshift modifications to derive another estimated vehicle speed. A final vehicle speed is selected based on satellite signal receiving conditions and the comparison result of engine speed with vehicle speed.